:root{
  --bg:#f3f6fb; --dot:#cfd9e8; --surface:#ffffff; --ink:#14213d; --muted:#556079; --line:#14213d;
  --primary:#2f6fe4; --primary-ink:#ffffff; --primary-soft:#e2ebfd;
  --ok:#17804a; --ok-soft:#e1f5e9; --warn:#8a5a00; --warn-soft:#fff3cf; --bad:#c23636; --bad-soft:#fde7e7;
  --s-blue:#a9c4ec; --s-pink:#efb2c9; --s-yellow:#f4d57a; --shade:#5b8def; --star:#f2b01e;
  --r-lg:22px; --r-md:14px; --r-pill:999px;
  --sp1:4px; --sp2:8px; --sp3:16px; --sp4:24px; --sp5:40px;
  --f-body:"Be Vietnam Pro",system-ui,-apple-system,sans-serif; --f-head:"Baloo 2","Be Vietnam Pro",system-ui,sans-serif;
  --shadow:6px 6px 0 var(--line); --shadow-sm:3px 3px 0 var(--line);
  --pet-ink:#14213d; --pet-white:#ffffff; --pet-egg:#fff6df; --pet-spot:#f4c86a; --pet-belly:#fff4e6; --pet-cheek:#ff9fb2; --pet-crown:#f6c032; --pet-gem:#e2466b; --pet-horn:#ffd66b; --pet-shadow:#14213d22;
  --pet-meo:#ffb56b; --pet-rong:#7fd4a4; --pet-cu:#b39ddb; --pet-tho:#f7c6d9; --pet-wing:#ffd9a0;
  --pv-bg:#ffffff; --pv-ink:#000000; --pv-muted:#3b4254; --pv-line:#1b2240; --pv-accent:#1f5fd6; --pv-soft:#e3ecff; --pv-bar:#eef2f8;
  --ws-ink:#000000; --ws-paper:#ffffff; --ws-line:#9aa0aa; --ws-soft:#f2f4f7; --ws-muted:#444a55;
  --pv-ok:#e1f5e9; --pv-bad:#fde7e7; --pv-warn:#fff3cf; --pv-dok:#153526; --pv-dbad:#3d1a1d; --pv-dwarn:#3a2f10;
  --pv-dbg:#0b1020; --pv-dink:#ffffff; --pv-dmuted:#c8d0e0; --pv-dline:#9fb3dd; --pv-daccent:#7fb0ff; --pv-dsoft:#1d2c55; --pv-dbar:#151c33;
  --acc-red:#e5484d; --acc-blue:#3e7bfa; --acc-yellow:#ffcf40; --acc-pink:#ff7eb6; --acc-purple:#9b6cff; --acc-dark:#23283a; --acc-gold:#f2b01e; --acc-gold-dark:#b77d00; --acc-white:#ffffff;
  --acc-sky:#d6ecff; --acc-grass:#8fd694; --acc-grass2:#6cc37a; --acc-sea:#5cb8ea; --acc-sand:#f5dfae; --acc-night:#1d2550; --acc-moon:#fff3c4; --acc-board:#2f5d50; --acc-wall:#fdf1dc; --acc-wood:#c99a6b; --acc-tear:#6cc3f0;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#0e1524; --dot:#1f2b44; --surface:#16213a; --ink:#e8eefa; --muted:#a7b3cc; --line:#7f96c4;
  --primary:#6b9bff; --primary-ink:#0e1524; --primary-soft:#1f3160;
  --ok:#5fd394; --ok-soft:#153526; --warn:#f3c95a; --warn-soft:#3a2f10; --bad:#ff8a8a; --bad-soft:#3d1a1d; --shade:#6b9bff;
  --pet-ink:#0e1524; --pet-white:#ffffff; --pet-egg:#f3ead2; --pet-spot:#d9a94a; --pet-belly:#fbeedd; --pet-cheek:#ff8fa6; --pet-crown:#f6c032; --pet-gem:#ff6b8e; --pet-horn:#ffd66b; --pet-shadow:#00000055;
  --pet-meo:#f5a55a; --pet-rong:#6cc795; --pet-cu:#a28ad4; --pet-tho:#eeb3cb; --pet-wing:#f3c98c;
  --acc-red:#e5484d; --acc-blue:#5a8dff; --acc-yellow:#ffcf40; --acc-pink:#ff7eb6; --acc-purple:#a483ff; --acc-dark:#0b0f1c; --acc-gold:#f2b01e; --acc-gold-dark:#b77d00; --acc-white:#f4f6fb;
  --acc-sky:#27406b; --acc-grass:#3f8f55; --acc-grass2:#347a47; --acc-sea:#2a6f9e; --acc-sand:#a88d5a; --acc-night:#0f1636; --acc-moon:#f6e7a8; --acc-board:#244a3f; --acc-wall:#3a3326; --acc-wood:#7a5a3c; --acc-tear:#7cc8f2;
  color-scheme:dark;}}
:root[data-theme="dark"]{
  --bg:#0e1524; --dot:#1f2b44; --surface:#16213a; --ink:#e8eefa; --muted:#a7b3cc; --line:#7f96c4;
  --primary:#6b9bff; --primary-ink:#0e1524; --primary-soft:#1f3160;
  --ok:#5fd394; --ok-soft:#153526; --warn:#f3c95a; --warn-soft:#3a2f10; --bad:#ff8a8a; --bad-soft:#3d1a1d; --shade:#6b9bff;
  --pet-ink:#0e1524; --pet-white:#ffffff; --pet-egg:#f3ead2; --pet-spot:#d9a94a; --pet-belly:#fbeedd; --pet-cheek:#ff8fa6; --pet-crown:#f6c032; --pet-gem:#ff6b8e; --pet-horn:#ffd66b; --pet-shadow:#00000055;
  --pet-meo:#f5a55a; --pet-rong:#6cc795; --pet-cu:#a28ad4; --pet-tho:#eeb3cb; --pet-wing:#f3c98c;
  --acc-red:#e5484d; --acc-blue:#5a8dff; --acc-yellow:#ffcf40; --acc-pink:#ff7eb6; --acc-purple:#a483ff; --acc-dark:#0b0f1c; --acc-gold:#f2b01e; --acc-gold-dark:#b77d00; --acc-white:#f4f6fb;
  --acc-sky:#27406b; --acc-grass:#3f8f55; --acc-grass2:#347a47; --acc-sea:#2a6f9e; --acc-sand:#a88d5a; --acc-night:#0f1636; --acc-moon:#f6e7a8; --acc-board:#244a3f; --acc-wall:#3a3326; --acc-wood:#7a5a3c; --acc-tear:#7cc8f2;
  color-scheme:dark;}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);background-image:radial-gradient(var(--dot) 1.3px,transparent 1.4px);background-size:22px 22px;
  color:var(--ink);font:500 18px/1.55 var(--f-body);-webkit-tap-highlight-color:transparent;touch-action:manipulation;min-height:100vh}
button,input{font:inherit;color:inherit}
button{cursor:pointer}
:focus-visible{outline:3px solid var(--primary);outline-offset:3px;border-radius:8px}
.wrap{max-width:920px;margin:0 auto;padding:0 max(16px,env(safe-area-inset-left)) 60px max(16px,env(safe-area-inset-right))}

/* Header */
.top{background:color-mix(in srgb,var(--s-blue) 45%,var(--surface));text-align:center;padding:calc(18px + env(safe-area-inset-top)) 16px 16px;position:relative}
.top::after{content:"";position:absolute;left:0;right:0;bottom:0;height:7px;background:linear-gradient(90deg,var(--s-blue) 0 25%,var(--s-pink) 25% 75%,var(--s-yellow) 75%)}
.brand{font:800 clamp(30px,5vw,42px)/1.1 var(--f-head);margin:0;color:var(--ink);letter-spacing:.3px}
.brand span{color:var(--primary)}
.sub{margin:6px 0 10px;font:700 13px/1.3 var(--f-body);letter-spacing:2.5px;text-transform:uppercase;color:var(--primary)}
.author{font-size:14px;color:var(--muted)}
.toolbar{display:flex;justify-content:space-between;align-items:center;gap:12px;margin:22px 0 8px;flex-wrap:wrap}
.back{display:inline-flex;align-items:center;gap:6px;color:var(--primary);font-weight:700;text-decoration:none;min-height:44px;font-size:18px}
.back:hover{text-decoration:underline}

/* Pills & buttons */
.pill{display:inline-flex;align-items:center;gap:6px;background:var(--ink);color:var(--bg);border-radius:var(--r-pill);padding:8px 18px;font:700 14px/1.2 var(--f-body);letter-spacing:.4px;text-transform:uppercase}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:50px;padding:10px 22px;border-radius:var(--r-pill);border:2.5px solid var(--line);background:var(--surface);
  font-weight:700;font-size:17px;box-shadow:var(--shadow-sm);transition:transform .12s ease-out,box-shadow .12s ease-out}
.btn:active{transform:translate(2px,2px);box-shadow:1px 1px 0 var(--line)}
.btn.primary{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.btn.small{min-height:44px;padding:6px 16px;font-size:15px}
.btn[disabled]{opacity:.45;cursor:not-allowed;box-shadow:none;transform:none}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.theme-btn{width:48px;height:48px;border-radius:50%;border:2.5px solid var(--line);background:var(--surface);box-shadow:var(--shadow-sm);font-size:20px}

/* Home */
h1{font:800 clamp(28px,4.4vw,38px)/1.2 var(--f-head);margin:16px 0 6px}
.lead{color:var(--muted);margin:0 0 18px;font-size:18px}
.stat{display:inline-flex;gap:8px;align-items:center;background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-pill);padding:8px 16px;font-weight:700;box-shadow:var(--shadow-sm)}
.tabs{display:inline-flex;border:2.5px solid var(--line);border-radius:var(--r-pill);background:var(--surface);padding:4px;gap:4px;box-shadow:var(--shadow-sm)}
.tabs button{border:0;background:transparent;border-radius:var(--r-pill);min-height:44px;padding:6px 20px;font-weight:700}
.tabs button[aria-selected="true"]{background:var(--ink);color:var(--bg)}
.topic{margin:28px 0 0}
.topic h2{font:800 23px/1.25 var(--f-head);margin:0 0 12px;display:flex;gap:10px;align-items:baseline}
.topic h2 small{font:700 13px/1 var(--f-body);letter-spacing:1.5px;color:var(--primary);text-transform:uppercase;white-space:nowrap}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:14px}
.tile{display:flex;flex-direction:column;justify-content:space-between;gap:10px;text-align:left;background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-md);
  padding:14px 16px;box-shadow:var(--shadow-sm);text-decoration:none;color:var(--ink);min-height:92px;transition:transform .12s ease-out,box-shadow .12s ease-out}
.tile:hover{transform:translate(-1px,-1px);box-shadow:4px 4px 0 var(--line)}
.tile:active{transform:translate(2px,2px);box-shadow:1px 1px 0 var(--line)}
.tile b{font-size:17px;line-height:1.35}
.tile .meta{display:flex;justify-content:space-between;align-items:center;font-size:14px;color:var(--muted)}
.stars{letter-spacing:1px;color:var(--star);font-size:16px}
.stars .off{color:var(--dot)}

/* Lesson */
.levels{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:18px 0}
.lvl{border:2.5px solid var(--line);background:var(--surface);border-radius:var(--r-md);padding:10px 12px;text-align:left;min-height:64px;box-shadow:var(--shadow-sm)}
.lvl b{display:block;font:800 18px/1.2 var(--f-head)}
.lvl span{font-size:14px;color:var(--muted)}
.lvl[aria-pressed="true"]{background:var(--primary);border-color:var(--line);color:var(--primary-ink)}
.lvl[aria-pressed="true"] span{color:var(--primary-ink);opacity:.9}
.progress{position:sticky;top:0;z-index:5;margin:6px -4px 16px;padding:10px 4px;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px)}
.bar{height:14px;border:2.5px solid var(--line);border-radius:var(--r-pill);background:var(--surface);overflow:hidden}
.bar i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--primary),var(--shade));transition:width .25s ease-out}
.progress .txt{display:flex;justify-content:space-between;font-size:15px;font-weight:600;color:var(--muted);margin-top:6px}

.card{background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-lg);box-shadow:var(--shadow);padding:20px 22px 22px;margin:0 0 26px;transition:border-color .2s}
.card.ok{border-color:var(--ok);box-shadow:6px 6px 0 var(--ok)}
.card.fail{border-color:var(--bad);box-shadow:6px 6px 0 var(--bad)}
.qhead{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.badge{background:var(--primary);color:var(--primary-ink);border-radius:var(--r-pill);padding:3px 14px;font-weight:700;font-size:15px}
.chip{background:var(--primary-soft);color:var(--ink);border-radius:var(--r-pill);padding:3px 12px;font-weight:600;font-size:14px}
.qhead .spacer{flex:1}
.linkbtn{background:none;border:0;color:var(--muted);text-decoration:underline;font-size:15px;min-height:44px;padding:0 4px}
.qtext{font-weight:600;font-size:20px;margin:12px 0 8px}
.qbody{display:grid;gap:14px;align-items:center}
@media (min-width:900px){.qbody.has-fig{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr)}}
.fig{display:flex;justify-content:center}
.fig svg{width:100%;max-width:380px;max-height:280px;height:auto;overflow:visible}
.answer{font-size:24px;font-weight:600;line-height:2.2}
.answer .eq{white-space:nowrap}
.blank{width:5.2ch;min-width:64px;height:52px;border:0;border-bottom:3px dashed var(--primary);background:var(--primary-soft);border-radius:10px 10px 0 0;text-align:center;
  font:700 24px/1 var(--f-body);padding:0 6px;margin:0 4px;vertical-align:middle;-moz-appearance:textfield}
.blank.wide{width:8.5ch}
.blank:focus{outline:none;border-bottom-style:solid;background:color-mix(in srgb,var(--primary-soft) 70%,var(--surface))}
.blank.wrong{border-bottom-color:var(--bad);background:var(--bad-soft)}
.blank.right{border-bottom-color:var(--ok);background:var(--ok-soft)}
.blank:disabled{opacity:1;-webkit-text-fill-color:var(--ink)}
.fr{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;line-height:1.15;margin:0 3px;font-weight:700}
.fr>span:first-child{border-bottom:2.5px solid currentColor;padding:0 4px}
.fr>span{padding:0 4px}
.fbar{display:block;width:100%;min-width:60px;height:3px;background:var(--ink);border-radius:2px}
.fr .blank{height:44px;width:3.6ch;min-width:54px;margin:3px 0;font-size:22px}
.big{font-size:28px;font-weight:700}
.choices{display:flex;flex-wrap:wrap;gap:12px;margin-top:4px}
.choice{min-height:56px;min-width:64px;padding:10px 20px;border:2.5px solid var(--line);border-radius:var(--r-md);background:var(--surface);font-weight:700;font-size:19px;box-shadow:var(--shadow-sm);text-align:left}
.choices.compact .choice{min-width:76px;font-size:28px;text-align:center;padding:6px 10px}
.choice[aria-pressed="true"]{background:var(--primary-soft);border-color:var(--primary);box-shadow:3px 3px 0 var(--primary)}
.choice.right{background:var(--ok-soft);border-color:var(--ok);box-shadow:3px 3px 0 var(--ok)}
.choice.wrong{background:var(--bad-soft);border-color:var(--bad);box-shadow:3px 3px 0 var(--bad)}
.choice:disabled{cursor:default}
.ctrls{display:flex;justify-content:center;gap:10px;flex-wrap:wrap;margin-top:10px}
.actions{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-top:18px}
.fb{margin-top:14px;border-radius:var(--r-md);padding:12px 16px;font-size:17px;display:none;border:2px solid transparent}
.fb.show{display:block;animation:pop .2s ease-out}
.fb.ok{background:var(--ok-soft);border-color:var(--ok)}
.fb.hint{background:var(--warn-soft);border-color:var(--warn)}
.fb.sol{background:var(--bad-soft);border-color:var(--bad)}
.fb.note{background:var(--primary-soft);border-color:var(--primary)}
.fb b.t{display:block;font:800 19px/1.3 var(--f-head);margin-bottom:2px}
.fb.ok b.t{color:var(--ok)} .fb.hint b.t{color:var(--warn)} .fb.sol b.t{color:var(--bad)}
@keyframes pop{from{transform:scale(.97);opacity:.4}to{transform:none;opacity:1}}
.summary{text-align:center}
.summary .stars{font-size:46px;letter-spacing:6px}
.summary h3{font:800 28px/1.2 var(--f-head);margin:6px 0}
.foot{text-align:center;color:var(--muted);font-size:14px;margin-top:30px;letter-spacing:1px}
.toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom));transform:translateX(-50%) translateY(30px);opacity:0;background:var(--ink);color:var(--bg);padding:12px 22px;border-radius:var(--r-pill);font-weight:700;transition:.2s ease-out;pointer-events:none;z-index:20}
.toast.show{opacity:1;transform:translateX(-50%)}

/* SVG */
.sv-ink{stroke:var(--ink);fill:none}
.sv-txt{fill:var(--ink);font-family:var(--f-body);font-weight:700}
.sv-muted{fill:var(--muted);font-family:var(--f-body)}
.sv-prot{fill:color-mix(in srgb,var(--primary-soft) 60%,transparent);stroke:var(--primary);stroke-width:1.5}
.sv-tick{stroke:var(--primary)}
.sv-part{fill:var(--surface);stroke:var(--ink);stroke-width:2.5}
.sv-part.on{fill:var(--shade)}
.interactive .sv-part{cursor:pointer}
.sv-bar{fill:var(--shade);stroke:var(--ink);stroke-width:2}
.sv-grid{stroke:var(--dot);stroke-width:1.5}
.sv-ray{stroke:var(--ink);stroke-width:4;stroke-linecap:round}
.sv-ray.mov{stroke:var(--primary)}
.sv-handle{fill:var(--primary);stroke:var(--surface);stroke-width:3;cursor:grab}
.sv-dot{fill:var(--star)}
.sv-axis{stroke:var(--ink);stroke-width:2}
.sv-hatch{stroke:var(--muted);stroke-width:1.6}
.sv-excl{fill:var(--muted);fill-opacity:.12;stroke:none}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
@media (max-width:600px){.levels{grid-template-columns:1fr}.answer{font-size:21px}.card{padding:16px}}

/* Chọn lớp */
.tile.grade{min-height:150px;gap:6px}
.tile.grade .gname{font:800 34px/1.1 var(--f-head);color:var(--primary)}
.tile.grade.soon{opacity:.55;box-shadow:none;border-style:dashed}
.tile.grade.soon:hover{transform:none}

/* ---------- Biểu thức THCS: hệ phương trình, dòng công thức (Lớp 9+) ---------- */
.mx{display:block;margin:10px 0 4px;font-size:22px;font-weight:600;overflow-x:auto;white-space:nowrap}
.sys{display:inline-grid;grid-template-columns:auto auto;align-items:center;vertical-align:middle;margin:4px 6px;line-height:1.5;white-space:nowrap;text-align:left}
.sys::before{content:'{';grid-row:1 / 3;font-size:2.7em;font-weight:300;line-height:1;margin-right:2px;transform:scaleX(.65);transform-origin:right}
.sys>span{grid-column:2;display:block}
.sys small{color:var(--muted);font-size:.7em;margin-left:6px}
.choice .sys{margin:0}
.fb .sys{font-size:1em}

/* ---------- Đăng nhập ---------- */
.login{max-width:520px;margin:18px auto 0}
.login h1{margin-top:0}
.login form{display:grid;gap:14px}
.login label{display:grid;gap:6px;font-weight:700;font-size:17px}
.login select,.login input{min-height:52px;border:2.5px solid var(--line);border-radius:var(--r-md);background:var(--surface);color:var(--ink);font:600 19px/1.2 var(--f-body);padding:0 14px}
.login select:focus,.login input:focus{outline:none;border-color:var(--primary);box-shadow:3px 3px 0 var(--primary)}
.btn.big{min-height:56px;font-size:20px;justify-content:center}
.userbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;margin:12px 0 0;padding:6px 14px;border:2px dashed var(--line);border-radius:var(--r-pill);background:var(--surface);font-size:16px}

/* ---------- Thú cưng ---------- */
.pet{display:block;width:100%;height:100%;overflow:visible}
.pet .pet-body{fill:var(--pb);stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet.sp-meo{--pb:var(--pet-meo)} .pet.sp-rong{--pb:var(--pet-rong)} .pet.sp-cu{--pb:var(--pet-cu)} .pet.sp-tho{--pb:var(--pet-tho)}
.pet.sp-phuong{--pb:#ff7043;--pet-egg:#fff0c7;--pet-spot:#ff9f1c;--pet-belly:#ffe7a3;--pet-cheek:#ff5f7e;--pet-crown:#ffd43b;--pet-gem:#ff2e63}
.pet.sp-kylan{--pb:#f8f0ff;--pet-belly:#fffaff;--pet-cheek:#ff91c8;--pet-crown:#ffe45e;--pet-gem:#8a5cff}
.pet .pet-belly{fill:var(--pet-belly)}
.pet .pet-egg{fill:var(--pet-egg);stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-spot{fill:var(--pet-spot)}
.pet .pet-crack{fill:none;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-eye{fill:var(--pet-ink)} .pet .pet-shine{fill:var(--pet-white)}
.pet .pet-cheek{fill:var(--pet-cheek);opacity:.75}
.pet .pet-mouth{fill:none;stroke:var(--pet-ink);stroke-width:2;stroke-linecap:round}
.pet .pet-beak{fill:var(--pet-horn);stroke:var(--pet-ink);stroke-width:1.5;stroke-linejoin:round}
.pet .pet-horn{fill:var(--pet-horn);stroke:var(--pet-ink);stroke-width:2;stroke-linejoin:round}
.pet .pet-wing{fill:var(--pet-wing);stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-tail{fill:none;stroke:var(--pet-ink);stroke-width:9;stroke-linecap:round}
.pet.sp-meo .pet-tail{stroke:var(--pet-meo)}
.pet .pet-crown{fill:var(--pet-crown);stroke:var(--pet-ink);stroke-width:2;stroke-linejoin:round}
.pet .pet-gem{fill:var(--pet-gem)}
.pet .pet-spark{fill:var(--pet-crown);animation:twinkle 1.6s ease-in-out infinite}
.pet .pet-spark.s2{animation-delay:.5s} .pet .pet-spark.s3{animation-delay:1s}
.pet .pet-flame-back{fill:#ff4d1c;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-flame-core{fill:#ffd43b;stroke:#ff7a00;stroke-width:2;stroke-linejoin:round}
.pet .pet-tail-fire{fill:#ff7a00;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-crest{fill:#ffd43b;stroke:var(--pet-ink);stroke-width:2;stroke-linejoin:round}
.pet .pet-phoenix-wing{fill:#ff9f1c;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet.sp-phuong .pet-wing{fill:#ff9f1c}
.pet .pet-rainbow{fill:none;stroke-width:7;stroke-linecap:round}.pet .pet-rainbow.r1{stroke:#ff5d8f}.pet .pet-rainbow.r2{stroke:#ffd43b}.pet .pet-rainbow.r3{stroke:#55d6be}
.pet .pet-cloud{fill:#fffaff;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-sprout{fill:none;stroke:#35a853;stroke-width:3;stroke-linecap:round}
.pet .pet-leaf{fill:#6ee7a0;stroke:var(--pet-ink);stroke-width:1.8}.pet .pet-leaf.alt{fill:#55d6be}
.pet .pet-ear{fill:#f8f0ff;stroke:var(--pet-ink);stroke-width:2.5;stroke-linejoin:round}
.pet .pet-unicorn-horn{fill:#ffe45e;stroke:var(--pet-ink);stroke-width:2;stroke-linejoin:round}
.pet .pet-horn-line{fill:none;stroke:#ff7ab6;stroke-width:2;stroke-linecap:round}
.pet .pet-mane{stroke:var(--pet-ink);stroke-width:2.2;stroke-linejoin:round}.pet .pet-mane.m1{fill:#ff7ab6}.pet .pet-mane.m2{fill:#8a7dff}
.pet .pet-star-wing{fill:#78dcff;stroke:var(--pet-ink);stroke-width:2.3;stroke-linejoin:round}.pet .pet-star-wing.alt{fill:#b995ff}
.pet .pet-legend-aura{fill:#7dd3fc22;stroke:#38bdf8;stroke-width:2;stroke-dasharray:4 5;animation:spin-aura 10s linear infinite;transform-origin:60px 61px}
.pet .pet-legend-ring{fill:none;stroke:#60a5fa;stroke-width:4;stroke-linecap:round;filter:drop-shadow(0 0 3px #60a5fa)}
.pet .pet-diamond{fill:#b9f3ff;stroke:#3578c9;stroke-width:1.7;filter:drop-shadow(0 0 4px #7dd3fc)}
.pet .pet-cosmic{fill:#fff;stroke:#7c3aed;stroke-width:1;filter:drop-shadow(0 0 4px #a78bfa)}
.pet.legend-r2 .pet-legend-aura{fill:#a5f3fc33;stroke:#22d3ee}.pet.legend-r2 .pet-legend-ring{stroke:#67e8f9}
.pet.legend-r3 .pet-legend-aura{fill:#7c3aed26;stroke:#8b5cf6}.pet.legend-r3 .pet-legend-ring{stroke:#c084fc}.pet.legend-r3 .pet-mane.m1{fill:#c084fc}.pet.legend-r3 .pet-mane.m2{fill:#60a5fa}
.pet.legend-r4 .pet-legend-aura{fill:#f472b62b;stroke:#f472b6}.pet.legend-r4 .pet-legend-ring{stroke:#f9a8d4;stroke-width:5}.pet.legend-r4 .pet-star-wing{fill:#f0abfc}.pet.legend-r4 .pet-star-wing.alt{fill:#818cf8}
.pet.legend-r5 .pet-legend-aura{fill:#fde04730;stroke:#facc15;stroke-width:3}.pet.legend-r5 .pet-legend-ring{stroke:#fb7185;stroke-width:5;filter:drop-shadow(0 0 5px #facc15)}.pet.legend-r5 .pet-unicorn-horn{fill:#fff;stroke:#f59e0b;filter:drop-shadow(0 0 5px #fde047)}
@keyframes spin-aura{to{transform:rotate(360deg)}}
.pet .pet-shadow{fill:var(--pet-shadow)}
.pet .pet-float,.pet .pet-wobble{transform-box:fill-box;transform-origin:50% 100%}
.pet.big .pet-float{animation:bob 2.4s ease-in-out infinite}
.pet.big .pet-wobble{animation:wobble 1.4s ease-in-out infinite}
@keyframes bob{50%{transform:translateY(-4px)}}
@keyframes wobble{0%,60%,100%{transform:rotate(0)}70%{transform:rotate(-7deg)}80%{transform:rotate(6deg)}90%{transform:rotate(-3deg)}}
@keyframes twinkle{50%{opacity:.2;transform:scale(.7)}}
.pet-card{display:grid;grid-template-columns:150px 1fr;gap:18px;align-items:center;margin:4px 0 18px}
.pet-card .pet-stage{width:150px;height:150px;cursor:pointer}
.pet-card .pet-stage.boing{animation:boing .5s ease-out}
@keyframes boing{30%{transform:scale(1.12,.9)}60%{transform:scale(.95,1.06)}}
.pet-info small{font:700 13px/1 var(--f-body);letter-spacing:1.2px;text-transform:uppercase;color:var(--primary)}
.pet-info h2{margin:6px 0 10px;font:800 28px/1.1 var(--f-head)}
.pet-info p{margin:10px 0 8px;font-size:17px}
.pet-info .bar{height:14px}
.pet-steps{display:flex;gap:6px}
.pet-steps.long{flex-wrap:wrap;max-width:700px}
.pet-steps span{width:40px;height:40px;opacity:.28;filter:grayscale(1)}
.pet-steps span.on{opacity:1;filter:none}
.legend-path{margin-top:12px;padding:10px 12px;border:2px dashed color-mix(in srgb,var(--primary) 45%,var(--line));border-radius:14px;background:color-mix(in srgb,var(--primary) 6%,var(--surface))}
.legend-path>b{display:block;margin-bottom:7px;color:var(--primary)}.legend-path>span{display:flex;flex-wrap:wrap;gap:6px}.legend-path i{font-style:normal;font-size:12px;padding:4px 7px;border-radius:999px;background:var(--paper);color:var(--muted);border:1px solid var(--line)}.legend-path i.on{background:color-mix(in srgb,#facc15 25%,var(--surface));color:var(--ink);border-color:#f0b400;font-weight:800}
@media (max-width:560px){.pet-card{grid-template-columns:1fr;justify-items:center;text-align:center}.pet-steps{justify-content:center}}
.tile-pet{position:absolute;right:12px;top:10px;width:56px;height:56px}
.tile.grade{position:relative}
.pet-mini{margin-left:auto;display:inline-flex;align-items:center;gap:4px;text-decoration:none;color:var(--ink);font-size:16px;min-height:44px}
.pet-mini svg{width:40px;height:40px}
.toolbar{flex-wrap:wrap}
/* Màn tiến hoá */
.evolve{position:fixed;inset:0;z-index:50;display:grid;place-items:center;padding:16px;background:color-mix(in srgb,var(--ink) 55%,transparent);animation:fadein .25s}
.evolve-card{max-width:420px;width:100%;text-align:center}
.evolve-card h2{font:800 28px/1.15 var(--f-head);margin:6px 0}
.evolve-stage{width:200px;height:200px;margin:0 auto}
.evolve-stage.shake{animation:shake .18s linear infinite}
.evolve-stage.flash{animation:flash .35s ease-in forwards}
.evolve-stage.pop{animation:pop .6s cubic-bezier(.2,1.6,.4,1)}
@keyframes fadein{from{opacity:0}}
@keyframes shake{25%{transform:translateX(-4px) rotate(-3deg)}75%{transform:translateX(4px) rotate(3deg)}}
@keyframes flash{to{opacity:0;transform:scale(1.4);filter:brightness(3)}}
@keyframes pop{from{transform:scale(.3);opacity:0}}
@media (prefers-reduced-motion:reduce){.pet *,.evolve-stage,.pet-card .pet-stage{animation:none!important}}

/* ---------- Công thức MathJax ---------- */
mjx-container{color:inherit}
mjx-container[jax="CHTML"][display="true"]{margin:.35em 0 !important;text-align:left !important}
.mxd{display:block;margin:6px 0;overflow-x:auto;overflow-y:hidden;max-width:100%;font-size:21px}
.qtext mjx-container{font-size:105%}
.answer mjx-container{font-size:92%}
.choice mjx-container{font-size:100%}
b.ans mjx-container,b.ans{color:var(--primary)}
.fb mjx-container[display="true"]{margin:.2em 0 !important}

/* Nút âm thanh + đổi giao diện */
.tbtns{display:inline-flex;gap:8px;align-items:center}
.lesson-monitor-btn{display:inline-flex;align-items:center;gap:6px;min-height:42px;padding:7px 12px;border:2px solid #7b61d1;border-radius:12px;background:#efeaff;color:#3a2677;font:800 .86rem var(--f-body);cursor:pointer}.lesson-monitor-btn:hover{transform:translateY(-1px);box-shadow:0 6px 14px #5136a526}
.lesson-monitor-overlay{position:fixed;inset:0;z-index:15000;display:grid;place-items:center;padding:18px;background:#081126d9;backdrop-filter:blur(7px)}.lesson-monitor-card{display:flex;flex-direction:column;width:min(1050px,96vw);max-height:94dvh;overflow:hidden;border:3px solid #8d73df;border-radius:26px;background:var(--surface);color:var(--ink);box-shadow:0 24px 80px #0009}.lesson-monitor-card>header{display:flex;align-items:center;gap:12px;padding:15px 18px;background:linear-gradient(115deg,#5f45bd,#8c6de3);color:#fff}.lesson-monitor-card>header>div{flex:1;min-width:0}.lesson-monitor-card>header small{font-size:.7rem;font-weight:900;letter-spacing:.13em;opacity:.82}.lesson-monitor-card h2{overflow:hidden;margin:2px 0 0;text-overflow:ellipsis;white-space:nowrap;font:900 clamp(1.2rem,2.5vw,1.75rem) var(--f-head)}.lesson-monitor-card>header button{display:grid;place-items:center;width:40px;height:40px;border:2px solid #ffffff88;border-radius:50%;background:#ffffff18;color:#fff;font:900 1.05rem var(--f-body);cursor:pointer}.lm-controls{display:flex;align-items:end;gap:10px;padding:12px 16px 6px}.lm-controls label{display:grid;flex:1;gap:4px;font-size:.78rem;font-weight:850}.lm-controls select{min-height:43px;padding:7px 10px;border:2px solid var(--line);border-radius:11px;background:var(--bg);color:var(--ink);font:750 .95rem var(--f-body)}.lm-controls .btn{min-height:43px}.lm-note{margin:0 16px 9px;color:var(--muted);font-size:.78rem}.lesson-monitor-card>main{overflow:auto;padding:4px 16px 18px}.lm-summary{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin:4px 0 12px}.lm-summary span{display:grid;justify-items:center;padding:9px;border:2px solid var(--line);border-radius:14px;background:var(--bg)}.lm-summary b{font:900 1.5rem var(--f-head)}.lm-summary small{color:var(--muted);font-size:.72rem;font-weight:800}.lm-summary .todo{border-color:#e45e6b;background:#fff0f1}.lm-summary .doing{border-color:#e0a82b;background:#fff8dc}.lm-summary .done{border-color:#35a76e;background:#e9fbf2}.lm-group{margin-top:11px;border:2px solid var(--line);border-radius:16px;overflow:hidden}.lm-group>h3{display:flex;align-items:center;gap:7px;margin:0;padding:9px 12px;background:var(--bg);font:850 1rem var(--f-head)}.lm-group>h3 b{margin-left:auto}.lm-group>p{margin:0;padding:12px;color:var(--muted)}.lm-students{display:grid;grid-template-columns:1fr 1fr;gap:7px;padding:8px}.lm-students article{display:grid;grid-template-columns:minmax(125px,1fr) auto auto;align-items:center;gap:8px;padding:8px 10px;border:1.5px solid var(--line);border-radius:12px;background:var(--surface)}.lm-students article>div:first-child{min-width:0}.lm-students strong,.lm-students small{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lm-students strong{font-size:.86rem}.lm-students small{color:var(--muted);font-size:.67rem}.lm-levels{display:flex;gap:3px}.lm-level{padding:3px 5px;border-radius:7px;background:#dcf6e8;color:#17623d;font-size:.65rem;font-weight:850}.lm-level.empty{background:#eceff5;color:#788292}.lm-students em{min-width:44px;color:var(--primary);text-align:right;font-size:.72rem;font-style:normal;font-weight:900}.lm-todo{border-color:#e8a4aa}.lm-doing{border-color:#e4cb81}.lm-done{border-color:#83cda8}.dark .lm-summary .todo{background:#4c2328}.dark .lm-summary .doing{background:#4b3d17}.dark .lm-summary .done{background:#173e2b}.dark .lesson-monitor-btn{background:#3b2d73;color:#f0ebff}
@media(max-width:700px){.lesson-monitor-btn span{display:none}.lesson-monitor-btn{width:42px;padding:7px;justify-content:center}.lesson-monitor-overlay{padding:7px}.lesson-monitor-card{width:100%;max-height:97dvh;border-radius:19px}.lesson-monitor-card>header{padding:11px 12px}.lm-controls{padding:9px 10px 5px}.lm-note{margin:0 10px 7px}.lesson-monitor-card>main{padding:3px 10px 12px}.lm-summary{gap:4px}.lm-summary span{padding:6px 2px}.lm-summary b{font-size:1.2rem}.lm-summary small{font-size:.62rem}.lm-students{grid-template-columns:1fr;padding:6px}.lm-students article{grid-template-columns:minmax(110px,1fr) auto}.lm-students article>em{grid-column:2;grid-row:1}.lm-levels{grid-column:1/3}.lm-level{flex:1;text-align:center}.lm-controls .btn{padding-inline:10px}}

/* ===== Nhà thú cưng (play.js) ===== */
.pet .acc-st{stroke:var(--pet-ink);stroke-width:1.6;stroke-linejoin:round}
.pet .acc-red{fill:var(--acc-red)} .pet .acc-blue{fill:var(--acc-blue)} .pet .acc-yellow{fill:var(--acc-yellow)} .pet .acc-pink{fill:var(--acc-pink)}
.pet .acc-purple{fill:var(--acc-purple)} .pet .acc-dark{fill:var(--acc-dark)} .pet .acc-gold{fill:var(--acc-gold)} .pet .acc-gold-dark{fill:var(--acc-gold-dark)} .pet .acc-white{fill:var(--acc-white)}
.pet .acc-gold-line{fill:none;stroke:var(--acc-gold);stroke-width:2;stroke-linecap:round}
.pet .acc-glass{fill:var(--acc-white);fill-opacity:.35} .pet .acc-line{fill:none;stroke:var(--pet-ink);stroke-width:2;stroke-linecap:round} .pet .acc-shine{fill:none;stroke:var(--acc-white);stroke-width:1.5;stroke-linecap:round}
.pet .acc-sky{fill:var(--acc-sky)} .pet .acc-grass{fill:var(--acc-grass)} .pet .acc-grass2{fill:var(--acc-grass2)} .pet .acc-grass-dark{fill:var(--acc-grass2);opacity:.6} .pet .acc-sea{fill:var(--acc-sea)} .pet .acc-sand{fill:var(--acc-sand)}
.pet .acc-foam{fill:none;stroke:var(--acc-white);stroke-width:2} .pet .acc-night{fill:var(--acc-night)} .pet .acc-moon{fill:var(--acc-moon)} .pet .acc-board{fill:var(--acc-board);stroke:var(--acc-wood);stroke-width:3}
.pet .acc-wall{fill:var(--acc-wall)} .pet .acc-wood{fill:var(--acc-wood)} .pet .acc-chalk{fill:var(--acc-white);font-weight:700}
.pet .acc-hand{filter:drop-shadow(0 2px 1px rgb(20 33 61 / .24))}.pet .acc-math{fill:var(--acc-white);stroke:none;font:900 11px/1 var(--f-head)}
.pet .pet-tear{fill:var(--acc-tear);stroke:var(--pet-ink);stroke-width:1}
.pchips{display:flex;flex-wrap:wrap;gap:6px;margin:0 0 8px}
.pchips span{display:inline-flex;align-items:center;gap:4px;padding:4px 10px;border:2px solid var(--line);border-radius:var(--r-pill);background:var(--bg);font-size:15px}
.meters{display:grid;gap:8px;margin:10px 0}
.meter{display:grid;grid-template-columns:96px 1fr 34px;gap:8px;align-items:center;font-size:15px;font-weight:600}
.meter .bar{height:14px} .meter b{text-align:right;font-size:14px;color:var(--muted)}
.meter .bar i{background:linear-gradient(90deg,var(--ok),var(--ok))} .meter.mid .bar i{background:var(--star)} .meter.low .bar i{background:var(--bad)}
.mood{margin:6px 0 10px;font-size:16px;color:var(--muted)}
.pet-info .row .btn{min-height:46px;padding:8px 16px;font-size:16px}
.quests h3{margin:0 0 10px;font:800 21px/1.2 var(--f-head)}
.quests ul,.qlist{list-style:none;margin:0 0 6px;padding:0;display:grid;gap:10px}
.quests li,.qlist li{display:grid;grid-template-columns:30px 1fr auto;gap:10px;align-items:center}
.quests li .bar,.qlist li .bar{height:10px;margin-top:5px;border-width:2px}
.quests li small,.qlist li small{text-align:right;color:var(--muted);font-weight:700;line-height:1.3}
.quests li.done b,.qlist li.done b{text-decoration:line-through;color:var(--muted)} .qi{font-size:22px}
.coin-pop{position:absolute;right:18px;top:12px;font:800 20px/1 var(--f-head);color:var(--star);animation:coinup 1.3s ease-out forwards;pointer-events:none}
@keyframes coinup{0%{opacity:0;transform:translateY(10px) scale(.8)}20%{opacity:1;transform:none}100%{opacity:0;transform:translateY(-34px)}}
#qs .card{position:relative}
.mini-xu{font-size:15px;margin-left:6px}
body.noscroll{overflow:hidden}
.pethome{align-items:start;overflow:auto}
.pethome .ph{position:relative;max-width:760px;width:100%;margin:8px auto;text-align:left}
.ph-x{position:absolute;right:12px;top:12px;width:44px;height:44px;border-radius:50%;border:2.5px solid var(--line);background:var(--surface);color:var(--ink);font-size:18px;cursor:pointer}
.ph-top{display:grid;grid-template-columns:150px 1fr;gap:16px;align-items:center;padding-right:44px}
.ph-top small{font:700 13px/1 var(--f-body);letter-spacing:1.2px;text-transform:uppercase;color:var(--primary)}
.ph-top h2{margin:6px 0 8px;font:800 26px/1.1 var(--f-head)}
.ph-pet{width:150px;height:150px} .ph-pet.boing{animation:boing .5s ease-out}
.ph-tabs{display:flex;gap:6px;overflow-x:auto;margin:14px -4px 12px;padding:4px}
.ph-tabs button{flex:0 0 auto;min-height:46px;padding:6px 14px;border-radius:var(--r-pill);border:2.5px solid var(--line);background:var(--surface);color:var(--ink);font:700 15px/1 var(--f-body);cursor:pointer}
.ph-tabs button[aria-selected="true"]{background:var(--primary);color:var(--primary-ink)}
.ph-body h3{margin:16px 0 8px;font:800 19px/1.2 var(--f-head)}
.care-btns .btn small{font-weight:500;opacity:.85}
.tips{margin:14px 0 0;padding-left:20px;color:var(--muted);line-height:1.6}
.note-line{color:var(--muted);margin:4px 0 10px}
.shop{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:10px}
.item{display:grid;justify-items:center;gap:4px;padding:10px 8px;border:2.5px solid var(--line);border-radius:var(--r-md);background:var(--surface);color:var(--ink);font:600 14px/1.25 var(--f-body);cursor:pointer;text-align:center}
.item svg{width:96px;height:96px} .item span{font-weight:800;color:var(--star)}
.item.own span{color:var(--primary)} .item.on{background:var(--primary-soft);box-shadow:var(--shadow-sm)} .item.on span{color:var(--ok)}
.item small{min-height:1.25em;color:var(--muted);font-size:11px;font-weight:750}.item.locked{border-color:color-mix(in srgb,var(--muted) 60%,var(--line));background:color-mix(in srgb,var(--bg) 82%,var(--surface))}.item.locked svg{filter:grayscale(.72);opacity:.62}.item.locked span{color:var(--bad)}
.stats{display:flex;flex-wrap:wrap;gap:8px}
.stats span{padding:6px 12px;border:2px solid var(--line);border-radius:var(--r-md);background:var(--bg)}
.badges{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px}
.badges .badge{display:grid;justify-items:center;text-align:center;gap:4px;padding:12px 8px;border:2.5px solid var(--line);border-radius:var(--r-md);background:var(--surface);opacity:.45;filter:grayscale(1)}
.badges .badge.got{opacity:1;filter:none;background:var(--warn-soft)} .badges .badge .bi{font-size:36px} .badges .badge small{color:var(--muted);line-height:1.35}
/* Phòng truyền thống Sticker */
.sticker-head{display:grid;grid-template-columns:1fr auto;gap:16px;align-items:center;padding:16px;border:2.5px solid color-mix(in srgb,var(--primary) 45%,var(--line));border-radius:var(--r-md);background:linear-gradient(135deg,var(--primary-soft),var(--surface) 60%,var(--warn-soft))}
.sticker-head small,.sticker-latest small{font:800 12px/1.2 var(--f-body);letter-spacing:1.2px;color:var(--primary)}
.sticker-head h3{margin:4px 0!important;font-size:24px}.sticker-head p{margin:4px 0;color:var(--muted);line-height:1.45}
.sticker-score{width:96px;height:96px;display:grid;place-content:center;text-align:center;border:3px solid var(--star);border-radius:50%;background:var(--surface);box-shadow:0 5px 0 color-mix(in srgb,var(--star) 55%,var(--line))}
.sticker-score b{font:800 31px/1 var(--f-head);color:var(--primary)}.sticker-score span{font-size:12px;font-weight:700;margin-top:4px}
.sticker-latest{display:flex;align-items:center;gap:14px;margin:12px 0;padding:10px 16px;border:2px dashed var(--star);border-radius:var(--r-md);background:var(--warn-soft)}
.sticker-latest>span{font-size:45px;filter:drop-shadow(0 3px 2px rgb(0 0 0 / .14));animation:stickerbob 2s ease-in-out infinite}.sticker-latest b{display:block;margin-top:3px;font:800 18px/1.2 var(--f-head)}
.sticker-empty{margin:12px 0;padding:18px;text-align:center;border:2px dashed var(--line);border-radius:var(--r-md);color:var(--muted);font-weight:700}
.sticker-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(128px,1fr));gap:10px}
.sticker{position:relative;min-height:154px;display:grid;grid-template-rows:72px auto auto;align-items:center;justify-items:center;gap:4px;padding:10px 7px;border:2.5px solid var(--line);border-radius:18px;background:color-mix(in srgb,var(--bg) 86%,var(--line));text-align:center;opacity:.48;filter:grayscale(1)}
.sticker.got{opacity:1;filter:none;background:var(--surface);box-shadow:0 4px 0 color-mix(in srgb,var(--line) 70%,transparent)}
.sticker.got.rare{border-color:#4aa9ff;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,#67c1ff 18%,var(--surface)))}
.sticker.got.epic{border-color:#a66bff;background:linear-gradient(145deg,var(--surface),color-mix(in srgb,#bd87ff 21%,var(--surface)))}
.sticker.got.legend{border-color:#f1b900;background:linear-gradient(145deg,#fff8d6,var(--surface) 46%,color-mix(in srgb,#ff9bd5 20%,var(--surface)));box-shadow:0 4px 0 #d99d00,0 0 18px color-mix(in srgb,#ffd84d 38%,transparent)}
.sticker.shine:after{content:'✨';position:absolute;right:5px;top:4px;font-size:19px;animation:stickertwinkle 1.2s ease-in-out infinite}
.sticker-icon{font-size:52px;line-height:1;filter:drop-shadow(0 4px 2px rgb(0 0 0 / .13));transition:transform .2s}.sticker.got:hover .sticker-icon{transform:scale(1.14) rotate(-5deg)}
.sticker b{font:800 14px/1.15 var(--f-head)}.sticker small{font-size:11px;font-weight:800;color:var(--muted)}
.sticker-reward{position:fixed;inset:0;z-index:70;display:grid;place-items:center;padding:18px;background:color-mix(in srgb,var(--ink) 62%,transparent);animation:fadein .25s}
.sr-card{position:relative;max-width:430px;width:100%;overflow:hidden;padding:24px;text-align:center;border:4px solid var(--star);border-radius:28px;background:linear-gradient(150deg,var(--surface),var(--warn-soft));box-shadow:0 18px 60px rgb(0 0 0 / .35);animation:stickerpop .65s cubic-bezier(.2,1.45,.35,1)}
.sticker-reward.rare .sr-card{border-color:#4aa9ff}.sticker-reward.epic .sr-card{border-color:#a66bff}.sticker-reward.legend .sr-card{border-color:#f1b900;background:linear-gradient(140deg,#fff8d6,var(--surface),color-mix(in srgb,#ff9bd5 24%,var(--surface)))}
.sr-spark{position:absolute;inset:8% 0 auto;text-align:center;font-size:32px;word-spacing:28px;animation:stickerspark 1.4s ease-in-out infinite;pointer-events:none}
.sr-perfect{display:inline-block;padding:6px 14px;border-radius:var(--r-pill);background:var(--primary);color:var(--primary-ink);font:800 17px/1 var(--f-head);letter-spacing:1px}
.sr-icon{margin:24px 0 8px;font-size:112px;line-height:1;filter:drop-shadow(0 8px 4px rgb(0 0 0 / .18));animation:stickerbob 1.5s ease-in-out infinite}
.sr-rarity{display:inline-block;padding:5px 10px;border:2px solid color-mix(in srgb,var(--star) 65%,var(--line));border-radius:var(--r-pill);background:var(--surface);font-weight:800}
.sr-card h2{margin:10px 0 5px;font:800 28px/1.15 var(--f-head)}.sr-card p{margin:0 0 16px;color:var(--muted);font-weight:600}.sr-card .row{justify-content:center}
@keyframes stickerpop{from{opacity:0;transform:scale(.35) rotate(-8deg)}}
@keyframes stickerbob{50%{transform:translateY(-7px) rotate(3deg)}}
@keyframes stickertwinkle{50%{opacity:.35;transform:scale(.72) rotate(20deg)}}
@keyframes stickerspark{50%{transform:scale(1.08);filter:brightness(1.25)}}
.rank-sort{margin-bottom:8px}
.rank{list-style:none;margin:0;padding:0;display:grid;gap:6px}
.rank li{display:grid;grid-template-columns:44px 48px 1fr auto;gap:10px;align-items:center;padding:6px 12px;border:2px solid var(--line);border-radius:var(--r-md);background:var(--surface)}
.rank li.me{background:var(--primary-soft);box-shadow:var(--shadow-sm)} .rank .rk{font:800 20px/1 var(--f-head);text-align:center}
.rank .rp svg{width:44px;height:44px} .rank .rv{font-weight:800}
@media (max-width:560px){.ph-top{grid-template-columns:1fr;justify-items:center;text-align:center;padding-right:0}.pchips{justify-content:center}.meter{grid-template-columns:80px 1fr 30px}.sticker-head{grid-template-columns:1fr;text-align:center}.sticker-score{margin:auto}.sticker-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.sr-icon{font-size:92px}.sr-card{padding:20px 14px}.sr-card .row{display:grid}}
@media (prefers-reduced-motion:reduce){.sticker-latest>span,.sticker.shine:after,.sr-card,.sr-icon,.sr-spark{animation:none!important}}

/* ===== Trình chiếu (present.js) – bảng màu riêng cho máy chiếu, chữ tự vừa màn hình ===== */
.pv{position:fixed;inset:0;z-index:100;display:flex;flex-direction:column;
  --bg:var(--pv-bg);--surface:var(--pv-bg);--ink:var(--pv-ink);--muted:var(--pv-muted);--line:var(--pv-line);--primary:var(--pv-accent);--primary-soft:var(--pv-soft);--dot:var(--pv-soft);--primary-ink:var(--pv-bg);--ok-soft:var(--pv-ok);--bad-soft:var(--pv-bad);--warn-soft:var(--pv-warn);
  background:var(--bg);color:var(--ink)}
.pv.dark{--bg:var(--pv-dbg);--surface:var(--pv-dbg);--ink:var(--pv-dink);--muted:var(--pv-dmuted);--line:var(--pv-dline);--primary:var(--pv-daccent);--primary-soft:var(--pv-dsoft);--dot:var(--pv-dsoft);--primary-ink:var(--pv-dbg);
  --ok-soft:var(--pv-dok);--bad-soft:var(--pv-dbad);--warn-soft:var(--pv-dwarn)}
.pv-slide{flex:1 1 0;min-height:0;overflow:hidden;display:flex;flex-direction:column;gap:.45em;padding:.6vh 1.2vw 0;font-size:var(--fs,48px);line-height:1.28}
.pv-q{font-weight:600} .pv-n{color:var(--primary);font-weight:800}
.pv .mxd{font-size:1em;margin:.15em 0;overflow:visible} .pv .big{font-size:1.15em} .pv .pill{font-size:.6em}
.pv-expr{margin-top:.2em}
.pv-main{flex:1 1 0;min-height:0;display:flex;flex-direction:column;gap:.5em}
.pv-slide.has-fig .pv-main{flex-direction:row;align-items:stretch}
.pv-fig{flex:0 0 44%;min-height:0;display:flex;align-items:center;justify-content:center}
.pv-fig svg{width:100%;height:100%;max-width:100%;max-height:100%!important}
.pv-side{flex:1;min-width:0}
.pv-opts{display:grid;grid-template-columns:1fr 1fr;gap:.35em .5em}
.pv-opts.one{grid-template-columns:1fr}
.pv-o{display:flex;align-items:center;gap:.45em;text-align:left;font:inherit;font-size:.92em;line-height:1.25;padding:.2em .45em;border:max(2px,.06em) solid var(--line);border-radius:.35em;background:var(--surface);color:var(--ink);cursor:pointer}
.pv-o>b{flex:0 0 auto;width:1.45em;height:1.45em;border-radius:50%;display:grid;place-items:center;background:var(--primary);color:var(--primary-ink);font-size:.75em}
.pv-o.right{background:var(--ok-soft);border-color:var(--ok);box-shadow:0 0 0 .08em var(--ok)} .pv-o.right>b{background:var(--ok)}
.pv-o.wrong{background:var(--bad-soft);border-color:var(--bad);animation:shake .3s} .pv-o.wrong>b{background:var(--bad)}
.pv-ans{font-size:.95em;line-height:1.6}
.pv-b{display:inline-block;min-width:2.4em;padding:0 .15em;border-bottom:max(3px,.07em) solid var(--ink);text-align:center;font-weight:800;color:var(--ok)}
.pv .fr>span:first-child{border-bottom-width:max(3px,.06em)}
.pv-note{margin-top:.45em;padding:.3em .5em;border-radius:.35em;font-size:.82em;line-height:1.35}
.pv-note.hint{background:var(--warn-soft)} .pv-note.sol{background:var(--ok-soft)}
.pv-bar{flex:0 0 auto;display:flex;align-items:center;gap:8px;padding:6px 10px calc(6px + env(safe-area-inset-bottom));background:var(--pv-bar);opacity:.6;transition:opacity .2s}
.pv.dark .pv-bar{background:var(--pv-dbar)}
.pv-bar:hover,.pv-bar:focus-within{opacity:1}
.pv-bar button{min-height:44px;min-width:44px;padding:4px 14px;border:2px solid var(--line);border-radius:var(--r-pill);background:var(--surface);color:var(--ink);font:700 17px/1 var(--f-body);cursor:pointer}
.pv-bar button:disabled{opacity:.35} .pv-bar button.on{background:var(--primary);color:var(--primary-ink)}
.pv-bar #pvPos{font:800 18px/1 var(--f-head);min-width:90px;text-align:center}
.pv-sp{flex:1}
@media (max-width:700px){.pv-bar{flex-wrap:wrap}.pv-slide.has-fig .pv-main{flex-direction:column}.pv-fig{flex:0 0 40%}}

/* ===== Bài giảng giáo viên (lecture.js) – dùng chung khung .pv của trình chiếu ===== */
.lk-tile{cursor:default} .lk-tile .row{margin-top:4px}
.lk-slide{gap:.35em}
.lk-tag{align-self:flex-start;display:inline-block;padding:.12em .55em;border-radius:var(--r-pill);font:800 .5em/1.3 var(--f-body);letter-spacing:.08em;text-transform:uppercase;background:var(--primary);color:var(--primary-ink)}
.lk-tag.kt{background:var(--ok)} .lk-tag.method{background:var(--star);color:var(--pv-ink)} .lk-tag.vd{background:var(--primary)} .lk-tag.lt{background:var(--bad)} .lk-tag.sum{background:var(--ok)}
.lk-title{display:flex;flex-direction:column;gap:.3em}
.lk-title h1{margin:0;font:800 1.55em/1.12 var(--f-head);color:var(--primary)}
.lk-sub{margin:0;font-size:.8em;color:var(--muted)}
.lk-goals{margin:.2em 0 0;padding-left:1.2em;line-height:1.35} .lk-goals li{margin:.12em 0}
.lk-h{margin:0;font:800 1.1em/1.15 var(--f-head)}
.lk-main{flex:1 1 0;min-height:0;display:flex;flex-direction:column;gap:.5em}
.lk-main.has-fig{flex-direction:row;align-items:stretch}
.lk-body{flex:1;min-width:0;line-height:1.32}
.lk-fig{flex:0 0 40%;min-height:0;display:flex;align-items:center;justify-content:center}
.lk-fig svg{width:100%;height:100%;max-height:100%!important}
.lk-fig.off{visibility:hidden} .lk-page .lk-fig.off{visibility:visible}
.lk-body p{margin:.15em 0 .3em}
.lk-body ul,.lk-steps{margin:.15em 0;padding-left:1.25em} .lk-body li,.lk-steps li{margin:.12em 0}
.lk-box{border-left:.18em solid var(--primary);background:var(--primary-soft);padding:.25em .5em;border-radius:.25em;margin:.25em 0}
.lk-note{border-left:.18em solid var(--star);background:var(--warn-soft);padding:.25em .5em;border-radius:.25em;margin:.25em 0}
.lk-de{font-weight:500;line-height:1.3} .lk-de>b:first-child{color:var(--primary)}
.lk-sol{visibility:hidden;border:max(2px,.05em) solid var(--line);border-radius:.3em;padding:.15em .5em .3em}
.lk-sol.open{visibility:visible}
.lk-solh{font:800 .7em/1.6 var(--f-body);letter-spacing:.06em;text-transform:uppercase;color:var(--ok)}
.lk-solsteps{margin:0;padding-left:1.3em;line-height:1.32}
.lk-solsteps.plain{list-style:none;padding-left:0}
.lk-solsteps li{visibility:hidden;margin:.08em 0} .lk-solsteps li.on{visibility:visible;animation:fadein .35s}
.lk-ans{visibility:hidden;margin-top:.25em;padding:.15em .5em;border-radius:.25em;background:var(--ok-soft);font-weight:700} .lk-ans.on{visibility:visible}
.lk-menu{position:absolute;right:12px;bottom:64px;max-width:min(560px,92vw);max-height:70vh;overflow:auto;background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-md);box-shadow:var(--shadow);padding:10px 14px;z-index:2}
.lk-menu h3{margin:4px 0 8px;font:800 18px/1.2 var(--f-head)} .lk-menu ol{margin:0;padding-left:22px}
.lk-menu button{display:block;width:100%;text-align:left;border:0;background:none;color:var(--ink);font:500 16px/1.3 var(--f-body);padding:6px 4px;border-radius:8px;cursor:pointer}
.lk-menu button span{font-weight:800;color:var(--primary);font-size:13px;text-transform:uppercase} .lk-menu button.on{background:var(--primary-soft)}
/* Xem trước / in */
.lk-doc{display:grid;gap:14px} .lk-page{font-size:18px;position:relative}
.lk-page .lk-sol,.lk-page .lk-solsteps li,.lk-page .lk-ans{visibility:visible}
.lk-page .lk-main.has-fig{flex-direction:row} .lk-page .lk-fig{flex:0 0 36%} .lk-page .lk-fig svg{max-height:300px!important}
.lk-page .lk-title h1{font-size:30px} .lk-page .lk-tag{font-size:12px}
.lk-go{position:absolute;right:14px;top:8px}
@media print{.top,.toolbar,.userbar,.lk-go,.foot,.pill{display:none!important}.lk-page{box-shadow:none;break-inside:avoid;border-width:1px}body{background:var(--pv-bg)}}
@media (max-width:700px){.lk-main.has-fig{flex-direction:column}.lk-fig{flex:0 0 38%}}

.lk-table{border-collapse:collapse;margin:.3em 0;font-size:.78em}
.lk-table th,.lk-table td{border:max(1.5px,.04em) solid var(--line);padding:.12em .35em;text-align:center}
.lk-table th{background:var(--primary-soft)} .lk-table.lk-left td,.lk-table.lk-left th{text-align:left}

/* ===== Phiếu học tập (lecture.js → worksheet) – tối giản, in A4 đen trắng ===== */
.ws{--ink:var(--ws-ink);--muted:var(--ws-muted);--line:var(--ws-ink);--surface:var(--ws-paper);--primary:var(--ws-ink);--dot:var(--ws-soft);--primary-soft:var(--ws-soft);--ok:var(--ws-ink);--ok-soft:var(--ws-soft);--warn-soft:var(--ws-soft);--star:var(--ws-ink);
  color:var(--ink);background:var(--ws-paper);max-width:210mm;margin:0 auto 30px;padding:14mm 15mm;box-shadow:0 2px 14px rgb(0 0 0 / .15);font:400 11.5pt/1.45 var(--f-body)}
.ws-head{border-bottom:1.5pt solid var(--ink);padding-bottom:6pt;margin-bottom:8pt}
.ws-brand{display:flex;justify-content:space-between;font:700 9pt/1.2 var(--f-body);letter-spacing:.06em;text-transform:uppercase}
.ws h1{margin:8pt 0 0;font:800 17pt/1.2 var(--f-head);text-align:center;letter-spacing:.03em} .ws h1 small{font-size:10pt;font-weight:600}
.ws h2{margin:2pt 0 6pt;font:700 13pt/1.25 var(--f-body);text-align:center}
.ws-who{margin:4pt 0 0;display:flex;gap:6pt;align-items:flex-end;white-space:nowrap}
.ws-fill{flex:1;border-bottom:1pt dotted var(--ink);height:1.1em} .ws-fill.s{flex:.35}
.ws h3{margin:12pt 0 4pt;font:800 12pt/1.3 var(--f-body);text-transform:uppercase;border-bottom:.8pt solid var(--ink);padding-bottom:2pt}
.ws h4{margin:7pt 0 2pt;font:700 11.5pt/1.3 var(--f-body)}
.ws-goals{margin:2pt 0;padding-left:16pt}
.ws-lines i{display:block;height:8.2mm;border-bottom:.7pt dotted var(--ws-line)}
.ws-hint{margin:2pt 0 0;font-style:italic;color:var(--muted)}
.ws-q{margin:6pt 0 4pt;break-inside:avoid} .ws-q>p{margin:0 0 2pt}
.ws-row{display:flex;gap:8pt;align-items:flex-start} .ws-work{flex:1;min-width:0}
.ws-fig{flex:0 0 36%;max-width:62mm} .ws-fig svg{width:100%;height:auto;max-height:52mm!important}
.ws .sv-grid{stroke:var(--ws-line);stroke-width:.8} .ws .sv-excl{fill:var(--ws-soft)}
.ws-sol,.ws-steps{margin:2pt 0;padding-left:16pt} .ws-ans{margin:2pt 0;font-weight:700}
.ws-key .lk-box,.ws-key .lk-note{border-left:2pt solid var(--ink);background:none;padding:2pt 6pt;margin:3pt 0}
.ws-key p{margin:2pt 0} .ws .lk-table{font-size:9.5pt} .ws .mxd{font-size:1em;overflow:visible}
.ws .fr>span:first-child{border-bottom-width:1pt}
.ws-foot{break-before:avoid;margin-top:12pt;padding-top:4pt;border-top:.8pt solid var(--ink);font-size:8.5pt;text-align:center;color:var(--muted)}
.ws-toggle{display:inline-flex;gap:6px;align-items:center;font-weight:600;min-height:44px}
@media print{
  @page{size:A4;margin:12mm 13mm 14mm}
  .ws{box-shadow:none;max-width:none;margin:0;padding:0;font-size:11pt}
  .ws-bar,.top,.userbar,.foot,.toast{display:none!important}
  .wrap{padding:0;max-width:none} body{background:var(--ws-paper)}
  .ws h3{break-after:avoid} .ws-kt,.ws-dang{break-inside:avoid}
}
@media (max-width:700px){.ws{padding:16px}.ws-row.has-fig{flex-direction:column}.ws-fig{max-width:none;width:70%}}

/* Danh sách bài giảng gọn (theo lớp) */
.lk-list{list-style:none;margin:0;padding:0;display:grid;gap:10px}
.lk-list li{display:flex;gap:12px;align-items:center;justify-content:space-between;flex-wrap:wrap;background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-md);box-shadow:var(--shadow-sm);padding:10px 14px}
.lk-li{display:grid;gap:3px;min-width:0;flex:1 1 320px} .lk-li b{font:700 17px/1.3 var(--f-body)} .lk-li small{color:var(--muted);font-size:14px;line-height:1.35}
.lk-acts{display:flex;gap:6px;flex-wrap:wrap} .lk-acts .btn{min-height:44px;padding:6px 14px}

/* Bài toán nhiều bước (giải toán có lời văn) */
.sv-cut{fill:none;stroke:var(--muted);stroke-width:2.5;stroke-dasharray:6 5}
.stp{list-style:none;margin:0;padding:0;display:grid;gap:12px}
.stp-i{border:2px solid var(--line);border-radius:var(--r-md);padding:10px 14px 12px;background:var(--surface)}
.stp-i.is-cur{border-color:var(--primary);box-shadow:4px 4px 0 var(--primary)}
.stp-i.is-ok{background:var(--ok-soft);border-color:var(--ok)}
.stp-i.is-shown{background:var(--warn-soft);border-color:var(--warn)}
.stp-h{display:flex;align-items:center;gap:8px;margin-bottom:4px}
.stp-tag{font:800 14px/1.2 var(--f-head);text-transform:uppercase;letter-spacing:.04em;color:var(--primary)}
.stp-mark{margin-left:auto;font-size:13px;color:var(--muted)} .stp-mark.ok{color:var(--ok);font-size:20px;font-weight:800}
.stp-ask{margin:0 0 6px;font-size:18px;font-weight:600;line-height:1.4}
.stp-i .answer{font-size:22px;line-height:2.1} .stp-done{font-size:18px;font-weight:600} .stp-done.answer{font-size:20px;line-height:1.6}
.stp-v{color:var(--ok)} .is-shown .stp-v{color:var(--warn)}
.stp-i .choices{gap:8px} .stp-i .choice{font-size:17px;min-height:48px;padding:8px 14px}
.stp-guide{margin-top:12px}
.stp-sol{margin-top:4px;line-height:1.65}
.pv-steps{margin:0;padding-left:1.1em;display:grid;gap:.25em;font-size:.72em;line-height:1.35} .pv-sa{color:var(--primary);font-weight:800}
.card.is-steps .qbody.has-fig>.fig{align-self:start;position:sticky;top:96px}
/* Phiếu luyện tập */
.pr-legend{margin:5pt 0 0;font-size:10pt;text-align:center}
.ws h3 small{font-weight:600;text-transform:none;letter-spacing:0}
.ws .pr-dang{margin:8pt 0 2pt;font-style:italic;break-after:avoid}
.ws.pr .ws-fig:not(.ws-blank) svg{max-height:31mm!important}
.ws.pr .ws-fig.ws-blank svg{max-height:37mm!important}
.ws.pr .ws-lines i{height:7.2mm}
@media print{.ws.pr{font-size:10.5pt}.ws.pr .ws-lines i{height:7mm}.ws.pr .ws h3,.ws.pr h3{margin-top:8pt}}
/* Hình đường tròn */
.sv-fill{fill:var(--shade);fill-opacity:.35;stroke:none}
.sv-arc{fill:none;stroke:var(--primary);stroke-width:5;stroke-linecap:round}
.sv-pt{fill:var(--ink)}
.ws .sv-fill{fill:var(--ws-muted);fill-opacity:.2}
/* Trang giáo viên: bài giảng (trái) + bảng xếp hạng (phải) */
.gv-wide .wrap{max-width:1360px}
.lk-2col{display:grid;grid-template-columns:minmax(0,1fr) minmax(340px,410px);gap:24px;align-items:start}
.lk-rank{position:sticky;top:12px;max-height:calc(100vh - 24px);overflow:auto;padding:14px 16px;margin:0}
.lk-rank:empty{display:none}
@media (max-width:1100px){.lk-2col{grid-template-columns:1fr}.lk-rank{position:static;max-height:none}}
.gr-head{display:flex;align-items:center;justify-content:space-between;gap:8px} .gr-head h2{margin:0;font-size:22px}
.gr-tabs{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0 8px}
.gr-tabs button{min-height:40px;padding:4px 14px;border:2px solid var(--line);border-radius:var(--r-pill);background:var(--surface);font:700 15px/1 var(--f-body);color:var(--ink)}
.gr-tabs button.on{background:var(--ink);color:var(--surface)}
.gr-stats{display:flex;flex-wrap:wrap;gap:6px 12px;font-size:14px;color:var(--muted);margin-bottom:8px} .gr-stats b{color:var(--ink)}
.gr-sort{display:flex;flex-wrap:wrap;gap:6px;margin-bottom:10px} .gr-sort .btn{min-height:38px;padding:4px 10px;font-size:14px}
.gr-list li.gr-row{grid-template-columns:34px 46px minmax(0,1fr) auto;gap:8px;padding:5px 10px;cursor:pointer}
.gr-list li.gr-row:hover,.gr-list li.gr-row.open{background:var(--primary-soft)}
.gr-who{display:grid;gap:1px;min-width:0} .gr-who b{font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis} .gr-who small{color:var(--muted);font-size:12.5px}
.gr-bar{display:block;height:5px;border-radius:3px;background:var(--dot);overflow:hidden} .gr-bar i{display:block;height:100%;background:var(--shade)}
.gr-list .rk{font-size:17px}
.gr-list li.gr-detail{display:block;border-style:dashed;padding:8px 10px;cursor:default}
.gr-evo{display:flex;align-items:flex-end;justify-content:space-between;gap:2px}
.gr-evo.long{justify-content:flex-start;overflow-x:auto;padding:5px 3px 10px}.gr-evo.long figure{flex:0 0 68px}.gr-evo.long .gr-arrow{flex:0 0 auto}
.gr-evo figure{margin:0;display:grid;justify-items:center;text-align:center;flex:1;min-width:0} .gr-evo svg{width:100%;max-width:56px;height:auto}
.gr-evo figcaption{font-size:10.5px;line-height:1.2;color:var(--muted)} .gr-evo .now figcaption{color:var(--ink);font-weight:800}
.gr-evo .todo svg{filter:grayscale(1);opacity:.35} .gr-evo .now svg{outline:2.5px solid var(--primary);outline-offset:2px;border-radius:12px}
.gr-arrow{color:var(--muted);font-weight:800;align-self:center}
.gr-detail p{margin:6px 0 0;font-size:14px} .gr-facts{display:flex;flex-wrap:wrap;gap:4px 12px;color:var(--muted)}
.gr-off{margin-top:10px;font-size:14px} .gr-off summary{cursor:pointer;font-weight:700;min-height:32px} .gr-off p{margin:4px 0;color:var(--muted)}
.gr-note{margin:10px 0 0;font-size:12.5px;color:var(--muted)}
/* Khung “Lớp học” khi trình chiếu (classpanel.js) */
.cp{position:fixed;top:0;right:0;bottom:0;z-index:101;display:flex;background:var(--pv-bg);border-left:2px solid var(--pv-line);box-shadow:-6px 0 18px rgb(0 0 0 / .18)}
.cp[hidden]{display:none}
.cp-grip{flex:0 0 16px;cursor:col-resize;display:flex;align-items:center;justify-content:center;background:var(--pv-bar);touch-action:none}
.cp-grip i{width:5px;height:56px;border-radius:3px;background:var(--pv-muted);opacity:.45}
.cp-grip:hover i,.cp-grip:focus-visible i,.cp.dragging .cp-grip i{opacity:1;background:var(--pv-accent)}
.cp-main{flex:1;min-width:0;display:flex;flex-direction:column;position:relative}
.cp-bar{display:flex;align-items:center;gap:6px;padding:5px 8px;background:var(--pv-bar);color:var(--pv-ink);font:700 15px/1 var(--f-body)}
.cp-bar button,.cp-bar a{min-height:38px;min-width:38px;padding:0 12px;border:2px solid var(--pv-line);border-radius:999px;background:var(--pv-bg);color:var(--pv-ink);font:700 14px/1 var(--f-body);display:inline-flex;align-items:center;justify-content:center;text-decoration:none;cursor:pointer}
.cp-sp{flex:1}
.cp iframe{flex:1;width:100%;min-height:0;border:0;background:var(--pv-bg)}
.cp-shield{position:absolute;inset:0;display:none} .cp.dragging .cp-shield{display:block;cursor:col-resize}
.pv-bar button{white-space:nowrap}
.pv-bar{overflow-x:auto;scrollbar-width:none}
.pv.narrow .pv-bar button{padding:4px 9px;font-size:15px} .pv.narrow .pv-bar{gap:5px}

/* ===== Đề kiểm tra (kiemtra.js) – in A4 tiết kiệm giấy: chữ 11pt, phương án xếp 4/2/1 cột ===== */
.kt{font:400 11pt/1.3 "Times New Roman","Liberation Serif",Times,serif;padding:10mm 11mm;page:kt}
.kt b{font-weight:700} .kt-small{font-size:9.5pt;margin:1pt 0 3pt} .kt-c{text-align:center}
.kt-head{display:grid;grid-template-columns:38% 1fr;gap:6pt;text-align:center;font-size:10.5pt;line-height:1.35;border-bottom:1pt solid var(--ink);padding-bottom:4pt}
.kt-head .kt-r b:first-child{font-size:12pt}
.kt-who{display:flex;gap:10pt;align-items:flex-end;margin:5pt 0 3pt;font-size:10.5pt} .kt-who>span{display:flex;gap:4pt;align-items:flex-end;flex:1} .kt-who .kt-cls{flex:.45}
.kt-dots{flex:1;border-bottom:1pt dotted var(--ink);height:1em}
.kt-code{flex:0 0 auto!important;border:1.2pt solid var(--ink);padding:1pt 8pt;font-weight:700}
.kt h3{margin:7pt 0 1pt;font:700 11pt/1.3 "Times New Roman","Liberation Serif",serif;text-transform:uppercase;border:0;padding:0} .kt h3 small{text-transform:none;font-weight:400}
.kt-fill{display:flex;gap:4pt;align-items:flex-end;margin:2pt 0 0 14pt;width:42%}
.kt-q{margin:2pt 0 1pt;break-inside:avoid}
.kt-opts{display:grid;column-gap:8pt;row-gap:2.5pt;align-items:center;margin:0 0 0 14pt} .kt-opts.c4{grid-template-columns:repeat(4,1fr)} .kt-opts.c2{grid-template-columns:repeat(2,1fr)} .kt-opts.c1{grid-template-columns:1fr}
.kt-tf{display:grid;grid-template-columns:1fr 1fr;column-gap:10pt;row-gap:0;align-items:center;margin:0 0 0 14pt}
.kt-grid{border-collapse:collapse;margin:2pt 0 4pt;font-size:9.5pt;width:100%;table-layout:fixed} .kt-grid th,.kt-grid td{border:.7pt solid var(--ink);padding:1.5pt 2pt;text-align:center;height:13pt} .kt-grid th{width:13%;font-weight:700;background:none}
.kt-ans{margin:4pt 0 2pt}
.kt .kt-grid,.kt .kt-mx,.kt .kt-rub{width:calc(100% - 2pt);margin-left:1pt;margin-right:1pt}
.kt-end{text-align:center;font-weight:700;margin:6pt 0 0;letter-spacing:.05em} .kt-end small{display:block;font-weight:400;font-style:italic;letter-spacing:0;font-size:9pt}
.kt-mx,.kt-rub{border-collapse:collapse;width:100%;font-size:9.5pt;margin:3pt 0 5pt} .kt-mx th,.kt-mx td,.kt-rub th,.kt-rub td{border:.7pt solid var(--ink);padding:2pt 4pt;text-align:center;vertical-align:middle}
.kt-lft{text-align:left!important} .kt-rub td:last-child{width:9%} .kt-rub td:first-child{width:12%}
.kt-scale{margin:2pt 0;padding-left:14pt;font-size:10pt}
.kt-key{break-inside:avoid;margin-top:4pt} .kt-key h3{margin-top:6pt}
.kt-tip{max-width:210mm;margin:0 auto 10px;color:var(--muted);font-size:14px}
.kt-doc .kt+.kt{margin-top:18px}
.ws-bar select{min-height:44px;border:2px solid var(--line);border-radius:999px;padding:4px 12px;font:600 15px var(--f-body);background:var(--surface);color:var(--ink)}
@media print{
  @page kt{size:A4;margin:9mm 11mm 9mm}
  .kt-tip{display:none}
  .kt{padding:0;font-size:11pt} .kt-doc .kt+.kt{margin-top:0;break-before:page}
  .kt-key{break-inside:avoid} .kt h3{break-after:avoid}
  .kt[style*="--kt-pages"]{min-height:calc(var(--kt-pages) * 279mm - 4mm)}     /* đề dài nhiều trang: luôn chiếm đúng số trang khai báo (pages) để in 2 mặt không lẫn mã đề */
}
@media (max-width:700px){.kt-opts.c4{grid-template-columns:1fr 1fr}.kt-tf{grid-template-columns:1fr}.kt-head{grid-template-columns:1fr}}
.kt-sec a.btn{text-decoration:none}

/* ===== Song ngữ (bi/bin trong core.js) + Kiến thức trọng tâm (introHTML) ===== */
.L-en{color:var(--muted);font-style:italic}
:root[data-lang="vi"] .L-en,:root:not([data-lang]) .L-en{display:none}
:root[data-lang="en"] .L-vi{display:none}
:root[data-lang="en"] .L-en{color:inherit;font-style:normal}
:root[data-lang="bi"] .L-en{display:block;font-size:.9em;margin-top:2px}
:root[data-lang="bi"] .L-en.L-in{display:inline;font-size:.92em;margin:0}
:root[data-lang="bi"] .L-en.L-in::before{content:" / ";font-style:normal}
:root[data-lang="en"] .L-en.L-in::before{content:none}
h1 .h1en{font-size:.55em;font-weight:600}
.langsw{display:flex;gap:6px;flex-wrap:wrap;margin:4px 0 10px} .langsw .btn{min-height:44px} .langsw .btn[aria-pressed="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.kt-intro{padding:14px 18px;margin:6px 0 14px} .kt-intro>summary{cursor:pointer;font:700 19px/1.35 var(--f-head);list-style-position:outside}
.kt-item{display:grid;gap:12px;padding:10px 0;border-top:1.5px dashed var(--line)} .kt-item:first-of-type{border-top:0}
.kt-item h3{margin:0 0 4px;font:700 18px/1.35 var(--f-body)} .kt-b{font-size:18px;line-height:1.5} .kt-ex{margin-top:6px;padding:8px 12px;border-radius:12px;background:var(--primary-soft);font-size:17px}
.kt-warn{margin-top:6px;padding:8px 12px;border-radius:12px;background:var(--warn-soft);border:1.5px solid var(--warn);color:inherit;font-size:17px}
.kt-item .fig svg{max-height:170px;width:100%}
@media (min-width:900px){.kt-item.has-fig{grid-template-columns:1fr 38%;align-items:center}}

/* Cảnh báo duy trì học tập: nhắc từ ngày 5, trừ sao từ ngày 8 */
.study-warning{display:grid;grid-template-columns:auto 1fr;gap:13px;align-items:start;margin:4px 0 16px;padding:14px 17px;border-color:#e5a400;background:linear-gradient(135deg,#fff7cc,var(--surface))}
.study-warning.loss{border-color:#e46a72;background:linear-gradient(135deg,#ffe0e3,var(--surface))}
.study-warning .sw-icon{font-size:32px;line-height:1}.study-warning b{font:800 18px/1.25 var(--f-head)}
.study-warning p{margin:4px 0 0;line-height:1.45}.study-warning small{display:block;margin-top:5px;color:var(--muted);font-weight:600}
.study-warning.compact{margin:0 0 14px;padding:11px 14px}.study-warning.compact .sw-icon{font-size:27px}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .study-warning{background:color-mix(in srgb,#e5a400 18%,var(--surface))}:root:not([data-theme="light"]) .study-warning.loss{background:color-mix(in srgb,#e46a72 18%,var(--surface))}}
:root[data-theme="dark"] .study-warning{background:color-mix(in srgb,#e5a400 18%,var(--surface))}:root[data-theme="dark"] .study-warning.loss{background:color-mix(in srgb,#e46a72 18%,var(--surface))}

/* Bài kiểm tra ba phần dành cho học sinh */
.test-tile{border-color:var(--primary);background:linear-gradient(145deg,var(--primary-soft),var(--surface) 70%)}
.test-tile>b{font-size:21px}.test-intro{max-width:820px;margin:0 auto 26px}.test-intro h1{margin-bottom:8px}
.test-facts,.result-parts{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:18px 0}
.test-facts span,.result-parts span{display:grid;gap:2px;place-items:center;text-align:center;padding:13px 8px;border:2px solid var(--line);border-radius:var(--r-md);background:var(--bg)}
.test-rules{padding:14px 18px;border-radius:var(--r-md);background:var(--primary-soft)}.test-rules h3{margin:0 0 6px}.test-rules ul{margin:0;padding-left:22px;line-height:1.65}
.test-best{text-align:center;font-size:18px}.test-intro>.btn{display:flex;margin:18px auto 0}
.test-head{position:sticky;top:8px;z-index:20;display:grid;grid-template-columns:auto auto minmax(120px,1fr);align-items:center;gap:14px;padding:10px 16px;margin-bottom:12px;background:color-mix(in srgb,var(--surface) 92%,transparent);backdrop-filter:blur(10px)}
.test-head>div{display:grid}.test-head small{color:var(--muted);font-weight:700;letter-spacing:.04em}.test-head b{font-size:19px}.test-clock{justify-self:end;padding:7px 16px;border-radius:var(--r-pill);background:var(--ink);color:var(--bg);font:800 25px/1 var(--f-head);font-variant-numeric:tabular-nums}.test-clock.urgent{background:var(--bad);color:#fff;animation:pulse 1s infinite}
.test-nav{display:flex;align-items:center;gap:12px;overflow-x:auto;padding:10px 14px;margin-bottom:22px}.test-nav>b{white-space:nowrap}.test-nav>div{display:flex;align-items:center;gap:5px;white-space:nowrap}.test-nav>div>span{color:var(--muted);font-size:13px;font-weight:700}
.test-nav-q{display:grid;place-items:center;width:34px;height:34px;flex:0 0 34px;border:2px solid var(--line);border-radius:50%;color:var(--ink);text-decoration:none;font-weight:800}.test-nav-q.done{border-color:var(--ok);background:var(--ok);color:#fff}
.test-part{scroll-margin-top:100px}.test-part>h2{margin:24px 0 2px;font-size:25px}.test-part>p{margin:0 0 14px;color:var(--muted)}
.test-q{scroll-margin-top:96px}.test-q .qtext{font-size:19px;line-height:1.65;margin:14px 0}.test-options{display:grid;grid-template-columns:1fr 1fr;gap:10px}
.test-options button{min-height:54px;padding:10px 14px;border:2px solid var(--line);border-radius:var(--r-md);background:var(--surface);color:var(--ink);text-align:left;font:600 17px/1.45 var(--f-body);cursor:pointer}.test-options button[aria-pressed="true"]{border-color:var(--primary);background:var(--primary-soft);box-shadow:0 0 0 2px var(--primary)}.test-options button b{color:var(--primary);margin-right:5px}
.test-tf{display:grid;gap:8px}.test-tf>div{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:12px;padding:10px 12px;border:2px solid var(--line);border-radius:var(--r-md)}.tf-buttons{display:flex;gap:6px}.tf-buttons button{min-width:70px;min-height:44px;border:2px solid var(--line);border-radius:var(--r-pill);background:var(--surface);color:var(--ink);font:700 15px var(--f-body)}.tf-buttons button[aria-pressed="true"]{border-color:var(--primary);background:var(--primary);color:var(--primary-ink)}
.test-short{display:flex;align-items:center;gap:12px;font-weight:800}.test-short input{width:min(240px,60%);min-height:52px;border:2.5px solid var(--line);border-radius:var(--r-md);padding:6px 12px;background:var(--surface);color:var(--ink);font:700 21px var(--f-body)}.test-short input:focus{border-color:var(--primary);outline:3px solid var(--primary-soft)}
.test-submit{text-align:center}.test-submit .btn{display:inline-flex}.test-timeout{margin-bottom:16px}.test-result{text-align:center}.result-score{display:flex;align-items:baseline;justify-content:center;color:var(--primary);margin:10px 0 0}.result-score b{font:800 72px/1 var(--f-head)}.result-score span{font-size:24px;font-weight:800}.test-result>.stars{font-size:30px}.test-result .row{justify-content:center}
.test-review{border-left-width:7px}.test-review.ok{border-left-color:var(--ok);box-shadow:var(--shadow)}.test-review.bad{border-left-color:var(--bad)}.test-review h3{display:flex;align-items:center;gap:9px;margin-top:0}.test-mark{font:800 14px var(--f-body);padding:3px 9px;border-radius:var(--r-pill)}.test-mark.ok{color:var(--ok);background:var(--ok-soft)}.test-mark.bad{color:var(--bad);background:var(--bad-soft)}
.test-solution,.review-tf>div{margin-top:9px;padding:11px 14px;border-radius:var(--r-md);background:var(--primary-soft);line-height:1.65}.test-solution>b{display:block;color:var(--primary);margin-bottom:4px}.test-solution p,.review-tf p{margin:4px 0}.review-tf{margin:10px 0;padding:10px 12px;border-left:5px solid var(--bad);border-radius:var(--r-md);background:var(--bg)}.review-tf.ok{border-left-color:var(--ok)}.review-tf>p{font-size:17px}.review-tf>small{color:var(--muted)}
@media (max-width:700px){.test-facts,.result-parts{grid-template-columns:1fr 1fr}.test-head{grid-template-columns:1fr 1fr}.test-clock{grid-column:1/-1;justify-self:stretch;text-align:center}.test-options{grid-template-columns:1fr}.test-tf>div{grid-template-columns:1fr}.tf-buttons button{flex:1}.test-part>h2{font-size:21px}.result-score b{font-size:58px}}

/* ---------- Phiếu học tập trên lớp (Markdown) ----------
   Phần A (học sinh) in ĐÚNG 2 trang A4: cỡ chữ do lecture.js (kdFit) chọn qua --kd-fs; phương án trắc nghiệm xếp 1–2 dòng (.kd-opts). */
@page kdsheet{size:A4;margin:9mm 11mm}
.ws.kd{font-size:10.5pt;line-height:1.4;page:kdsheet}
.ws.kd .kd-a{font-size:var(--kd-fs,10pt);line-height:1.34} .ws.kd .kd-b{font-size:10.5pt}
.ws.kd .kd-a + .kd-b{margin-top:18pt;padding-top:10pt;border-top:1px dashed var(--ws-line)}
.ws.kd h1{font:800 1.35em/1.25 var(--f-body);text-align:center;margin:0 0 3pt;text-transform:uppercase}
.ws.kd .kd-sub{margin:0 0 5pt;text-align:center;font-weight:700;font-size:1.05em}
.ws.kd h2{margin:.7em 0 .15em;font:800 1.05em/1.3 var(--f-body);border-bottom:.8pt solid var(--ink);padding-bottom:1pt;break-after:avoid}
.ws.kd h3{margin:.5em 0 .1em;font:700 1em/1.3 var(--f-body);border:0;text-transform:none}
.ws.kd p{margin:.18em 0} .ws.kd ul,.ws.kd ol{margin:.1em 0 .25em;padding-left:1.4em} .ws.kd li{margin:.05em 0}
.ws.kd blockquote{margin:.3em 0;padding:.2em .6em;border-left:3pt solid var(--ink);background:var(--ws-soft);break-inside:avoid}
.ws.kd table{width:calc(100% - 2pt);margin:.3em 1pt;border-collapse:collapse;font-size:.97em;break-inside:avoid}
.ws.kd th,.ws.kd td{border:.8pt solid var(--ink);padding:1pt 5pt;text-align:left;vertical-align:top} .ws.kd th{background:var(--ws-soft)}
.ws.kd .kd-opts{display:grid;gap:0 1.2em;margin:.1em 0 .3em 1.2em;break-inside:avoid;grid-template-columns:1fr}
.ws.kd .kd-opts.o4{grid-template-columns:repeat(4,1fr)} .ws.kd .kd-opts.o2{grid-template-columns:repeat(2,1fr)} .ws.kd .kd-opts.o3{grid-template-columns:repeat(3,1fr)}
.ws.kd .kd-opts > span{display:block}
.ws.kd .kd-sec{break-inside:avoid}
@media print{.ws.kd{padding:0}}

/* Nhóm chủ đề trong menu (vd. Toán tư duy) */
.grp-title{margin:28px 0 4px;padding:10px 14px;border-radius:12px;background:var(--card,#f4f1ff);font-size:1.15rem;border-left:5px solid #7c5cff}

/* ---------- Góc chung (hub.js): menu dùng chung cho học sinh và giáo viên ---------- */
.hub-tabs{margin:12px 0 6px} .hub-grades,.hub-classes{margin:4px 0}
.hub-av{display:grid;place-items:center;width:40px;height:40px;border-radius:50%;background:var(--primary-soft);border:2px solid var(--line);font:800 18px/1 var(--f-head)}
.hub-rank li{grid-template-columns:44px 48px 1fr auto}
.hub-who{display:grid;gap:3px;min-width:0} .hub-icons{display:flex;flex-wrap:wrap;gap:2px;align-items:center} .hub-icons small{font-weight:700;color:var(--muted)}
.hub-ic{font-size:22px;line-height:1;filter:grayscale(.15)} .hub-ic.rare{filter:drop-shadow(0 0 2px #4aa3ff)} .hub-ic.epic{filter:drop-shadow(0 0 3px #a06bff)} .hub-ic.legend{filter:drop-shadow(0 0 4px #ffbf1f)}

/* ---------- Góc chung: tab thi đua & gắn bài học (hub-plus.js) ---------- */
.hub-tabs{flex-wrap:nowrap;overflow-x:auto;-webkit-overflow-scrolling:touch;padding-bottom:4px;scrollbar-width:thin} .hub-tabs button{flex:0 0 auto;white-space:nowrap}
.hub-card{background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-card,18px);box-shadow:6px 6px 0 var(--line);padding:14px 16px;margin:14px 0}
.hub-card h3{margin:0 0 8px} .hub-card h3 small{font-weight:600;color:var(--muted);font-size:.8em} .hub-card p{margin:6px 0}
.hub-bar{height:12px;border-radius:99px;background:var(--primary-soft);border:2px solid var(--line);overflow:hidden;margin:6px 0} .hub-bar i{display:block;height:100%;background:var(--primary);border-radius:99px;transition:width .4s}
.hub-bar.ok i{background:var(--ok,var(--ok))}
.hub-q{list-style:none;padding:0;margin:8px 0;display:grid;gap:8px} .hub-q li{display:grid;grid-template-columns:32px 1fr auto;gap:10px;align-items:center} .hub-q li.done b{text-decoration:line-through;opacity:.7} .hub-q small{color:var(--muted);font-weight:700}
.hub-reward{padding:8px 12px;border-radius:12px;background:var(--primary-soft);border:2px dashed var(--line);font-weight:600} .hub-reward.got{background:var(--ok-soft);border-style:solid}
.hub-goal{margin:8px 0} .hub-stops{display:flex;justify-content:space-between;font-size:22px;filter:grayscale(1);} .hub-stops span{display:grid;justify-items:center;opacity:.45} .hub-stops span.on{filter:none;opacity:1} .hub-stops small{font-size:12px;font-weight:700}
.hub-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:8px} .hub-chip{display:inline-flex;align-items:center;gap:6px;padding:3px 10px 3px 4px;border:2px solid var(--line);border-radius:99px;background:var(--surface);font-weight:600} .hub-chip.me{background:var(--primary-soft)} .hub-chip b{color:var(--primary)}
.hub-av.s{width:26px;height:26px;font-size:13px;font-style:normal}
.hub-f{display:grid;gap:4px;font-weight:600;margin:8px 0} .hub-f textarea,.hub-f input:not([type=radio]),.hub-f select{font:inherit;padding:8px 10px;border:2px solid var(--line);border-radius:10px;background:var(--surface);color:var(--ink);width:100%;box-sizing:border-box}
.hub-opts-in{display:grid;grid-template-columns:1fr 1fr;gap:0 12px} .hub-row{display:grid;grid-template-columns:repeat(3,1fr);gap:0 12px}
@media(max-width:700px){.hub-opts-in,.hub-row{grid-template-columns:1fr}}
.hub-qh{display:flex;justify-content:space-between;align-items:center;gap:8px;flex-wrap:wrap} .hub-qh small{color:var(--muted);font-weight:700} .hub-qt{font-size:1.15em;font-weight:600}
.hub-opts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:10px 0} @media(max-width:700px){.hub-opts{grid-template-columns:1fr}}
.hub-opt{min-height:52px;text-align:left;padding:8px 12px;border:2.5px solid var(--line);border-radius:14px;background:var(--surface);color:var(--ink);font:600 17px/1.3 var(--f-body);cursor:pointer} .hub-opt b{display:inline-grid;place-items:center;width:28px;height:28px;border-radius:50%;background:var(--primary-soft);margin-right:6px}
.hub-opt.sel{background:var(--primary-soft);border-color:var(--primary)} .hub-opt.ok{background:var(--ok-soft);border-color:var(--ok)} .hub-opt.no{background:var(--bad-soft);border-color:var(--bad)}
.hub-res{padding:8px 12px;border-radius:12px;border:2px solid var(--line)} .hub-res.ok{background:var(--ok-soft)} .hub-res.no{background:var(--warn-soft)}
.hub-ol{list-style:none;padding:0;margin:6px 0;display:grid;gap:4px} .hub-ol li.ok{font-weight:800;color:var(--ok)} .hub-q-t.closed{opacity:.7}
.hub-hot,.hub-path,.hub-rev{list-style:none;padding:0;margin:6px 0;display:grid;gap:8px}
.hub-hot li{display:grid;grid-template-columns:1fr auto;gap:10px;align-items:center;padding:8px 10px;border:2px solid var(--line);border-radius:12px} .hub-hot li a,.hub-hot li>span:first-child{display:grid;color:inherit;text-decoration:none} .hub-hot small,.hub-path small,.hub-rev small{color:var(--muted);font-weight:600;font-size:.82em}
.hub-pct{display:grid;justify-items:end;font:800 20px/1 var(--f-head)} .hub-pct small{font:600 12px/1.2 var(--f-body)} .hub-pct.r{color:var(--bad)} .hub-pct.y{color:var(--warn)} .hub-pct.g{color:var(--ok)}
.hub-path li{display:grid;grid-template-columns:1fr auto auto;gap:10px;align-items:center;padding:6px 10px;border:2px solid var(--line);border-radius:12px} .hub-path li a{display:flex;gap:8px;align-items:center;color:inherit;text-decoration:none;min-height:40px} .hub-path li.full{background:var(--ok-soft)} .hub-path li.next{border-color:var(--primary);box-shadow:3px 3px 0 var(--primary)}
.hub-lv{display:flex;gap:4px} .hub-lv i{font-style:normal;min-width:34px;text-align:center;padding:2px 6px;border-radius:99px;border:1.5px solid var(--line);color:var(--muted);font-weight:700;font-size:13px} .hub-lv i.on{color:var(--warn);background:var(--warn-soft)}
.hub-cls{white-space:nowrap}
@media(max-width:700px){.hub-path li{grid-template-columns:1fr auto}.hub-path .hub-lv{grid-column:1/-1}}
.hub-rev li{display:grid;grid-template-columns:34px 1fr auto;gap:10px;align-items:center;padding:8px 10px;border:2px solid var(--line);border-radius:12px} .hub-rev li.due{border-color:var(--primary);background:var(--primary-soft)} .hub-rev li div{display:grid}
.hub-race li{grid-template-columns:44px 1fr auto} .hub-race .hub-who{width:100%}

.hub-bank{padding:10px 12px;margin:0 0 10px;border:2px dashed var(--line);border-radius:14px;background:var(--primary-soft)} .hub-bank .hub-row{align-items:end}

/* ---------- Phiếu cả chương cho học sinh (lecture.js chapterSheet): tiết kiệm giấy – 2 cột, chữ nhỏ, không dòng kẻ ---------- */
.lk-ch-acts{margin:-4px 0 8px}
.cs-bar .row{flex-wrap:wrap;gap:6px 12px} .cs-bar select{font:inherit;padding:4px 6px;border:2px solid var(--line);border-radius:8px;background:var(--surface);color:var(--ink)} .cs-pages{font-weight:700;color:var(--muted)}
.ws.cs{font-size:var(--cs-fs,9.5pt);line-height:1.34;padding:10mm 11mm}
.cs-head{margin-bottom:4pt;padding-bottom:3pt} .cs h1{font-size:14pt;margin-top:3pt} .cs h2{font-size:11pt;margin:1pt 0 3pt} .cs-toc{margin:3pt 0 0;font-size:.92em;color:var(--muted)}
.cs-cols{column-count:2;column-gap:7mm;column-rule:.6pt solid var(--ws-line)} .ws.cs.one .cs-cols{column-count:1}
.cs-lesson{margin:7pt 0 2pt;padding:1.5pt 0;border-top:1.5pt solid var(--ink);border-bottom:.7pt solid var(--ink);font:800 10.5pt/1.3 var(--f-body);text-transform:uppercase;break-after:avoid}
.cs-sec{margin:5pt 0 1pt;font:800 1em/1.3 var(--f-body);text-decoration:underline;break-after:avoid} .cs-sec small{font-weight:600;text-decoration:none}
.cs h5{margin:4pt 0 1pt;font:700 1em/1.3 var(--f-body);break-after:avoid}
.cs p{margin:1pt 0} .cs-q{break-inside:avoid;margin:3pt 0} .cs-kt,.cs-dang{break-inside:avoid-column}
.cs-sol,.cs-steps{margin:1pt 0;padding-left:12pt} .cs-sol li,.cs-steps li{margin:0}
.cs-ans{font-weight:700} .cs-fig{max-width:48mm;margin:2pt auto} .cs-fig svg{width:100%;height:auto;max-height:40mm!important} .cs-blank{max-width:44mm}
.cs .lk-box,.cs .lk-note{border-left:2pt solid var(--ink);background:none;padding:1pt 5pt;margin:2pt 0} .cs .lk-table{font-size:.95em} .cs .lk-body,.cs .cs-body{font-size:1em}
.cs-lines{margin:1pt 0 2pt} .cs-lines i{height:6.6mm}
.cs-ansl{list-style:none;margin:2pt 0;padding:0;column-count:1} .cs-ansl li{margin:0;break-inside:avoid}
.cs mjx-container[display="true"]{margin:2pt 0!important}
@page cs{size:A4;margin:9mm 10mm 10mm}
@media print{ .ws.cs{padding:0;font-size:var(--cs-fs,9.5pt);page:cs} .cs-bar{display:none!important} }

/* ===== STICKER BIẾN ĐỔI KIM LOẠI: Bạc ×2 · Vàng ×3 · Bạch kim ×5 · Kim cương ×8 (hạng suy ra từ số lần mở, StickerDB.tierOf) ===== */
:root{
  --mt-silver:linear-gradient(135deg,#fdfdff,#b9c2cf 26%,#f6f8fc 48%,#8995a6 74%,#e9edf3);
  --mt-gold:linear-gradient(135deg,#fff4b8,#f6c21b 26%,#fff1a6 48%,#c98a00 74%,#ffe27a);
  --mt-plat:linear-gradient(135deg,#f6fdff,#a9bccb 24%,#e4f5ff 48%,#6f9dbf 74%,#e8f7ff);
  --mt-diamond:linear-gradient(120deg,#7cf9ff,#b69cff,#ff9be3,#fff2a8,#8dffc1,#7cf9ff,#b69cff);
  --mt-ink:#2b2f38;
}
.sticker.got.t-silver,.sticker.got.t-gold,.sticker.got.t-plat,.sticker.got.t-diamond{overflow:hidden;border:3px solid transparent;box-shadow:0 4px 0 color-mix(in srgb,var(--ink) 22%,transparent)}
.sticker.got.t-silver{background:linear-gradient(155deg,color-mix(in srgb,#c9d2de 30%,var(--surface)),var(--surface) 55%,color-mix(in srgb,#aeb9c8 26%,var(--surface))) padding-box,var(--mt-silver) border-box;box-shadow:0 4px 0 #8995a6,0 0 14px color-mix(in srgb,#dfe6ef 70%,transparent)}
.sticker.got.t-gold{background:linear-gradient(155deg,color-mix(in srgb,#ffe58a 34%,var(--surface)),var(--surface) 55%,color-mix(in srgb,#f6c21b 24%,var(--surface))) padding-box,var(--mt-gold) border-box;box-shadow:0 4px 0 #c98a00,0 0 18px color-mix(in srgb,#ffd84d 55%,transparent)}
.sticker.got.t-plat{background:linear-gradient(155deg,color-mix(in srgb,#cfeaff 38%,var(--surface)),var(--surface) 55%,color-mix(in srgb,#9cc3e0 28%,var(--surface))) padding-box,var(--mt-plat) border-box;box-shadow:0 4px 0 #6f9dbf,0 0 20px color-mix(in srgb,#bfe6ff 70%,transparent)}
.sticker.got.t-diamond{background:linear-gradient(155deg,color-mix(in srgb,#d4f6ff 40%,var(--surface)),var(--surface) 50%,color-mix(in srgb,#f1d8ff 36%,var(--surface))) padding-box,var(--mt-diamond) border-box;background-size:100% 100%,300% 100%;box-shadow:0 4px 0 #7aa7d9,0 0 24px color-mix(in srgb,#9be7ff 75%,transparent);animation:stkprism 5s linear infinite}
/* vệt sáng quét chéo qua thẻ */
.sticker.got.t-silver:before,.sticker.got.t-gold:before,.sticker.got.t-plat:before,.sticker.got.t-diamond:before{content:'';position:absolute;inset:-30% -60%;pointer-events:none;background:linear-gradient(112deg,transparent 42%,rgb(255 255 255 / .85) 50%,transparent 58%);transform:translateX(-70%);animation:stkglint 3.4s ease-in-out infinite}
.sticker.got.t-gold:before{animation-delay:.6s}.sticker.got.t-plat:before{animation-delay:1.1s;animation-duration:2.8s}.sticker.got.t-diamond:before{animation-duration:2.2s}
.sticker.got.t-silver .sticker-icon{filter:drop-shadow(0 0 5px #fff) drop-shadow(0 3px 2px rgb(0 0 0 / .18))}
.sticker.got.t-gold .sticker-icon{filter:drop-shadow(0 0 7px #ffd24a) drop-shadow(0 3px 2px rgb(0 0 0 / .2))}
.sticker.got.t-plat .sticker-icon{filter:drop-shadow(0 0 8px #bfe6ff) drop-shadow(0 0 2px #fff) drop-shadow(0 3px 2px rgb(0 0 0 / .18))}
.sticker.got.t-diamond .sticker-icon{filter:drop-shadow(0 0 9px #8be9ff) drop-shadow(0 0 3px #ff9be3);animation:stkhue 4s linear infinite}
.sticker.got.t-silver:after,.sticker.got.t-plat:after{content:'✦'}.sticker.got.t-diamond:after{content:'💎';font-size:16px}
/* nhãn hạng góc thẻ + chip hạng dùng chung */
.tchip,.tier-chip{display:inline-block;padding:2px 8px;border-radius:var(--r-pill);font:800 11px/1.3 var(--f-body);color:var(--mt-ink);border:1.5px solid rgb(0 0 0 / .18);text-shadow:0 1px 0 rgb(255 255 255 / .55);font-style:normal}
.tchip{position:absolute;left:6px;top:6px;z-index:2}.tier-chip{font-size:13px;padding:3px 10px}
.t-silver.tchip,.t-silver.tier-chip{background:var(--mt-silver)}.t-gold.tchip,.t-gold.tier-chip{background:var(--mt-gold)}.t-plat.tchip,.t-plat.tier-chip{background:var(--mt-plat)}
.t-diamond.tchip,.t-diamond.tier-chip{background:var(--mt-diamond);background-size:300% 100%;animation:stkprism 4s linear infinite}
.tier-chip small{font-weight:700;opacity:.7}
.tier-legend{display:flex;flex-wrap:wrap;align-items:center;gap:6px 8px;margin:10px 0;padding:10px 12px;border:2px dashed var(--line);border-radius:var(--r-md);background:var(--surface)}
.tier-legend>b{margin-right:4px}.tier-legend>i{font-style:normal;color:var(--muted);font-weight:800}
/* hộp thưởng khi mở sticker */
.sticker-reward.t-silver .sr-card,.sticker-reward.t-gold .sr-card,.sticker-reward.t-plat .sr-card,.sticker-reward.t-diamond .sr-card{border:5px solid transparent}
.sticker-reward.t-silver .sr-card{background:linear-gradient(150deg,#fff,color-mix(in srgb,#c9d2de 40%,var(--surface))) padding-box,var(--mt-silver) border-box}
.sticker-reward.t-gold .sr-card{background:linear-gradient(150deg,#fff9d6,color-mix(in srgb,#ffe58a 45%,var(--surface))) padding-box,var(--mt-gold) border-box}
.sticker-reward.t-plat .sr-card{background:linear-gradient(150deg,#f6fdff,color-mix(in srgb,#bfdcf0 50%,var(--surface))) padding-box,var(--mt-plat) border-box}
.sticker-reward.t-diamond .sr-card{background:linear-gradient(150deg,#f2fdff,color-mix(in srgb,#e6d7ff 45%,var(--surface))) padding-box,var(--mt-diamond) border-box;background-size:100% 100%,300% 100%;animation:stickerpop .65s cubic-bezier(.2,1.45,.35,1),stkprism 5s linear infinite}
.sticker-reward.t-silver .sr-card:before,.sticker-reward.t-gold .sr-card:before,.sticker-reward.t-plat .sr-card:before,.sticker-reward.t-diamond .sr-card:before{content:'';position:absolute;inset:-30% -60%;pointer-events:none;background:linear-gradient(112deg,transparent 43%,rgb(255 255 255 / .8) 50%,transparent 57%);transform:translateX(-70%);animation:stkglint 2.6s ease-in-out .5s infinite}
.sticker-reward.t-gold .sr-icon{filter:drop-shadow(0 0 16px #ffd24a) drop-shadow(0 8px 4px rgb(0 0 0 / .2))}.sticker-reward.t-plat .sr-icon{filter:drop-shadow(0 0 16px #bfe6ff) drop-shadow(0 8px 4px rgb(0 0 0 / .2))}
.sticker-reward.t-silver .sr-icon{filter:drop-shadow(0 0 12px #fff) drop-shadow(0 8px 4px rgb(0 0 0 / .2))}.sticker-reward.t-diamond .sr-icon{filter:drop-shadow(0 0 18px #8be9ff) drop-shadow(0 0 6px #ff9be3)}
.sr-card .tier-chip{margin-left:6px}
/* Góc chung: biểu tượng nhỏ cạnh tên */
.hub-ic.t-silver{filter:drop-shadow(0 0 3px #fff) drop-shadow(0 0 1px #8995a6)}.hub-ic.t-gold{filter:drop-shadow(0 0 4px #ffc928)}.hub-ic.t-plat{filter:drop-shadow(0 0 4px #9bd6ff)}.hub-ic.t-diamond{filter:drop-shadow(0 0 5px #8be9ff) drop-shadow(0 0 2px #ff9be3)}
@keyframes stkglint{0%,55%{transform:translateX(-70%)}100%{transform:translateX(70%)}}
@keyframes stkprism{to{background-position:0 0,300% 0}}
@keyframes stkhue{to{filter:drop-shadow(0 0 9px #8be9ff) drop-shadow(0 0 3px #ff9be3) hue-rotate(360deg)}}
@media (prefers-reduced-motion:reduce){.sticker.got.t-silver:before,.sticker.got.t-gold:before,.sticker.got.t-plat:before,.sticker.got.t-diamond:before,.sticker-reward .sr-card:before,.sticker.got.t-diamond,.sticker.got.t-diamond .sticker-icon,.t-diamond.tchip,.t-diamond.tier-chip{animation:none!important}}
.sticker.got.t-silver,.sticker.got.t-gold,.sticker.got.t-plat,.sticker.got.t-diamond{padding-top:28px;min-height:172px}
/* Chiếu bài kiểm tra học sinh (test-deck.js) */
.lk .td-opts{display:grid;grid-template-columns:1fr 1fr;gap:.35em 1.4em;margin-top:.7em}
.lk .td-opts.one{grid-template-columns:1fr}
.lk .td-tf{margin-top:.6em;display:grid;gap:.3em}
@media(max-width:700px){.lk .td-opts{grid-template-columns:1fr}}
.td-bar{display:flex;flex-wrap:wrap;align-items:center;gap:.6rem 1rem;padding:.7rem 1rem;margin:0 0 1rem}.td-bar span{display:flex;flex-wrap:wrap;gap:.5rem}

/* ===== Trang chọn bài (học sinh): tiến độ, lọc, tìm kiếm, gọn trên điện thoại ===== */
.overall{padding:14px 16px;margin:14px 0 12px}
.ov-top{display:flex;justify-content:space-between;align-items:baseline;gap:10px;margin-bottom:8px;flex-wrap:wrap}
.ov-top b{font:800 20px/1.2 var(--f-head)}.ov-top span{color:var(--muted);font-size:14px}
.learning-overview{display:grid;gap:10px}
.home-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.home-stats button{display:flex;align-items:center;gap:9px;min-height:54px;padding:8px 12px;border:2px solid var(--line);border-radius:14px;background:var(--bg);color:var(--ink);text-align:left;cursor:pointer}
.home-stats button:nth-child(1){border-color:color-mix(in srgb,var(--ok) 70%,var(--line))}.home-stats button:nth-child(2){border-color:color-mix(in srgb,var(--star) 75%,var(--line))}
.home-stats button b{font:900 25px/1 var(--f-head)}.home-stats button span{font-size:13px;font-weight:800}
.home-stats button[aria-pressed="true"]{background:var(--ink);color:var(--bg);box-shadow:3px 3px 0 var(--line)}
.ov-missing{margin:0;padding-top:1px;color:var(--muted);font-size:13px}.ov-missing b{color:var(--ink)}
.pbar{display:block;height:10px;border-radius:99px;background:color-mix(in srgb,var(--line) 14%,var(--surface));border:1.5px solid var(--line);overflow:hidden;flex:1}
.pbar i{display:block;height:100%;background:var(--primary);border-radius:99px;min-width:0;transition:width .3s}
.pbar.big{height:14px}
.prog{display:flex;align-items:center;gap:8px}.pct{font:700 13px/1 var(--f-body);min-width:38px;text-align:right;color:var(--muted)}
.st-done .pbar i{background:var(--ok,#2e9e5b)}
.chip{font:700 12px/1 var(--f-body);padding:5px 9px;border-radius:99px;border:1.5px solid var(--line);white-space:nowrap;background:var(--surface);color:var(--muted)}
.chip.st-doing{background:color-mix(in srgb,var(--star,#f4b400) 30%,var(--surface));color:var(--ink)}
.chip.st-done{background:color-mix(in srgb,var(--ok,#2e9e5b) 28%,var(--surface));color:var(--ink)}
.les-top{display:flex;justify-content:space-between;align-items:flex-start;gap:8px}
.tile.les.st-todo{border-style:dashed}
.les-levels{display:grid;grid-template-columns:repeat(3,1fr);gap:5px}
.les-lv{display:flex;align-items:center;justify-content:center;gap:5px;min-height:28px;padding:3px 5px;border:1.5px solid var(--line);border-radius:8px;background:var(--bg);font-size:11px}
.les-lv b{font-size:11px}.les-lv i{color:var(--muted);font-style:normal;font-weight:900}
.les-lv.st-doing{border-color:var(--star);background:color-mix(in srgb,var(--star) 18%,var(--surface))}.les-lv.st-doing i{color:var(--ink)}
.les-lv.st-done{border-color:var(--ok);background:color-mix(in srgb,var(--ok) 18%,var(--surface))}.les-lv.st-done i{color:var(--ok)}
.tdesc{font-size:13px;color:var(--muted);line-height:1.4}
.next-btn{display:flex;flex-direction:column;gap:2px;text-decoration:none;color:var(--bg);background:var(--ink);border-radius:var(--r-md);padding:12px 16px;margin:0 0 14px;box-shadow:var(--shadow-sm)}
.next-btn span{font-size:13px;opacity:.85}.next-btn b{font-size:17px;line-height:1.3}
.finder{position:sticky;top:0;z-index:5;background:var(--bg);padding:10px 0 8px;margin-top:12px;display:grid;gap:8px}
.finder input{width:100%;min-height:48px;border:2.5px solid var(--line);border-radius:var(--r-pill);padding:0 18px;font:600 16px var(--f-body);background:var(--surface);color:var(--ink)}
.chips{display:flex;gap:6px;overflow-x:auto;scrollbar-width:none;padding-bottom:2px}.chips::-webkit-scrollbar{display:none}
.fchip{flex:0 0 auto;min-height:40px;padding:0 14px;border:2px solid var(--line);border-radius:99px;background:var(--surface);color:var(--ink);font:700 14px var(--f-body)}
.fchip small{opacity:.7;margin-left:2px}.fchip[aria-pressed="true"]{background:var(--ink);color:var(--bg)}
.tcount{margin-left:auto;font:700 13px/1 var(--f-body);color:var(--muted);font-style:normal;white-space:nowrap}
.empty{text-align:center;color:var(--muted);padding:30px 10px}
.tile[hidden],.topic[hidden]{display:none}
.home-topic{margin:12px 0 0;border:2.5px solid var(--line);border-radius:var(--r-md);background:var(--surface);box-shadow:var(--shadow-sm);overflow:hidden}
.home-topic-head{display:flex;align-items:center;justify-content:space-between;gap:14px;min-height:66px;padding:10px 14px;cursor:pointer;list-style:none}.home-topic-head::-webkit-details-marker{display:none}
.home-topic-head:hover,.home-topic-head:focus-visible{background:var(--primary-soft);outline:none}
.home-topic-title{display:grid;gap:2px;min-width:0}.home-topic-title small{color:var(--primary);font-size:11px;font-weight:850;letter-spacing:.09em;text-transform:uppercase}.home-topic-title strong{overflow:hidden;text-overflow:ellipsis;font:800 18px/1.25 var(--f-head)}
.topic-summary{display:grid;grid-template-columns:auto 72px 36px 18px;align-items:center;gap:7px;flex:0 0 auto}.topic-summary em{color:var(--muted);font-size:11px;font-style:normal;font-weight:800}.topic-summary>b{color:var(--muted);font-size:11px}.topic-pbar{height:7px;overflow:hidden;border:1px solid var(--line);border-radius:99px;background:var(--bg)}.topic-pbar i{display:block;height:100%;border-radius:99px;background:var(--primary)}
.topic-chev{color:var(--primary);font-size:18px;font-style:normal;transition:transform .18s}.home-topic[open] .topic-chev{transform:rotate(180deg)}
.home-topic[open]>.home-topic-head{border-bottom:2.5px solid var(--line)}
.home-grid{grid-template-columns:repeat(auto-fill,minmax(285px,1fr));gap:9px;padding:10px}
.home-grid .tile.les{min-height:0;padding:10px 12px;gap:7px;border-width:2px;box-shadow:2px 2px 0 var(--line)}
@media (max-width:600px){
  .hide-sm{display:none}.home-h{font-size:24px;margin:6px 0 0}
  .overall{padding:10px 12px;margin:10px 0}.ov-top b{font-size:17px}
  .home-stats{gap:5px}.home-stats button{display:grid;justify-items:center;gap:2px;min-height:58px;padding:6px 3px;text-align:center}.home-stats button b{font-size:21px}.home-stats button span{font-size:10px}.ov-missing{font-size:12px}
  .topic{margin-top:18px}.topic h2{font-size:18px;flex-wrap:wrap;gap:4px 8px}.home-topic{margin-top:8px}
  .home-topic-head{min-height:58px;padding:8px 10px;gap:7px}.home-topic-title strong{font-size:15px}.topic-summary{grid-template-columns:auto 28px 15px;gap:4px}.topic-summary em{font-size:9px}.topic-summary .topic-pbar{display:none}.topic-summary>b{font-size:9px}.topic-chev{font-size:15px}
  .grid{grid-template-columns:1fr;gap:8px}
  .home-grid{padding:7px}.tile.les{min-height:0;padding:9px 10px;gap:6px;box-shadow:2px 2px 0 var(--line)}
  .tile.les b{font-size:16px}.tile .meta{font-size:13px}
  .les-lv b{font-size:10px}.les-lv{min-height:26px;font-size:10px}
  .chips{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));overflow:visible;gap:4px}.fchip{min-width:0;padding:0 3px;font-size:11px}.fchip small{margin-left:0}
  .tabs{display:flex}.tabs button{flex:1;padding:6px 8px}
}
.petfold{padding:0;margin:0 0 12px}.petfold>summary{padding:12px 16px;font:800 16px var(--f-head);cursor:pointer;min-height:48px;display:flex;align-items:center}
.petfold[open]>summary{border-bottom:2px solid var(--line)}.petfold>*:not(summary){margin-left:12px;margin-right:12px}

/* Thi đua theo nhóm trong trình chiếu bài giảng: ngăn kéo thay đổi độ rộng. */
.lk-slide{transition:margin-right .18s ease}.lk.team-on .lk-slide{margin-right:var(--team-w,390px)}.lk-team-panel[hidden]{display:none!important}.lk-team-panel{position:absolute;z-index:6;top:0;right:0;bottom:58px;display:flex;overflow:hidden;background:var(--surface);color:var(--ink);box-shadow:-10px 0 28px #0004;font-family:var(--f-body)}.lk-team-grip{flex:0 0 15px;display:flex;align-items:center;justify-content:center;background:var(--pv-bar);cursor:col-resize;touch-action:none}.lk-team-grip i{width:5px;height:58px;border-radius:3px;background:var(--pv-muted);opacity:.55}.lk-team-grip:hover i,.lk-team-grip:focus-visible i,.lk-team-panel.dragging .lk-team-grip i{background:var(--pv-accent);opacity:1}.lk-team-main{flex:1;min-width:0;overflow:auto;border-left:2px solid var(--primary)}.lk-team-main>header{position:sticky;z-index:2;top:0;display:flex;align-items:center;gap:7px;min-height:48px;padding:6px 9px;background:linear-gradient(110deg,var(--primary),#f2b629);color:var(--primary-ink)}.lk-team-main>header>b{flex:1;font:900 clamp(16px,1.4vw,20px)/1.15 var(--f-head)}.lk-team-main>header>button{min-width:34px;min-height:34px;border:2px solid currentColor;border-radius:50%;background:#ffffff36;color:inherit;font:900 16px/1 var(--f-body);cursor:pointer}.lk-team-setup,.lk-team-ready,.lk-team-play,.lk-team-rank{display:grid;gap:9px;padding:11px}.lk-team-setup label{display:grid;gap:4px;font-size:13px;font-weight:800}.lk-team-setup input,.lk-team-setup select{width:100%;min-height:39px;padding:6px 8px;border:2px solid var(--line);border-radius:9px;background:var(--bg);color:var(--ink);font:700 14px var(--f-body)}.lk-team-two{display:grid;grid-template-columns:1fr 1fr;gap:7px}.lk-team-names{display:grid;grid-template-columns:1fr 1fr;gap:6px}.lk-team-setup p{margin:0;padding:7px;border-radius:9px;background:var(--primary-soft);font-size:11px;line-height:1.35}.lk-team-panel .btn{width:100%;min-height:39px;padding:6px 10px}.lk-team-ready>small{text-align:center;color:var(--primary);font-size:11px;font-weight:900;letter-spacing:.09em}.lk-team-ready>h2{margin:0;text-align:center;font:900 21px/1.1 var(--f-head)}.lk-team-list{display:grid;gap:5px}.lk-team-card{display:grid;grid-template-columns:minmax(82px,.75fr) minmax(90px,1.25fr) auto;align-items:center;gap:5px;padding:6px;border:2px solid var(--line);border-radius:11px;background:var(--bg);transition:.15s}.lk-team-card.right{border-color:var(--ok);background:var(--ok-soft)}.lk-team-card.wrong{border-color:var(--bad);background:var(--bad-soft)}.lk-team-info{display:grid;grid-template-columns:8px minmax(0,1fr);align-items:center;gap:5px;min-width:0}.lk-team-info b{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}.lk-team-info small{grid-column:2;color:var(--muted);font-size:10px;font-weight:800}.lk-team-color{grid-row:1/3;width:7px;height:31px;border-radius:6px;background:#7769e9}.lk-team-color.c1{background:#ee4d5a}.lk-team-color.c2{background:#1ea8d7}.lk-team-color.c3{background:#ef9e21}.lk-team-color.c4{background:#22ad67}.lk-team-color.c5{background:#cb56c8}.lk-team-color.c6{background:#7caa2d}.lk-team-color.c7{background:#d86c28}.lk-team-rounds{display:flex;align-items:center;gap:3px;overflow-x:auto;min-width:0;padding:2px;scrollbar-width:thin}.lk-team-rounds i{flex:0 0 19px;display:grid;place-items:center;width:19px;height:19px;border:1.5px solid var(--line);border-radius:50%;background:var(--surface);color:var(--muted);font:800 9px/1 var(--f-body);font-style:normal}.lk-team-rounds i.current{outline:2px solid var(--primary);outline-offset:1px}.lk-team-rounds i.right{border-color:var(--ok);background:var(--ok);color:#fff}.lk-team-rounds i.wrong{border-color:var(--bad);background:var(--bad);color:#fff}.lk-team-mark{display:flex;gap:3px}.lk-team-mark button{display:grid;place-items:center;width:29px;height:29px;padding:0;border:2px solid var(--line);border-radius:9px;background:var(--surface);color:var(--ink);font:900 15px/1 var(--f-body);cursor:pointer}.lk-team-mark button:first-child.on{border-color:var(--ok);background:var(--ok);color:#fff}.lk-team-mark button:last-child.on{border-color:var(--bad);background:var(--bad);color:#fff}.lk-team-progress{height:9px;overflow:hidden;border:1.5px solid var(--line);border-radius:99px;background:var(--bg)}.lk-team-progress i{display:block;height:100%;border-radius:99px;background:linear-gradient(90deg,var(--primary),#f3c431);transition:width .2s}.lk-team-play>p{margin:0;text-align:center;font-size:12px}.lk-team-rank ol{display:grid;gap:5px;margin:0;padding:0;list-style:none}.lk-team-rank li{display:grid;grid-template-columns:28px minmax(0,1fr) auto;align-items:center;gap:6px;padding:7px;border:2px solid var(--line);border-radius:11px;background:var(--bg)}.lk-team-rank li.top{box-shadow:0 4px 12px #0002}.lk-team-rank li.top1{border-color:#eab414;background:#fff5bd}.lk.dark .lk-team-rank li.top1{background:#554814}.lk-team-rank li.top2{border-color:#aebdca}.lk-team-rank li.top3{border-color:#c8874e}.lk-team-rank li>em{display:grid;place-items:center;width:27px;height:27px;border-radius:50%;background:var(--primary);color:var(--primary-ink);font-size:12px;font-style:normal;font-weight:900}.lk-team-rank li>span b,.lk-team-rank li>span small,.lk-team-rank li>strong small{display:block}.lk-team-rank li>span b{font-size:13px}.lk-team-rank li>span small{color:var(--muted);font-size:10px}.lk-team-rank li>strong{text-align:right;color:var(--primary);font:900 18px/1 var(--f-head)}.lk-team-rank li>strong small{font:700 9px var(--f-body)}.lk-team-rank li>.lk-team-rounds{grid-column:2/4}.lk-team-cup{text-align:center;font-size:48px}.lk-team-rank>h2{margin:0;text-align:center;font:900 19px var(--f-head)}
.lk-team-loading,.lk-team-error{text-align:center;font-weight:800}.lk-team-error{color:var(--bad)}.lk-team-setup label.lk-team-hope-mode{display:flex;align-items:center;gap:9px;padding:8px;border:2px solid #f0bd26;border-radius:11px;background:linear-gradient(120deg,#fff8cf,#ffe48a);color:#5a3b00;cursor:pointer}.lk.dark .lk-team-setup label.lk-team-hope-mode{background:linear-gradient(120deg,#514316,#6c5312);color:#fff4b2}.lk-team-setup .lk-team-hope-mode input{flex:0 0 22px;width:22px;min-height:22px;margin:0;accent-color:#e3a500}.lk-team-hope-mode span{display:grid;gap:1px}.lk-team-hope-mode small{font-size:10px;font-weight:700}.lk-team-hope-note{margin:0;padding:7px;border-radius:9px;background:#fff2a8;color:#5c4000;text-align:center;font-size:11px;font-weight:800}.lk.dark .lk-team-hope-note{background:#564812;color:#fff2a8}.lk-team-members{grid-column:1/-1;margin:0;padding:4px 6px;border-radius:7px;background:var(--surface);color:var(--muted);font-size:10px;line-height:1.35}.lk-team-actions{display:flex;align-items:center;gap:4px}.lk-team-actions>button{display:grid;place-items:center;width:29px;height:29px;padding:0;border:2px solid #e1aa0d;border-radius:9px;background:#fff7c5;font-size:14px;cursor:pointer}.lk-team-actions>button.on{background:#ffd52d;box-shadow:0 0 0 3px #ffd52d55,0 0 14px #f0b800}.lk-team-actions>button:disabled{cursor:not-allowed;filter:grayscale(1);opacity:.35}.lk-team-card.hope{border-color:#e4ad00;box-shadow:0 0 0 2px #ffd52d55}.lk-team-rounds i.hope{outline:2px solid #f5bd0b;outline-offset:1px;box-shadow:0 0 7px #ffc400}.lk-team-rounds i.hope.right,.lk-team-rounds i.hope.wrong{background-image:linear-gradient(135deg,#ffd52d 0 25%,transparent 26%)}
.lk-team-card.number-ready{padding:8px}.lk-team-card.number-ready .lk-team-members{padding:10px 8px;border:2px solid #8fb2f5;background:linear-gradient(120deg,#edf4ff,#fff);color:#1658c7;text-align:center;font:900 clamp(24px,2.25vw,34px)/1.25 var(--f-head);letter-spacing:.02em}.lk.dark .lk-team-card.number-ready .lk-team-members{background:#17294b;color:#bcd4ff}.lk-team-hope-row{grid-column:1/-1}.lk-team-hope-row>button{width:100%;min-height:34px;padding:5px 8px;border:2px solid #e1aa0d;border-radius:9px;background:#fff7c5;color:#594000;font:900 12px var(--f-body);cursor:pointer}.lk.dark .lk-team-hope-row>button{background:#514316;color:#fff1a8}.lk-team-hope-row>button.on{background:#ffd52d;box-shadow:0 0 0 3px #ffd52d55,0 0 14px #f0b800}.lk-team-hope-row>button:disabled{cursor:not-allowed;filter:grayscale(.6);opacity:.7}.lk-team-hope-confirm{display:grid;gap:6px;padding:7px;border:2px solid #e1aa0d;border-radius:10px;background:#fff6bd;color:#513900;text-align:center;font-size:11px}.lk.dark .lk-team-hope-confirm{background:#514316;color:#fff1a8}.lk-team-hope-confirm span{display:grid;grid-template-columns:1fr 1fr;gap:6px}.lk-team-hope-confirm button{min-height:32px;border:2px solid #8c6a00;border-radius:8px;background:#fff;color:#4b3700;font-weight:900;cursor:pointer}.lk-team-hope-confirm button:first-child{background:#e9b600;color:#231900}.lk-team-mark button:disabled{cursor:not-allowed;opacity:.35}
.lk-team-card.roster-ready{padding:8px}.lk-team-card.roster-ready .lk-team-members{padding:9px 8px;border:2px solid #8fd6b2;background:linear-gradient(120deg,#eafff3,#fff);color:#087640;text-align:center;font:900 clamp(18px,1.55vw,24px)/1.35 var(--f-head)}.lk.dark .lk-team-card.roster-ready .lk-team-members{background:#133828;color:#baf3d3}.lk-team-compact{grid-column:2;overflow:hidden;color:var(--muted);font-size:9px;font-weight:700;line-height:1.2;text-overflow:ellipsis;white-space:nowrap}
.lk-team-active{display:grid;grid-template-columns:1fr 1fr;gap:5px;margin:0;padding:7px;border:2px solid var(--line);border-radius:10px}.lk-team-active legend{padding:0 5px;color:var(--primary);font-size:11px;font-weight:900}.lk-team-setup .lk-team-active label{display:flex;align-items:center;gap:5px;padding:5px;border-radius:7px;background:var(--bg);font-size:10px}.lk-team-setup .lk-team-active input{width:17px;min-height:17px;margin:0;accent-color:var(--primary)}.lk-team-active-note{margin:0;padding:6px;border-radius:8px;background:var(--primary-soft);text-align:center;font-size:10px;font-weight:800}.lk-team-tools{display:grid;grid-template-columns:1fr 1fr;gap:5px}.lk-team-tools button{min-height:34px;padding:5px;border:2px solid var(--line);border-radius:9px;background:var(--surface);color:var(--ink);font-weight:900;cursor:pointer}.lk-team-tools button.on{border-color:#dc9710;background:#fff0a8;color:#553900}.lk-team-tools button:disabled{opacity:.55;cursor:not-allowed}.lk-team-ambassador{grid-column:1/-1;padding:5px 7px;border:1.5px dashed var(--line);border-radius:8px;background:var(--surface);color:var(--muted);text-align:center;font-size:10px}.lk-team-ambassador.on{border-style:solid;border-color:#8a6bea;background:#efeaff;color:#4b3298}.lk.dark .lk-team-ambassador.on{background:#35275b;color:#dfd5ff}.lk-team-hunt-mark{display:grid;grid-template-columns:repeat(4,27px);gap:3px}.lk-team-hunt-mark button{height:29px;padding:0;border:2px solid var(--line);border-radius:8px;background:var(--surface);color:var(--ink);font-size:9px;font-weight:900;cursor:pointer}.lk-team-hunt-mark button.on{border-color:#d79412;background:#ffe791;color:#513700}.lk-team-card.hunt{border-color:#dfaa32}.lk-team-rounds i.hunt{border-color:#d99c18;background:#fff0a8;color:#664500}.lk-team-rounds i.hunt3{background:#e5aa18;color:#fff}.lk-team-power{grid-column:1/-1;border:1.5px solid var(--line);border-radius:8px;background:var(--surface);font-size:10px}.lk-team-power summary{display:flex;justify-content:space-between;padding:5px 7px;font-weight:900;cursor:pointer}.lk-team-power>div{display:grid;grid-template-columns:1fr 1fr;gap:4px;padding:0 6px 6px}.lk-team-power button,.lk-team-power select{min-height:30px;padding:4px;border:1.5px solid var(--line);border-radius:7px;background:var(--bg);color:var(--ink);font:800 9px var(--f-body)}.lk-team-power button{cursor:pointer}.lk-team-power button:disabled{opacity:.45;cursor:not-allowed}.lk-team-challenge{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;gap:4px}.lk-team-power>p{margin:0;padding:5px 7px;border-top:1px solid var(--line);color:var(--primary);font-size:9px;font-weight:800}
@media(max-width:850px){.lk-team-panel{width:100%!important}.lk-team-grip{display:none}.lk-team-main{border-left:0}.lk.team-on .lk-slide{margin-right:0;visibility:hidden}.lk-team-names{grid-template-columns:1fr 1fr}}
@media(max-width:480px){.lk-team-names{grid-template-columns:1fr}.lk-team-card{grid-template-columns:minmax(80px,.8fr) minmax(80px,1.2fr) auto}.lk-team-panel{bottom:100px}}
.lk-team-power-confirm{display:grid!important;grid-template-columns:1fr!important;gap:5px!important;margin:0 6px 6px;padding:7px!important;border:2px solid #8a6bea;border-radius:9px;background:#efeaff;color:#3f297e;text-align:center}.lk.dark .lk-team-power-confirm{background:#35275b;color:#eee8ff}.lk-team-power-confirm small{font-size:9px}.lk-team-power-confirm span{display:grid;grid-template-columns:1fr 1fr;gap:5px}.lk-team-power-confirm button{min-height:31px!important;font-size:10px!important}.lk-team-power-confirm button:first-child{border-color:#694bc8;background:#795bdd;color:#fff}
/* Mở khóa kho báu: đồ họa nhẹ bằng CSS, không tải ảnh ngoài. */
.lk-team-treasure-btn{grid-column:1/-1;min-height:36px;border:2px solid #d99813;border-radius:10px;background:linear-gradient(105deg,#fff0a6,#ffd34e 55%,#ffad32);color:#573500;font:900 11px var(--f-head);cursor:pointer;box-shadow:0 3px 0 #b66d0b}.lk-team-treasure-btn b{display:inline-grid;place-items:center;min-width:21px;height:21px;margin-left:4px;border-radius:50%;background:#7b3e0d;color:#fff}.lk-treasure-bar{background:linear-gradient(105deg,#086f91,#14a6af 58%,#efbd38)!important}.lk-treasure-map{position:relative;isolation:isolate;min-height:100%;overflow:hidden;padding:10px;background:radial-gradient(circle at 50% 42%,#d9ffba 0 17%,#76cd63 18% 31%,transparent 32%),radial-gradient(circle at 20% 75%,#b5ee83 0 10%,#53b35d 11% 19%,transparent 20%),linear-gradient(160deg,#51d5df,#147fb4 70%,#075e99);color:#fff}.lk-treasure-map:before{content:"";position:absolute;z-index:-1;inset:0;background:radial-gradient(circle,#fff8 1px,transparent 2px) 0 0/26px 26px;opacity:.28}.lk-treasure-sky{display:flex;justify-content:space-between;align-items:center;height:28px;padding:0 7px;font-size:20px}.lk-treasure-sky i{font-style:normal;filter:drop-shadow(0 2px 1px #075a7a88)}.lk-treasure-sky i:nth-child(2){font-size:27px;animation:lkTreasureSun 3s ease-in-out infinite}.lk-treasure-title{margin:2px 3px 10px;padding:9px;border:2px solid #ffffffaa;border-radius:14px;background:#064f70bb;text-align:center;box-shadow:0 7px 18px #00354d66;backdrop-filter:blur(3px)}.lk-treasure-title small{font-size:9px;font-weight:900;letter-spacing:.13em}.lk-treasure-title h2{margin:2px 0;font:900 21px/1.1 var(--f-head);color:#fff4a4}.lk-treasure-title p{margin:0;font-size:11px}.lk-treasure-route{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;padding:10px 7px;border:2px dashed #fff8;border-radius:18px;background:#f7d88952;box-shadow:inset 0 0 25px #4a6e1f55}.lk-treasure-chest{position:relative;display:grid;place-items:center;gap:3px;min-height:67px;padding:7px 2px 4px;border:2px solid #fff7c8;border-radius:13px;background:linear-gradient(#fff6b3,#e5a637);color:#623500;cursor:pointer;box-shadow:0 4px 0 #8c5316,0 7px 12px #003b5555;transition:transform .16s,filter .16s}.lk-treasure-chest:not(:disabled):hover,.lk-treasure-chest.chosen{transform:translateY(-4px) scale(1.05);filter:brightness(1.12);outline:3px solid #fff}.lk-treasure-chest:disabled{cursor:default}.lk-treasure-chest.opened{background:#c6d0c8;color:#44534b;box-shadow:0 3px 0 #66746c;opacity:.72}.lk-treasure-chest small{font:900 8px var(--f-body)}.lk-chest-art{position:relative;width:38px;height:25px;border:3px solid #6d370d;border-radius:5px;background:linear-gradient(90deg,#9d4f13 0 17%,#f2bc36 18% 28%,#a85214 29% 70%,#f2bc36 71% 81%,#954611 82%);box-shadow:inset 0 4px #e57b20}.lk-chest-art:before{content:"";position:absolute;left:-3px;right:-3px;top:-12px;height:14px;border:3px solid #6d370d;border-bottom-width:2px;border-radius:13px 13px 3px 3px;background:linear-gradient(90deg,#a85817,#f0a52a 48%,#91400f)}.lk-chest-art:after{content:"◆";position:absolute;z-index:2;left:50%;top:3px;display:grid;place-items:center;width:13px;height:13px;transform:translateX(-50%);border:2px solid #6d370d;border-radius:3px;background:#ffe262;color:#783d0e;font-size:7px}.opened .lk-chest-art{filter:grayscale(.8);transform:rotate(-4deg)}.lk-treasure-confirm,.lk-treasure-reveal{position:relative;z-index:3;display:grid;gap:7px;margin:10px 3px 4px;padding:10px;border:3px solid #ffe269;border-radius:15px;background:#173867e8;color:#fff;text-align:center;box-shadow:0 10px 25px #002a45aa}.lk-treasure-confirm span{display:grid;grid-template-columns:1fr 1fr;gap:7px}.lk-treasure-confirm button,.lk-treasure-reveal button{min-height:36px;border:2px solid #fff3ae;border-radius:10px;background:#ffd24b;color:#512f00;font-weight:900;cursor:pointer}.lk-treasure-confirm button:last-child{background:#fff;color:#243653}.lk-treasure-reveal{animation:lkTreasureReveal .45s cubic-bezier(.2,.9,.3,1.3)}.lk-treasure-reveal>div{font-size:38px;line-height:1;animation:lkTreasureSpark 1s ease-in-out infinite alternate}.lk-treasure-reveal>b{font:900 12px var(--f-head);letter-spacing:.12em}.lk-treasure-reveal>strong{color:#ffe56f;font:900 30px/1 var(--f-head);text-shadow:0 2px #813e00}.lk-treasure-reveal p{margin:0;font-size:11px;font-weight:800}.lk-treasure-tip{margin:9px 3px 0;padding:6px;border-radius:9px;background:#003f62aa;text-align:center;font-size:9px;font-weight:800}.lk-team-rank li>span small{line-height:1.3}@keyframes lkTreasureReveal{from{opacity:0;transform:scale(.65) rotate(-3deg)}to{opacity:1;transform:scale(1) rotate(0)}}@keyframes lkTreasureSpark{to{transform:scale(1.14) rotate(5deg)}}@keyframes lkTreasureSun{50%{transform:translateY(3px) scale(1.08)}}
@media(max-width:480px){.lk-treasure-route{gap:5px;padding:8px 5px}.lk-treasure-chest{min-height:62px}.lk-chest-art{transform:scale(.9)}}
.lk-treasure-claims{display:grid;grid-template-columns:1fr 1fr;gap:5px;padding:7px;border:2px solid #e3af25;border-radius:11px;background:#fff4b9}.lk.dark .lk-treasure-claims{background:#534614}.lk-treasure-claims>small{grid-column:1/-1;text-align:center;color:#795100;font-size:9px;font-weight:900;letter-spacing:.08em}.lk.dark .lk-treasure-claims>small{color:#ffe98d}.lk-treasure-claims button{min-height:34px;border:1.5px solid #b97a0b;border-radius:8px;background:linear-gradient(#ffe985,#ffc43a);color:#593500;font:900 9px var(--f-body);cursor:pointer}.lk-treasure-claims button b{display:inline-grid;place-items:center;min-width:18px;height:18px;border-radius:50%;background:#713b0e;color:#fff}

/* Trang giáo viên: chương / đề kiểm tra thu gọn, bấm tiêu đề để mở */
.lk-lessons .topic.fold{margin:12px 0 0;background:var(--surface);border:2.5px solid var(--line);border-radius:var(--r-md);box-shadow:var(--shadow-sm);overflow:hidden}
.lk-lessons .topic.fold>h2.fold-h{margin:0;padding:12px 16px;cursor:pointer;user-select:none;align-items:center;font-size:20px}
.lk-lessons .topic.fold>h2.fold-h:hover,.lk-lessons .topic.fold>h2.fold-h:focus-visible{background:var(--primary-soft);outline:none}
.fold-n{margin-left:auto;font:700 13px/1 var(--f-body);color:var(--muted);white-space:nowrap}
.fold-chev{font-size:18px;color:var(--primary);transition:transform .18s}
.topic.fold.open>.fold-h .fold-chev{transform:rotate(90deg)}
.topic.fold:not(.open)>.fold-body{display:none}
.topic.fold.open>.fold-h{border-bottom:2.5px solid var(--line)}
.fold-body{padding:12px 14px 14px}
.fold-bar{display:flex;gap:8px;margin:0 0 4px}

/* Bảng tổng hợp tiến độ cả lớp (class-matrix.js) */
.cm-overlay{position:fixed;inset:0;z-index:15000;display:grid;place-items:center;padding:14px;background:#081126d9;backdrop-filter:blur(7px)}
.cm-card{display:flex;flex-direction:column;width:min(1280px,98vw);max-height:95dvh;overflow:hidden;border:3px solid #8d73df;border-radius:24px;background:var(--surface);color:var(--ink);box-shadow:0 24px 80px #0009}
.cm-card>header{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:13px 18px;background:linear-gradient(115deg,#6f55d4,#3d7be8);color:#fff}
.cm-card>header small{font:800 11px/1 var(--f-body);letter-spacing:1.5px;opacity:.85}.cm-card>header h2{margin:3px 0 0;font:800 20px/1.25 var(--f-head)}
.cm-card>header button{min-width:42px;min-height:42px;border:0;border-radius:12px;background:#ffffff2e;color:#fff;font:800 18px var(--f-body);cursor:pointer}
.cm-ctl{display:flex;flex-wrap:wrap;gap:10px;align-items:center;padding:10px 16px}.cm-ctl label{font-weight:800;display:flex;gap:8px;align-items:center}.cm-ctl select{min-height:40px;border:2px solid var(--line);border-radius:10px;padding:4px 10px;font:700 15px var(--f-body);background:var(--surface);color:var(--ink)}
.cm-card>main{padding:0 16px 14px;overflow:auto;min-height:0}
.cm-sum{display:flex;flex-wrap:wrap;gap:8px;margin:2px 0 8px}.cm-sum span{flex:1 1 110px;text-align:center;padding:7px 4px;border:2px solid var(--line);border-radius:12px;background:var(--bg)}.cm-sum b{display:block;font:800 22px/1.1 var(--f-head)}.cm-sum small{font-weight:700;color:var(--muted)}
.cm-sum .d{background:#c8efd5;color:#0d4a28}.cm-sum .o{background:#fff0b3;color:#5a3d00}.cm-sum .t{background:#f8d0d0;color:#6b1717}.cm-sum .d small,.cm-sum .o small,.cm-sum .t small{color:inherit}
.cm-leg{margin:0 0 8px;font-size:14px;color:var(--muted)}.cm-leg i{font-style:normal;font-weight:800;display:inline-block;min-width:30px;text-align:center;padding:1px 6px;border-radius:6px;border:1.5px solid #0004;color:#14213d}
.cm-leg i.done,.cm-c.done{background:#c8efd5}.cm-leg i.doing,.cm-c.doing{background:#fff0b3}.cm-leg i.todo,.cm-c.todo{background:#f8d0d0}
.cm-scroll{overflow:auto;max-height:58dvh;border:2px solid var(--line);border-radius:12px}
.cm-tb{border-collapse:separate;border-spacing:0;font-size:14px;width:max-content;min-width:100%}
.cm-tb th,.cm-tb td{border-right:1px solid #9aa0aa88;border-bottom:1px solid #9aa0aa88;padding:4px 6px;text-align:center;background:var(--surface);white-space:nowrap}
.cm-tb thead th{position:sticky;top:0;z-index:2;background:#dbe6fb;color:#14213d;font-weight:800}
.cm-tb thead tr:nth-child(2) th{top:var(--cm-h1,34px)}
.cm-tb .cm-topic{font-size:12px;max-width:260px;overflow:hidden;text-overflow:ellipsis}
.cm-tb .cm-name{position:sticky;left:34px;z-index:1;text-align:left;min-width:170px;max-width:220px;overflow:hidden;text-overflow:ellipsis}.cm-tb .cm-name small{display:block;color:var(--muted);font-size:11px}
.cm-tb .cm-n{position:sticky;left:0;z-index:1;min-width:34px}.cm-tb thead .cm-n,.cm-tb thead .cm-name{z-index:3}
.cm-les{cursor:pointer;height:150px;vertical-align:bottom;padding:4px 2px;min-width:30px}.cm-les span{writing-mode:vertical-rl;transform:rotate(180deg);display:inline-block;max-height:140px;overflow:hidden;font-size:12px}
.cm-les:hover,.cm-les:focus-visible{background:#b9cdf5;outline:none}
.cm-c{font-weight:800;min-width:30px}.cm-f{font-weight:800;background:#f8d0d0;color:#6b1717}.cm-tb tfoot td{position:sticky;bottom:0;background:#f4e3e3;font-weight:700}
.cm-detail:not(:empty){margin-top:10px;padding:10px 14px;border:2px solid var(--line);border-radius:12px;background:var(--bg)}.cm-detail h4{margin:0 0 6px;font:800 16px var(--f-head)}
.cm-g{margin:4px 0;padding:6px 10px;border-radius:8px;font-size:14px;line-height:1.5}.cm-g b{display:block}.cm-g.todo{background:#f8d0d0;color:#5c1212}.cm-g.doing{background:#fff0b3;color:#4a3300}.cm-g.done{background:#c8efd5;color:#0d4a28}
@media(max-width:700px){.cm-card{width:100%;max-height:97dvh;border-radius:18px}.cm-card>header h2{font-size:16px}.cm-scroll{max-height:52dvh}}

/* Ma trận đề theo mẫu của tổ (kiemtra.js, t.matrix) */
.kt-mx2{font-size:7.6pt}.kt-mx2 td,.kt-mx2 th{padding:1.5pt 2.5pt;line-height:1.25}.kt-mx2 .kt-lft{text-align:left}
.kt-dt{border-collapse:collapse;margin:3pt auto;font-size:9pt}.kt-dt th,.kt-dt td{border:.7pt solid var(--ink);padding:1pt 6pt;text-align:center}
.hub-chtab{width:100%;border-collapse:collapse;margin:8px 0}.hub-chtab caption{text-align:left;font-weight:700;padding:4px 0}.hub-chtab td{padding:6px 4px;border-top:1px solid var(--line,#e5e7eb)}.hub-chtab td:last-child{width:84px}.hub-chtab input{width:64px;min-height:40px;font-size:16px;text-align:center;border:1px solid var(--line,#cbd5e1);border-radius:10px;background:transparent;color:inherit}