:root{
  --bg:#F6F7FB; --paper:#FFFFFF; --paper-2:#EEF1F8; --ink:#101733; --ink-2:#434D6B; --ink-3:#687190;
  --line:#E1E5EF; --navy:#1D2B5C; --deep:#101B45; --sun:#FFC233; --sun-soft:rgba(255,194,51,.2); --mint:#0E9F7E; --coral:#EE5A45;
  --link:#2B48C8; --btn:#1D2B5C; --btn-ink:#FFFFFF; --focus:#2B48C8;
  --good:#0F8A5F; --good-soft:rgba(15,138,95,.11); --bad:#C8363D; --bad-soft:rgba(200,54,61,.09); --warn:#A86A00;
  --pro:#0B8A72; --pro-soft:rgba(11,138,114,.11); --plus:#A86400; --plus-soft:rgba(255,194,51,.22);
  --b0:#2B48C8; --b1:#0B8A72; --b2:#C2590C; --b3:#9B3389; --b4:#5B6D0B; --b5:#1C73B7;
  --grid:rgba(29,43,92,.05);
  --shadow:0 1px 2px rgba(16,23,51,.04),0 10px 30px -12px rgba(16,23,51,.18);
  --shadow-lg:0 2px 4px rgba(16,23,51,.05),0 24px 60px -20px rgba(16,23,51,.35);
  --f-display:"Fraunces","Be Vietnam Pro",Georgia,serif;
  --f-body:"Be Vietnam Pro",system-ui,-apple-system,"Segoe UI",sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,Menlo,Consolas,monospace;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    color-scheme:dark;
    --bg:#0A0F22; --paper:#111934; --paper-2:#19223F; --ink:#EDF0FA; --ink-2:#B3BAD2; --ink-3:#8A92B0;
    --line:#252E52; --deep:#16214D; --link:#A3B3FF; --btn:#FFC233; --btn-ink:#1A1300; --focus:#A3B3FF;
    --good:#45C994; --good-soft:rgba(69,201,148,.14); --bad:#FF7C80; --bad-soft:rgba(255,124,128,.12); --warn:#FFC24D;
    --pro:#3FD2B4; --pro-soft:rgba(63,210,180,.14); --plus:#FFC94D; --plus-soft:rgba(255,194,51,.16);
    --b0:#93A6FF; --b1:#3FD2B4; --b2:#F49A55; --b3:#E37CD3; --b4:#B9CC4E; --b5:#62B5F3;
    --grid:rgba(160,180,255,.05);
    --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.6);
    --shadow-lg:0 2px 4px rgba(0,0,0,.4),0 24px 60px -20px rgba(0,0,0,.8);
  }
}
:root[data-theme="dark"]{
  color-scheme:dark;
  --bg:#0A0F22; --paper:#111934; --paper-2:#19223F; --ink:#EDF0FA; --ink-2:#B3BAD2; --ink-3:#8A92B0;
  --line:#252E52; --deep:#16214D; --link:#A3B3FF; --btn:#FFC233; --btn-ink:#1A1300; --focus:#A3B3FF;
  --good:#45C994; --good-soft:rgba(69,201,148,.14); --bad:#FF7C80; --bad-soft:rgba(255,124,128,.12); --warn:#FFC24D;
  --pro:#3FD2B4; --pro-soft:rgba(63,210,180,.14); --plus:#FFC94D; --plus-soft:rgba(255,194,51,.16);
  --b0:#93A6FF; --b1:#3FD2B4; --b2:#F49A55; --b3:#E37CD3; --b4:#B9CC4E; --b5:#62B5F3;
  --grid:rgba(160,180,255,.05);
  --shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px -12px rgba(0,0,0,.6);
  --shadow-lg:0 2px 4px rgba(0,0,0,.4),0 24px 60px -20px rgba(0,0,0,.8);
}
:root[data-theme="light"]{color-scheme:light}
*{box-sizing:border-box}
[hidden]{display:none!important}
html,body{background:var(--bg)}
body{color:var(--ink);font-family:var(--f-body);font-size:15px;line-height:1.55;padding-inline:16px;padding-block:0 40px;
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:28px 28px}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
a{color:var(--link)}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
h1,h2,h3{font-family:var(--f-display);font-weight:800;text-wrap:balance;margin:0;letter-spacing:-.02em;line-height:1.1}
h2{font-size:clamp(26px,3.2vw,36px)}
h3{font-size:18px;font-weight:600;letter-spacing:-.01em}
.wrap{max-width:1200px;margin:0 auto}
.eyebrow{font-size:12px;text-transform:uppercase;letter-spacing:.1em;font-weight:600;color:var(--ink-3)}
.muted{color:var(--ink-3)}
.hint{font-size:13px;color:var(--ink-3)}

/* nav */
.nav{position:sticky;top:env(safe-area-inset-top,0px);z-index:10;margin-inline:-16px;padding-inline:16px;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:14px;height:64px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink)}
.brand svg{flex:none}
.wordmark{font-family:var(--f-display);font-weight:800;font-size:22px;letter-spacing:-.03em}
.wordmark .ai{background:linear-gradient(transparent 58%,var(--sun) 58%,var(--sun) 92%,transparent 92%);padding:0 1px}
.links{display:flex;gap:2px;margin-left:12px}
.links a{text-decoration:none;color:var(--ink-2);font-weight:500;padding:8px 12px;border-radius:9px;font-size:14.5px;white-space:nowrap}
.links a:hover{color:var(--ink);background:var(--paper-2)}
.links a.on{color:var(--ink);background:var(--paper);box-shadow:var(--shadow)}
.links a.admin{color:var(--plus)}
.spacer{flex:1}
.me{display:flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--paper);border-radius:99px;padding:3px 10px 3px 3px;text-decoration:none;color:var(--ink);font-size:14px;font-weight:500;max-width:220px}
.me span.n{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.av{width:30px;height:30px;border-radius:50%;object-fit:cover;flex:none;background:var(--paper-2)}
.av.sm{width:24px;height:24px}
.av.lg{width:44px;height:44px}
.btn.menu-btn{display:none}
@media (max-width:900px){
  .links{position:fixed;left:0;right:0;top:calc(64px + env(safe-area-inset-top,0px));flex-direction:column;background:var(--paper);border-bottom:1px solid var(--line);padding:8px 16px 14px;margin:0;display:none;box-shadow:var(--shadow)}
  .links.open{display:flex}
  .btn.menu-btn{display:inline-flex}
  .me span.n{display:none}
}
.plan{display:inline-flex;align-items:center;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;border-radius:99px;padding:2px 8px;white-space:nowrap;line-height:1.5}
.plan.free{background:var(--paper-2);color:var(--ink-2)}
.plan.pro{background:var(--pro-soft);color:var(--pro)}
.plan.plus{background:var(--plus-soft);color:var(--plus)}
.plan.team{background:var(--navy);color:#fff}

/* buttons */
.btn{border:1px solid var(--line);background:var(--paper);border-radius:10px;padding:8px 14px;font-size:14px;font-weight:600;display:inline-flex;align-items:center;justify-content:center;gap:8px;text-decoration:none;color:var(--ink);white-space:nowrap}
.btn:hover{border-color:var(--ink-3)}
.btn.primary{background:var(--btn);border-color:var(--btn);color:var(--btn-ink)}
.btn.primary:hover{filter:brightness(1.12)}
.btn.sun{background:var(--sun);border-color:var(--sun);color:#1A1300}
.btn.sun:hover{filter:brightness(1.05)}
.btn.ghost{border-color:transparent;background:transparent;color:var(--link);padding-inline:6px}
.btn.danger{color:var(--bad)}
.btn.lg{padding:12px 20px;font-size:15.5px;border-radius:12px}
.btn.sm{padding:5px 10px;font-size:13px;border-radius:8px}
.btn.sq{width:34px;height:34px;padding:0}
.btn:disabled{opacity:.5;cursor:default;filter:none}
.card{background:var(--paper);border:1px solid var(--line);border-radius:16px}
.note{font-size:13.5px;color:var(--ink-2);background:var(--paper-2);border-radius:12px;padding:12px 14px}
.note.warn{background:var(--plus-soft);color:var(--ink)}
.err{color:var(--bad);background:var(--bad-soft);border-radius:10px;padding:10px 12px;font-size:14px}
input[type=text],input[type=search],input[type=url],textarea,select{border:1px solid var(--line);border-radius:10px;padding:9px 12px;background:var(--paper);width:100%}
select{width:auto;padding:7px 10px}
textarea{resize:vertical}
label.f{display:grid;gap:6px;font-size:13.5px;font-weight:600;color:var(--ink-2)}
.toast{position:fixed;left:50%;bottom:calc(20px + env(safe-area-inset-bottom,0px));transform:translateX(-50%);background:var(--ink);color:var(--bg);padding:10px 16px;border-radius:12px;font-size:14px;z-index:40;box-shadow:var(--shadow);max-width:calc(100% - 32px)}
main{padding-top:28px;min-height:60vh}
.spin{display:inline-block;width:12px;height:12px;border-radius:50%;border:2px solid currentColor;border-right-color:transparent;animation:sp .8s linear infinite;vertical-align:-1px}
@keyframes sp{to{transform:rotate(360deg)}}

/* home */
.hero{display:grid;grid-template-columns:1.05fr .95fr;gap:40px;align-items:center;padding-block:24px 56px}
@media (max-width:900px){.hero{grid-template-columns:1fr}}
.hero h1{font-size:clamp(38px,5.6vw,66px);margin:14px 0 18px}
.hero h1 .hl{background:linear-gradient(transparent 62%,var(--sun) 62%,var(--sun) 94%,transparent 94%);padding:0 4px}
.hero p.lead{font-size:18px;color:var(--ink-2);max-width:52ch;margin:0 0 26px}
.cta{display:flex;flex-wrap:wrap;gap:10px}
.stats{display:flex;flex-wrap:wrap;gap:28px;margin-top:34px}
.stats div b{display:block;font-family:var(--f-display);font-size:30px;font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:-.02em}
.stats div span{font-size:13px;color:var(--ink-3)}
.chip-live{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;color:var(--ink-2);background:var(--paper);border:1px solid var(--line);border-radius:99px;padding:5px 12px 5px 8px}
.chip-live i{width:8px;height:8px;border-radius:50%;background:var(--mint);box-shadow:0 0 0 3px var(--pro-soft)}
.art{position:relative;min-height:440px}
.art .c{position:absolute;background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow);padding:16px}
.art .doc{left:0;top:18px;width:58%;transform:rotate(-3deg);animation:rise .7s ease-out both}
.art .map{right:0;top:0;width:66%;animation:rise .7s .15s ease-out both}
.art .quizc{left:12%;bottom:0;width:62%;transform:rotate(1.5deg);animation:rise .7s .3s ease-out both}
@keyframes rise{from{translate:0 18px}to{translate:0 0}}
@media (prefers-reduced-motion:reduce){.art .c,.spin{animation:none}}
.doc .fn{display:flex;align-items:center;gap:10px;font-weight:600;font-size:14px;margin-bottom:12px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ft{width:30px;height:36px;border-radius:6px;display:grid;place-items:center;font-family:var(--f-mono);font-size:9px;color:#fff;background:#5B6378;flex:none}
.ft.pdf{background:#C8414A}.ft.docx{background:#2F63C8}.ft.pptx{background:#C8642F}
.lines i{display:block;height:7px;border-radius:4px;background:var(--paper-2);margin:7px 0}
.lines i.m{background:var(--sun-soft)}
.map svg{width:100%;height:auto;display:block}
.quizc .q{font-weight:600;font-size:14px;margin:6px 0 10px}
.quizc .o{display:flex;gap:8px;align-items:center;font-size:13px;padding:7px 10px;border:1px solid var(--line);border-radius:9px;margin-top:6px}
.quizc .o.r{border-color:var(--good);background:var(--good-soft)}
.quizc .o b{font-family:var(--f-mono);font-size:11px;width:20px;height:20px;border-radius:5px;display:grid;place-items:center;background:var(--paper-2)}
.quizc .o.r b{background:var(--good);color:#fff}
.section{padding-block:40px}
.section-head{display:flex;flex-wrap:wrap;align-items:end;justify-content:space-between;gap:12px;margin-bottom:22px}
.section-head p{margin:8px 0 0;color:var(--ink-2);max-width:60ch}
.feats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:14px}
@media (max-width:980px){.feats{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:560px){.feats{grid-template-columns:1fr}}
.feat{padding:20px;display:grid;gap:10px;align-content:start}
.feat .ic{width:42px;height:42px;border-radius:12px;display:grid;place-items:center}
.feat p{margin:0;color:var(--ink-2);font-size:14.5px}
.ic.a{background:var(--sun-soft);color:var(--plus)}.ic.b{background:var(--pro-soft);color:var(--pro)}.ic.c{background:rgba(42,71,212,.12);color:var(--b0)}.ic.d{background:var(--bad-soft);color:var(--coral)}
.steps3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;counter-reset:s}
@media (max-width:760px){.steps3{grid-template-columns:1fr}}
.steps3 li{list-style:none;padding:18px 20px;display:grid;gap:6px}
.steps3 li::before{counter-increment:s;content:counter(s);font-family:var(--f-display);font-weight:800;font-size:28px;color:var(--sun);line-height:1}
.steps3 p{margin:0;color:var(--ink-2);font-size:14.5px}
footer{margin-top:40px;padding-top:24px;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;gap:12px;justify-content:space-between;color:var(--ink-3);font-size:13.5px}

/* pricing */
.prices{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;align-items:stretch}
@media (max-width:900px){.prices{grid-template-columns:1fr}}
.price{padding:24px;display:flex;flex-direction:column;gap:14px;position:relative}
.price.pop{border:2px solid var(--sun);box-shadow:var(--shadow)}
.price .ribbon{position:absolute;top:-12px;left:24px;background:var(--sun);color:#1A1300;font-size:11.5px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;padding:3px 10px;border-radius:99px}
.price .amt{font-family:var(--f-display);font-weight:800;font-size:38px;letter-spacing:-.03em;font-variant-numeric:tabular-nums;line-height:1}
.price .amt small{font-family:var(--f-body);font-size:14px;font-weight:500;color:var(--ink-3);letter-spacing:0}
.price ul{margin:0;padding:0;list-style:none;display:grid;gap:8px;font-size:14.5px;flex:1}
.price li{display:grid;grid-template-columns:18px 1fr;gap:8px}
.price li svg{margin-top:4px}
.price .cur{font-size:13px;font-weight:600;color:var(--good);text-align:center}

/* study */
.study{display:grid;grid-template-columns:290px minmax(0,1fr);gap:20px;align-items:start}
@media (max-width:900px){.study{grid-template-columns:1fr}}
.side{display:flex;flex-direction:column;gap:14px}
.drop{position:relative;display:flex;flex-direction:column;align-items:center;text-align:center;gap:6px;padding:22px 16px;border:2px dashed var(--line);border-radius:16px;background:var(--paper);cursor:pointer;transition:border-color .15s,background .15s}
.drop:hover,.drop.over{border-color:var(--sun);background:var(--sun-soft)}
.drop strong{font-family:var(--f-display);font-weight:600;font-size:17px}
.drop small{color:var(--ink-3);font-size:12.5px}
.drop input{position:absolute;width:1px;height:1px;opacity:0;pointer-events:none}
.upicon{width:42px;height:42px;border-radius:12px;background:var(--navy);display:grid;place-items:center;color:#fff;margin-bottom:4px}
.meter{display:grid;gap:6px;padding:12px 14px}
.meter .row{display:flex;justify-content:space-between;font-size:13px;font-variant-numeric:tabular-nums}
.bar{height:6px;border-radius:99px;background:var(--paper-2);overflow:hidden}
.bar i{display:block;height:100%;background:var(--sun);border-radius:99px;transition:width .3s}
.lib{display:flex;flex-direction:column;gap:6px}
.lib-item{display:grid;grid-template-columns:30px 1fr auto;gap:10px;align-items:center;text-align:left;width:100%;padding:9px 10px;border-radius:12px;border:1px solid transparent;background:transparent;cursor:pointer}
.lib-item:hover{background:var(--paper)}
.lib-item.on{background:var(--paper);border-color:var(--line);box-shadow:var(--shadow)}
.lib-item .nm{font-weight:600;font-size:13.5px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lib-item .st{font-size:12px;color:var(--ink-3);display:flex;align-items:center;gap:6px}
.lib-item .x{border:0;background:transparent;color:var(--ink-3);border-radius:6px;padding:2px 6px;font-size:12px}
.lib-item .x:hover{color:var(--bad);background:var(--bad-soft)}
.dot{width:8px;height:8px;border-radius:50%;background:var(--ink-3);display:inline-block}
.dot.ok{background:var(--good)}.dot.off{background:var(--bad)}.dot.wait{background:var(--sun)}
.paste{padding:10px 14px}
.paste summary{cursor:pointer;font-weight:600;font-size:14px}
.paste[open]{display:grid;gap:8px}
.work{display:flex;flex-direction:column;gap:16px;min-width:0}
.dochead{padding:22px 24px;display:flex;flex-direction:column;gap:12px}
.dochead h1{font-size:28px}
.meta{display:flex;flex-wrap:wrap;gap:6px 14px;color:var(--ink-3);font-size:13.5px;font-variant-numeric:tabular-nums;align-items:center}
.linkbtn{background:none;border:0;padding:0;color:var(--link);font-weight:600}
.summary{margin:0;padding-left:20px;display:grid;gap:4px;color:var(--ink-2);max-width:80ch}
.summary li::marker{color:var(--sun)}
.stepchips{display:flex;flex-wrap:wrap;gap:8px}
.stepc{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;padding:4px 10px;border-radius:99px;background:var(--paper-2);color:var(--ink-3)}
.stepc.done{color:var(--good);background:var(--good-soft)}.stepc.run{color:var(--plus);background:var(--plus-soft)}.stepc.fail{color:var(--bad);background:var(--bad-soft)}
.tabs{display:flex;gap:4px;padding:4px;background:var(--paper-2);border-radius:12px;width:max-content;max-width:100%;overflow-x:auto}
.tab{border:0;background:transparent;padding:8px 16px;border-radius:9px;font-weight:600;color:var(--ink-2);white-space:nowrap}
.tab.on{background:var(--paper);color:var(--ink);box-shadow:var(--shadow)}
.panel{padding:16px}
.toolbar{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin-bottom:12px}
.mm-wrap{position:relative;overflow:auto;border-radius:12px;background:radial-gradient(circle at 1px 1px,var(--line) 1px,transparent 0) 0 0/20px 20px,var(--paper);border:1px solid var(--line);height:min(560px,70vh);cursor:grab}
.mm-wrap.drag{cursor:grabbing;user-select:none}
.mm-wrap svg{display:block}
.mm-node,.mm-toggle{cursor:pointer}
.mm-node text{font-family:var(--f-body)}
.mm-sel{margin-top:12px;display:flex;flex-wrap:wrap;align-items:center;gap:10px;padding:10px 12px;border-radius:12px;background:var(--paper-2)}
.empty{display:grid;place-items:center;text-align:center;gap:10px;padding:48px 16px;color:var(--ink-3)}
.empty p{margin:0;max-width:52ch}
.quiz{max-width:740px}
.qprog{display:flex;align-items:center;gap:12px;font-size:13px;color:var(--ink-3);font-variant-numeric:tabular-nums;margin-bottom:14px}
.qprog .bar{flex:1}
.qtext{font-family:var(--f-display);font-weight:600;font-size:20px;line-height:1.35;margin-bottom:14px;letter-spacing:-.01em}
.opts{display:grid;gap:8px}
.opt{display:grid;grid-template-columns:30px 1fr;gap:10px;align-items:start;text-align:left;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--paper)}
.opt:hover:not(:disabled){border-color:var(--sun)}
.opt .k{width:28px;height:28px;border-radius:8px;display:grid;place-items:center;background:var(--paper-2);font-family:var(--f-mono);font-size:12px}
.opt:disabled{cursor:default}
.opt.right{border-color:var(--good);background:var(--good-soft)}.opt.right .k{background:var(--good);color:#fff}
.opt.wrong{border-color:var(--bad);background:var(--bad-soft)}.opt.wrong .k{background:var(--bad);color:#fff}
.explain{margin-top:14px;padding:12px 14px;border-radius:12px;background:var(--paper-2);display:grid;gap:8px}
.explain .v{font-weight:700}.explain .v.ok{color:var(--good)}.explain .v.no{color:var(--bad)}
.qnav{display:flex;flex-wrap:wrap;gap:8px;margin-top:14px;align-items:center}
.score{display:flex;align-items:baseline;gap:12px;margin-bottom:6px}
.score b{font-family:var(--f-display);font-size:52px;font-weight:800;font-variant-numeric:tabular-nums;line-height:1;letter-spacing:-.03em}
.topics{display:grid;gap:10px;margin:16px 0}
.trow{display:grid;grid-template-columns:minmax(110px,200px) 1fr 52px;gap:10px;align-items:center;font-size:14px}
.trow .bar{height:8px}
.trow .bar i.lo{background:var(--bad)}.trow .bar i.mid{background:var(--sun)}.trow .bar i.hi{background:var(--good)}
.trow span:last-child{text-align:right;font-variant-numeric:tabular-nums;color:var(--ink-3)}
.wronglist{display:grid;gap:8px;margin:0 0 16px;padding:0;list-style:none}
.wronglist li{padding:10px 12px;border-radius:12px;border:1px solid var(--line);display:grid;gap:4px}
.wronglist .a{font-size:13.5px;color:var(--ink-2)}
.chat{display:flex;flex-direction:column;height:min(620px,74vh)}
.msgs{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:12px;padding:4px 2px 12px}
.msg{max-width:min(660px,92%);padding:10px 14px;border-radius:14px;line-height:1.6}
.msg.u{align-self:flex-end;background:var(--navy);color:#fff;border-bottom-right-radius:4px}
.msg.a{align-self:flex-start;background:var(--paper-2);border-bottom-left-radius:4px}
.msg.a p{margin:0 0 8px}.msg.a p:last-child{margin:0}
.msg.a ul,.msg.a ol{margin:0 0 8px;padding-left:20px}
.cite{display:inline-flex;align-items:center;font-family:var(--f-mono);font-size:11px;padding:1px 6px;margin:0 2px;border-radius:6px;border:1px solid var(--line);background:var(--paper);color:var(--link);vertical-align:1px}
.cite:hover{border-color:var(--link)}
.sugs{display:flex;flex-wrap:wrap;gap:8px;justify-content:center}
.sug{border:1px solid var(--line);background:var(--paper);border-radius:99px;padding:6px 12px;font-size:13.5px}
.sug:hover{border-color:var(--sun)}
.compose{display:flex;gap:8px;align-items:flex-end;border-top:1px solid var(--line);padding-top:12px}
.compose textarea{flex:1;resize:none;min-height:46px;max-height:140px}

/* forum */
.forum{display:grid;grid-template-columns:220px minmax(0,1fr);gap:24px;align-items:start}
@media (max-width:900px){.forum{grid-template-columns:1fr}}
.cats{display:flex;flex-direction:column;gap:4px}
@media (max-width:900px){.cats{flex-direction:row;overflow-x:auto;padding-bottom:4px}}
.cat{display:flex;align-items:center;gap:10px;border:0;background:transparent;padding:8px 10px;border-radius:10px;text-align:left;font-weight:500;color:var(--ink-2);white-space:nowrap}
.cat:hover{background:var(--paper)}
.cat.on{background:var(--paper);color:var(--ink);box-shadow:var(--shadow);font-weight:600}
.cat i{width:10px;height:10px;border-radius:3px;flex:none}
.cat .n{margin-left:auto;font-size:12px;color:var(--ink-3);font-variant-numeric:tabular-nums}
.tag{display:inline-flex;align-items:center;gap:6px;font-size:12px;font-weight:600;padding:2px 9px;border-radius:99px;background:var(--paper-2);color:var(--ink-2)}
.tag i{width:7px;height:7px;border-radius:2px}
.threads{display:grid;gap:10px}
.thread{display:grid;grid-template-columns:44px 1fr auto;gap:14px;padding:16px 18px;text-align:left;width:100%;cursor:pointer;transition:border-color .15s,transform .15s}
.thread:hover{border-color:var(--sun)}
.thread h3{font-size:17px;margin:4px 0 4px}
.thread p{margin:0;color:var(--ink-2);font-size:14px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.thread .by{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:8px;font-size:13px;color:var(--ink-3)}
.thread .rc{text-align:center;font-variant-numeric:tabular-nums;color:var(--ink-3);font-size:12px;min-width:48px}
.thread .rc b{display:block;font-family:var(--f-display);font-size:22px;color:var(--ink)}
@media (max-width:560px){.thread{grid-template-columns:1fr auto}.thread>.av{display:none}}
.composer{padding:18px;display:grid;gap:12px}
.composer .row{display:grid;grid-template-columns:1fr 200px;gap:12px}
@media (max-width:560px){.composer .row{grid-template-columns:1fr}}
.post{padding:20px 22px;display:grid;gap:12px}
.post .body{white-space:pre-wrap;word-wrap:break-word;line-height:1.65}
.who{display:flex;align-items:center;gap:10px;font-size:14px}
.who b{font-weight:600}
.replies{display:grid;gap:10px;margin:14px 0}
.reply{padding:14px 16px;display:grid;gap:8px;border-left:3px solid var(--line)}
.reply.op{border-left-color:var(--sun)}
.reply .body{white-space:pre-wrap;word-wrap:break-word}
.toolbar-s{display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:14px}
.toolbar-s input{max-width:320px}

/* admin */
.kpis{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin-bottom:24px}
.kpi{padding:16px 18px}
.kpi b{display:block;font-family:var(--f-display);font-size:30px;font-weight:800;font-variant-numeric:tabular-nums;letter-spacing:-.02em;line-height:1.15;margin-top:4px}
.kpi .s{font-size:12.5px;color:var(--ink-3)}
.kpi.accent{background:var(--navy);border-color:var(--navy);color:#fff}
.kpi.accent .eyebrow,.kpi.accent .s{color:rgba(255,255,255,.7)}
.mix{display:flex;height:10px;border-radius:99px;overflow:hidden;background:var(--paper-2);margin-top:10px}
.mix i{display:block;height:100%}
.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:14px;background:var(--paper)}
table{border-collapse:collapse;width:100%;font-size:14px}
th,td{text-align:left;padding:10px 14px;border-bottom:1px solid var(--line);vertical-align:middle;white-space:nowrap}
th{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--ink-3);font-weight:600;background:var(--paper-2)}
tr:last-child td{border-bottom:0}
td.num{font-variant-numeric:tabular-nums;text-align:right}
.person{display:flex;align-items:center;gap:10px}
.person div{display:grid;line-height:1.3}
.person small{color:var(--ink-3);font-size:12.5px}
.admin-grid{display:grid;gap:28px}

/* modal/drawer */
.scrim{position:fixed;inset:0;background:rgba(8,10,24,.45);z-index:30}
.drawer{position:fixed;top:0;right:0;bottom:0;width:min(520px,100%);background:var(--paper);border-left:1px solid var(--line);z-index:31;display:flex;flex-direction:column;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}
.dhead{display:flex;align-items:center;gap:8px;padding:14px 16px;border-bottom:1px solid var(--line)}
.dhead h3{flex:1;font-size:16px}
.dbody{padding:16px 20px;overflow-y:auto;white-space:pre-wrap;line-height:1.7}
.dbody mark{background:var(--sun-soft);color:inherit;border-radius:3px;padding:0 1px}
.pg{font-family:var(--f-mono);font-size:12px;color:var(--ink-3)}
.modal{position:fixed;z-index:31;left:50%;top:50%;transform:translate(-50%,-50%);width:min(480px,calc(100% - 32px));max-height:calc(100% - 40px);overflow:auto;padding:24px;display:grid;gap:14px}
.profile-top{display:flex;gap:14px;align-items:center}

/* ===== bổ sung cho bản chạy thật ===== */
.auth{max-width:440px;margin:24px auto;padding:28px;display:grid;gap:16px}
.auth h2{font-size:30px}
.auth form{display:grid;gap:12px}
.auth .alt{font-size:14px;color:var(--ink-2);text-align:center}
.divider{display:flex;align-items:center;gap:10px;color:var(--ink-3);font-size:12.5px}
.divider::before,.divider::after{content:"";flex:1;height:1px;background:var(--line)}
input[type=email],input[type=password],input[type=number]{border:1px solid var(--line);border-radius:10px;padding:9px 12px;background:var(--paper);width:100%}
.ok-note{color:var(--good);background:var(--good-soft);border-radius:10px;padding:10px 12px;font-size:14px}
.acts{display:flex;align-items:center;gap:8px}
.subtabs{display:flex;gap:4px;padding:4px;background:var(--paper-2);border-radius:12px;width:max-content;max-width:100%;overflow-x:auto;margin-bottom:20px}
.subtabs button{border:0;background:transparent;padding:8px 14px;border-radius:9px;font-weight:600;color:var(--ink-2);white-space:nowrap}
.subtabs button.on{background:var(--paper);color:var(--ink);box-shadow:var(--shadow)}
.subtabs .cnt{display:inline-grid;place-items:center;min-width:20px;height:20px;padding:0 6px;border-radius:99px;background:var(--sun);color:#1A1300;font-size:11.5px;margin-left:6px}
td input[type=text],td input[type=number],td select{padding:6px 8px;font-size:13.5px}
td input.model{min-width:260px;font-family:var(--f-mono);font-size:12.5px}
td input.num{width:96px}
.status{font-size:12px;font-weight:700;border-radius:99px;padding:2px 8px}
.status.active{background:var(--good-soft);color:var(--good)}
.status.banned{background:var(--bad-soft);color:var(--bad)}
.status.pending{background:var(--plus-soft);color:var(--plus)}
.pay{display:grid;gap:8px;padding:16px;border-radius:12px;background:var(--paper-2);font-size:14.5px}
.pay code{font-family:var(--f-mono);background:var(--paper);border:1px solid var(--line);border-radius:6px;padding:2px 6px}
.mm-edit{margin-top:12px;display:grid;gap:10px;padding:12px;border-radius:12px;background:var(--paper-2)}
.mm-edit .row{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.mm-edit input{flex:1;min-width:200px}
.save-state{font-size:12.5px;color:var(--ink-3)}
.save-state.dirty{color:var(--warn)}
.kbd{font-family:var(--f-mono);font-size:11px;border:1px solid var(--line);border-bottom-width:2px;border-radius:5px;padding:0 5px;background:var(--paper)}
.mm-wrap:focus-visible{outline:2px solid var(--sun);outline-offset:2px}
.modelpill{font-family:var(--f-mono);font-size:11px;color:var(--ink-3)}
.pinned{color:var(--plus);font-weight:700;font-size:12px}
input[type=date]{border:1px solid var(--line);border-radius:10px;padding:6px 8px;background:var(--paper);font-size:13.5px}
/* thương hiệu F&D Education */
.wordmark{white-space:nowrap}
.wordmark .amp{color:var(--plus);margin:0 1px}
.wordmark .edu{font-weight:600;font-size:.78em;color:var(--ink-2);letter-spacing:-.01em}
@media (max-width:420px){.wordmark .edu{display:none}}
/* ===== chuỗi ngày học ===== */
.flame-ic{display:inline-block;vertical-align:-2px}
.streak-chip{display:inline-flex;align-items:center;gap:2px;font-size:12px;font-weight:700;color:#E8590C;background:rgba(232,89,12,.12);border-radius:99px;padding:2px 8px 2px 6px;font-variant-numeric:tabular-nums;white-space:nowrap}
.streak-chip.nav{margin-right:2px}
.hbadge{display:inline-flex;font-size:11px;font-weight:700;border-radius:99px;padding:2px 8px;background:var(--sun-soft);color:var(--plus);white-space:nowrap}
.streak-mini{gap:8px}
.streak-big{display:inline-flex;align-items:center;gap:6px;color:#E8590C;font-size:13.5px}
.streak-big b{font-family:var(--f-display);font-size:22px;line-height:1}
.streak-big .flame-ic{width:20px;height:20px}
.week{display:grid;grid-template-columns:repeat(7,1fr);gap:4px;margin:4px 0}
.wd{display:grid;justify-items:center;gap:3px;font-size:11px;color:var(--ink-3)}
.wd i{width:26px;height:26px;border-radius:50%;display:grid;place-items:center;background:var(--paper-2);color:#fff}
.wd.on i{background:#E8590C}
.wd.today{color:var(--ink);font-weight:700}
.wd.today i{box-shadow:0 0 0 2px var(--paper),0 0 0 4px #E8590C}
.streak-head{display:flex;flex-wrap:wrap;align-items:end;justify-content:space-between;gap:10px}
.streak-num{display:flex;align-items:center;gap:8px;color:#E8590C}
.streak-num .flame-ic{width:34px;height:34px}
.streak-num b{font-family:var(--f-display);font-size:48px;line-height:1;letter-spacing:-.03em}
.streak-num span{color:var(--ink-2);font-size:14px;max-width:8em;line-height:1.3}
.milestones{list-style:none;margin:0;padding:0;display:grid;gap:8px}
.milestones li{display:grid;grid-template-columns:56px 1fr auto;gap:12px;align-items:center;padding:10px 12px;border:1px solid var(--line);border-radius:12px}
.milestones li.got{background:var(--good-soft);border-color:transparent}
.ms-day{display:grid;justify-items:center;font-family:var(--f-display);font-weight:800;font-size:20px;line-height:1}
.ms-day small{font-family:var(--f-body);font-size:11px;font-weight:500;color:var(--ink-3)}
.ms-title{display:grid;font-weight:600;font-size:14px}
.ms-title small{font-weight:500;color:var(--ink-3);font-size:12px}
.ms-state{font-size:12.5px;font-weight:600;color:var(--ink-3);white-space:nowrap}
.milestones li.got .ms-state{color:var(--good)}
.bonus-line{display:flex;align-items:center;gap:6px;flex-wrap:wrap;margin-top:8px;font-size:13px;color:#E8590C}
.leaders{margin-top:14px;padding:14px 16px}
.leaders ol{margin:0;padding-left:20px;display:grid;gap:6px;font-size:14px}
.leaders li span{margin-right:6px}
@media (max-width:900px){.leaders{display:none}}
.modal.reward{z-index:32;text-align:left}
.reward-top{display:flex;align-items:center;gap:14px}
.reward-flame{width:56px;height:56px;border-radius:16px;display:grid;place-items:center;background:rgba(232,89,12,.12);color:#E8590C}
.reward-flame .flame-ic{width:32px;height:32px}
.reward-list{margin:0;padding:0;list-style:none;display:grid;gap:8px}
.reward-list li{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:12px;background:var(--sun-soft);font-weight:600}
.reward-list .rk{font-size:11.5px;font-weight:700;color:#E8590C;background:var(--paper);border-radius:99px;padding:2px 8px;white-space:nowrap}
@media (prefers-reduced-motion:no-preference){.modal.reward{animation:pop .35s ease-out}}
@keyframes pop{from{transform:translate(-50%,-46%) scale(.96)}to{transform:translate(-50%,-50%) scale(1)}}
.me .streak-chip{margin-left:4px}
/* ===== thanh toán ===== */
.paybox{display:grid;grid-template-columns:1fr auto;gap:18px;align-items:start}
@media (max-width:640px){.paybox{grid-template-columns:1fr}.pay-qr{justify-self:center}}
.pay-info{display:grid;gap:8px}
.pay-row{display:grid;grid-template-columns:110px 1fr auto;gap:10px;align-items:center;padding:6px 0;border-bottom:1px dashed var(--line)}
.pay-row span{color:var(--ink-3);font-size:13.5px}
.pay-qr{width:270px;max-width:100%;height:auto;border-radius:14px;background:#fff;border:1px solid var(--line)}
.modal.paymodal{width:min(760px,calc(100% - 32px));z-index:32}

/* ---------- khóa học ---------- */
.courses{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:18px}
.card.course{display:flex;flex-direction:column;overflow:hidden;padding:0;text-decoration:none;color:var(--ink);transition:transform .15s,box-shadow .15s}
.card.course:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.c-cover{display:block;width:100%;aspect-ratio:16/9;object-fit:cover;background:var(--paper-2)}
.c-cover.gen{display:flex;align-items:flex-end;padding:16px;background:linear-gradient(135deg,var(--h) 0%,color-mix(in srgb,var(--h) 55%,#0b1230) 100%);position:relative;overflow:hidden}
.c-cover.gen::after{content:"";position:absolute;right:-30px;top:-30px;width:140px;height:140px;border-radius:50%;background:rgba(255,255,255,.12);box-shadow:-60px 70px 0 -20px rgba(255,179,31,.35)}
.c-cover.gen span{position:relative;z-index:1;color:#fff;font-family:"Bricolage Grotesque",sans-serif;font-weight:700;font-size:20px;line-height:1.2;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.c-cover.lg{border-radius:14px}
.course-body{padding:14px 16px 16px;display:grid;gap:8px;align-content:start}
.course-body h3{font-size:18px;margin:0;line-height:1.3}
.course-body p{margin:0;color:var(--ink-2);font-size:14px}
.course-tags{display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.course-meta{display:flex;gap:6px;flex-wrap:wrap;font-size:13px;color:var(--ink-3);font-weight:500}
.course-hero{display:grid;grid-template-columns:minmax(0,360px) 1fr;gap:22px;padding:18px;align-items:center;margin-bottom:18px}
.course-hero h1{font-size:clamp(24px,3.6vw,34px);margin:8px 0 4px;line-height:1.15}
.lead-s{color:var(--ink-2);margin:0 0 6px}
@media (max-width:760px){.course-hero{grid-template-columns:1fr}}
.learn{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:18px;align-items:start}
@media (max-width:960px){.learn{grid-template-columns:1fr}}
.player{padding:0;overflow:hidden}
.vwrap{position:relative;aspect-ratio:16/9;background:#000}
.vwrap iframe,.vwrap video{position:absolute;inset:0;width:100%;height:100%;border:0}
.player-body{padding:18px 20px 20px;display:grid;gap:12px}
.player-body h2{margin:0}
.player .note{margin:16px 20px 0}
.locked-box{padding:46px 20px;text-align:center;display:grid;gap:8px;justify-items:center}
.lock-big{font-size:38px}
.outline{padding:0;overflow:hidden;position:sticky;top:84px;max-height:calc(100vh - 100px);overflow-y:auto}
@media (max-width:960px){.outline{position:static;max-height:none}}
.outline ol{list-style:none;margin:0;padding:0 8px 10px}
.ol-item{display:flex;gap:10px;align-items:flex-start;width:100%;text-align:left;border:0;background:transparent;padding:10px;border-radius:10px;color:var(--ink);font:inherit;cursor:pointer}
.ol-item:hover{background:var(--paper-2)}
.ol-item.on{background:var(--sun-soft)}
.ol-item.locked{color:var(--ink-3)}
.ol-n{flex:none;display:inline-grid;place-items:center;width:26px;height:26px;border-radius:50%;background:var(--paper-2);font-size:12.5px;font-weight:700;color:var(--ink-2)}
.ol-item.on .ol-n{background:var(--sun);color:#1A1300}
.ol-t{flex:1;display:grid;gap:2px;font-weight:600;font-size:14px;line-height:1.35}
.ol-t small{font-weight:500;color:var(--ink-3);font-size:12px}
.ol-lock{font-size:13px}
.c-desc{margin-top:18px;padding:20px}
.c-desc h3{margin-top:0}
.md{line-height:1.65;color:var(--ink-2)}
.md h3,.md h4,.md h5{color:var(--ink);margin:14px 0 6px}
.md p{margin:0 0 10px}
.md ul,.md ol{margin:0 0 10px;padding-left:22px}
.lessons-ed{display:grid;gap:14px}
.lesson-ed{padding:16px;display:grid;gap:10px}
.lesson-ed .row3{display:grid;grid-template-columns:auto 1fr 150px;gap:10px;align-items:center}
.lesson-ed .row3b{display:grid;grid-template-columns:1fr auto 130px 100px;gap:10px;align-items:end}
@media (max-width:680px){.lesson-ed .row3{grid-template-columns:auto 1fr}.lesson-ed .row3 select{grid-column:1/-1}.lesson-ed .row3b{grid-template-columns:1fr 1fr}}
.lesson-ed input[type=text],.lesson-ed input[type=url],.lesson-ed input[type=number],.lesson-ed select,.lesson-ed textarea{width:100%}
input[type=file]{font-size:13.5px;max-width:100%}
label.f input,label.f textarea,label.f select{font-weight:400;color:var(--ink)}

/* ---------- học nhóm ---------- */
.rooms{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.room-card{padding:18px;display:grid;gap:10px;align-content:start}
.room-card.live{border-color:color-mix(in srgb,var(--good) 45%,var(--line))}
.room-card h3{margin:0;font-size:19px}
.room-card p{margin:0;color:var(--ink-2);font-size:14px}
.room-card .by{display:flex;gap:6px;align-items:center;font-size:13px;color:var(--ink-3)}
.room-card .acts{margin-top:4px}
.room-top{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.live-dot{display:inline-flex;align-items:center;gap:7px;font-size:12.5px;font-weight:700;color:var(--good);background:var(--good-soft);padding:3px 10px;border-radius:99px}
.live-dot i{width:8px;height:8px;border-radius:50%;background:var(--good);animation:pulse 1.6s infinite}
@keyframes pulse{0%{box-shadow:0 0 0 0 color-mix(in srgb,var(--good) 60%,transparent)}100%{box-shadow:0 0 0 8px transparent}}
@media (prefers-reduced-motion:reduce){.live-dot i{animation:none}}
.lobby{padding:26px;display:grid;gap:12px;max-width:760px}
.lobby h2{margin:0}
.lobby .btn svg{vertical-align:-4px;margin-right:4px}
.room-head{display:flex;gap:14px;align-items:flex-start;flex-wrap:wrap;margin-bottom:14px}
.room-head>div:first-child{flex:1;min-width:220px}
.room-head h2{margin:2px 0 0;font-size:clamp(22px,3vw,30px)}
.room-head p{margin:4px 0 0}
.room-timer{display:flex;align-items:center;gap:8px;background:var(--sun-soft);border-radius:12px;padding:6px 6px 6px 12px;font-size:14px}
.room-timer b{font-family:var(--f-mono);font-size:20px;font-variant-numeric:tabular-nums}
.room-timer span{color:var(--ink-2)}
.room-body{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:14px;align-items:start}
.tiles{display:grid;gap:10px;grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.tiles[data-n="1"]{grid-template-columns:minmax(0,820px)}
.tiles[data-n="2"]{grid-template-columns:repeat(2,minmax(0,1fr))}
.tile{position:relative;aspect-ratio:16/10;background:#141B33;border-radius:16px;overflow:hidden;box-shadow:var(--shadow)}
.tile video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:0;background:#0B1021}
.tile.sharing video{object-fit:contain}
.tile.has-video video{opacity:1}
.tile video.mirror{transform:scaleX(-1)}
.tile-av{position:absolute;inset:0;display:grid;place-items:center}
.tile-av img{width:min(96px,32%);aspect-ratio:1;border-radius:50%}
.tile.has-video .tile-av{display:none}
.tile-name{position:absolute;left:10px;bottom:10px;max-width:calc(100% - 20px);display:flex;gap:6px;align-items:center;background:rgba(11,16,33,.72);color:#fff;font-size:13px;font-weight:600;padding:4px 10px;border-radius:99px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.tile-name .mute{display:inline-flex;color:#FF8A8E}
.tile-name .mute svg{width:15px;height:15px}
.tile-state{position:absolute;top:10px;left:10px;right:10px;font-size:12.5px;color:#fff;background:rgba(200,58,63,.85);padding:4px 10px;border-radius:8px;width:max-content;max-width:calc(100% - 20px)}
.room-chat{display:flex;flex-direction:column;height:min(560px,calc(100vh - 260px));min-height:320px;padding:0;overflow:hidden}
.chat-list{flex:1;overflow-y:auto;padding:6px 14px;display:grid;gap:10px;align-content:start}
.chat-list .msg{font-size:14px}
.chat-list .msg b{font-size:13px}
.chat-list .msg .t{font-size:11.5px;color:var(--ink-3);margin-left:6px}
.chat-list .msg p{margin:2px 0 0;white-space:pre-wrap;word-break:break-word}
.chat-list .msg.me b{color:var(--link)}
.chat-form{display:flex;gap:8px;padding:10px;border-top:1px solid var(--line)}
.ctrls{position:sticky;bottom:12px;margin:16px auto 0;width:max-content;max-width:100%;display:flex;gap:6px;flex-wrap:wrap;justify-content:center;background:var(--paper);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:18px;padding:8px;z-index:5}
.cbtn{display:grid;justify-items:center;gap:2px;min-width:68px;padding:8px 10px;border:0;border-radius:12px;background:var(--paper-2);color:var(--ink);font:inherit;font-size:12px;font-weight:600;cursor:pointer}
.cbtn:hover{filter:brightness(.97)}
.cbtn.off{background:var(--bad-soft);color:var(--bad)}
.cbtn.on{background:var(--sun-soft)}
.cbtn.leave{background:var(--bad);color:#fff}
.cbtn.chat-btn{display:none}
.cwrap{position:relative;display:inline-flex}
.tmenu{position:absolute;bottom:calc(100% + 8px);left:50%;transform:translateX(-50%);display:grid;gap:6px;padding:8px;min-width:150px;z-index:6}
@media (max-width:980px){
  .room-body{grid-template-columns:1fr}
  .cbtn.chat-btn{display:grid}
  .room-chat{display:none;position:fixed;left:12px;right:12px;bottom:96px;height:min(60vh,460px);z-index:7;box-shadow:var(--shadow)}
  .room-chat.open{display:flex}
}
@media (max-width:560px){
  .tiles,.tiles[data-n="2"]{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
  .tiles[data-n="1"]{grid-template-columns:1fr}
  .tile{aspect-ratio:3/4}
  .cbtn{min-width:54px;padding:7px 6px;font-size:11px}
  .cbtn span{display:none}
}
.tag.lock{background:var(--sun-soft);color:var(--ink)}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.movecat{display:inline-flex;align-items:center;gap:6px;background:var(--paper-2);border-radius:99px;padding:2px 4px 2px 10px}
.movecat i{width:7px;height:7px;border-radius:2px}
.movecat select{border:0;background:transparent;font-size:12.5px;font-weight:600;padding:3px 4px;color:var(--ink-2)}
.cat-mgr{padding:18px;margin-top:14px}
.passform{min-width:240px}
.passform .hint{font-size:12px}
#ownerCtl{display:inline-flex;gap:6px;flex-wrap:wrap}

/* ---------- hỗ trợ, avatar, thông báo gói ---------- */
.note.ok{background:var(--good-soft);color:var(--ink)}
.help-fab{position:fixed;right:16px;bottom:calc(16px + env(safe-area-inset-bottom,0px));z-index:9;display:inline-flex;align-items:center;gap:7px;background:var(--navy);color:#fff;font-weight:700;font-size:14px;padding:10px 16px;border-radius:99px;text-decoration:none;box-shadow:0 8px 24px rgba(17,24,51,.25)}
.help-fab:hover{filter:brightness(1.12)}
body[data-view="support"] .help-fab,body[data-view="room"] .help-fab,body[data-view="study"] .help-fab,body[data-view="setup"] .help-fab,body[data-view="admin"] .help-fab{display:none}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .help-fab{background:var(--sun);color:#1A1300}}
:root[data-theme="dark"] .help-fab{background:var(--sun);color:#1A1300}
.sup-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px;margin-bottom:22px}
.sup-card{display:flex;align-items:center;gap:14px;padding:18px;text-decoration:none;color:var(--ink)}
.sup-card>div{flex:1;display:grid;gap:2px;min-width:0}
.sup-card>div span{font-size:13.5px;color:var(--ink-2);overflow-wrap:anywhere}
.sup-ic{flex:none;width:46px;height:46px;border-radius:14px;display:grid;place-items:center;background:#1877F2;color:#fff}
.sup-ic.mail{background:var(--sun-soft);color:var(--ink)}
.sup-card .arr{font-size:20px;color:var(--ink-3)}
a.sup-card:hover{box-shadow:var(--shadow)}
.sup-grid{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:22px;align-items:start}
@media (max-width:860px){.sup-grid{grid-template-columns:1fr}}
.faq{display:grid;gap:10px}
.faq details{padding:0}
.faq summary{cursor:pointer;padding:14px 16px;font-weight:600;list-style:none;display:flex;justify-content:space-between;gap:10px}
.faq summary::after{content:"+";font-size:20px;line-height:1;color:var(--ink-3)}
.faq details[open] summary::after{content:"–"}
.faq summary::-webkit-details-marker{display:none}
.faq details p{margin:0;padding:0 16px 14px;color:var(--ink-2);font-size:14.5px;line-height:1.6}
.tickets{display:grid;gap:10px}
.ticket{padding:14px}
.ticket p{margin:8px 0 0;white-space:pre-wrap;font-size:14px;color:var(--ink-2)}
.t-top{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.mail-st{display:flex;gap:10px 20px;flex-wrap:wrap;font-size:14px}
.mail-st>div{display:flex;gap:8px;align-items:center}
@media (max-width:640px){#mailBox .row{grid-template-columns:1fr !important}}
.av-edit{position:relative;flex:none}
.av-edit img{object-fit:cover}
.av-btn{position:absolute;right:-4px;bottom:-4px;width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:var(--sun);color:#1A1300;border:2px solid var(--paper);cursor:pointer}
.av-actions{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
img.av{object-fit:cover}
.steps-note{display:grid;gap:8px;background:var(--paper-2);border-radius:14px;padding:12px 14px;margin:4px 0 12px}
.steps-note>div{display:flex;gap:10px;align-items:flex-start;font-size:14px;line-height:1.5}
.steps-note .n{font-style:normal;font-weight:700;flex:none;width:22px;height:22px;border-radius:50%;display:grid;place-items:center;background:var(--sun);color:#1A1300;font-size:12px}
.cf-ts{min-height:65px;display:flex;justify-content:center}
.guest-card{padding:16px;display:grid;gap:8px;background:var(--sun-soft);border-color:rgba(255,179,31,.45)}
.guest-perks{margin:0;padding-left:20px;display:grid;gap:6px;color:var(--ink-2);font-size:14.5px}

/* ===== giải đấu ===== */
.tgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:16px}
.gsect{margin:22px 0 12px;font-size:17px}
.tcard{display:grid;gap:8px;align-content:start;padding:18px;text-decoration:none;color:var(--ink);transition:transform .15s,box-shadow .15s;border-top:4px solid var(--line)}
.tcard:hover{transform:translateY(-2px)}
.tcard.ph-open,.tcard.ph-live{border-top-color:var(--sun)}
.tcard.ph-upcoming{border-top-color:var(--b0)}
.tcard h3{font-size:18px;font-weight:700;line-height:1.25}
.tcard p{margin:0;color:var(--ink-2);font-size:14px}
.ttags{display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.tag.subj{background:var(--navy);color:#fff}
.tstate{font-size:12px;font-weight:700;color:var(--ink-3);display:inline-flex;align-items:center;gap:5px;margin-left:auto}
.tcard.ph-open .tstate,.tcard.ph-live .tstate,.tstate.ph-open,.tstate.ph-live{color:var(--good)}
.dotlive{width:8px;height:8px;border-radius:50%;background:var(--bad);animation:gpulse 1.2s infinite}
@keyframes gpulse{50%{opacity:.25}}
@media (prefers-reduced-motion:reduce){.dotlive{animation:none}.tcard{transition:none}}
.tmeta{display:flex;flex-wrap:wrap;gap:4px 14px;font-size:13px;color:var(--ink-3)}
.garena-foot{display:grid;grid-template-columns:1.2fr 1fr;gap:18px;margin-top:30px}
@media (max-width:860px){.garena-foot{grid-template-columns:1fr}}
.gbox{padding:20px}
.grules{margin:10px 0 0;padding-left:18px;display:grid;gap:8px;color:var(--ink-2);font-size:14px}
.gfame{list-style:none;margin:10px 0 0;padding:0;display:grid;gap:10px}
.gfame li{display:flex;align-items:center;gap:10px}
.gfame li>span:nth-child(2){flex:1;min-width:0;display:grid}
.gfame small{color:var(--ink-3);font-size:12.5px}
.gfame .num{font-weight:700;font-variant-numeric:tabular-nums}
.gmed{font-size:24px;width:32px;text-align:center}
.ghead{padding:22px;display:grid;gap:8px;margin-bottom:16px}
.ghead h1{font-size:clamp(24px,3.4vw,34px)}
.ghead .lead-s{margin:0}
.glayout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:18px;align-items:start}
@media (max-width:900px){.glayout{grid-template-columns:1fr}}
.gmain{display:grid;gap:16px;min-width:0}
.gstage{padding:22px;min-height:280px}
.gwait{display:grid;justify-items:center;text-align:center;gap:8px;padding:18px 0}
.gwait h3{font-size:22px;font-family:var(--f-display);font-weight:800}
.gwait p{margin:0}
.gbig{font-size:46px;line-height:1}
.gready{color:var(--good);font-weight:600}
.gresult{text-align:center;background:var(--paper-2);border-radius:12px;padding:12px;margin-top:12px}
.gresult p{margin:0}
.gplay{display:grid;gap:14px}
.gq-top{display:flex;justify-content:space-between;align-items:center;gap:10px}
.gsec{font-weight:800;font-variant-numeric:tabular-nums;font-size:15px}
.gq-top .gsec{margin:0}
.gbar{height:8px;border-radius:99px;background:var(--paper-2);overflow:hidden}
.gbar i{display:block;height:100%;width:100%;background:var(--good);border-radius:99px}
.gbar i.low{background:var(--bad)}
.gq{font-size:clamp(18px,2.4vw,22px);font-weight:700;line-height:1.4;white-space:pre-line;overflow-wrap:anywhere}
.gopts{display:grid;grid-template-columns:1fr 1fr;gap:10px}
@media (max-width:560px){.gopts{grid-template-columns:1fr}}
.gopt{--c:var(--b0);display:flex;align-items:center;gap:12px;text-align:left;padding:14px;border-radius:14px;border:2px solid color-mix(in srgb,var(--c) 45%,transparent);background:color-mix(in srgb,var(--c) 10%,var(--paper));color:var(--ink);font-weight:600;font-size:16px;min-height:62px;position:relative;overflow:hidden}
.gopt.o1{--c:var(--b1)}.gopt.o2{--c:var(--b2)}.gopt.o3{--c:var(--b3)}
.gopt b{flex:none;display:grid;place-items:center;width:34px;height:34px;border-radius:10px;background:var(--c);color:#fff;font-size:15px}
.gopt > span{flex:1;overflow-wrap:anywhere;white-space:pre-line}
button.gopt:not(:disabled):hover{background:color-mix(in srgb,var(--c) 20%,var(--paper))}
button.gopt:disabled{cursor:default;opacity:.55}
.gopt.chosen{opacity:1!important;border-color:var(--c);box-shadow:0 0 0 3px color-mix(in srgb,var(--c) 35%,transparent)}
.gopt.right{border-color:var(--good);background:var(--good-soft)}
.gopt.right b{background:var(--good)}
.gopt.wrong{opacity:.6}
.gopt.wrong.chosen{border-color:var(--bad);background:var(--bad-soft);opacity:1}
.gopt.wrong.chosen b{background:var(--bad)}
.gopt em{font-style:normal;font-size:12.5px;color:var(--ink-3);white-space:nowrap;display:grid;gap:3px;min-width:64px}
.gopt em i{display:block;height:5px;border-radius:99px;background:var(--c)}
.gres{border-radius:12px;padding:10px 14px;font-weight:700}
.gres.good{background:var(--good-soft);color:var(--good)}
.gres.bad{background:var(--bad-soft);color:var(--bad)}
.gexpl{background:var(--paper-2);border-radius:12px;padding:12px 14px;font-size:14.5px;white-space:pre-line}
.gboardbox{padding:16px;position:sticky;top:80px}
.gboard-h{display:flex;justify-content:space-between;align-items:baseline;gap:8px;margin-bottom:10px}
.gboard{list-style:none;margin:0;padding:0;display:grid;gap:4px;max-height:560px;overflow:auto}
.gboard li{display:flex;align-items:center;gap:9px;padding:7px 8px;border-radius:10px}
.gboard li.mine{background:var(--sun-soft)}
.gboard .rk{width:26px;text-align:center;font-weight:700;color:var(--ink-3);font-variant-numeric:tabular-nums}
.gboard li.top .rk{font-size:18px}
.gboard .nm{flex:1;min-width:0;display:grid;font-weight:600;font-size:14px;overflow-wrap:anywhere}
.gboard .nm small{font-weight:400;color:var(--ink-3);font-size:12px}
.gboard .sc{font-variant-numeric:tabular-nums}
.podium{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));align-items:end;gap:10px;width:100%;max-width:460px;margin-top:10px}
.pod{display:grid;justify-items:center;gap:4px;text-align:center;font-size:13.5px}
.pod .av{width:48px;height:48px}
.pod b{overflow-wrap:anywhere}
.pod span{color:var(--ink-3);font-size:12.5px}
.pod .step{width:100%;display:grid;place-items:center;border-radius:12px 12px 0 0;background:var(--paper-2);font-size:26px}
.pod.p1 .step{height:110px;background:var(--sun-soft)}
.pod.p2 .step{height:80px}
.pod.p3 .step{height:60px}
.ghost-box{padding:14px 16px;display:flex;flex-wrap:wrap;gap:12px;align-items:center;justify-content:space-between;border:1px dashed var(--line)}
.ghost-box>div:first-child{display:grid;gap:2px}
.ghost-box.host{border:2px solid var(--sun)}
.ghost-box .acts{flex-wrap:wrap}
.greview{padding:20px;display:grid;gap:14px}
.grv{border:1px solid var(--line);border-radius:12px;padding:12px 14px;display:grid;gap:8px}
.grv.ok{border-left:4px solid var(--good)}
.grv.no{border-left:4px solid var(--bad)}
.grv-h{display:flex;gap:10px;align-items:flex-start}
.gq-s{flex:1;font-weight:600;white-space:pre-line;overflow-wrap:anywhere}
.grv-p{font-weight:800;font-variant-numeric:tabular-nums;color:var(--ink-3)}
.grv.ok .grv-p{color:var(--good)}
.grv ul{list-style:none;margin:0;padding:0;display:grid;gap:4px;font-size:14px}
.grv li{display:flex;gap:8px;padding:5px 8px;border-radius:8px;overflow-wrap:anywhere}
.grv li b{flex:none;width:18px}
.grv li.right{background:var(--good-soft);color:var(--good);font-weight:600}
.grv li.wrongpick{background:var(--bad-soft);color:var(--bad)}
.grv li small{opacity:.8}
.tmode{border:0;padding:0;margin:0;display:grid;grid-template-columns:1fr 1fr;gap:10px}
.tmode legend{font-size:14px;font-weight:600;margin-bottom:6px;padding:0}
.tmode label{display:grid;grid-template-columns:auto 1fr;gap:2px 10px;padding:12px;border:2px solid var(--line);border-radius:12px;cursor:pointer}
.tmode label.on{border-color:var(--sun);background:var(--sun-soft)}
.tmode input{grid-row:span 2;margin-top:3px}
.tmode span{font-size:13px;color:var(--ink-2)}
@media (max-width:640px){.tmode{grid-template-columns:1fr}.composer .row{grid-template-columns:1fr}}
.qeds{display:grid;gap:12px}
.qed{padding:16px;display:grid;gap:10px}
.qed-top{display:flex;gap:10px;align-items:flex-start}
.qed-top textarea{flex:1;font-weight:600}
.qed-opts{display:grid;grid-template-columns:1fr 1fr;gap:8px}
@media (max-width:640px){.qed-opts{grid-template-columns:1fr}}
.qopt{--c:var(--b0);display:flex;align-items:center;gap:8px;padding:6px 8px;border-radius:10px;border:1px solid var(--line);background:var(--paper)}
.qopt.o1{--c:var(--b1)}.qopt.o2{--c:var(--b2)}.qopt.o3{--c:var(--b3)}
.qopt b{display:grid;place-items:center;width:24px;height:24px;border-radius:7px;background:var(--c);color:#fff;font-size:12.5px;flex:none}
.qopt input[type=text]{flex:1;min-width:0;border:0;background:transparent;padding:6px 2px}
.qopt input[type=radio]{width:18px;height:18px;accent-color:var(--good);flex:none}
.qopt:has(input[type=radio]:checked){border-color:var(--good);background:var(--good-soft)}
.qed-foot{display:flex;flex-wrap:wrap;gap:12px;align-items:end}
.qed-foot .f{width:130px}
.qed-foot .acts{margin-left:auto}
.bulk{padding:18px;display:grid;gap:10px;margin-bottom:14px}
.bulk textarea{font-family:var(--f-mono);font-size:13px;width:100%}
.bulk-err{margin:0;padding-left:18px;color:var(--bad);font-size:13.5px}
.bulk-prev{margin:0;padding-left:20px;display:grid;gap:8px;font-size:14px;max-height:320px;overflow:auto}
.bulk-prev li span{display:flex;flex-wrap:wrap;gap:4px 12px;color:var(--ink-3);font-size:13px}
.bulk-prev i{font-style:normal}
.bulk-prev i.right{color:var(--good);font-weight:700}
body[data-view="tour"] .help-fab{display:none}
.bulk .row3b{display:flex;flex-wrap:wrap;gap:12px;align-items:end;justify-content:space-between}
.bulk .row3b .f{width:220px}
input[type=datetime-local]{border:1px solid var(--line);border-radius:10px;padding:8px 12px;background:var(--paper);width:100%}
.qopt input[type=text]{border:0;border-radius:6px;padding:6px 2px;background:transparent;width:auto}
#gHost:empty,#gReview:empty{display:none}
.subtabs:empty{display:none}
.garena-foot{align-items:start}

/* =====================================================================
   GIAO DIỆN MỚI (10/2026) – "sổ tay mực xanh": nền sạch, tiêu đề Fraunces,
   vàng bút dạ quang làm điểm nhấn tương tác. Lớp này ghi đè các kiểu cũ phía trên.
   ===================================================================== */
body{margin:0;background:var(--bg);background-image:none;font-size:15.5px;line-height:1.6;padding-block:0;overflow-x:clip;-webkit-font-smoothing:antialiased}
::selection{background:var(--sun-soft)}
h1,h2{font-family:var(--f-display);font-weight:650;letter-spacing:-.018em;font-variation-settings:"SOFT" 50;line-height:1.08}
h2{font-size:clamp(28px,3.4vw,40px)}
h3{font-family:var(--f-body);font-weight:700;letter-spacing:-.01em}
.eyebrow{text-transform:none;letter-spacing:0;font-size:13.5px;font-weight:600;color:var(--plus)}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px;border-radius:6px}
main{padding-top:32px;padding-bottom:56px}

/* thanh điều hướng */
.nav{background:color-mix(in srgb,var(--paper) 86%,transparent);backdrop-filter:saturate(1.4) blur(14px);-webkit-backdrop-filter:saturate(1.4) blur(14px)}
.nav .wrap{height:68px}
.wordmark{font-family:var(--f-display);font-weight:700;letter-spacing:-.02em;font-variation-settings:"SOFT" 50}
.wordmark .edu{font-family:var(--f-body);font-weight:600}
.links a{position:relative;font-weight:500;color:var(--ink-2);background:none}
.links a:hover{background:var(--paper-2)}
.links a.on{color:var(--ink);font-weight:600;background:none;box-shadow:none}
.links a.on::after{content:"";position:absolute;left:12px;right:12px;bottom:1px;height:3px;border-radius:3px;background:var(--sun)}
@media (max-width:900px){.links a.on::after{left:0;right:auto;top:10px;bottom:10px;width:3px;height:auto}.links a{padding-left:14px}}
.theme-btn{border-color:transparent;background:transparent;color:var(--ink-2)}
.theme-btn:hover{background:var(--paper-2);border-color:transparent;color:var(--ink)}
.theme-btn .i-sun{display:none}
:root[data-theme="dark"] .theme-btn .i-sun{display:block}
:root[data-theme="dark"] .theme-btn .i-moon{display:none}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .theme-btn .i-sun{display:block}:root:not([data-theme="light"]) .theme-btn .i-moon{display:none}}

/* nút & thẻ */
.btn{border-radius:10px;font-weight:600;transition:background-color .15s,border-color .15s,box-shadow .15s}
.btn:hover{border-color:color-mix(in srgb,var(--ink) 35%,var(--line))}
.btn.primary:hover{filter:none;background:color-mix(in srgb,var(--btn) 88%,#fff)}
.btn.sun{background:var(--sun);border-color:var(--sun);color:#1A1300;box-shadow:inset 0 -2px 0 rgba(0,0,0,.12)}
.btn.sun:hover{filter:none;background:#FFCD52}
.btn.lg{padding:13px 22px;font-size:16px;border-radius:12px}
.card{border-radius:16px;border-color:var(--line);background:var(--paper)}
.section{padding-block:56px 8px}
.section-head{margin-bottom:24px}
.section-head h2{margin-top:4px}
input[type=text],input[type=search],input[type=url],input[type=email],input[type=password],input[type=number],input[type=datetime-local],textarea,select{transition:border-color .15s,box-shadow .15s}
input:focus,textarea:focus,select:focus{outline:none;border-color:var(--focus);box-shadow:0 0 0 3px color-mix(in srgb,var(--focus) 18%,transparent)}
.subtabs{background:var(--paper);border:1px solid var(--line)}
.subtabs button.on{background:var(--navy);color:#fff;box-shadow:none}
:root[data-theme="dark"] .subtabs button.on{background:var(--sun);color:#1A1300}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .subtabs button.on{background:var(--sun);color:#1A1300}}
.toast{background:var(--deep);color:#fff;border-radius:14px;box-shadow:var(--shadow-lg)}
.modal,.card.modal{box-shadow:var(--shadow-lg)}

/* trang chủ – khối mở đầu */
.hero-x{position:relative;border-radius:28px;background-color:var(--deep);color:#fff;overflow:hidden;margin-top:-8px;isolation:isolate;
  background-image:repeating-linear-gradient(to bottom,transparent 0 35px,rgba(255,255,255,.055) 35px 36px)}
.hero-x::before{content:"";position:absolute;inset:0 auto 0 56px;width:2px;background:rgba(238,90,69,.38);z-index:-1}
.hero-x .hero{padding:64px 56px 64px 92px;gap:48px}
.hero-x h1{color:#fff;font-size:clamp(38px,5.2vw,64px);font-weight:600;margin:16px 0 20px;max-width:15ch}
.hero-x .hero p.lead{color:rgba(255,255,255,.8);font-size:18px}
.hero-kicker{display:inline-flex;align-items:center;gap:10px;margin:0;font-size:14px;font-weight:600;color:var(--sun)}
.hero-kicker::before{content:"";width:28px;height:2px;background:var(--sun);border-radius:2px}
.hero-x .btn:not(.sun){background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.22);color:#fff}
.hero-x .btn:not(.sun):hover{background:rgba(255,255,255,.15)}
.hero-x .stats{border-top:1px solid rgba(255,255,255,.14);padding-top:22px;margin-top:36px;gap:36px}
.hero-x .stats b{font-family:var(--f-display);font-weight:600;font-size:34px;color:#fff}
.hero-x .stats span{color:rgba(255,255,255,.65)}
.hero-x .art{--ink:#101733;--ink-2:#434D6B;--ink-3:#687190;--paper:#fff;--paper-2:#EEF1F8;--line:#E1E5EF;--good:#0F8A5F;--good-soft:rgba(15,138,95,.1);--plus:#A86400;color:#101733;
  --b0:#2B48C8;--b1:#0B8A72;--b2:#C2590C;--b3:#9B3389}
.hero-x .art .c{border-color:transparent;box-shadow:0 30px 60px -20px rgba(0,0,0,.55)}
.hero-x .art .lines i.m{background:#FFE29A;transform-origin:left;animation:mark .6s .9s ease-out both}
.hero-x .quizc .o.r{animation:pick .4s 1.6s ease-out both}
.hero-x .quizc .o.r b{animation:pickb .4s 1.6s ease-out both}
@keyframes mark{from{transform:scaleX(0)}to{transform:scaleX(1)}}
@keyframes pick{from{border-color:#E1E5EF;background:transparent}to{border-color:#0F8A5F;background:rgba(15,138,95,.1)}}
@keyframes pickb{from{background:#EEF1F8;color:inherit}to{background:#0F8A5F;color:#fff}}
@media (prefers-reduced-motion:reduce){.hero-x .art .lines i.m,.hero-x .quizc .o.r,.hero-x .quizc .o.r b{animation:none}}
@media (max-width:900px){.hero-x .hero{padding:44px 24px 40px 40px}.hero-x::before{left:22px}.hero-x .art{min-height:380px}}
@media (max-width:560px){.hero-x{border-radius:22px;margin-inline:-6px}.hero-x .hero{padding:36px 20px 28px 34px}.hero-x::before{left:18px}.hero-x .art{display:none}.hero-x .stats{gap:22px}.hero-x .stats b{font-size:28px}}

/* tính năng */
.feat{padding:24px;gap:12px;border-radius:18px}
.feat .ic{width:46px;height:46px;border-radius:14px}
.feat h3{font-size:17.5px}

/* bảng giá */
.price{border-radius:20px;padding:28px}
.price .amt{font-family:var(--f-display);font-weight:600;letter-spacing:-.02em}
.price.pop{border-width:2px;box-shadow:var(--shadow)}
.price .ribbon{text-transform:none;letter-spacing:0;font-size:12.5px}
.plan{text-transform:none;letter-spacing:0;font-size:11.5px;font-weight:700}

/* chân trang */
.site-foot{margin:24px -16px 0;padding:56px 16px 28px;background:var(--deep);color:rgba(255,255,255,.72);font-size:14.5px}
.site-foot .foot-in{display:grid;grid-template-columns:1.3fr 2fr;gap:40px}
.site-foot .brand{color:#fff}
.site-foot .wordmark .edu{color:rgba(255,255,255,.75)}
.site-foot .wordmark .amp{color:var(--sun)}
.foot-brand p{margin:14px 0 0;max-width:38ch}
.foot-cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.foot-cols h4{margin:0 0 10px;color:#fff;font-size:14.5px;font-weight:700}
.foot-cols a{display:block;color:rgba(255,255,255,.72);text-decoration:none;padding:3px 0;overflow-wrap:anywhere}
.foot-cols a:hover{color:var(--sun)}
.foot-bottom{grid-column:1/-1;border-top:1px solid rgba(255,255,255,.12);padding-top:20px;font-size:13px;color:rgba(255,255,255,.5)}
@media (max-width:760px){.site-foot .foot-in{grid-template-columns:1fr}.foot-cols{grid-template-columns:repeat(2,minmax(0,1fr))}}
/* thanh menu: gọn hơn ở màn hình vừa, chuyển sang nút menu sớm hơn để không tràn */
@media (max-width:1340px){.links{margin-left:6px}.links a{padding:8px 9px;font-size:14px}.links a.on::after{left:9px;right:9px}.me span.n{display:none}}
@media (max-width:1100px){
  .links{position:fixed;left:0;right:0;top:calc(68px + env(safe-area-inset-top,0px));flex-direction:column;background:var(--paper);border-bottom:1px solid var(--line);padding:8px 16px 14px;margin:0;display:none;box-shadow:var(--shadow)}
  .links.open{display:flex}
  .links a{padding:10px 14px;font-size:15px}
  .links a.on::after{left:0;right:auto;top:10px;bottom:10px;width:3px;height:auto}
  .btn.menu-btn{display:inline-flex}
}

/* =====================================================================
   ĐẤU TRƯỜNG (giải đấu) – giao diện thi đấu
   ===================================================================== */
.btn.xl{padding:16px 34px;font-size:18px;border-radius:14px}
/* khối mở đầu trang Đấu trường – cùng chất liệu với trang chủ */
.arena-hero{position:relative;border-radius:28px;background-color:var(--deep);color:#fff;overflow:hidden;isolation:isolate;margin-top:-8px;
  background-image:repeating-linear-gradient(to bottom,transparent 0 35px,rgba(255,255,255,.055) 35px 36px)}
.arena-hero::before{content:"";position:absolute;inset:0 auto 0 56px;width:2px;background:rgba(238,90,69,.38);z-index:-1}
.ah-in{display:grid;grid-template-columns:1.1fr .9fr;gap:44px;align-items:center;padding:56px 52px 56px 92px}
.arena-hero h1{color:#fff;font-size:clamp(34px,4.4vw,54px);font-weight:600;margin:14px 0 16px;max-width:16ch}
.ah-lead{color:rgba(255,255,255,.8);font-size:17px;max-width:48ch;margin:0}
.ah-stats{display:flex;flex-wrap:wrap;gap:34px;margin-top:30px;padding-top:20px;border-top:1px solid rgba(255,255,255,.14)}
.ah-stats b{display:block;font-family:var(--f-display);font-weight:600;font-size:34px;line-height:1.1;font-variant-numeric:tabular-nums}
.ah-stats span{font-size:13px;color:rgba(255,255,255,.65)}
@media (max-width:900px){.ah-in{grid-template-columns:1fr;padding:40px 24px 32px 40px}.arena-hero::before{left:22px}}
@media (max-width:560px){.arena-hero{border-radius:22px;margin-inline:-6px}.ah-in{padding:34px 18px 22px 32px;gap:26px}.arena-hero::before{left:16px}.ah-stats{gap:22px}.ah-stats b{font-size:28px}}
/* thẻ giải nổi bật (luôn nền sáng để nổi trên nền xanh đậm) */
.feat-card{--ink:#101733;--ink-2:#434D6B;--ink-3:#687190;--paper-2:#EEF1F8;--good:#0F8A5F;--bad:#C8363D;--b0:#2B48C8;--b1:#0B8A72;--b2:#C2590C;--b3:#9B3389;--b4:#5B6D0B;--b5:#1C73B7;--coral:#D9472F;--plus:#A86400;
  display:grid;gap:12px;background:#fff;color:#101733;border-radius:22px;padding:24px;text-decoration:none;border-top:6px solid var(--sc,var(--sun));box-shadow:0 30px 60px -24px rgba(0,0,0,.6)}
.feat-card h3{font-family:var(--f-display);font-size:26px;font-weight:600;line-height:1.15;letter-spacing:-.01em}
.feat-card.empty{text-align:center;justify-items:center;border-top-color:var(--sun)}
.feat-card .fc-cta{width:100%;margin-top:4px}
.fc-cdl{font-size:13px;font-weight:600;color:var(--ink-3)}
.fc-live{display:flex;align-items:center;gap:8px;font-weight:700;color:var(--bad)}
.cd{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}
.cd span{display:grid;justify-items:center;background:var(--paper-2);border-radius:12px;padding:8px 4px}
.cd b{font-family:var(--f-display);font-weight:600;font-size:clamp(26px,3vw,36px);line-height:1.05;font-variant-numeric:tabular-nums;color:var(--ink)}
.cd small{font-size:11.5px;color:var(--ink-3)}
/* bộ lọc môn */
.gfilter{display:flex;flex-wrap:wrap;gap:8px;margin:28px 0 4px}
.gfilter:empty{display:none}
.gfilter button{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--paper);color:var(--ink-2);border-radius:99px;padding:7px 14px;font-weight:600;font-size:14px}
.gfilter button i{width:9px;height:9px;border-radius:50%;background:var(--sc)}
.gfilter button:hover{border-color:var(--sc,var(--ink-3));color:var(--ink)}
.gfilter button.on{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.gsec-b{margin-top:28px}
.gsect{display:flex;align-items:center;gap:10px;font-size:24px;margin:0 0 14px}
.gsect span{font-family:var(--f-body);font-size:13px;font-weight:700;background:var(--paper-2);color:var(--ink-2);border-radius:99px;padding:2px 10px}
/* thẻ giải */
.tgrid{grid-template-columns:repeat(auto-fill,minmax(290px,1fr))}
.tcard{position:relative;display:flex;flex-direction:column;gap:10px;padding:20px 20px 16px 24px;border-radius:18px;background:var(--paper);border:1px solid var(--line);border-top:1px solid var(--line);color:var(--ink);text-decoration:none;overflow:hidden;transition:border-color .15s,transform .15s}
.tcard::before{content:"";position:absolute;inset:0 auto 0 0;width:5px;background:var(--sc)}
.tcard:hover{border-color:color-mix(in srgb,var(--sc) 55%,var(--line));transform:translateY(-2px)}
.tcard h3{font-family:var(--f-display);font-size:21px;font-weight:600;line-height:1.2;letter-spacing:-.01em}
.tcard p{margin:0;color:var(--ink-2);font-size:14px}
.tcard.ph-ended{opacity:.8}
.tcard.ph-ended::before{background:var(--ink-3)}
.tc-top{display:flex;flex-wrap:wrap;align-items:center;gap:8px}
.tc-subj{font-size:12.5px;font-weight:700;color:var(--sc);background:color-mix(in srgb,var(--sc) 13%,transparent);border-radius:99px;padding:3px 10px}
.tc-mode{font-size:12.5px;font-weight:600;color:var(--ink-3)}
.tc-state{margin-left:auto;display:inline-flex;align-items:center;gap:6px;font-size:12.5px;font-weight:700;color:var(--ink-3)}
.ph-open .tc-state,.ph-live .tc-state,.tc-state.ph-open,.tc-state.ph-live{color:var(--good)}
.ph-upcoming .tc-state,.tc-state.ph-upcoming{color:var(--link)}
.tc-meta{display:flex;flex-wrap:wrap;gap:6px 16px;font-size:13.5px;color:var(--ink-2)}
.tc-meta span{display:inline-flex;align-items:center;gap:6px}
.tc-meta svg{color:var(--ink-3)}
.tc-foot{margin-top:auto;display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:8px;padding-top:12px;border-top:1px dashed var(--line);font-size:13px;color:var(--ink-3)}
.tc-cd{display:inline-flex;align-items:center;gap:6px}
.tc-cd b{color:var(--ink);font-variant-numeric:tabular-nums}
.tc-badge{font-size:12px;font-weight:700;color:var(--plus);background:var(--plus-soft);border-radius:99px;padding:3px 10px;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
/* cách chơi + bảng phong thần */
.gsteps{list-style:none;margin:14px 0 0;padding:0;display:grid;gap:16px;counter-reset:gs}
.gsteps li{position:relative;padding-left:46px;display:grid;gap:3px;counter-increment:gs}
.gsteps li::before{content:counter(gs);position:absolute;left:0;top:0;width:32px;height:32px;border-radius:50%;display:grid;place-items:center;background:var(--sun);color:#1A1300;font-family:var(--f-display);font-weight:700}
.gsteps span{color:var(--ink-2);font-size:14px}
.gfame{counter-reset:none}
.gfame li{padding:8px 10px;border-radius:12px}
.gfame li:nth-child(1){background:var(--sun-soft)}
.gfame .gf-n{width:22px;text-align:center;font-family:var(--f-display);font-weight:700;color:var(--ink-3)}
.gfame li>b{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.gf-m{display:flex;gap:8px;font-size:13.5px;font-weight:700;font-variant-numeric:tabular-nums}
.gf-m i{font-style:normal}
/* đầu trang của một giải */
.ghead-x{position:relative;display:grid;grid-template-columns:1fr auto;gap:28px;align-items:center;border-radius:24px;background-color:var(--deep);color:#fff;padding:30px 32px 30px 38px;margin-bottom:18px;overflow:hidden;
  background-image:repeating-linear-gradient(to bottom,transparent 0 35px,rgba(255,255,255,.05) 35px 36px)}
.ghead-x::before{content:"";position:absolute;inset:0 auto 0 0;width:6px;background:var(--sc)}
.ghead-x h1{color:#fff;font-size:clamp(28px,3.6vw,42px);font-weight:600;margin:10px 0 8px}
.ghead-x .tc-subj{color:#fff;background:color-mix(in srgb,var(--sc) 70%,transparent)}
.ghead-x .tc-mode,.ghead-x .tc-state{color:rgba(255,255,255,.7);margin-left:0}
.ghead-x .tc-state.ph-open,.ghead-x .tc-state.ph-live{color:#6FE3B4}
.gh-desc{margin:0 0 4px;color:rgba(255,255,255,.78);white-space:pre-line;max-width:62ch}
.gh-chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.gh-chips span{display:inline-flex;align-items:center;gap:6px;font-size:13.5px;background:rgba(255,255,255,.09);border:1px solid rgba(255,255,255,.14);border-radius:99px;padding:5px 12px}
.gh-chips .gh-badge{background:rgba(255,194,51,.16);border-color:rgba(255,194,51,.4);color:#FFD772;font-weight:700}
.gh-acts{margin-top:16px}
.ghead-x .btn.gh-share{background:rgba(255,255,255,.08);border-color:rgba(255,255,255,.22);color:#fff}
.ghead-x .btn.gh-share:hover{background:rgba(255,255,255,.16)}
.gh-side{min-width:280px;display:grid;gap:8px}
.gh-side .fc-cdl{color:rgba(255,255,255,.7)}
.gh-side .cd span{background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.12)}
.gh-side .cd b{color:#fff}
.gh-side .cd small{color:rgba(255,255,255,.6)}
.gh-when{font-size:13px;color:rgba(255,255,255,.65)}
.gh-when.big{display:flex;align-items:center;gap:8px;font-size:16px;font-weight:700;color:#fff}
@media (max-width:900px){.ghead-x{grid-template-columns:1fr;padding:26px 22px 24px 28px}.gh-side{min-width:0}}
/* sân thi */
.gstage{position:relative;overflow:hidden;border-radius:24px;border:1px solid var(--line);background:var(--paper);padding:26px;min-height:300px}
.gstage.is-play,.gstage.is-reveal,.gstage.is-321,.gstage.is-lobby{
  --t0:#2B48C8;--t1:#0B8A72;--t2:#C2590C;--t3:#9B3389;
  background-color:var(--deep);color:#fff;border-color:transparent;
  background-image:repeating-linear-gradient(to bottom,transparent 0 35px,rgba(255,255,255,.045) 35px 36px)}
.gstage .hint{color:var(--ink-3)}
.gstage.is-play .hint,.gstage.is-reveal .hint,.gstage.is-lobby .hint{color:rgba(255,255,255,.65)}
.gstage .gq-top{display:grid;grid-template-columns:1fr auto auto;align-items:center;gap:14px}
.gq-n{font-family:var(--f-display)}
.gq-n b{font-size:26px;font-weight:600}
.gq-n span{font-size:16px;color:rgba(255,255,255,.6)}
.gq-pts{font-family:var(--f-display);font-weight:600;font-size:22px;font-variant-numeric:tabular-nums;background:var(--sun);color:#1A1300;border-radius:12px;padding:4px 14px;min-width:96px;text-align:center}
.picked .gq-pts{background:rgba(255,255,255,.12);color:#fff}
.gring{position:relative;width:62px;height:62px;display:grid;place-items:center}
.gring svg{position:absolute;inset:0;transform:rotate(-90deg)}
.gring circle{fill:none;stroke-width:4}
.gring .tr{stroke:rgba(255,255,255,.14)}
.gring .fg{stroke:var(--sun);stroke-dasharray:100;stroke-linecap:round}
.gring.low .fg{stroke:#FF6B57}
.gring b{position:relative;font-family:var(--f-display);font-size:22px;font-weight:600;font-variant-numeric:tabular-nums}
.gprog{display:flex;gap:4px;margin:16px 0 4px}
.gprog i{flex:1;height:5px;border-radius:99px;background:rgba(255,255,255,.14)}
.gprog i.done{background:rgba(255,194,51,.55)}
.gprog i.cur{background:var(--sun)}
.gstage .gq{font-size:clamp(20px,2.6vw,27px);font-weight:700;line-height:1.35;margin:14px 0 18px;color:inherit}
.gstage .gopts{gap:12px}
.gstage.is-play .gopt,.gstage.is-reveal .gopt{--c:var(--t0);background:var(--c);border:0;color:#fff;min-height:74px;padding:16px 18px;border-radius:16px;font-size:17px;box-shadow:inset 0 -4px 0 rgba(0,0,0,.22);transition:transform .12s,opacity .2s,box-shadow .12s}
.gstage .gopt.o1{--c:var(--t1)}.gstage .gopt.o2{--c:var(--t2)}.gstage .gopt.o3{--c:var(--t3)}
.gstage.is-play .gopt b,.gstage.is-reveal .gopt b{background:rgba(255,255,255,.2);color:#fff;width:38px;height:38px;border-radius:11px;font-size:16px}
.gstage.is-play button.gopt:not(:disabled):hover{transform:translateY(-2px);background:color-mix(in srgb,var(--c) 88%,#fff)}
.gstage.is-play button.gopt:not(:disabled):active{transform:translateY(1px);box-shadow:inset 0 -1px 0 rgba(0,0,0,.22)}
.gstage.is-play button.gopt:disabled{opacity:1;cursor:default}
.gstage.picked .gopt:not(.chosen){opacity:.32}
.gstage.is-play .gopt.chosen{box-shadow:0 0 0 4px #fff,inset 0 -4px 0 rgba(0,0,0,.22)}
.gnote{margin:14px 0 0;color:rgba(255,255,255,.7);font-size:14px;text-align:center}
.gstage.is-reveal .gopt.wrong{opacity:.3}
.gstage.is-reveal .gopt.right{background:#0F8A5F;box-shadow:0 0 0 4px rgba(111,227,180,.55)}
.gstage.is-reveal .gopt.wrong.chosen{opacity:.85;box-shadow:0 0 0 4px #FF6B57}
.gstage.is-reveal .gopt em{color:rgba(255,255,255,.85)}
.gstage.is-reveal .gopt em i{background:rgba(255,255,255,.75)}
.gq-me{font-weight:700;font-variant-numeric:tabular-nums;display:flex;align-items:center;gap:10px}
.gq-me em{font-style:normal;font-size:13px;border-radius:99px;padding:2px 9px}
.gq-me em.up{background:rgba(111,227,180,.2);color:#6FE3B4}
.gq-me em.down{background:rgba(255,107,87,.2);color:#FF9A8B}
.gstage .gres{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:14px;border-radius:16px;padding:14px 18px;font-size:18px}
.gstage .gres.good{background:#0F8A5F;color:#fff}
.gstage .gres.bad{background:rgba(255,107,87,.18);color:#FFB0A5}
.gres .pop{font-family:var(--f-display);font-size:30px;font-weight:600;animation:gpop .5s cubic-bezier(.2,1.6,.4,1) both}
@keyframes gpop{from{transform:scale(.4);opacity:0}to{transform:scale(1);opacity:1}}
.gstage .gexpl{background:rgba(255,255,255,.08);color:rgba(255,255,255,.88);margin-top:14px}
.gstage.is-ended .gexpl,.greview .gexpl{background:var(--paper-2);color:var(--ink)}
/* đếm ngược 3-2-1 */
.g321{min-height:300px;display:grid;place-items:center;align-content:center;gap:6px}
.g321 b{font-family:var(--f-display);font-size:140px;line-height:1;font-weight:600;color:var(--sun);animation:gpop .7s cubic-bezier(.2,1.6,.4,1) both}
.g321 span{color:rgba(255,255,255,.7);font-weight:600}
/* màn chờ / sẵn sàng */
.g-facts{display:flex;gap:10px;margin:8px 0 6px;flex-wrap:wrap;justify-content:center}
.g-facts div{min-width:104px;background:var(--paper-2);border-radius:14px;padding:10px 14px;display:grid;justify-items:center}
.g-facts b{font-family:var(--f-display);font-size:26px;font-weight:600;font-variant-numeric:tabular-nums}
.g-facts span{font-size:12.5px;color:var(--ink-3)}
.g-gate{display:grid;gap:10px;justify-items:center}
.g-gate p{margin:0}
.gstage .gwait h3{font-size:26px}
.gstage.is-ready .gbig{font-size:56px}
/* phòng chờ */
.lobby-n{display:grid;justify-items:center}
.lobby-n b{font-family:var(--f-display);font-size:72px;font-weight:600;line-height:1;color:var(--sun);font-variant-numeric:tabular-nums}
.lobby-n span{color:rgba(255,255,255,.75);font-weight:600}
.lobby-wall{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;max-width:640px;margin:14px 0}
.lw{display:grid;justify-items:center;gap:4px;width:58px;animation:gpop .4s ease-out both}
.lw .av{width:44px;height:44px;box-shadow:0 0 0 2px rgba(255,255,255,.25)}
.lw small{font-size:11.5px;color:rgba(255,255,255,.75);max-width:58px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lw.more{width:auto;align-self:center;font-weight:700;color:var(--sun)}
.gstage .gready{display:flex;align-items:center;gap:8px;color:#6FE3B4}
/* kết thúc: bục vinh quang */
.pod-title{font-size:28px!important}
.podium{max-width:520px;gap:12px}
.pod-av{position:relative}
.pod .av{width:60px;height:60px;box-shadow:0 0 0 3px var(--ring,#C3CAD9)}
.pod.p1 .av{width:76px;height:76px}
.pod.p1{--ring:#FFC233}.pod.p2{--ring:#B9C2D3}.pod.p3{--ring:#D9915A}
.pod-av span{position:absolute;right:-6px;bottom:-4px;font-size:22px}
.pod b{font-size:14.5px;margin-top:6px}
.pod-sc{font-variant-numeric:tabular-nums}
.pod .step{font-family:var(--f-display);font-weight:600;font-size:34px;color:var(--ink-2);margin-top:6px;background:color-mix(in srgb,var(--ring,#C3CAD9) 28%,var(--paper))}
.pod.p1 .step{height:120px;background:color-mix(in srgb,#FFC233 32%,var(--paper));color:var(--ink)}
.pod.empty .step{background:var(--paper-2)}
.gstage .gresult{display:grid;justify-items:center;gap:2px;background:var(--paper-2);border-radius:16px;padding:14px;margin-top:16px}
.gresult>span{font-size:13.5px;color:var(--ink-2)}
.gresult>b{font-family:var(--f-display);font-size:34px;font-weight:600;font-variant-numeric:tabular-nums}
/* pháo giấy */
.confetti{position:absolute;inset:0;pointer-events:none;overflow:hidden}
.confetti i{position:absolute;top:-16px;width:8px;height:14px;border-radius:2px;animation:gfall 3s ease-in forwards}
@keyframes gfall{to{top:110%;transform:rotate(540deg) translateX(30px)}}
/* bảng xếp hạng */
.gboardbox{border-radius:20px}
.gboard li{padding:8px 10px;border-radius:12px}
.gboard li.top{background:color-mix(in srgb,var(--rc) 14%,transparent)}
.gboard li.r1{--rc:#FFC233}.gboard li.r2{--rc:#9AA6BD}.gboard li.r3{--rc:#D9915A}
.gboard li.mine{box-shadow:inset 0 0 0 2px var(--sun)}
.gboard .rk{font-family:var(--f-display);font-weight:600;color:var(--ink-3)}
.gboard .sc{font-family:var(--f-display);font-weight:600;font-size:17px}
.gb-note{margin:0 4px 10px;font-size:13px;color:var(--ink-3);background:var(--paper-2);border-radius:10px;padding:8px 10px}
.gb-empty{text-align:center;padding:18px 6px;color:var(--ink-3)}
.gb-empty .gbig{font-size:36px}
.gb-empty p{margin:6px 0 0}
.grv-head{display:flex;justify-content:space-between;align-items:baseline;gap:10px}
@media (max-width:640px){
  .gstage{padding:18px;border-radius:20px}
  .gstage .gq-top{grid-template-columns:1fr auto;gap:10px}
  .gq-pts{grid-row:2;grid-column:1/-1;justify-self:start;font-size:18px;min-width:0}
  .gring{width:54px;height:54px}
  .gstage.is-play .gopt,.gstage.is-reveal .gopt{min-height:60px;font-size:16px}
  .g321 b{font-size:110px}
  .lobby-n b{font-size:56px}
}
@media (prefers-reduced-motion:reduce){.gres .pop,.g321 b,.lw,.tcard{animation:none;transition:none}}
.arena-hero h1{max-width:20ch}
.tc-new{color:var(--good);font-weight:600}
.gh-champ{display:grid;gap:8px}
.gh-champ .fc-cdl{color:rgba(255,255,255,.7)}
.gh-champ-in{display:flex;align-items:center;gap:12px;background:rgba(255,194,51,.12);border:1px solid rgba(255,194,51,.35);border-radius:16px;padding:12px 16px}
.gh-champ-in .av{width:48px;height:48px;box-shadow:0 0 0 3px #FFC233}
.gh-champ-in div{display:grid;flex:1}
.gh-champ-in b{font-size:16px}
.gh-champ-in span{font-size:13px;color:rgba(255,255,255,.7)}
.gh-champ-in i{font-style:normal;font-size:28px}
.gstage{scroll-margin-top:84px}
.tcard.ph-open,.tcard.ph-live,.tcard.ph-upcoming{border-top-color:var(--line)}
.gstage.is-play.picked .gopt:not(.chosen){opacity:.32}
.gstage.is-reveal .gopt.wrong{background:#2E3760;opacity:.55;box-shadow:none}
.gstage.is-reveal .gopt.wrong.chosen{background:#6E2632;opacity:1;box-shadow:0 0 0 3px #FF6B57}
.gstage .gres.bad{flex-direction:column;align-items:flex-start;gap:2px}

/* ===== F&D Tools (khu Công cụ) ===== */
.tools-hero{border-radius:28px;background-color:var(--deep);color:#fff;padding:44px 48px;margin-top:-8px;
  background-image:repeating-linear-gradient(to bottom,transparent 0 35px,rgba(255,255,255,.05) 35px 36px)}
.tools-hero h1{color:#fff;font-size:clamp(32px,4.4vw,52px);font-weight:600;margin:12px 0}
.tools-hero p{color:rgba(255,255,255,.8);max-width:60ch;margin:0;font-size:16.5px}
.tools-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px;margin-top:22px}
.tool-card{display:grid;grid-template-rows:auto 1fr auto;gap:12px;padding:22px;border-radius:20px;border:1px solid var(--line);background:var(--paper);color:var(--ink);text-decoration:none}
.tool-card h3{font-family:var(--f-display);font-size:22px;font-weight:600;margin:0 0 6px}
.tool-card h3 small{font-family:var(--f-body);font-size:12px;font-weight:700;color:var(--ink-3);background:var(--paper-2);border-radius:99px;padding:2px 9px;vertical-align:3px}
.tool-card p{margin:0;color:var(--ink-2);font-size:14.5px}
.tool-ic{width:58px;height:58px;border-radius:16px;display:grid;place-items:center;font-size:32px;background:var(--paper-2)}
.tool-card.live{grid-column:span 2;grid-template-columns:auto 1fr auto;grid-template-rows:auto;align-items:center;border:2px solid var(--sun);background:color-mix(in srgb,var(--sun) 7%,var(--paper))}
.tool-card.live .tool-ic{background:var(--deep);color:var(--sun);width:72px;height:72px;font-size:40px}
.tool-card.live:hover{border-color:color-mix(in srgb,var(--sun) 70%,var(--ink))}
.tool-card.soon{opacity:.75}
.tool-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px}
.tool-tags span{font-size:12px;font-weight:700;color:var(--good);background:var(--good-soft);border-radius:99px;padding:2px 9px}
@media (max-width:640px){.tools-hero{padding:32px 22px;border-radius:22px}.tool-card.live{grid-column:auto;grid-template-columns:1fr}.tool-card.live .btn{justify-self:start}}
/* 🔴 MỚI: thẻ F&D Focus trong #tools và trang #focus */
.tool-card.app .tool-ic img{display:block}
.tool-acts{display:flex;flex-direction:column;align-items:center;gap:6px}
.focus-hero{display:flex;align-items:center;justify-content:space-between;gap:32px}
.fh-icon{flex:none;border-radius:30px;box-shadow:0 18px 40px rgba(0,0,0,.35)}
.fh-acts{display:flex;flex-wrap:wrap;align-items:center;gap:12px 16px;margin-top:22px}
.fh-acts span{color:rgba(255,255,255,.72);font-size:14px}
.focus-sec{margin-top:34px}
.focus-sec h2{font-family:var(--f-display);font-size:clamp(24px,3vw,32px);font-weight:600;margin:0 0 14px}
.focus-feats{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px}
.focus-feats>div{padding:18px;border-radius:18px;border:1px solid var(--line);background:var(--paper)}
.focus-feats b{display:block;font-size:16px;margin-bottom:6px}
.focus-feats p{margin:0;color:var(--ink-2);font-size:14.5px}
.fp-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px}
.fp-grid>div{padding:18px 20px;border-radius:18px}
.fp-grid h3{margin:0 0 8px;font-size:16px}
.fp-grid ul{margin:0;padding-left:20px;color:var(--ink-2);font-size:14.5px;line-height:1.65}
.fp-yes{background:var(--good-soft)}.fp-yes h3{color:var(--good)}
.fp-no{background:var(--bad-soft)}.fp-no h3{color:var(--bad)}
.fp-note{color:var(--ink-2);font-size:14.5px;margin:14px 0 0}
.focus-shots{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.focus-shots a{display:block;color:var(--ink-2);text-decoration:none;font-size:13.5px}
.focus-shots img{display:block;width:100%;aspect-ratio:16/11;object-fit:cover;object-position:top;border-radius:14px;border:1px solid var(--line);background:var(--paper-2);margin-bottom:8px}
.focus-shots a:hover img{border-color:var(--sun)}
.focus-steps{margin:0;padding-left:22px;line-height:1.75;color:var(--ink-2)}
.focus-steps b{color:var(--ink)}
.focus-faq details{border:1px solid var(--line);border-radius:14px;background:var(--paper);padding:0 18px;margin-bottom:10px}
.focus-faq summary{cursor:pointer;font-weight:600;padding:14px 0}
.focus-faq details p{margin:0 0 14px;color:var(--ink-2);font-size:14.5px}
.focus-hash{word-break:break-all;font-size:12.5px}
.focus-log{margin-top:14px;padding:16px 20px;border-radius:16px;border:1px solid var(--line);background:var(--paper)}
.focus-log h3{margin:0 0 6px;font-size:17px}.focus-log h3 small{color:var(--ink-3);font-weight:500;font-size:13px}
.focus-log ul{margin:0;padding-left:20px;color:var(--ink-2);font-size:14.5px;line-height:1.65}
@media (max-width:640px){.focus-hero{flex-direction:column-reverse;align-items:flex-start;gap:18px}.fh-icon{width:84px;height:84px;border-radius:20px}.fp-grid{grid-template-columns:1fr}.tool-acts{flex-direction:row;align-self:start}}

/* ===== hộp chia sẻ ===== */
.share-box{z-index:33;width:min(520px,calc(100% - 24px))}
.share-h{display:flex;justify-content:space-between;align-items:center;gap:10px}
.share-h h3{font-family:var(--f-display);font-size:24px;font-weight:600;margin:0}
.share-title{margin:-6px 0 0;color:var(--ink-2);font-weight:600}
.share-link{display:flex;gap:8px}
.share-link input{flex:1;min-width:0;font-family:var(--f-mono);font-size:13px}
.share-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:8px}
.share-btn{display:flex;align-items:center;gap:10px;border:1px solid var(--line);background:var(--paper);border-radius:14px;padding:10px 12px;font-weight:700;font-size:14px;color:var(--ink);text-decoration:none;text-align:left;flex-wrap:wrap}
.share-btn:hover{border-color:var(--ink-3)}
.share-btn b{width:32px;height:32px;border-radius:10px;display:grid;place-items:center;color:#fff;font-size:17px;flex:none}
.share-btn small{flex-basis:100%;font-weight:500;font-size:12px;color:var(--ink-3);margin:-6px 0 0 42px}
.share-btn.fb b{background:#1877F2}.share-btn.ms b{background:#A033FF}.share-btn.zl b{background:#0068FF}.share-btn.more b{background:var(--ink-3)}
.share-box textarea{font-size:14px}
.ah-share{margin-top:12px;width:100%;background:rgba(255,255,255,.08)!important;border-color:rgba(255,255,255,.25)!important;color:#fff!important}
.ah-share:hover{background:rgba(255,255,255,.16)!important}

/* ===== Ảnh trong Học với AI ===== */
.ft.img{background:#2E8B6E}
.drop-tip{margin:8px 2px 0;font-size:12.5px;line-height:1.5}
.compose .attach-btn{flex:none;width:46px;height:46px;padding:0;display:grid;place-items:center;cursor:pointer;color:var(--ink-2,inherit)}
.compose .attach-btn:hover{color:var(--navy);border-color:var(--sun)}
.compose .attach-btn.off{opacity:.45;pointer-events:none}
.ask-tray{display:flex;flex-wrap:wrap;align-items:center;gap:10px;padding:10px 2px 0;border-top:1px solid var(--line)}
.ask-tray[hidden]{display:none}
.ask-tray + .compose{border-top:0;padding-top:8px}
.tray-img{position:relative;width:64px;height:64px;border-radius:10px;overflow:hidden;border:1px solid var(--line);background:var(--paper);flex:none}
.tray-img img{width:100%;height:100%;object-fit:cover;display:block}
.tray-x{position:absolute;top:3px;right:3px;width:22px;height:22px;border-radius:50%;border:0;background:rgba(10,20,40,.75);color:#fff;font-size:15px;line-height:22px;padding:0;cursor:pointer}
.tray-x:hover{background:#C8414A}
.msg-imgs{display:flex;flex-wrap:wrap;gap:6px;margin:2px 0 6px}
.msg-imgs img{width:110px;height:110px;object-fit:cover;border-radius:8px;cursor:zoom-in;background:#fff;border:1px solid rgba(255,255,255,.25)}
.msg.u .msg-imgs:last-child{margin-bottom:0}
#sp-chat.over{outline:2px dashed var(--sun);outline-offset:-6px}
.modal.img-zoom{width:min(900px,calc(100% - 32px));padding:14px;z-index:32}
.modal.img-zoom img{width:100%;max-height:75vh;object-fit:contain;border-radius:8px;background:#fff}
@media (max-width:560px){.msg-imgs img{width:84px;height:84px}.tray-img{width:56px;height:56px}}

/* ===== Luyện tập (giải đấu) ===== */
.tcard.ph-practice{border-top-color:var(--mint)}
.tcard.ph-practice .tc-state{color:var(--mint)}
.tc-go{font-weight:700;color:var(--link);font-size:14px}
.tc-prac{color:var(--mint);font-weight:600}
.gsec-b.prac .gsect{color:var(--ink)}
.ah-prac{background:rgba(255,255,255,.12);color:#fff;border-color:rgba(255,255,255,.35)}
.ah-prac:hover{background:rgba(255,255,255,.2)}
.gprac-cta{display:grid;justify-items:center;gap:8px;margin-top:18px;text-align:center}
.prac{display:grid;gap:18px;max-width:900px;margin:0 auto}
.prac-head{display:grid;gap:10px}
.prac-head h1{font-family:var(--f-display);font-weight:600;font-size:clamp(26px,3.4vw,38px);margin:0}
.prac-head .tc-top{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.prac-head .tc-state{color:var(--mint);font-weight:700;font-size:13px}
.prac-bar{display:grid;gap:6px;font-size:14px;color:var(--ink-2)}
.prac-prog{height:8px;border-radius:99px;background:var(--paper-2);overflow:hidden}
.prac-prog i{display:block;height:100%;background:linear-gradient(90deg,var(--mint),var(--sun));border-radius:99px;transition:width .3s}
.prac-dots{display:flex;flex-wrap:wrap;gap:6px}
.prac-dots button{width:34px;height:34px;border-radius:10px;border:1.5px solid var(--line);background:var(--paper);color:var(--ink-2);font-weight:700;font-size:13px;cursor:pointer}
.prac-dots button.ok{background:var(--good-soft);border-color:var(--good);color:var(--good)}
.prac-dots button.no{background:var(--bad-soft);border-color:var(--bad);color:var(--bad)}
.prac-dots button.cur{box-shadow:0 0 0 3px var(--sun);border-color:var(--sun)}
.prac-q{padding:22px!important;display:grid;gap:16px}
.prac-qn{font-size:13px;font-weight:700;color:var(--ink-3);text-transform:uppercase;letter-spacing:.06em}
.prac-body{font-size:19px;font-weight:600;line-height:1.55;white-space:pre-line;overflow-wrap:anywhere}
.prac-opts{display:grid;grid-template-columns:1fr 1fr;gap:10px}
@media (max-width:640px){.prac-opts{grid-template-columns:1fr}}
.prac-opts .gopt{cursor:pointer}
.prac-opts .gopt:disabled{cursor:default}
.prac-ex{border-radius:12px;padding:12px 14px;border:1px solid var(--line)}
.prac-ex.ok{background:var(--good-soft);border-color:color-mix(in srgb,var(--good) 35%,transparent)}
.prac-ex.no{background:var(--bad-soft);border-color:color-mix(in srgb,var(--bad) 30%,transparent)}
.prac-ex b{display:block;margin-bottom:4px}
.prac-ex.ok b{color:var(--good)}.prac-ex.no b{color:var(--bad)}
.prac-ex p{margin:0;white-space:pre-line}
.prac-nav{display:flex;gap:10px;align-items:center;flex-wrap:wrap}
.prac-sum{display:grid;justify-items:center;text-align:center;gap:10px;padding:30px 22px!important}
.prac-sum h2{font-family:var(--f-display);margin:0}
.prac-wrong{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;align-items:center}
.prac-wrong .chip{border:1px solid var(--line);background:var(--paper-2);border-radius:99px;padding:4px 12px;cursor:pointer;color:var(--ink)}

/* ===== Học với AI: chuyển giữa Tài liệu và Gia sư AI ===== */
.learn-tabs{display:flex;gap:6px;padding:4px;border:1px solid var(--line);border-radius:14px;background:var(--paper);margin-bottom:16px;width:max-content;max-width:100%;overflow-x:auto}
.learn-tabs a{display:inline-flex;align-items:center;gap:7px;padding:9px 16px;border-radius:10px;font-weight:600;font-size:14.5px;color:var(--ink-2);text-decoration:none;white-space:nowrap}
.learn-tabs a:hover{background:var(--paper-2);color:var(--ink)}
.learn-tabs a.on{background:var(--deep);color:#fff}
:root[data-theme="dark"] .learn-tabs a.on{background:var(--sun);color:#1A1300}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .learn-tabs a.on{background:var(--sun);color:#1A1300}}
.lt-new{font-size:10.5px;font-weight:800;text-transform:uppercase;letter-spacing:.04em;background:var(--sun);color:#1A1300;border-radius:99px;padding:1px 7px}

/* ---- Doanh thu (cập nhật 8) ---- */
.kpi-btn{font:inherit;text-align:left;color:inherit;cursor:pointer;width:100%}
.kpi-btn:hover{border-color:var(--sun)}
.rev-top{display:flex;flex-wrap:wrap;gap:10px 16px;align-items:center;justify-content:space-between;margin-bottom:14px}
.rev-top .subtabs{margin-bottom:0}
.rev-reset{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.rev-add{display:flex;flex-wrap:wrap;gap:8px;align-items:center;padding:14px 16px;margin-top:4px}
.rev-add b{margin-right:4px}
.rev-add input[type=text]{flex:1 1 240px;min-width:0}
.rev-add input[type=number]{width:150px}
.rev-table tr.rv-ex td{opacity:.5}
.rev-table tr.rv-old td{background:var(--paper-2)}
.rev-prices{padding:14px 16px;margin-top:22px}
.rev-prices summary{cursor:pointer}
.rev-prices .model{min-width:230px}
@media (max-width:640px){.rev-add input[type=number],.rev-add select,.rev-add input[type=date]{flex:1 1 40%}}

/* 🔴 SỬA: điện thoại nhỏ (≤420px) khi chưa đăng nhập – nút menu bị tràn ra ngoài 8px */
@media (max-width:420px){.nav .wrap{gap:8px}#authArea .acts{gap:6px}#authArea .btn.sm{padding-inline:9px}}

/* 🔴 thông báo "Học tập an tâm" + trang chính sách */
.trust-note{margin-top:18px;padding:16px 18px;border-radius:14px;background:var(--paper-2);border:1px solid var(--line);font-size:13.5px;color:var(--ink-2);text-align:left}
.trust-note h3{display:flex;align-items:center;gap:8px;margin:0 0 8px;font-size:15px;color:var(--ink)}
.trust-note h3 svg{color:var(--good);flex:none}
.trust-note ul{margin:0;padding-left:18px;display:grid;gap:5px;line-height:1.5}
.trust-note a{color:var(--link)}
.trust-links{display:flex;flex-wrap:wrap;gap:6px 14px;align-items:center;margin-top:10px;font-weight:600}
.sup-cards + .trust-note{margin:0 0 22px}
.legal{max-width:760px;margin:0 auto;padding:28px;line-height:1.7}
.legal h3{margin:26px 0 8px}.legal h3:first-of-type{margin-top:6px;font-size:26px}
.legal ul{padding-left:20px}
.legal h4{margin:22px 0 6px;font-size:17px}
@media (max-width:560px){.legal{padding:18px}.trust-note{padding:14px}}

/* 🔴 đăng nhập dễ hơn */
.auth-notice{display:grid;gap:4px;padding:12px 14px;border-radius:12px;background:var(--plus-soft);color:var(--ink);font-size:14px;line-height:1.5}
.pw-wrap{position:relative;display:block}
.pw-wrap input{width:100%;padding-right:48px}
.pw-eye{position:absolute;right:4px;top:50%;transform:translateY(-50%);width:40px;height:36px;border:0;background:transparent;border-radius:8px;font-size:18px;cursor:pointer;color:var(--ink-2)}
.pw-eye:focus-visible{outline:2px solid var(--focus)}
.auth #resend,.auth #resend2{width:100%;margin-top:8px}
.auth .btn.primary[href="#login"]{width:100%;margin-top:8px;text-align:center}
.steps-mini{margin:8px 0 0;padding-left:20px;display:grid;gap:3px}

/* =====================================================================
   🔴 F&D TOURNAMENT – bổ sung cho bản tách riêng
   ===================================================================== */
.foot-cols{grid-template-columns:repeat(2,minmax(0,1fr))}
/* ảnh minh họa câu hỏi + công thức Toán */
.gq-img{display:block;max-width:100%;max-height:340px;margin:4px auto 6px;border-radius:12px;border:1px solid var(--line);background:#fff;object-fit:contain}
.grv-h .gq-img{margin:8px 0 0;max-height:220px}
.katex{font-size:1.04em}
.gopt .katex,.gq .katex{white-space:nowrap}
.qed-img{display:flex;flex-wrap:wrap;gap:8px;align-items:center}
.qed-img img{height:48px;border-radius:8px;border:1px solid var(--line);background:#fff;vertical-align:middle}
/* trang quản trị ngân hàng câu hỏi */
.qbx .section-head h2{font-size:clamp(24px,3vw,32px)}
.qrow{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.grid2{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.grid3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.grid4{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}
@media (max-width:720px){.grid3,.grid4{grid-template-columns:repeat(2,minmax(0,1fr))}.grid2{grid-template-columns:1fr}}
.qbx label.f select,.qbx label.f input,.modal.qbx label.f select{width:100%}
.filters{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;padding:14px;margin-bottom:12px}
@media (max-width:900px){.filters{grid-template-columns:repeat(2,minmax(0,1fr))}}
.pill{display:inline-flex;align-items:center;gap:4px;padding:2px 9px;border-radius:99px;font-size:12px;font-weight:700;background:var(--paper-2);color:var(--ink-2);white-space:nowrap}
.pill.easy{color:var(--good);background:var(--good-soft)}
.pill.medium{color:var(--plus);background:var(--plus-soft)}
.pill.hard{color:var(--bad);background:var(--bad-soft)}
.pill.approved{color:var(--good);background:var(--good-soft)}
.pill.review{color:var(--link);background:color-mix(in srgb,var(--link) 14%,transparent)}
.pill.draft{color:var(--ink-3)}
.pill.archived{color:var(--ink-3);text-decoration:line-through}
.code{font-family:var(--f-mono);font-size:12.5px;font-weight:700;color:var(--ink-2);white-space:nowrap}
table.t{width:100%;border-collapse:collapse;font-size:13.5px}
table.t th{position:sticky;top:0;background:var(--paper-2);text-align:left;font-size:12px;text-transform:uppercase;letter-spacing:.4px;color:var(--ink-2);padding:9px 10px;white-space:nowrap}
table.t td{padding:8px 10px;border-top:1px solid var(--line);vertical-align:top}
table.t tr:hover td{background:color-mix(in srgb,var(--paper-2) 60%,transparent)}
table.t td.txt{max-width:340px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
table.t tr.bad td{background:var(--bad-soft)}
table.t tr.warn td{background:var(--plus-soft)}
table.t .acts{flex-wrap:nowrap;gap:4px}
.selbar{position:sticky;bottom:12px;z-index:5;display:flex;gap:8px;align-items:center;flex-wrap:wrap;padding:10px 14px;margin-top:12px;box-shadow:var(--shadow-lg)}
.optrow{display:grid;grid-template-columns:34px minmax(0,1fr) auto auto;gap:8px;align-items:center}
.optrow .lb{width:30px;height:30px;border-radius:50%;display:grid;place-items:center;font-weight:800;background:var(--paper-2)}
.check{display:inline-flex;gap:6px;align-items:center;font-weight:600;font-size:13.5px;cursor:pointer;white-space:nowrap}
.modal.qbx{z-index:32}
.modal.qbx.wide{width:min(860px,calc(100% - 24px));max-height:calc(100% - 24px)}
.qb-preview{border:2px dashed var(--line);border-radius:16px;padding:12px;background:var(--bg)}
.qb-prev .gopt{cursor:default}
.qbx .drop{cursor:pointer}
/* KaTeX trong đáp án: không để quy tắc của ô đáp án làm vỡ công thức */
.gopt .katex,.grv li .katex,.gq .katex{white-space:nowrap;overflow-wrap:normal}