/* Trí Lữ Design Tokens V1 — shared values for new learning interfaces. */
:root {
  --tl-font-ui:"Avenir Next","Be Vietnam Pro",system-ui,-apple-system,sans-serif;
  --tl-font-jp:"Yu Mincho","Hiragino Mincho ProN","Noto Serif JP",serif;
  --tl-font-shodo:"YuKyokasho","Klee","Hiragino Mincho ProN","Noto Serif JP",serif;
  --tl-font-mono:"JetBrains Mono",ui-monospace,monospace;

  --tl-ink:#172833;
  --tl-ink-soft:#52616a;
  --tl-seal:#a53b2e;
  --tl-sepia:#80582f;
  --tl-paper:rgba(255,252,244,.70);
  --tl-paper-soft:rgba(245,240,228,.54);
  --tl-glass:rgba(250,252,249,.64);
  --tl-glass-strong:rgba(250,252,249,.82);
  --tl-glass-border:rgba(255,255,255,.62);
  --tl-hair:color-mix(in srgb,var(--tl-ink) 16%,transparent);
  --tl-wash:rgba(165,59,46,.075);
  --tl-focus:#1f7087;
  --tl-success:#34745a;
  --tl-danger:#a53b2e;

  --tl-subject-math:#5667a8;
  --tl-subject-physics:#287d8e;
  --tl-subject-chemistry:#a36a2d;
  --tl-subject-biology:#4d7658;
  --tl-subject-japanese:#a53b2e;

  --tl-space-1:4px;
  --tl-space-2:8px;
  --tl-space-3:12px;
  --tl-space-4:18px;
  --tl-space-5:26px;
  --tl-space-6:38px;
  --tl-space-7:52px;
  --tl-space-8:72px;

  --tl-radius-control:12px;
  --tl-radius-panel:22px;
  --tl-radius-surface:28px;
  --tl-control-min:44px;
  --tl-control-primary:50px;
  --tl-menu-level1-max:6;
  --tl-blur:18px;
  --tl-shadow:0 24px 64px rgba(23,40,51,.15),inset 0 1px rgba(255,255,255,.66);

  --tl-text-meta:11px;
  --tl-text-body:16px;
  --tl-text-body-large:18px;
  --tl-text-jp:24px;
  --tl-text-title:clamp(38px,4.5vw,60px);
}

html[data-mode="dark"],html[data-theme="dark"] {
  --tl-ink:#f0eee6;
  --tl-ink-soft:#bec6c8;
  --tl-seal:#e88977;
  --tl-sepia:#d4b075;
  --tl-paper:rgba(8,26,43,.72);
  --tl-paper-soft:rgba(5,18,30,.56);
  --tl-glass:rgba(5,18,30,.64);
  --tl-glass-strong:rgba(5,18,30,.84);
  --tl-glass-border:rgba(255,255,255,.16);
  --tl-hair:rgba(210,235,248,.19);
  --tl-wash:rgba(232,137,119,.09);
  --tl-focus:#78c9db;
  --tl-shadow:0 26px 68px rgba(0,0,0,.32),inset 0 1px rgba(255,255,255,.07);
}

@media (prefers-reduced-transparency:reduce) {
  :root { --tl-blur:0px; }
}

@media (prefers-reduced-motion:reduce) {
  :root { scroll-behavior:auto; }
}
*{box-sizing:border-box}body{margin:0;background:var(--tl-paper-soft);color:var(--tl-ink);font-family:var(--tl-font-ui);font-size:16px;line-height:1.6}main{max-width:960px;margin:26px auto;padding:38px;background:var(--tl-paper);border-radius:var(--tl-radius-surface)}nav{display:flex;justify-content:space-between;gap:12px;margin-bottom:26px}a{color:var(--tl-seal)}h1{font-size:clamp(28px,4vw,42px);line-height:1.2}h2{font-size:25px}h3{font-size:20px}.muted{color:var(--tl-ink-soft)}.eyebrow{color:var(--tl-seal);letter-spacing:.1em;font-size:13px}button,select,.action{min-height:44px;border:1px solid var(--tl-hair);border-radius:12px;background:var(--tl-paper);color:var(--tl-ink);font:inherit;padding:8px 18px;cursor:pointer}.primary{background:var(--tl-seal);color:white}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid var(--tl-focus);outline-offset:3px}.actions{display:flex;flex-wrap:wrap;gap:12px;margin:26px 0}.jp{font-family:var(--tl-font-jp);font-size:24px;line-height:2.1;overflow-wrap:anywhere}rt{font-size:11px;line-height:1.1}fieldset{padding:0;border:0;margin:18px 0}legend{width:100%;margin-bottom:18px}.option{display:flex;gap:12px;align-items:flex-start;border-top:1px solid var(--tl-hair);padding:16px 4px;min-height:50px;cursor:pointer}.option input{width:20px;height:20px;flex-shrink:0;margin-top:15px;accent-color:var(--tl-seal)}.option .letter{font-family:var(--tl-font-ui);font-size:16px;margin-top:9px}.flow{display:flex;justify-content:center;align-items:center;flex-wrap:wrap;gap:12px;margin:16px 0;padding:16px;border-block:1px solid var(--tl-hair);font-family:var(--tl-font-jp);font-size:20px}.flow>span:not(.arrow){padding:8px}.diagram{border-collapse:collapse;margin:18px auto;width:100%;font-family:var(--tl-font-jp);font-size:20px}.diagram th,.diagram td{padding:10px;border:1px solid var(--tl-hair);text-align:center}.diagram th{background:var(--tl-wash)}progress{width:100%;height:6px;accent-color:var(--tl-seal)}.topline{display:flex;justify-content:space-between;gap:12px;font-variant-numeric:tabular-nums}.feedback{border-left:3px solid var(--tl-seal);padding:8px 18px;margin:18px 0}.feedback li{margin:12px 0}.qnav{display:grid;grid-template-columns:repeat(8,1fr);gap:6px}.qnav button{padding:4px}.qnav .answered{border:2px solid var(--tl-success)}.qnav .current{background:var(--tl-seal);color:white}dialog{max-width:700px;width:90%;max-height:90vh;overflow:auto;background:var(--tl-glass-strong);color:var(--tl-ink);border:1px solid var(--tl-hair);border-radius:22px;padding:26px}dialog::backdrop{background:#0008}label.setting{display:block;margin:18px 0}footer{margin-top:38px;border-top:1px solid var(--tl-hair);padding-top:18px;font-size:14px}.hidden,[hidden]{display:none!important}.result-row{padding:12px 0;border-bottom:1px solid var(--tl-hair)}html[data-mode=dark] body{background:#0b1c2c}html[data-furi=off] rt{visibility:hidden}.print-page{break-after:page}.print-page:last-child{break-after:auto}.print-q{margin:0 0 10mm;padding-bottom:4mm;border-bottom:1px solid #ddd}.print-q .jp{font-size:14pt;line-height:1.95}.print-q rt{font-size:8.5pt}.print-q .opt{display:flex;gap:12px;margin-top:1mm}.print-head{display:flex;justify-content:space-between;color:#666;font-size:10pt;margin-bottom:8mm;border-bottom:1px solid #aaa;padding-bottom:3mm}.print-q .diagram{font-size:12pt;margin:3mm 0}.print-q .diagram td,.print-q .diagram th{padding:2mm}.print-q .flow{font-size:12pt;margin:3mm 0;padding:2mm}.print-q .flow span{padding:1mm}.answer-grid{display:grid;grid-template-columns:repeat(8,1fr);gap:8px;margin:12mm 0}.answer-grid span{border-bottom:1px solid #bbb;padding:5px;text-align:center}.answer-entry{margin-bottom:7mm;border-bottom:1px solid #ddd;padding-bottom:3mm;font-size:10.5pt;line-height:1.55}.answer-entry h3{margin:0 0 2mm;font-size:12pt}.answer-entry p{margin:2mm 0}.answer-entry ul{margin:2mm 0;padding-left:5mm}.answer-entry li{margin:1mm 0}.source{font-size:9pt;color:#666}.print-cover{padding:15mm 0}.print-cover h1{font-size:30pt}.print-cover p,.print-cover li{font-size:12pt}.print-cover table{border-collapse:collapse;width:100%;margin:6mm 0;font-size:11pt}.print-cover td,.print-cover th{border-bottom:1px solid #bbb;text-align:left;padding:2mm}.print-cover .scope{font-family:var(--tl-font-jp);font-size:16pt}.print-body main{max-width:none;margin:0;padding:0;border:0;border-radius:0;background:#fff}.print-body{background:#fff;color:#172833}.print-body .diagram th{background:#f4f1e9}@media(max-width:600px){main{margin:0;padding:22px 18px;border-radius:0}.jp{font-size:22px}.qnav{grid-template-columns:repeat(5,1fr)}nav{align-items:center}h1{font-size:30px}.actions button{flex:1}.diagram{font-size:18px}.flow{font-size:18px}.topline{font-size:14px}}@media print{@page{size:A4;margin:14mm 15mm 16mm}body{background:white}main{margin:0;padding:0;background:white}a{color:inherit}.print-page{min-height:245mm}.print-head{break-after:avoid}.print-q,.answer-entry{break-inside:avoid}}
.print-body main{width:180mm}.print-cover{padding:2mm 0}.print-cover h1{font-size:24pt;margin:4mm 0}.print-cover h2{font-size:16pt;margin:4mm 0}.print-cover p,.print-cover li{font-size:10.5pt;margin:3mm 0}.print-cover .scope{font-size:14pt}.print-cover table{margin:4mm 0;font-size:10pt}.print-cover .answer-grid{margin:5mm 0;gap:4px;font-size:10pt}.print-cover .answer-grid span{padding:3px}.print-page{min-height:245mm}.illustration{margin:18px 0}.illustration svg{display:block;width:100%;height:auto;max-height:340px}.print-q .illustration{margin:3mm 0}.print-q .illustration svg{max-height:64mm}.print-q:has(.illustration) .jp{font-size:13.5pt}select{max-width:100%;width:100%;white-space:normal}#dialog-content label{display:block;margin:12px 0}#dialog-content input,#dialog-content select{min-height:44px;max-width:100%;font:inherit;background:var(--tl-paper);color:var(--tl-ink);border:1px solid var(--tl-hair);border-radius:12px;padding:8px}#dialog-content input{width:100%}.qnav button{min-width:0;font-size:15px}#answered-count{white-space:nowrap}@media(max-width:420px){.qnav{grid-template-columns:repeat(4,1fr)}}

.table-wrap{overflow-x:auto}.diagram td,.diagram th{overflow-wrap:anywhere}summary{min-height:44px;cursor:pointer}#title{font-size:clamp(26px,4vw,38px)}#dialog-content label{display:block;margin:12px 0}#dialog-content input{min-height:44px;max-width:100%;font:inherit}#select{width:100%;max-width:100%}


html.food-design{font-size:16px!important}html.food-design body{background:transparent;color:var(--tl-ink);font-family:var(--tl-font-ui);font-size:16px;line-height:1.65}body::before{content:"";position:fixed;inset:0;z-index:-1;background:linear-gradient(0deg,rgba(220,235,242,.35),transparent),url('/anh-art/lesson-dawn-1200.avif') center/cover no-repeat}html[data-mode=dark] body::before{background:linear-gradient(0deg,rgba(2,7,19,.45),transparent),url('/anh-art/lesson-night-900.avif') center/cover no-repeat}.food-design main{max-width:960px;margin:var(--tl-space-6) auto;padding:var(--tl-space-7);background:var(--tl-glass);border:1px solid var(--tl-glass-border);border-radius:var(--tl-radius-surface);backdrop-filter:blur(var(--tl-blur));box-shadow:var(--tl-shadow)}.food-design .food-top{max-width:1064px;margin:auto;padding:var(--tl-space-4) var(--tl-space-5);display:flex;align-items:center;justify-content:space-between;gap:var(--tl-space-3)}.food-brand{display:inline-flex;align-items:center;gap:var(--tl-space-3);text-decoration:none;font-weight:700;color:var(--tl-ink)}.food-brand span{font-family:var(--tl-font-jp);background:var(--tl-seal);color:var(--tl-paper);padding:var(--tl-space-2);border-radius:var(--tl-radius-control)}.food-design h1{font-size:var(--tl-text-title);line-height:1.15;letter-spacing:-.035em;margin:var(--tl-space-4) 0 var(--tl-space-5);overflow-wrap:anywhere}.food-design h1::after{display:none}.food-design h2{font-size:24px}.food-design .eyebrow{font:600 12px var(--tl-font-mono);letter-spacing:.14em;color:var(--tl-seal)}.food-design .intro{font-size:var(--tl-text-body-large);color:var(--tl-ink-soft);max-width:620px;margin-bottom:var(--tl-space-6)}.food-design .branches{margin-top:var(--tl-space-5)}.food-design .branch{display:block;border-top:1px solid var(--tl-hair);padding:0}.food-design .branch>summary,.food-design a.branch{display:flex;align-items:center;gap:var(--tl-space-4);padding:var(--tl-space-4) 0;min-height:80px;cursor:pointer;list-style:none;text-decoration:none;color:var(--tl-ink)}.branch summary::-webkit-details-marker{display:none}.branch .num{font:14px var(--tl-font-mono);color:var(--tl-seal);width:30px;flex-shrink:0}.branch strong{display:block;font-size:24px;line-height:1.35}.branch small{display:block;font-size:16px;color:var(--tl-ink-soft);font-weight:400}.branch .arrow{margin-left:auto;font-size:26px;color:var(--tl-seal)}.branch[open]>summary .arrow{transform:rotate(90deg)}.branch-content{padding:var(--tl-space-2) 0 var(--tl-space-5) var(--tl-space-7)}.food-design a,.food-design button,.food-design summary,.food-design select{min-height:44px}.food-design main a,.food-design dialog a{display:inline-flex;align-items:center;padding:var(--tl-space-2) 0}.food-design .lesson-link,.food-design .exam-link{display:flex;padding:var(--tl-space-3) 0;border-top:1px solid var(--tl-hair);text-decoration:none;gap:var(--tl-space-3);font-size:18px}.food-design .lesson-link span{font:14px var(--tl-font-mono);color:var(--tl-ink-soft)}.food-design .primary{background:var(--tl-seal);color:var(--tl-paper);font-weight:600;min-height:50px}.food-design :focus-visible{outline:3px solid var(--tl-focus);outline-offset:4px}.food-design dialog{background:var(--tl-glass-strong);backdrop-filter:blur(var(--tl-blur));max-height:85dvh;max-width:800px;padding:var(--tl-space-5)}.food-design select{max-width:100%;width:100%;margin-top:var(--tl-space-2)}.food-design #title{font-size:clamp(28px,3vw,38px)}.food-design .qnav{grid-template-columns:repeat(auto-fit,minmax(44px,1fr))}.food-design .option{background:transparent;border-radius:0;align-items:center}.food-design .option input{margin-top:0}.food-design .option .jp{font-size:var(--tl-text-jp)}.food-design .actions{gap:var(--tl-space-3)}.food-design .diagram{table-layout:fixed;overflow-wrap:anywhere}.food-design #th-fab{position:relative!important;inset:auto!important;transform:none!important;width:50px!important;height:50px!important;box-shadow:none!important;background:var(--tl-glass-strong)!important;color:var(--tl-ink)!important;border:1px solid var(--tl-hair)!important;flex-shrink:0}.food-design #th-fab.open{position:fixed!important;right:18px!important;top:18px!important}.food-design #th-fab span,.food-design #th-fab span::before,.food-design #th-fab span::after{background:var(--tl-ink)!important}.food-design #th-tien{display:none}.food-design .food-back{font-size:16px;min-height:44px;display:inline-flex;align-items:center}.food-design footer{font-size:16px;color:var(--tl-ink-soft)}.food-design .jp{font-family:var(--tl-font-jp)}.food-design #body>p.jp{margin-top:var(--tl-space-5)}.food-design .doc-row{border-top:1px solid var(--tl-hair);padding:var(--tl-space-3) 0}.doc-row strong{font-size:18px}.doc-row a{margin-right:var(--tl-space-4)}.food-design #th-drawer a{min-height:44px}.food-design .setting{min-height:44px;display:flex;align-items:center;gap:12px}html[data-furi=off] rt{visibility:hidden}
@media(max-width:1000px){.food-design main{margin:var(--tl-space-4) var(--tl-space-4);padding:var(--tl-space-6)}}
@media(max-width:600px){.food-design .food-top{padding:var(--tl-space-3) var(--tl-space-4)}.food-design main{padding:var(--tl-space-5) var(--tl-space-4);margin:var(--tl-space-2) var(--tl-space-3) var(--tl-space-5);border-radius:var(--tl-radius-panel)}.food-design h1{font-size:38px}.food-design .intro{font-size:16px;margin-bottom:var(--tl-space-5)}.branch strong{font-size:22px}.branch small{font-size:16px}.food-design .branch>summary,.food-design a.branch{gap:var(--tl-space-3);min-height:80px}.branch-content{padding-left:0}.food-design .jp,.food-design .option .jp{font-size:22px}.food-design .actions button{flex:1 1 130px}.food-design .diagram{font-size:16px}.food-design .diagram td,.food-design .diagram th{padding:var(--tl-space-2)}.food-design .topline{font-size:16px;flex-wrap:wrap}.food-design dialog{width:calc(100% - 24px);padding:var(--tl-space-4)}}
@media(prefers-reduced-transparency:reduce){.food-design main{background:var(--tl-glass-strong);backdrop-filter:none}}@media(prefers-reduced-motion:reduce){.food-design *{scroll-behavior:auto!important;transition:none!important}}