:root{--accent: #2b5bd7;--accent-dark: #1f46a8;--ok: #1a8f4b;--ok-bg: #e7f6ec;--bad: #c62828;--bad-bg: #fdecec;--warn: #9a6700;--warn-bg: #fff6d6;--ink: #1b1f24;--muted: #5b6470;--line: #d9dee5;--bg: #f5f7fa;--card: #ffffff;--radius: 12px;--focus: 0 0 0 3px rgba(43, 91, 215, .35);color-scheme:light}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:17px;line-height:1.45;padding-top:env(safe-area-inset-top,0px);padding-bottom:env(safe-area-inset-bottom,0px)}a{color:var(--accent)}h1,h2,h3{line-height:1.2;margin:1.2em 0 .5em}h2{font-size:1.25rem}h3{font-size:1.05rem}.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 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0}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 18px;border-radius:10px;border:1px solid transparent;font:inherit;font-weight:600;cursor:pointer;text-decoration:none;transition:background .12s,transform .05s}.btn:active{transform:translateY(1px)}.btn:focus-visible,.input:focus-visible,.option:focus-visible,a:focus-visible,summary:focus-visible{outline:none;box-shadow:var(--focus)}.btn:disabled{opacity:.55;cursor:not-allowed;transform:none}.btn--primary{background:var(--accent);color:#fff}.btn--primary:not(:disabled):hover{background:var(--accent-dark)}.btn--ghost{background:var(--card);color:var(--accent);border-color:var(--line)}.btn--danger{background:var(--bad);color:#fff}.btn--sm{min-height:36px;padding:6px 12px;font-size:.9rem}.btn--xl{min-height:56px;font-size:1.15rem}.btn--block{display:flex;width:100%;margin:10px 0}.form{display:flex;flex-direction:column;gap:6px}.label{font-weight:600;margin-top:10px}.input{width:100%;min-height:44px;padding:10px 12px;border:1px solid var(--line);border-radius:10px;background:var(--card);font:inherit;color:var(--ink)}.input--lg{min-height:52px;font-size:1.1rem}.input--code{min-height:60px;font-size:2rem;letter-spacing:.15em;text-align:center;font-variant-numeric:tabular-nums}.input--num{width:120px;margin-left:32px}.fieldset{border:1px solid var(--line);border-radius:10px;padding:8px 12px 12px;margin:10px 0 0;display:flex;flex-direction:column;gap:6px}.radio{display:flex;align-items:center;gap:10px;min-height:40px}.radio input{width:22px;height:22px}.notice{padding:10px 12px;border-radius:10px;margin:10px 0;border:1px solid transparent}.notice--ok{background:var(--ok-bg);color:var(--ok);border-color:#bfe6cc}.notice--bad{background:var(--bad-bg);color:var(--bad);border-color:#f3c1c1}.notice--warn{background:var(--warn-bg);color:var(--warn);border-color:#f0dc9a}.hero{text-align:center;padding:28px 0 8px}.hero__title{font-size:2.8rem;font-weight:900;letter-spacing:.12em;color:var(--accent)}.hero__level{font-size:1.1rem;color:var(--muted);margin-bottom:8px}.hero__sub{color:var(--muted);margin:4px 0 20px}.topics{list-style:none;padding:0;margin:0;counter-reset:topic}.topic{counter-increment:topic;display:grid;grid-template-columns:28px 1fr auto;grid-template-areas:"n title count" "n sub count";align-items:center;gap:0 10px;background:var(--card);border:1px solid var(--line);border-radius:10px;padding:10px 12px;margin-bottom:8px}.topic:before{content:counter(topic);grid-area:n;font-weight:800;color:var(--accent)}.topic__title{grid-area:title;font-weight:700}.topic__sub{grid-area:sub;font-size:.9rem}.topic__count{grid-area:count;color:var(--muted);font-size:.9rem;white-space:nowrap}.best{margin-top:20px;padding:14px;background:var(--card);border:1px dashed var(--line);border-radius:10px;text-align:center}.best__value{font-size:1.3rem;font-weight:700}.best__at{font-size:.85rem;font-weight:400}.foot{margin-top:32px;text-align:center}.foot__link{font-size:.85rem;color:var(--muted)}.quiz__top{position:sticky;top:0;background:var(--bg);padding:8px 0 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var(--line);vertical-align:middle;white-space:nowrap}th{font-size:.8rem;text-transform:uppercase;letter-spacing:.04em;color:var(--muted);background:#f9fafc}tr:last-child td{border-bottom:0}.sections td:first-child{white-space:normal}.board__name{font-weight:700;white-space:normal;min-width:140px}.board__answered{min-width:140px}.board__answered .progress{height:6px;margin-top:4px}.board__row--kicked{opacity:.5}.board__actions{text-align:right}.board__empty{padding:16px;text-align:center}.badge{display:inline-block;padding:2px 10px;border-radius:999px;font-size:.8rem;font-weight:700}.badge--ok{background:var(--ok-bg);color:var(--ok)}.badge--info{background:#e8eefc;color:var(--accent)}.badge--warn{background:var(--warn-bg);color:var(--warn)}.badge--muted{background:#eceff3;color:var(--muted)}.lobby__wait{display:flex;justify-content:center;gap:10px;margin:18px 0}.dot{width:14px;height:14px;border-radius:50%;background:var(--accent);animation:bounce 1.2s infinite ease-in-out}.dot:nth-child(2){animation-delay:.2s}.dot:nth-child(3){animation-delay:.4s}@keyframes bounce{0%,80%,to{transform:scale(.6);opacity:.5}40%{transform:scale(1);opacity:1}}@media(prefers-reduced-motion:reduce){.dot{animation:none}}.lobby__name{font-size:1.6rem;font-weight:800}.lobby__title{font-weight:600;margin:4px 0}.lobby__timer{margin-top:8px;font-weight:600}.play__bar{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:6px 0;border-bottom:1px solid var(--line);margin-bottom:6px}.play__name{font-weight:700}.countdown{display:inline-flex;align-items:center;gap:6px;font-variant-numeric:tabular-nums;font-weight:800;font-size:1.2rem;padding:4px 10px;border-radius:8px;background:#e8eefc;color:var(--accent)}.countdown--warn{background:var(--bad-bg);color:var(--bad)}.teacher__head{display:flex;justify-content:space-between;align-items:flex-start;gap:12px;flex-wrap:wrap}.teacher__nav{display:flex;gap:14px;align-items:center;padding-top:8px}.joinbox{display:flex;gap:20px;align-items:center;justify-content:space-between;flex-wrap:wrap}.joinbox__code{font-size:clamp(2.4rem,9vw,4rem);font-weight:900;letter-spacing:.08em;font-variant-numeric:tabular-nums;line-height:1.1;color:var(--accent)}.joinbox__url{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.9rem;word-break:break-all;color:var(--muted)}.joinbox__qr{width:220px;height:220px;max-width:100%;background:#fff;border-radius:8px;border:1px solid var(--line)}.controls{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap}.controls__info{display:flex;align-items:center;gap:6px;flex-wrap:wrap;font-size:1.05rem}