:root{--bg: #0B0713;--bg-panel: #141021;--bg-elevated: #1C1731;--bg-veil: rgba(7, 3, 14, .72);--gold: #C9A24B;--gold-bright: #F2D888;--gold-deep: #8C6A2A;--gold-grad: linear-gradient(160deg, #F2D888 0%, #C9A24B 46%, #8C6A2A 100%);--gold-sheen: linear-gradient(105deg, transparent 40%, rgba(242,216,136,.55) 50%, transparent 60%);--ink: #F4ECD8;--ink-dim: #B7AC90;--ink-faint: rgba(244, 236, 216, .52);--on-gold: #1A1206;--line: rgba(201, 162, 75, .3);--line-strong: rgba(201, 162, 75, .58);--correct: #74C69B;--correct-bg: rgba(116, 198, 155, .14);--wrong: #D98A82;--wrong-bg: rgba(217, 138, 130, .14);--self: var(--gold-bright);--medal-1: #F2D888;--medal-2: #CBD1DA;--medal-3: #C8894F;--font-display: "Noto Serif TC", "Songti TC", "PMingLiU", Georgia, "Times New Roman", serif;--font-body: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;--radius: 14px;--radius-sm: 9px;--shadow: 0 8px 30px rgba(0, 0, 0, .45);--glow-gold: 0 0 18px rgba(242, 216, 136, .28)}.brand-surface{background:radial-gradient(120% 90% at 50% -10%,rgba(201,162,75,.1),transparent 55%),var(--bg);color:var(--ink);font-family:var(--font-body)}.brand-display{font-family:var(--font-display);color:var(--gold-bright);letter-spacing:.02em}.brand-frame{border:1px solid var(--line-strong);border-radius:var(--radius);background:var(--bg-panel)}.brand-btn{font-family:var(--font-body);font-weight:600;color:var(--on-gold);background:var(--gold-grad);border:none;border-radius:var(--radius-sm);padding:12px 22px;min-height:44px;cursor:pointer;box-shadow:var(--glow-gold)}.brand-btn:disabled{filter:grayscale(.5) brightness(.7);cursor:not-allowed;box-shadow:none}.brand-btn--ghost{color:var(--gold-bright);background:transparent;border:1px solid var(--line-strong);box-shadow:none}.brand-star:before{content:"✦";color:var(--gold);opacity:.7}*{box-sizing:border-box}html,body{margin:0;padding:0;width:100%;height:100%;background:var(--bg);font-family:var(--font-body);overflow:hidden}#app{position:relative;width:100vw;height:100vh;color:var(--ink)}.app-veil{position:fixed;top:0;right:0;bottom:0;left:0;z-index:200;display:flex;align-items:center;justify-content:center;background:var(--bg-veil);-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);padding:16px}#stage{position:absolute;top:0;right:0;bottom:0;left:0;background:var(--bg);overflow:hidden}#slide-host{position:absolute;width:960px;height:540px;box-shadow:var(--shadow)}#loading-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:300;display:flex;align-items:center;justify-content:center;background:var(--bg);color:var(--ink-dim);font-family:var(--font-display);font-size:18px;letter-spacing:.05em}#loading-overlay[hidden]{display:none}#join-screen{position:fixed;top:0;right:0;bottom:0;left:0;z-index:250;display:flex;align-items:center;justify-content:center;padding:16px}.join-card{width:min(420px,100%);padding:32px 28px;display:flex;flex-direction:column;align-items:center;text-align:center;gap:12px;box-shadow:var(--shadow)}.join-badge{font-size:20px;margin-bottom:-4px}.join-logo{width:96px;height:96px;object-fit:contain;margin-bottom:4px;filter:drop-shadow(var(--glow-gold))}.join-title{font-size:26px;margin:0}.join-sub{margin:0 0 8px;color:var(--ink-dim);font-size:14px;line-height:1.6}.join-input{width:100%;min-height:48px;padding:12px 16px;font-size:18px;color:var(--ink);background:var(--bg);border:1px solid var(--line-strong);border-radius:var(--radius-sm);text-align:center}.join-input:focus{outline:none;border-color:var(--gold-bright);box-shadow:var(--glow-gold)}.join-error{margin:0;color:var(--wrong);font-size:13px}.join-error[hidden]{display:none}.join-submit{width:100%;font-size:18px;margin-top:4px}#instructor-topbar{position:fixed;top:12px;left:50%;transform:translate(-50%);z-index:50;display:flex;align-items:center;gap:14px;padding:8px 18px;max-width:calc(100vw - 24px);overflow-x:auto;white-space:nowrap;font-size:14px;color:var(--ink)}.dash-conn,.hud-conn{font-size:12px;color:var(--wrong);transition:color .2s ease}.dash-conn[data-state=connected],.hud-conn[data-state=connected]{color:var(--correct)}.dash-slide-counter{font-variant-numeric:tabular-nums;color:var(--gold-bright);font-weight:600}.dash-question{color:var(--ink-dim);max-width:36ch;overflow:hidden;text-overflow:ellipsis}.dash-question[hidden],.dash-counts[hidden],.dash-timer[hidden]{display:none}.dash-counts{font-variant-numeric:tabular-nums}.dash-timer{color:var(--gold-bright);font-variant-numeric:tabular-nums}#instructor-controls{position:fixed;left:50%;bottom:16px;transform:translate(-50%);z-index:50;display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:10px;padding:10px 16px;max-width:calc(100vw - 24px)}.dash-sep{width:1px;align-self:stretch;background:var(--line-strong)}.dash-btn{font-size:14px;padding:10px 16px;white-space:nowrap}body[data-role=student] #instructor-topbar,body[data-role=student] #instructor-controls{display:none}#student-hud{position:fixed;top:10px;right:10px;z-index:50;display:flex;align-items:center;gap:10px;padding:8px 14px;font-size:14px}.hud-timer{color:var(--gold-bright);font-variant-numeric:tabular-nums}.hud-timer[hidden]{display:none}.hud-total{font-weight:700;color:var(--gold-bright);font-variant-numeric:tabular-nums}body[data-role=instructor] #student-hud{display:none}#question-toast{position:fixed;top:68px;left:50%;transform:translate(-50%);z-index:60;min-width:260px;max-width:min(360px,calc(100vw - 32px));padding:16px 20px;background:var(--bg-elevated);border:1px solid var(--line-strong);border-radius:var(--radius);box-shadow:var(--shadow)}#question-toast[hidden]{display:none}.lb-toast-title{font-family:var(--font-display);font-size:14px;color:var(--gold-bright);margin-bottom:8px;letter-spacing:.05em;text-align:center}.lb-list{margin:0;padding:0;list-style:none;display:flex;flex-direction:column;gap:6px}.lb-row{display:flex;align-items:center;gap:8px;font-size:15px;padding:4px 8px;border-radius:var(--radius-sm)}.lb-rank{min-width:2em;font-weight:700;text-align:center}.lb-name{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lb-pts{color:var(--correct);font-variant-numeric:tabular-nums}.lb-row--self{background:#f2d8881f;border:1px solid var(--line-strong)}.lb-row--self .lb-name{color:var(--self);font-weight:700}.lb-row--self-detached{margin-top:4px;border-top:1px dashed var(--line);padding-top:8px}.lb-row--muted{color:var(--ink-faint);font-size:13px;justify-content:center}.lb-panel{width:min(480px,100%);max-height:min(80vh,640px);overflow-y:auto;padding:28px 24px;display:flex;flex-direction:column;align-items:center;gap:12px;text-align:center;box-shadow:var(--shadow)}.lb-panel-title{font-size:22px}.lb-panel-sub{margin:0 0 8px;color:var(--ink-dim);font-size:13px}.lb-list--panel{width:100%;max-height:50vh;overflow-y:auto}.lb-panel-close{margin-top:8px}@media (orientation: portrait) and (max-width: 768px){#app:after{content:"提示：橫放體驗更完整";position:fixed;right:8px;bottom:8px;z-index:40;padding:4px 10px;font-size:12px;color:var(--ink-dim);background:var(--bg-elevated);border:1px solid var(--line);border-radius:999px;pointer-events:none}#instructor-topbar{top:6px;font-size:12px;gap:8px}#instructor-controls{bottom:8px}.dash-btn{padding:8px 12px;font-size:13px}.dash-question{max-width:20ch}#student-hud{top:6px;right:6px;font-size:12px;padding:6px 10px}}@media (orientation: landscape) and (max-height: 500px){#app:after{content:none}}.interaction-buzzer,.interaction-multichoice,.interaction-truefalse,.interaction-opentext{display:flex;flex-direction:column;height:100%;color:var(--ink);font-family:var(--font-body)}.interaction-buzzer{align-items:center;justify-content:center;gap:20px;text-align:center}.interaction-multichoice,.interaction-truefalse,.interaction-opentext{gap:16px;padding:8px 4px}.mc-question,.tf-question,.ot-question,.buzzer-question{margin:0;font-size:22px;line-height:1.5;font-family:var(--font-display);color:var(--ink)}.interaction-buzzer .buzzer-question{max-width:90%}.mc-status,.tf-status,.ot-status,.buzzer-status{min-height:1.4em;margin:0;font-size:15px;color:var(--gold-bright)}.mc-result,.tf-result,.ot-result{font-size:18px;font-weight:600;padding:10px 14px;border-radius:var(--radius-sm);background:var(--bg-elevated);border:1px solid var(--line)}.mc-result[hidden],.tf-result[hidden],.ot-result[hidden]{display:none}.interaction-buzzer .buzzer-buzz-btn{min-width:180px;min-height:64px;padding:12px 32px;font-size:24px;font-weight:700;font-family:var(--font-body);color:var(--on-gold);background:var(--gold-grad);border:none;border-radius:999px;cursor:pointer;box-shadow:var(--glow-gold)}.interaction-buzzer .buzzer-buzz-btn:active{transform:translateY(2px)}.interaction-buzzer .buzzer-buzz-btn:disabled{cursor:not-allowed;filter:grayscale(.5) brightness(.7);box-shadow:none}.interaction-buzzer .buzzer-options{display:flex;flex-wrap:wrap;gap:12px;justify-content:center}.interaction-buzzer .buzzer-options[hidden]{display:none}.interaction-buzzer .buzzer-option-btn{min-width:120px;min-height:48px;padding:10px 20px;font-size:18px;color:var(--ink);background:var(--bg-panel);border:2px solid var(--line-strong);border-radius:var(--radius-sm);cursor:pointer}.interaction-buzzer .buzzer-option-btn.is-selected{border-color:var(--gold-bright);background:#f2d88824}.interaction-buzzer .buzzer-option-btn:disabled{cursor:not-allowed;opacity:.7}.mc-options{display:flex;flex-direction:column;gap:10px}.mc-option-btn{min-height:48px;padding:10px 18px;font-size:17px;text-align:left;color:var(--ink);background:var(--bg-panel);border:2px solid var(--line-strong);border-radius:var(--radius-sm);cursor:pointer}.mc-option-btn.is-selected{border-color:var(--gold-bright);background:#f2d88824}.mc-option-btn:disabled{cursor:not-allowed;opacity:.7}.mc-submit-btn{align-self:flex-start;min-width:120px;min-height:48px;padding:10px 24px;font-size:17px;font-weight:600;color:var(--on-gold);background:var(--gold-grad);border:none;border-radius:var(--radius-sm);cursor:pointer;box-shadow:var(--glow-gold)}.mc-submit-btn:disabled{cursor:not-allowed;filter:grayscale(.5) brightness(.7);box-shadow:none}.mc-distribution{display:flex;flex-direction:column;gap:10px}.mc-distribution-empty{color:var(--ink-faint);font-size:14px;margin:0}.mc-distribution-empty[hidden]{display:none}.mc-bar-row{display:grid;grid-template-columns:minmax(8em,1fr) 3fr auto;align-items:center;gap:10px;font-size:14px}.mc-bar-label{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.mc-bar-track{height:16px;background:var(--bg-panel);border:1px solid var(--line);border-radius:999px;overflow:hidden}.mc-bar-fill{height:100%;background:var(--gold-grad);transition:width .3s ease}.mc-bar-count{min-width:2em;text-align:right;font-variant-numeric:tabular-nums;color:var(--ink-dim)}.tf-options{display:flex;gap:16px}.tf-true-btn,.tf-false-btn{flex:1;min-height:64px;font-size:22px;font-weight:700;color:var(--ink);background:var(--bg-panel);border:2px solid var(--line-strong);border-radius:var(--radius);cursor:pointer}.tf-true-btn.is-selected{border-color:var(--correct);background:var(--correct-bg);color:var(--correct)}.tf-false-btn.is-selected{border-color:var(--wrong);background:var(--wrong-bg);color:var(--wrong)}.tf-true-btn:disabled,.tf-false-btn:disabled{cursor:not-allowed;opacity:.7}.tf-roster{display:grid;grid-template-columns:1fr 1fr;gap:16px}.tf-roster-empty{grid-column:1 / -1;color:var(--ink-faint);font-size:14px;margin:0}.tf-roster-empty[hidden]{display:none}.tf-roster-correct ul,.tf-roster-incorrect ul{list-style:none;margin:4px 0 0;padding:0;display:flex;flex-direction:column;gap:4px;max-height:160px;overflow-y:auto}.tf-roster-correct li,.tf-roster-incorrect li{padding:4px 8px;border-radius:var(--radius-sm);font-size:14px}.tf-roster-correct li{background:var(--correct-bg)}.tf-roster-incorrect li{background:var(--wrong-bg)}.ot-input{min-height:48px;padding:10px 16px;font-size:17px;color:var(--ink);background:var(--bg-panel);border:1px solid var(--line-strong);border-radius:var(--radius-sm)}.ot-input:focus{outline:none;border-color:var(--gold-bright);box-shadow:var(--glow-gold)}.ot-input:disabled{opacity:.6}.ot-submit-btn{align-self:flex-start;min-width:120px;min-height:48px;padding:10px 24px;font-size:17px;font-weight:600;color:var(--on-gold);background:var(--gold-grad);border:none;border-radius:var(--radius-sm);cursor:pointer;box-shadow:var(--glow-gold)}.ot-submit-btn:disabled{cursor:not-allowed;filter:grayscale(.5) brightness(.7);box-shadow:none}.ot-wordcloud{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:10px 16px;padding:8px;min-height:120px}.ot-wordcloud-empty{color:var(--ink-faint);font-size:14px;width:100%;text-align:center}.ot-wordcloud-empty[hidden]{display:none}.ot-word{font-family:var(--font-display);line-height:1.1}