:root{color:#15212f;background:#edf1f5;font-family:Microsoft YaHei,PingFang SC,system-ui,-apple-system,BlinkMacSystemFont,sans-serif;font-synthesis:none;text-rendering:optimizeLegibility}*{box-sizing:border-box}body{margin:0;min-width:320px;min-height:100vh}button{font:inherit}.app-shell{width:min(1180px,calc(100vw - 32px));margin:0 auto;padding:28px 0 40px}.topbar{display:flex;align-items:flex-end;justify-content:space-between;gap:20px;margin-bottom:18px}.eyebrow{margin:0 0 4px;color:#536273;font-size:14px}h1,h2,h3,p{margin-top:0}h1{margin-bottom:0;font-size:clamp(28px,4vw,42px);line-height:1.1}.stats{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}.stats span,.question-meta span{border:1px solid #cbd5df;border-radius:999px;background:#fff;color:#354456;padding:7px 12px;font-size:14px}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:18px}.segmented,.actions{display:flex;gap:8px;flex-wrap:wrap}.segmented button,.ghost,.primary,.secondary{min-height:42px;border:1px solid #c6d0dc;border-radius:8px;background:#fff;color:#223044;padding:9px 14px;cursor:pointer}.segmented button{display:inline-flex;align-items:center;gap:8px}.segmented small{color:#69798a}.segmented .active,.ghost.active{border-color:#2563eb;background:#2563eb;color:#fff}.segmented .active small{color:#dbe7ff}.quiz-layout{display:grid;grid-template-columns:minmax(0,1fr) 280px;gap:18px;align-items:start}.question-panel,.side-panel,.empty-state{border:1px solid #d5dee8;border-radius:8px;background:#fff;box-shadow:0 12px 30px #18273a14}.question-panel{padding:22px}.type-banner{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:14px;border:1px solid;border-radius:8px;padding:12px 14px}.type-banner strong{flex:0 0 auto;border-radius:999px;color:#fff;padding:7px 14px;font-size:18px;line-height:1}.type-banner span{color:#344457;line-height:1.5;text-align:right}.type-banner.single{border-color:#9ec5fe;background:#f0f6ff}.type-banner.single strong{background:#2563eb}.type-banner.multi{border-color:#f3c07a;background:#fff7ed}.type-banner.multi strong{background:#c76a12}.type-banner.judge{border-color:#8fd4ae;background:#effaf4}.type-banner.judge strong{background:#168346}.question-meta{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}.question-panel h2{margin-bottom:18px;font-size:24px;line-height:1.45}.question-image{margin:0 0 18px;border:1px solid #dde5ee;border-radius:8px;overflow:hidden;background:#f8fafc}.question-image img{display:block;max-width:100%;max-height:520px;margin:0 auto;object-fit:contain}.image-fallback{margin-bottom:18px;border:1px solid #f0aaaa;border-radius:8px;background:#fff5f5;color:#8b1d1d;padding:14px;line-height:1.6}.image-fallback span{display:block;color:#9f6b6b;font-size:13px;word-break:break-all}.options{display:grid;gap:10px}.option-button{display:grid;grid-template-columns:44px minmax(0,1fr);gap:10px;align-items:center;width:100%;min-height:56px;border:1px solid #cbd6e2;border-radius:8px;background:#fbfdff;color:#1f2d3d;padding:10px 14px;text-align:left;cursor:pointer}.option-button strong{display:grid;place-items:center;width:34px;height:34px;border-radius:50%;background:#e8eef5}.option-button:hover,.option-button.picked{border-color:#2563eb;background:#eef5ff}.option-button.correct{border-color:#16a34a;background:#eefaf1}.option-button.correct strong{background:#16a34a;color:#fff}.option-button.wrong{border-color:#dc2626;background:#fff1f1}.option-button.wrong strong{background:#dc2626;color:#fff}.side-panel{position:sticky;top:18px;padding:18px}.answer-box h3{margin-bottom:8px;font-size:20px}.answer-box p{color:#526276;line-height:1.6}.primary,.secondary{width:100%;margin-top:10px}.primary{border-color:#2563eb;background:#2563eb;color:#fff}.primary:disabled{cursor:not-allowed;opacity:.5}.secondary{background:#f8fafc}.feedback{margin-top:14px;border-radius:8px;padding:13px;line-height:1.55}.feedback strong,.feedback span{display:block}.feedback.ok{border:1px solid #93d4a5;background:#f0fbf3}.feedback.bad{border:1px solid #f0aaaa;background:#fff5f5}.empty-state{padding:36px;text-align:center}.empty-state h2{margin-bottom:8px}.empty-state p{color:#536273}@media(max-width:860px){.topbar,.toolbar{align-items:stretch;flex-direction:column}.stats{justify-content:flex-start}.quiz-layout{grid-template-columns:1fr}.side-panel{position:static}.type-banner{align-items:flex-start;flex-direction:column}.type-banner span{text-align:left}}