:root{font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;color:#172938;background:#f5f7f9;font-synthesis:none;line-height:1.6;--accent:#126c61;--line:#dce4e9;--muted:#647483}
*{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:100px}
body{margin:0}
button,a,input{touch-action:manipulation}
button,input{font:inherit}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #57a6ef;outline-offset:3px}
button{cursor:pointer}
[hidden]{display:none!important}
.site-header{background:#fff;border-bottom:1px solid var(--line)}
.header-inner,main{max-width:1280px;margin:0 auto;padding:0 32px}
.header-inner{min-height:76px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{display:flex;gap:13px;align-items:center;color:#263f4b;font-weight:650;font-size:15px}
.brand:hover{text-decoration:none}
.brand-mark{display:inline-flex;align-items:center;justify-content:center;width:49px;height:38px;border-radius:10px;background:#183a43;color:#fff;font-weight:800;letter-spacing:-1px;font-size:17px}
.dataset-link{font-size:14px;font-weight:650;white-space:nowrap}
.hero{padding:50px 0 25px}
.eyebrow{margin:0 0 10px;color:var(--accent);font-size:13px;font-weight:700;letter-spacing:.15em}
h1{font-size:clamp(29px,4vw,43px);letter-spacing:-.045em;line-height:1.25;margin:0 0 16px;font-weight:750}
.intro{margin:0;color:var(--muted);font-size:16px}
.stats{display:flex;margin:30px 0 25px;gap:0;flex-wrap:wrap}
.stats>div{padding:0 34px;border-right:1px solid #d0dce3;display:flex;align-items:baseline;gap:9px}
.stats>div:first-child{padding-left:0}
.stats>div:last-child{border-right:0}
.stats strong{font-size:34px;line-height:1.15;letter-spacing:-.055em;font-variant-numeric:tabular-nums}
.stats span{font-size:13px;color:var(--muted)}
.scope-note{display:flex;align-items:flex-start;gap:9px;font-size:13px;color:#657584;margin:0;max-width:860px}
.note-dot{margin-top:8px;width:6px;height:6px;background:#72938b;border-radius:50%;flex-shrink:0}
.task-nav{display:flex;gap:8px;flex-wrap:wrap;padding:8px 0 26px}
.task-nav a{border:1px solid #d6e1e5;border-radius:100px;padding:7px 17px;color:#435965;font-size:14px;background:#fff}
.task-nav a:hover{background:#eaf3ef;border-color:#a9c9bf;text-decoration:none}
.catalog-status{display:flex;align-items:center;justify-content:center;gap:12px;flex-wrap:wrap;min-height:180px;border:1px solid var(--line);border-radius:18px;background:#fff;color:var(--muted);padding:30px;text-align:center}
.catalog-status p{margin:0}
.catalog-status.is-error{color:#854e26;background:#fffaf5}
.task-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}
.task-card{background:#fff;border:1px solid var(--line);border-radius:18px;overflow:hidden;box-shadow:0 3px 15px #243c5010;scroll-margin-top:22px}
.card-heading{padding:24px 24px 18px}
.card-title-line{display:flex;align-items:center;gap:10px;margin-bottom:7px}
.task-number{font-size:12px;letter-spacing:.05em;font-weight:650;color:#90a1ac}
h2{margin:0;font-size:24px;letter-spacing:-.025em;line-height:1.4}
.description{font-size:14px;color:#647482;margin:0;min-height:45px}
.count-row{display:flex;gap:7px;flex-wrap:wrap;margin-top:13px}
.count-chip{font-size:12px;border-radius:6px;padding:3px 8px;background:#eef3f6;color:#466171;font-variant-numeric:tabular-nums}
.task-detail{margin:11px 0 0;font-size:12px;line-height:1.6;color:#5a746e}
.expert-badge{font-size:11px;font-weight:650;color:#176653;background:#e8f4ee;border-radius:5px;padding:2px 7px;margin-left:2px}
.source-comparison{margin:0 24px 20px;border-top:1px solid var(--line);padding-top:12px;color:#687b86;font-size:12px}
.source-comparison summary{cursor:pointer;width:fit-content;line-height:1.8}
.source-comparison summary:focus-visible{outline:3px solid #57a6ef;outline-offset:3px}
.comparison-body{padding:6px 0 0}
.comparison-body p{margin:0 0 8px}
.comparison-links{display:flex;gap:12px;flex-wrap:wrap}
.candidate-note{color:#906626;background:#fff6e7;border:1px solid #f1deb8;border-radius:7px;padding:7px 10px;margin:11px 0 0;font-size:12px}
.sample-picker{display:flex;gap:7px;flex-wrap:wrap;padding:0 24px 16px;min-height:52px;align-content:flex-start}
.choice-button{border:1px solid #d9e2e7;background:#fff;color:#61717c;border-radius:7px;min-height:34px;padding:6px 10px;font-size:12px;line-height:1.5;transition:background .12s,border-color .12s,color .12s}
.choice-button:hover{border-color:#8cb1a9;background:#f0f7f4}
.choice-button[aria-pressed="true"]{color:#0a655a;background:#e8f4ee;border-color:#90c0ae;font-weight:650}
.video-panel{position:relative;background:#12242f;aspect-ratio:4/3;overflow:hidden}
video{display:block;width:100%;height:100%;object-fit:contain;background:#12242f}
.media-state{position:absolute;inset:0 0 48px;display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;gap:12px;padding:25px;color:#d9e6eb;pointer-events:none;background:linear-gradient(#12242fb8,#12242f90)}
.media-state p{font-size:13px;max-width:340px;margin:0}
.media-state.is-error{background:#14242fed;color:#f6dfce}
.spinner{width:20px;height:20px;border:2px solid #acbfcb50;border-top-color:#75a998;border-radius:50%;animation:spin .85s linear infinite;flex-shrink:0}
@keyframes spin{to{transform:rotate(360deg)}}
.player-controls{padding:14px 24px 18px}
.camera-row{display:flex;gap:6px;flex-wrap:wrap;align-items:center}
.camera-label{font-size:12px;color:#8c9aa5;margin-right:3px}
.camera-row .choice-button{min-height:31px;padding:4px 10px}
.sample-meta{display:flex;align-items:center;gap:7px;flex-wrap:wrap;font-size:12px;color:#7a8994;margin-top:12px;min-height:22px}
.sample-meta .review-badge{padding:1px 6px;background:#eef3f6;border-radius:4px;color:#5f7683}
.sample-meta .review-badge.warning{background:#fff2d9;color:#946121}
.playback-row{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:12px;flex-wrap:wrap}
.playback-options{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.loop-label{display:flex;align-items:center;gap:5px;font-size:12px;color:#657784;cursor:pointer}
.loop-label input{accent-color:var(--accent);width:15px;height:15px;margin:0}
.source-actions{display:flex;gap:10px;align-items:center;font-size:12px}
.button{border:1px solid #cbd8de;background:#fff;color:#47636e;border-radius:7px;padding:7px 12px;font-size:13px}
.button.primary{background:var(--accent);color:#fff;border-color:var(--accent)}
.retry-video{padding:4px 8px;font-size:12px}
.page-footer{padding:34px 0 38px;color:#87959f;font-size:12px}
.page-footer p{margin:0 0 6px}
.version-note{font-size:11px}
@media(max-width:760px){.header-inner,main{padding-left:18px;padding-right:18px}.header-inner{min-height:65px}.hero{padding-top:34px}.task-grid{grid-template-columns:1fr;gap:20px}.stats>div{padding:0 16px;gap:5px;flex-direction:column}.stats strong{font-size:30px}.stats span{font-size:11px}.card-heading{padding:20px 19px 15px}.sample-picker{padding-left:19px;padding-right:19px;min-height:auto}.player-controls{padding:13px 19px 18px}.description{min-height:0}.task-nav{gap:6px}.task-nav a{padding:6px 13px;font-size:13px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.spinner{animation:none}}