.video-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 28px; margin-top: 34px; }
.video-card { overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.video-card-cover { display:block; position:relative; aspect-ratio: 4/3; background:#000; }
.video-card-cover img { width:100%;height:100%;object-fit:cover; }
.video-play { position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);display:grid;place-items:center;width:58px;height:58px;border:1px solid var(--gold-2);border-radius:50%;background:rgba(0,0,0,.7);color:var(--gold-2); }
.video-card > div { padding:26px; }
.video-card h2 { font-size:23px;line-height:1.5;margin:12px 0; }
.video-card p { color:var(--muted);line-height:1.8; }
.video-card .small-btn { padding:0 18px; }
.video-heading { padding: 24px 0 36px;max-width:900px; }
.video-heading h1 { font-size:clamp(28px,3.5vw,48px);line-height:1.4; }
.video-heading p { color:var(--muted);line-height:1.8; }
.video-detail-layout { display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:44px;padding-bottom:70px;align-items:start; }
.site-video-player { display:block;width:100%;max-height:75vh;background:#000;border:1px solid var(--line);border-radius:var(--radius); }
.video-transcript { margin-top:32px; }
.video-source { color:var(--gold-2);margin-top:26px; }
.video-grid .knowledge-empty { grid-column:1/-1; }
@media(max-width:1000px){.video-grid{grid-template-columns:repeat(2,minmax(0,1fr));}.video-detail-layout{grid-template-columns:1fr;}}
@media(max-width:560px){.video-grid{grid-template-columns:1fr;}.video-card>div{padding:22px;}.video-detail-layout{gap:30px;}.video-heading{padding-top:12px;}}
.model-index { display:flex;flex-wrap:wrap;gap:12px;margin:30px 0; }
.model-index a { display:inline-flex;align-items:center;padding:10px 22px;border:1px solid var(--line);border-radius:6px;background:var(--surface);color:var(--gold-2);font-weight:700; }
.model-index a:hover { border-color:var(--gold-2); }
.video-model-section { scroll-margin-top:100px;margin-top:44px; }
.video-model-heading { display:flex;align-items:center;gap:20px;border-bottom:1px solid var(--line);padding-bottom:16px; }
.video-model-heading h3 { color:var(--gold-2);font-size:28px;margin:0; }
.video-model-heading span { color:var(--muted);font-size:14px; }
.video-model-section .video-grid { margin-top:24px; }
.model-index button { display:inline-flex;align-items:center;padding:10px 22px;border:1px solid var(--line);border-radius:6px;background:var(--surface);color:var(--gold-2);font:inherit;font-weight:700;cursor:pointer; }
.model-index button:hover,.model-index button.active { border-color:var(--gold-2);background:rgba(216,170,85,.15); }
.video-card[hidden] { display:none !important; }
.video-card-cover img { object-fit: contain; background: #111; }