.site-course{max-width:1280px;margin:0 auto;padding:24px 20px 64px;color:#111827;font-size:18px;line-height:1.6}.site-course .course-head h1{font-size:28px;font-weight:700;margin:0}.site-course .course-head p{color:#667085;margin:4px 0 20px}.site-course .course-watch{display:grid;grid-template-columns:minmax(0,1fr) 380px;gap:24px;align-items:start}.site-course .course-player video{width:100%;aspect-ratio:16/9;background:#000;border-radius:12px;display:block}.site-course .course-title{font-size:24px;font-weight:700;margin:16px 0 2px}.site-course .course-sub{color:#667085;font-size:16px}.site-course .course-nav{display:flex;gap:12px;margin:16px 0 12px}.site-course .course-nav button{flex:1;padding:12px;border-radius:10px;border:1px solid rgba(92,103,141,.25);background:#fff;font-size:18px;cursor:pointer}.site-course .course-nav button.primary{background:#635BFF;border-color:#635BFF;color:#fff}.site-course .course-nav button.primary:hover{background:#4D43E6}.site-course .course-nav button:disabled{opacity:.35;cursor:default}.site-course .course-auto{display:flex;align-items:center;gap:8px;color:#667085;font-size:16px;cursor:pointer}.site-course .course-auto input{width:20px;height:20px;accent-color:#635BFF}.site-course .course-list{background:#fff;border:1px solid rgba(92,103,141,.14);border-radius:12px;max-height:calc(100vh - 112px);overflow-y:auto;position:sticky;top:88px}.site-course .course-list-head{position:sticky;top:0;background:#fff;font-weight:700;padding:12px 16px;border-bottom:1px solid rgba(92,103,141,.14);z-index:1}.site-course .course-list a{display:flex;gap:12px;align-items:center;padding:8px 12px;border-bottom:1px solid rgba(92,103,141,.08);font-size:16px;line-height:1.4}.site-course .course-list a:hover{background:#F6F8FF}.site-course .course-list a.on{background:#ECEBFF}.site-course .course-list img{width:120px;height:auto;aspect-ratio:16/9;-o-object-fit:cover;object-fit:cover;border-radius:6px;flex:none}.site-course .course-list small{display:block;color:#667085;font-size:14px}.site-course .course-list b{color:#2E7D32;font-weight:600}@media (max-width:1023px){.site-course{padding:0 0 48px}.site-course .course-head{padding:16px 16px 0}.site-course .course-head h1{font-size:22px}.site-course .course-watch{grid-template-columns:minmax(0,1fr);gap:16px}.site-course .course-main{padding:0 16px}.site-course .course-player{position:sticky;top:64px;z-index:2;margin:0 -16px}.site-course .course-player video{border-radius:0}.site-course .course-list{position:static;max-height:none;margin:0 16px}}