html body .lesson-app.lsk{background:#fff;min-height:100vh}html body .lsk .lesson-header{position:sticky;top:0}html body .lsk-block{background:#eceef2;border-radius:8px;flex-shrink:0;display:block}@media (prefers-reduced-motion:no-preference){html body .lsk-block{background:linear-gradient(100deg,#eceef2 30%,#f6f7f9 50%,#eceef2 70%) 0 0/220% 100%;animation:1.4s linear infinite lsk-shimmer}@keyframes lsk-shimmer{to{background-position:-220% 0}}}html body .lsk-line{height:14px}html body .lsk-line.is-sm{height:10px}html body .lsk-line.is-text{height:12px}html body .lsk-pill{border-radius:999px;height:40px}html body .lsk-ring{border-radius:50%;width:42px;height:42px}html body .lsk-chip{border-radius:999px;height:28px}html body .lsk-title{width:min(60%,420px);height:30px;margin-top:14px}html body .lsk-bar{border-radius:2px;height:4px}html body .lsk-check{border-radius:5px;width:18px;height:18px}html body .lsk-brand,html body .lsk-actions{align-items:center;gap:14px;display:flex}html body .lsk-brand>span{gap:7px;display:grid}html body .lsk-logo{border-radius:13px;width:46px;height:46px}html body .lsk-divider{background:#e6e0dd;width:1px;height:28px}html body .lsk-player{background:radial-gradient(circle at 50% 28%,#2f3040 0,#1b1b24 57%,#111117 100%);place-items:center;min-height:clamp(440px,56vw,680px);display:grid}html body .lsk-player .lsk-play{background:#ffffff1a;border-radius:50%;width:68px;height:68px;animation:none}@media (prefers-reduced-motion:no-preference){html body .lsk-player .lsk-play{background:#ffffff1a;animation:1.6s ease-in-out infinite lsk-pulse}@keyframes lsk-pulse{50%{background:#fff3}}}html body .lsk-content{gap:14px;max-width:980px;margin:0 auto;padding:0 36px 40px;display:grid}html body .lsk-tabs{border-bottom:1px solid #eceef2;gap:30px;margin-bottom:8px;padding:20px 4px 18px;display:flex}html body .lsk-card{border:1px solid #eceef2;border-radius:16px;gap:14px;margin-top:10px;padding:24px;display:grid}html body .lsk-sidebar{display:block;overflow:hidden}html body .lsk-side-head{gap:10px;padding:20px 18px 16px;display:grid}html body .lsk-group{margin-top:8px;display:grid}html body .lsk-group-head{background-color:#edf1f8;border-radius:0;height:44px}html body .lsk-row{border-top:1px solid #f0f1f4;justify-content:space-between;align-items:center;gap:16px;padding:14px 18px;display:flex}@media (max-width:820px){html body .lsk-content{padding:0 16px 30px}html body .lsk-player{min-height:220px}html body .lsk-actions .lsk-pill:first-child,html body .lsk-brand>span:last-child,html body .lsk-divider,html body .lsk-sidebar{display:none}}