.kn{--primary:#4a7cff;--bg:#f5f6f8;--card:#fff;--bg-input:#f0f1f4;--text:#17181a;--text-mid:#5a5d63;--text-light:#949699;--border-light:#f2f3f5;--radius-sm:.3125rem;--radius-md:.4375rem;--shadow-sm:0 1px 4px #4a7cff0a,0 4px 12px #00000008;color:var(--text);font-family:Outfit,-apple-system,BlinkMacSystemFont,PingFang SC,Segoe UI,sans-serif;overflow-x:hidden}.kn .page{background:var(--bg);min-height:100vh;padding-bottom:2rem}.kn .topbar{padding:.75rem .875rem .5rem}.kn .back{color:var(--text-mid);font-size:.8125rem;text-decoration:none}.kn .back:active{color:var(--primary)}.kn .cover{border-radius:var(--radius-md);background:var(--bg-input);aspect-ratio:16/9;margin:0 .875rem .75rem;position:relative;overflow:hidden}.kn .cover-img{-o-object-fit:cover;object-fit:cover;width:100%;height:100%;display:block}.kn .cover-blank{background:linear-gradient(135deg,#eef3ff,#f8f9fb);width:100%;height:100%}.kn .cover-play{cursor:pointer;background:#0000002e;border:0;justify-content:center;align-items:center;width:100%;padding:0;display:flex;position:absolute;inset:0}.kn .cover-play i{width:3rem;height:3rem;color:var(--primary);box-sizing:border-box;background:#ffffffeb;border-radius:50%;justify-content:center;align-items:center;padding-left:.1875rem;font-size:1rem;font-style:normal;display:flex}.kn .head{padding:0 .875rem .875rem}.kn .title{letter-spacing:-.01em;margin:0;font-size:1.0625rem;font-weight:700;line-height:1.4}.kn .meta{flex-wrap:wrap;align-items:center;gap:.4375rem;margin-top:.5rem;display:flex}.kn .meta-item{color:var(--text-light);font-size:.75rem}.kn .ktag{color:var(--primary);background:#4a7cff14;border-radius:.25rem;padding:.125rem .4375rem;font-size:.6875rem;font-weight:600}.kn .panel{background:var(--card);border-radius:var(--radius-md);border:1px solid var(--border-light);margin:0 .875rem .75rem;overflow:hidden}.kn .panel-hd{border-bottom:1px solid var(--border-light);justify-content:space-between;align-items:center;padding:.75rem .875rem;font-size:.875rem;font-weight:700;display:flex}.kn .panel-hd span{color:var(--text-light);font-size:.6875rem;font-weight:500}.kn .lesson{border:0;border-bottom:1px solid var(--border-light);text-align:left;cursor:pointer;background:0 0;align-items:center;gap:.625rem;width:100%;padding:.6875rem .875rem;font-family:inherit;display:flex}.kn .lesson:last-child{border-bottom:0}.kn .lesson:active{background:var(--bg)}.kn .ls-no{background:var(--bg-input);width:1.375rem;height:1.375rem;color:var(--text-light);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:.6875rem;font-weight:600;display:flex}.kn .ls-title{min-width:0;color:var(--text);text-overflow:ellipsis;-webkit-line-clamp:2;-webkit-box-orient:vertical;flex:1;font-size:.8125rem;line-height:1.4;display:-webkit-box;overflow:hidden}.kn .ls-dur{color:var(--text-light);flex-shrink:0;font-size:.6875rem}.kn .teacher{background:var(--card);border-radius:var(--radius-md);border:1px solid var(--border-light);align-items:center;gap:.625rem;margin:0 .875rem;padding:.75rem .875rem;display:flex}.kn .tc-avatar{-o-object-fit:cover;object-fit:cover;background:var(--bg-input);border-radius:50%;flex-shrink:0;width:2.25rem;height:2.25rem}.kn .tc-name{font-size:.875rem;font-weight:600}.kn .tc-role{color:var(--text-light);margin-top:.0625rem;font-size:.6875rem}.kn-overlay{z-index:300;background:#000000eb;justify-content:center;align-items:center;display:flex;position:fixed;inset:0}.kn-overlay .frame{aspect-ratio:16/9;background:#000;width:100%;max-width:60rem}.kn-overlay iframe,.kn-overlay video{border:0;width:100%;height:100%;display:block}.kn-overlay .close{color:#fff;cursor:pointer;background:#ffffff26;border:0;border-radius:50%;width:2.25rem;height:2.25rem;font-size:1rem;line-height:1;position:absolute;top:.75rem;right:.75rem}.kn-overlay .close:active{background:#ffffff4d}.kn .empty{text-align:center;padding:3.75rem .625rem}.kn .empty-text{color:var(--text-light);font-size:.875rem}.kn .empty-back{color:var(--primary);margin-top:1rem;font-size:.875rem;text-decoration:none;display:inline-block}@media (min-width:768px){.kn{background:#e8e9eb}.kn .page{max-width:60rem;margin:0 auto;box-shadow:0 0 40px #00000014}.kn .topbar{padding:.75rem 1.25rem .5rem}.kn .cover,.kn .head,.kn .panel,.kn .teacher{margin-left:1.25rem;margin-right:1.25rem}.kn .head{padding:0 1.25rem .875rem}.kn .lesson:hover{background:var(--bg)}.kn .cover-play i{width:3.75rem;height:3.75rem;font-size:1.25rem}}