.lt-root{display:flex;flex-direction:column;gap:12px}.lt-collapse{display:grid;grid-template-rows:0fr;transition:grid-template-rows .3s cubic-bezier(.4,0,.2,1)}.lt-collapse.lt-open{grid-template-rows:1fr}.lt-collapse>.lt-inner{overflow:hidden;min-height:0}.lt-children{opacity:0;transform:translateY(-4px);transition:opacity .24s ease .05s,transform .24s ease .05s}.lt-collapse.lt-open .lt-children{opacity:1;transform:none}.lt-chevron{transition:transform .24s cubic-bezier(.4,0,.2,1);flex-shrink:0}.lt-chevron.lt-open{transform:rotate(90deg)}.lt-node{border:1px solid var(--border-color);border-radius:16px;background:var(--background-secondary);box-shadow:0 18px 40px -34px var(--shadow-color,rgba(0,0,0,.6));overflow:hidden}.lt-head{display:flex;align-items:center;gap:12px;width:100%;padding:15px 18px;background:none;border:none;cursor:pointer;color:var(--text-primary);font:inherit;text-align:left;transition:background .15s ease}.lt-head:hover{background:rgba(109,123,255,.05)}.lt-titlewrap{flex:1;min-width:0}.lt-title{font-family:var(--font-display),"Archivo",sans-serif;font-weight:750;letter-spacing:-.01em;color:var(--text-primary);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lt-sub{font-size:12px;color:var(--text-muted);margin-top:2px}.lt-pct{font-size:12px;font-weight:700;color:var(--text-secondary);flex-shrink:0}.lt-group{border:1px solid var(--border-color);border-radius:14px;background:var(--background-primary);overflow:hidden}.lt-group .lt-head{padding:13px 16px}.lt-lesson{display:flex;align-items:center;gap:13px;padding:12px 14px;border:1px solid var(--border-color);border-radius:12px;background:var(--background-secondary);text-decoration:none;color:inherit;transition:border-color .15s ease,background .15s ease,transform .12s ease}.lt-lesson:hover{border-color:rgba(109,123,255,.5);background:rgba(109,123,255,.05);transform:translateY(-1px)}.lt-lesson-title{font-size:14.5px;font-weight:600;color:var(--text-primary);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lt-lesson-meta{font-size:11.5px;color:var(--text-muted);margin-top:2px}.lt-tierbadge{font-size:9px;font-weight:800;letter-spacing:.09em;text-transform:uppercase;color:rgba(155,141,255,.9)}