@keyframes _si{from{opacity:0}to{opacity:1}}

.legacy-content .lesson-header .kicker {color:var(--al)}.legacy-content .l-callout b {color:var(--al)}.legacy-content .task-box {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);padding:20px 22px}.legacy-content .task-node {margin:0}.legacy-content .task-node .tn-card {
  display:flex;align-items:center;gap:10px;
  border:1.5px solid var(--border);border-radius:var(--radius-sm);
  padding:10px 14px;background:var(--card);
  cursor:pointer;transition:border-color .2s,background .3s,box-shadow .2s;
  user-select:none;
}.legacy-content .task-node .tn-card:hover {border-color:var(--al-line)}.legacy-content .task-node.expanded > .tn-card {cursor:default;border-color:var(--al-line);background:var(--al-soft)}.legacy-content .task-node.done > .tn-card {background:rgba(22,163,74,.1)!important;border-color:rgba(22,163,74,.4)!important}.legacy-content .tn-icon {font-size:18px;flex-shrink:0}.legacy-content .tn-label {font-size:14px;font-weight:800;color:var(--text)}.legacy-content .tn-hint {margin-left:auto;font-size:11px;font-weight:800;color:var(--al);background:rgba(219,39,119,.08);padding:2px 10px;border-radius:99px;flex-shrink:0;transition:opacity .3s}.legacy-content .task-node.expanded > .tn-card .tn-hint, .legacy-content .task-node.done > .tn-card .tn-hint {display:none}.legacy-content .tn-leaf-tag {margin-left:auto;font-size:11.5px;font-weight:800;color:var(--amber);flex-shrink:0}.legacy-content .task-node.done > .tn-card .tn-leaf-tag {color:var(--success)}.legacy-content .tn-done-tag {margin-left:auto;font-size:12px;font-weight:800;color:var(--success);flex-shrink:0}.legacy-content .tn-children {
  margin:0 0 0 20px;padding-left:16px;border-left:2px dashed var(--al-line);
  display:none;flex-direction:column;gap:8px;padding-top:8px;
}.legacy-content .task-node.expanded > .tn-children {display:flex;animation:tnIn .35s ease}@keyframes tnIn{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}.legacy-content .task-controls {display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-top:16px}.legacy-content .btn-al {background:var(--al);color:#fff;border:none;padding:10px 26px;border-radius:999px;font-size:14px;font-weight:800;cursor:pointer;font-family:inherit;transition:filter .15s,transform .15s}.legacy-content .btn-al:hover:not(:disabled) {filter:brightness(1.08);transform:translateY(-1px)}.legacy-content .btn-al:disabled {background:#c4c8cf;cursor:not-allowed}.legacy-content .task-status {font-size:12.5px;color:var(--sub);font-weight:600}.legacy-content .task-verdict {margin-top:14px;padding:14px 18px;background:var(--al-soft);border:1.5px dashed var(--al-line);border-radius:var(--radius-sm);font-size:13.5px;line-height:1.8;color:var(--sub);opacity:0;transform:translateY(6px);transition:opacity .35s,transform .35s}.legacy-content .task-verdict.show {opacity:1;transform:translateY(0)}.legacy-content .task-verdict b {color:var(--al-deep)}.legacy-content .fractal-box {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);overflow:hidden}.legacy-content .fractal-stage {background:linear-gradient(to bottom,#fdf6fa,#fdf2f8);padding:8px 8px 0}.legacy-content .fractal-stage svg {display:block;width:100%;height:auto}.legacy-content .fractal-rule {padding:10px 18px;font-size:12.5px;font-weight:700;color:var(--al-deep);background:var(--al-soft);border-top:1px dashed var(--al-line);border-bottom:1px solid var(--border)}.legacy-content .fractal-foot {padding:14px 18px;display:flex;align-items:center;gap:14px;flex-wrap:wrap}.legacy-content .fractal-foot label {font-size:13.5px;font-weight:800;color:var(--text);flex-shrink:0}.legacy-content .fractal-foot input[type=range] {flex:1;min-width:150px;accent-color:var(--al)}.legacy-content .fractal-depth {font-size:15px;font-weight:900;color:var(--al);font-variant-numeric:tabular-nums;min-width:64px}.legacy-content .fractal-count {font-size:12.5px;color:var(--sub);font-weight:700;font-variant-numeric:tabular-nums}.legacy-content .trio-grid {display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.legacy-content .trio-card {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow-card);position:relative}.legacy-content .trio-card .tr-num {position:absolute;top:-12px;left:16px;width:26px;height:26px;border-radius:50%;background:var(--al);color:#fff;font-size:13px;font-weight:900;display:flex;align-items:center;justify-content:center}.legacy-content .trio-card h4 {font-size:15px;font-weight:800;color:var(--text);margin:6px 0 6px}.legacy-content .trio-card p {font-size:13px;color:var(--sub);line-height:1.75}.legacy-content .trio-card p b {color:var(--text)}.legacy-content .trio-card.danger {border-color:rgba(220,38,38,.3)}.legacy-content .trio-card.danger .tr-num {background:var(--danger)}.legacy-content .takeaway-box {background:linear-gradient(135deg,#fdf2f8,#fce7f3);border:1.5px solid #fbcfe8;border-radius:var(--radius);padding:24px 28px;margin-top:36px}.legacy-content .takeaway-box h3 {font-size:17px;font-weight:800;color:#9d174d;margin-bottom:10px}.legacy-content .takeaway-box ul {list-style:none;padding:0;margin:0}.legacy-content .takeaway-box li {font-size:14.5px;color:#831843;line-height:1.8;padding:4px 0 4px 22px;position:relative}.legacy-content .takeaway-box li::before {content:'';position:absolute;left:0;top:13px;width:8px;height:8px;border-radius:50%;background:#db2777}@media (max-width:768px){.legacy-content .trio-grid {grid-template-columns:1fr}.legacy-content .tn-label {font-size:13px}.legacy-content .tn-children {margin-left:10px;padding-left:10px}}

.legacy-content .xa-tldr {margin:18px 0 4px;padding:14px 18px;background:rgba(0,102,255,0.04);border:1px solid rgba(0,102,255,0.16);border-radius:10px}.legacy-content .xa-tldr .xa-tldr-tag {display:block;font-size:11px;font-weight:800;letter-spacing:1px;color:var(--accent,#0066ff);margin-bottom:6px}.legacy-content .xa-tldr p {margin:0;font-size:15px;line-height:1.8;color:var(--text,#1f2937)}