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

.legacy-content .lesson-header .kicker {color:var(--ds)}.legacy-content .l-callout b {color:var(--ds)}.legacy-content .task-list {display:flex;flex-direction:column;gap:16px}.legacy-content .task-card {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-card);overflow:hidden}.legacy-content .task-head {padding:16px 20px;display:flex;align-items:center;gap:13px;border-bottom:1px solid var(--border);background:rgba(0,0,0,.015)}.legacy-content .task-medal {font-size:26px;flex-shrink:0}.legacy-content .task-title {flex:1;min-width:0}.legacy-content .task-title h4 {font-size:15.5px;font-weight:800;color:var(--text)}.legacy-content .task-title p {font-size:12px;color:var(--sub);margin-top:2px}.legacy-content .task-time {flex-shrink:0;font-size:11.5px;font-weight:800;padding:4px 13px;border-radius:99px}.legacy-content .task-card.lv1 .task-time {background:rgba(22,163,74,.1);color:var(--success)}.legacy-content .task-card.lv2 .task-time {background:rgba(217,119,6,.1);color:var(--amber)}.legacy-content .task-card.lv3 .task-time {background:var(--ds-soft);color:var(--ds-deep)}.legacy-content .task-body {padding:18px 20px}.legacy-content .task-body > p {font-size:13.5px;color:var(--sub);line-height:1.8}.legacy-content .task-body > p b {color:var(--text)}.legacy-content .task-prompt {background:rgba(0,0,0,.035);border:1px solid var(--border);border-radius:var(--radius-sm);padding:14px 16px;font-size:13px;line-height:1.85;color:var(--text);white-space:pre-wrap;margin-top:12px}.legacy-content .task-prompt-foot {display:flex;justify-content:flex-end;margin-top:10px}.legacy-content .btn-copy {background:var(--ds);color:#fff;border:none;padding:8px 22px;border-radius:999px;font-size:13px;font-weight:800;cursor:pointer;font-family:inherit;transition:filter .15s,transform .15s}.legacy-content .btn-copy:hover {filter:brightness(1.08);transform:translateY(-1px)}.legacy-content .btn-copy.ok {background:var(--success)}.legacy-content .task-pass {margin-top:14px;padding:11px 15px;background:var(--ds-soft);border-radius:var(--radius-sm);font-size:12.5px;line-height:1.7;color:var(--sub)}.legacy-content .task-pass b {color:var(--ds-deep)}.legacy-content .check-box {margin-top:14px;border:1.5px dashed var(--ds-line);border-radius:var(--radius-sm);padding:15px 17px;background:var(--ds-soft)}.legacy-content .check-box h5 {font-size:13.5px;font-weight:800;color:var(--ds-deep);margin-bottom:10px}.legacy-content .check-item {display:flex;align-items:flex-start;gap:10px;padding:6px 0;cursor:pointer;user-select:none}.legacy-content .check-item .ck {width:19px;height:19px;border:2px solid var(--ds-line);border-radius:6px;flex-shrink:0;margin-top:2px;display:flex;align-items:center;justify-content:center;font-size:12px;font-weight:900;color:#fff;background:var(--card);transition:background .15s,border-color .15s}.legacy-content .check-item.on .ck {background:var(--ds);border-color:var(--ds)}.legacy-content .check-item .ck-txt {font-size:13px;line-height:1.7;color:var(--text)}.legacy-content .check-item .ck-txt b {color:var(--ds-deep)}.legacy-content .check-cheer {display:none;margin-top:10px;padding:11px 14px;background:var(--card);border:1.5px solid var(--ds-line);border-radius:var(--radius-sm);font-size:13px;line-height:1.75;color:var(--ds-deep);font-weight:700}.legacy-content .check-cheer.show {display:block;animation:_si .35s ease}.legacy-content .flag-grid {display:grid;grid-template-columns:1fr 1fr 1fr;gap:12px}.legacy-content .flag-card {background:var(--card);border:1.5px solid var(--border);border-radius:var(--radius-sm);box-shadow:var(--shadow-card);padding:15px 17px}.legacy-content .flag-card .fg-icon {font-size:21px;margin-bottom:6px}.legacy-content .flag-card h5 {font-size:13.5px;font-weight:800;color:var(--text);margin-bottom:5px}.legacy-content .flag-card p {font-size:12.5px;color:var(--sub);line-height:1.7}.legacy-content .flag-card p b {color:var(--ds-deep)}.legacy-content .takeaway-box {background:linear-gradient(135deg,#f0f9ff,#e0f2fe);border:1.5px solid #bae6fd;border-radius:var(--radius);padding:24px 28px;margin-top:36px}.legacy-content .takeaway-box h3 {font-size:17px;font-weight:800;color:var(--ds-deep);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:#0c4a6e;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:var(--ds)}@media (max-width:768px){.legacy-content .task-head {padding:14px 15px}.legacy-content .task-body {padding:15px}.legacy-content .task-time {font-size:10.5px;padding:3px 10px}.legacy-content .flag-grid {grid-template-columns:1fr}}

.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)}