@keyframes _si{to{opacity:1}}

.legacy-content .lesson-header {position:relative;overflow:hidden}.legacy-content .lesson-header:after {content:"";position:absolute;right:-70px;top:-70px;width:220px;height:220px;border:1px solid rgba(77,107,254,.25);border-radius:50%;box-shadow:0 0 0 26px rgba(77,107,254,.05),0 0 0 52px rgba(77,107,254,.03)}.legacy-content .sec-label {margin:56px 0 20px}.legacy-content .objective {display:grid;grid-template-columns:auto 1fr;gap:16px;align-items:center;background:linear-gradient(135deg,var(--accent-soft),rgba(255,255,255,.75));border:1px solid rgba(77,107,254,.28);border-radius:var(--radius);padding:24px;margin:24px 0 32px}.legacy-content .objective svg {color:var(--accent)}.legacy-content .objective b {display:block;color:var(--accent);margin-bottom:6px}.legacy-content .objective span {font-size:14px;line-height:1.9;color:var(--text)}.legacy-content .prose {font-size:15px;line-height:2;color:var(--text);margin:0 0 20px}.legacy-content .ask {font-size:15px;font-weight:800;color:var(--accent-deep);margin:32px 0 12px;display:flex;align-items:center;gap:8px}.legacy-content .ask svg {flex:none;color:var(--accent)}.legacy-content .src-note {font-size:12px;color:var(--sub);line-height:1.8;margin:0 0 20px}.legacy-content .src-note code {color:var(--sub)}.legacy-content .stress {margin:32px auto;padding:24px;max-width:640px;border-radius:14px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.25);color:var(--accent-deep);font-size:18px;font-weight:800;text-align:center;line-height:1.8}.legacy-content .core-visual {background:var(--card);border:1px solid var(--border);border-radius:18px;padding:24px;box-shadow:var(--shadow-card);margin:24px 0}.legacy-content .core-visual svg {width:100%;height:auto;display:block}.legacy-content .visual-caption {font-size:12px;color:var(--sub);text-align:center;margin-top:12px}.legacy-content .source {background:var(--card);border:1px solid var(--border);border-radius:14px;overflow:hidden;margin:24px 0 0;box-shadow:var(--shadow-card)}.legacy-content .source-head {display:flex;justify-content:space-between;gap:12px;padding:10px 16px;background:var(--accent-soft);color:var(--accent-deep);font:12px ui-monospace,SFMono-Regular,Menlo,monospace}.legacy-content .source pre {margin:0;padding:20px;overflow:auto}.legacy-content .source code {color:var(--text);font:12.5px/1.7 ui-monospace,SFMono-Regular,Menlo,monospace;background:none;padding:0}.legacy-content .kw {color:#3450d4}.legacy-content .ty {color:#7c3aed}.legacy-content .fn {color:#0891b2}.legacy-content .cm {color:#9ca3af}.legacy-content .str {color:#16a34a}.legacy-content .snapshot {margin:16px 0 20px;padding:14px 16px;border:1px solid var(--border);border-radius:8px;background:var(--bg);font-size:12px;line-height:1.8;color:var(--sub)}.legacy-content .snapshot code {color:var(--text)}.legacy-content .compare {display:grid;grid-template-columns:1fr 1fr;gap:20px;margin:24px 0}.legacy-content .compare-card {background:var(--card);border:1px solid var(--border);border-radius:14px;padding:24px;box-shadow:var(--shadow-card)}.legacy-content .compare-card:last-child {grid-column:1/-1}.legacy-content .compare-card h3 {margin:0 0 10px;font-size:15px;color:var(--text);display:flex;align-items:center;gap:8px}.legacy-content .compare-card h3 svg {color:var(--accent)}.legacy-content .compare-card p {font-size:14px;line-height:1.9;color:var(--sub);margin:0 0 10px}.legacy-content .compare-card p:last-child {margin-bottom:0}.legacy-content .compare-card .tag {display:inline-block;font-size:12px;font-weight:800;padding:3px 10px;border-radius:999px;margin-bottom:10px;background:var(--accent-soft);color:var(--accent-deep)}.legacy-content .exercise {display:grid;grid-template-columns:52px 1fr;gap:18px;background:linear-gradient(135deg,var(--accent-soft),var(--card));border:1px solid rgba(77,107,254,.3);border-radius:14px;padding:24px;margin-top:16px}.legacy-content .exercise-num {width:46px;height:46px;border-radius:12px;background:var(--accent);color:white;display:grid;place-items:center;font-weight:900}.legacy-content .exercise h3 {margin:0 0 10px;color:var(--text);font-size:16px}.legacy-content .exercise p {margin:0 0 10px;color:var(--sub);font-size:14px;line-height:1.9}.legacy-content .exercise p:last-child {margin-bottom:0}.legacy-content .takeaway {margin-top:32px;padding:24px;border-radius:14px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.25);color:var(--text);display:flex;gap:14px;line-height:1.9;font-size:14px}.legacy-content .takeaway svg {flex:0 0 auto;color:var(--accent)}.legacy-content .takeaway b {color:var(--accent-deep)}.legacy-content .demo {background:var(--card);border:1px solid rgba(77,107,254,.25);border-radius:18px;padding:24px;box-shadow:var(--shadow-card)}.legacy-content .demo-bar {display:flex;flex-wrap:wrap;gap:12px;align-items:center;margin-bottom:20px}.legacy-content .demo-bar .grow {flex:1}.legacy-content .demo button {display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:44px;padding:9px 15px;border-radius:11px;border:1px solid rgba(77,107,254,.3);background:var(--bg);color:var(--accent-deep);font:600 13px/1.2 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;cursor:pointer;transition:all .2s}.legacy-content .demo button:hover {border-color:var(--accent)}.legacy-content .demo button.active {background:var(--accent);border-color:var(--accent);color:#fff;box-shadow:0 4px 14px rgba(77,107,254,.3)}.legacy-content .demo button svg {flex:none}.legacy-content .demo-stage {display:grid;grid-template-columns:1.15fr 1fr;gap:20px;align-items:start;margin-top:4px}.legacy-content .layer-stack {display:flex;flex-direction:column-reverse;gap:10px}.legacy-content .layer {border:1.5px solid var(--border);background:var(--bg);border-radius:12px;padding:13px 16px;transition:all .35s;position:relative}.legacy-content .layer .lyr-head {display:flex;align-items:center;gap:8px;flex-wrap:wrap}.legacy-content .layer .lyr-name {font-weight:800;font-size:13px;color:var(--text)}.legacy-content .layer .lyr-file {font:10.5px ui-monospace,Menlo,monospace;color:var(--sub);word-break:break-all}.legacy-content .layer .lyr-desc {margin-top:8px;font-size:12.5px;line-height:1.8;color:var(--sub)}.legacy-content .layer.on {border-color:rgba(77,107,254,.45);background:var(--accent-soft)}.legacy-content .layer.applying {border-color:var(--accent);box-shadow:0 0 0 3px rgba(77,107,254,.18)}.legacy-content .layer.skipped {opacity:.38;filter:grayscale(1)}.legacy-content .lyr-toggle {margin-left:auto;min-height:32px!important;min-width:64px;padding:4px 10px!important;font-size:11px!important;border-radius:999px!important}.legacy-content .lyr-order {position:absolute;left:-9px;top:50%;transform:translateY(-50%);width:20px;height:20px;border-radius:50%;background:var(--accent);color:#fff;font:800 11px/20px sans-serif;text-align:center;opacity:0;transition:opacity .3s}.legacy-content .layer.applying .lyr-order, .legacy-content .layer.done .lyr-order {opacity:1}.legacy-content .layer.done {border-color:rgba(77,107,254,.35)}.legacy-content .result-pane {border:1.5px solid var(--border);border-radius:14px;background:var(--bg);overflow:hidden}.legacy-content .result-head {padding:9px 14px;background:var(--accent-soft);color:var(--accent-deep);font:700 11.5px ui-monospace,Menlo,monospace}.legacy-content .result-body {padding:12px 14px;min-height:150px}.legacy-content .field-row {display:flex;align-items:center;gap:10px;padding:7px 10px;border-radius:9px;margin-bottom:6px;background:var(--card);border:1px solid var(--border);font:12px ui-monospace,Menlo,monospace;transition:all .35s}.legacy-content .field-row .fk {color:var(--sub);min-width:96px}.legacy-content .field-row .fv {color:var(--text);font-weight:700;word-break:break-all}.legacy-content .field-row .fsrc {margin-left:auto;font:700 9.5px sans-serif;letter-spacing:.4px;padding:2px 8px;border-radius:999px;background:var(--accent-soft);color:var(--accent-deep);white-space:nowrap}.legacy-content .field-row.gone {background:rgba(220,38,38,.06);border-color:rgba(220,38,38,.35)}.legacy-content .field-row.gone .fv {color:var(--danger);text-decoration:line-through;font-weight:600}.legacy-content .field-row.gone .fsrc {background:rgba(220,38,38,.12);color:var(--danger)}.legacy-content .field-row.fresh {border-color:rgba(77,107,254,.5);box-shadow:0 0 0 2px rgba(77,107,254,.15)}.legacy-content .field-row.kept {border-color:rgba(22,163,74,.45);background:rgba(22,163,74,.07)}.legacy-content .field-row.kept .fsrc {background:rgba(22,163,74,.12);color:var(--success)}.legacy-content .result-empty {font-size:12.5px;color:var(--sub);padding:10px 4px}.legacy-content .demo-caption {margin-top:20px;padding:14px 18px;border-radius:12px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.2);font-size:14px;line-height:1.8;color:var(--text);display:flex;gap:10px;align-items:flex-start;min-height:56px}.legacy-content .demo-caption svg {flex:0 0 auto;color:var(--accent);margin-top:3px}.legacy-content .demo-note {font-size:12px;color:var(--sub);margin-top:16px;line-height:1.8}.legacy-content .mode-hint {font:700 11px sans-serif;color:var(--sub);letter-spacing:.4px;margin-right:2px}@media(max-width:760px){.legacy-content .compare {grid-template-columns:1fr}.legacy-content .demo-stage {grid-template-columns:1fr}.legacy-content .demo-bar {flex-direction:column;align-items:stretch}.legacy-content .demo-bar .grow {display:none}.legacy-content .demo button {width:100%}.legacy-content .lyr-toggle {width:auto!important}.legacy-content .source-head {flex-direction:column;gap:2px}.legacy-content .objective {grid-template-columns:1fr}.legacy-content .exercise {grid-template-columns:1fr}.legacy-content .lesson-header:after {display:none}}

.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)}