@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,.22);border-radius:50%;box-shadow:0 0 0 26px rgba(77,107,254,.04),0 0 0 52px rgba(77,107,254,.025)}.legacy-content .lesson .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 .key-line {margin:32px 0;padding:24px;border-radius:14px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.25);text-align:center;font-size:18px;font-weight:800;line-height:1.8;color:var(--accent-deep)}.legacy-content .flow {background:var(--card);border:1px solid var(--border);border-radius:16px;padding:24px;margin:24px 0;box-shadow:var(--shadow-card)}.legacy-content .flow svg {width:100%;height:auto;display:block}.legacy-content .visual-caption {font-size:12.5px;color:var(--sub);text-align:center;margin-top:12px;line-height:1.7}.legacy-content .src-note {font-size:12.5px;color:var(--sub);line-height:1.8;margin:-8px 0 20px}.legacy-content .src-note code {font-size:11.5px}.legacy-content .facts {display:grid;grid-template-columns:1fr;gap:20px;margin-top:20px}.legacy-content .fact {background:var(--card);border:1px solid var(--border);border-radius:12px;padding:24px;box-shadow:var(--shadow-card)}.legacy-content .fact code {color:var(--accent);font-weight:800}.legacy-content .fact p {font-size:14px;line-height:1.9;color:var(--sub);margin:9px 0 0}.legacy-content .source {background:var(--card);border:1px solid var(--border);border-radius:14px;overflow:hidden;margin-top:12px;box-shadow:var(--shadow-card)}.legacy-content .source-head {display:flex;justify-content:space-between;gap:12px;padding:12px 18px;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/1.75 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-top:14px;padding:14px 18px;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;gap:20px;margin-top:20px}.legacy-content .cmp-card {background:var(--card);border:1px solid var(--border);border-radius:14px;padding:24px;box-shadow:var(--shadow-card)}.legacy-content .cmp-card .cmp-title {display:flex;align-items:center;gap:8px;font-weight:800;color:var(--text);margin-bottom:10px}.legacy-content .cmp-card .cmp-title svg {color:var(--accent);flex:none}.legacy-content .cmp-card p {font-size:14px;line-height:1.9;color:var(--sub);margin:10px 0 0}.legacy-content .exercise {display:grid;grid-template-columns:52px 1fr;gap:18px;background:linear-gradient(135deg,#eef1ff,var(--card));border:1px solid rgba(77,107,254,.3);border-radius:14px;padding:24px;margin-top:12px}.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;color:var(--sub);font-size:14px;line-height:1.9}.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;font-size:14px;line-height:1.9}.legacy-content .takeaway svg {flex:0 0 auto;color:var(--accent)}.legacy-content .takeaway b {color:var(--accent-deep)}.legacy-content #demo-meter {background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow-card);margin-top:12px}.legacy-content .demo-bar {display:flex;justify-content:flex-end;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:20px}.legacy-content #demo-meter button {display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:48px;padding:10px 16px;border-radius:11px;border:1px solid rgba(77,107,254,.4);background:var(--accent-soft);color:var(--accent-deep);font:600 13px/1.2 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;cursor:pointer;transition:background .2s,border-color .2s}.legacy-content #demo-meter button.primary {background:var(--accent);border-color:var(--accent);color:#fff}.legacy-content #demo-meter button svg {flex:none}.legacy-content .gm-stage {display:grid;grid-template-columns:1fr 1fr;gap:14px}.legacy-content .gauge-card {background:var(--bg);border:1px solid var(--border);border-radius:12px;padding:14px;text-align:center;transition:border-color .3s,box-shadow .3s}.legacy-content .gauge-card.focus {border-color:var(--accent);box-shadow:0 0 0 3px rgba(77,107,254,.16)}.legacy-content .gauge-card.diverge {border-color:var(--amber);box-shadow:0 0 0 3px rgba(217,119,6,.15)}.legacy-content .g-head {font-size:13px;font-weight:800;color:var(--text)}.legacy-content .g-sub {display:block;font-size:11px;font-weight:600;color:var(--sub);margin-top:2px}.legacy-content .gauge-card svg {width:100%;max-width:230px;height:auto;display:block;margin:6px auto 0}.legacy-content .g-arc-bg {fill:none;stroke:rgba(0,0,0,.07);stroke-width:14;stroke-linecap:round}.legacy-content .g-arc {fill:none;stroke:var(--accent);stroke-width:14;stroke-linecap:round;transition:stroke-dasharray .6s ease,stroke .3s}.legacy-content .g-arc.hot {stroke:var(--danger)}.legacy-content .g-arc.idle {stroke:rgba(0,0,0,.12)}.legacy-content .g-num {font:800 24px/1 ui-monospace,SFMono-Regular,Menlo,monospace;fill:var(--text)}.legacy-content .g-pct {font:700 12px/1 ui-monospace,SFMono-Regular,Menlo,monospace;fill:#6b7280}.legacy-content .g-tick {stroke:var(--amber);stroke-width:2.5}.legacy-content .g-meta {font-size:11.5px;color:var(--sub);margin-top:6px;min-height:18px}.legacy-content .g-meta b {color:var(--accent-deep);font-family:ui-monospace,Menlo,monospace}.legacy-content .g-meta b.pop {display:inline-block;animation:gmPop .45s ease}@keyframes gmPop{50%{transform:scale(1.4)}}.legacy-content .gm-evts {display:flex;gap:7px;flex-wrap:wrap;margin-top:14px;min-height:34px}.legacy-content .gm-chip {display:inline-flex;align-items:center;gap:5px;background:var(--card);border:1px solid var(--border);border-radius:999px;padding:5px 12px;font:600 11.5px/1.4 ui-monospace,SFMono-Regular,Menlo,monospace;color:var(--sub);opacity:0;transform:translateY(5px);transition:opacity .3s,transform .3s}.legacy-content .gm-chip.in {opacity:1;transform:translateY(0)}.legacy-content .gm-chip.now {border-color:var(--accent);color:var(--accent-deep);background:var(--accent-soft)}.legacy-content .gm-note {display:none;margin-top:12px;background:rgba(217,119,6,.07);border:1px solid rgba(217,119,6,.4);border-radius:10px;padding:13px 16px;font-size:13px;line-height:1.75;color:var(--text)}.legacy-content .gm-note.show {display:block}.legacy-content .gm-note .q-src {display:block;margin-top:6px;font-size:11.5px;color:var(--sub)}.legacy-content .gm-cap {display:flex;gap:11px;align-items:flex-start;margin-top:16px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.25);border-radius:10px;padding:16px 18px;font-size:14px;line-height:1.8;color:var(--text);min-height:56px}.legacy-content .gm-cap svg {flex:0 0 auto;color:var(--accent);margin-top:2px}@media(max-width:760px){.legacy-content .facts {grid-template-columns:1fr}.legacy-content .compare {grid-template-columns:1fr}.legacy-content .gm-stage {grid-template-columns:1fr}.legacy-content .source-head {flex-direction:column}.legacy-content .flow {padding:12px}.legacy-content .objective {grid-template-columns:1fr}.legacy-content .lesson-header:after {display:none}.legacy-content .demo-bar {justify-content:stretch}.legacy-content #demo-meter button {flex:1 1 auto}}

.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)}