@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 .lesson p.reveal {font-size:15px;line-height:2;color:var(--text);margin:0 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 .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 .doc-quote {background:var(--accent-soft);border:1px solid rgba(77,107,254,.25);border-radius:10px;padding:20px 22px;margin:12px 0 20px;font-size:14px;line-height:1.9;color:var(--text)}.legacy-content .doc-quote .q-src {display:block;margin-top:8px;font-size:12px;color:var(--sub)}.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 .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 .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;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-kvcache {background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow-card);margin-top:12px}.legacy-content .kv-toolbar {display:flex;flex-wrap:wrap;gap:10px;align-items:center;margin-bottom:14px}.legacy-content .kv-btn {display:inline-flex;align-items:center;gap:8px;border:1px solid rgba(77,107,254,.4);background:var(--accent-soft);color:var(--accent-deep);border-radius:11px;padding:12px 18px;font-size:14px;font-weight:700;cursor:pointer;font-family:inherit;min-height:48px}.legacy-content .kv-btn svg {flex:0 0 auto}.legacy-content .kv-btn.primary {background:var(--accent);border-color:var(--accent);color:#fff}.legacy-content .kv-mode {display:flex;gap:0;border:1px solid rgba(77,107,254,.35);border-radius:11px;overflow:hidden;margin-left:auto}.legacy-content .kv-mode button {border:none;background:var(--card);color:var(--sub);padding:12px 14px;font:700 12.5px/1.2 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;cursor:pointer;min-height:48px}.legacy-content .kv-mode button.active {background:var(--accent);color:#fff}.legacy-content .kv-stage {display:grid;grid-template-columns:1fr 250px;gap:14px;align-items:start}.legacy-content .kv-ribbon-wrap {background:var(--bg);border:1px solid var(--border);border-radius:12px;padding:14px}.legacy-content .kv-ribbon-title {font-size:12px;font-weight:800;color:var(--sub);margin-bottom:10px}.legacy-content .kv-ribbon {display:flex;gap:2px;height:52px;border-radius:8px;overflow:hidden}.legacy-content .kv-seg {position:relative;display:grid;place-items:center;font:700 9.5px/1.2 ui-monospace,Menlo,monospace;color:#fff;text-align:center;overflow:hidden;transition:background .35s,flex-basis .45s;min-width:0;padding:0 2px}.legacy-content .kv-seg span {white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100%}.legacy-content .kv-seg.s-id {background:#3450d4}.legacy-content .kv-seg.s-persona {background:#7c3aed}.legacy-content .kv-seg.s-tool {background:#0891b2}.legacy-content .kv-seg.s-tool.alt {background:#0aa5c9}.legacy-content .kv-seg.s-ctx {background:#d97706}.legacy-content .kv-seg.s-hist {background:#9ca3af}.legacy-content .kv-seg.hit {filter:saturate(.35) brightness(1.28)}.legacy-content .kv-seg.hit:after {content:"";position:absolute;left:0;right:0;bottom:0;height:4px;background:var(--success)}.legacy-content .kv-seg.miss {filter:none}.legacy-content .kv-seg.miss:after {content:"";position:absolute;left:0;right:0;bottom:0;height:4px;background:var(--danger)}.legacy-content .kv-seg.pulse {animation:kvpulse .6s ease}@keyframes kvpulse{50%{transform:translateY(-4px)}}.legacy-content .kv-legend {display:flex;flex-wrap:wrap;gap:12px;margin-top:10px;font-size:11.5px;color:var(--sub)}.legacy-content .kv-legend i {display:inline-block;width:10px;height:10px;border-radius:3px;margin-right:4px;vertical-align:-1px}.legacy-content .kv-hitline {margin-top:10px;font:700 12px/1.6 ui-monospace,Menlo,monospace;color:var(--text);min-height:20px}.legacy-content .kv-hitline b.ok {color:var(--success)}.legacy-content .kv-hitline b.bad {color:var(--danger)}.legacy-content .kv-meter {background:var(--bg);border:1px solid var(--border);border-radius:12px;padding:14px}.legacy-content .kv-meter-title {font-size:12px;font-weight:800;color:var(--sub);margin-bottom:10px;display:flex;align-items:center;gap:6px}.legacy-content .kv-meter-title svg {color:var(--accent)}.legacy-content .kv-meter-num {font:800 30px/1.1 ui-monospace,Menlo,monospace;color:var(--danger)}.legacy-content .kv-meter-num.pop {animation:kvpop .45s ease}@keyframes kvpop{50%{transform:scale(1.22)}}.legacy-content .kv-meter-sub {font-size:11.5px;color:var(--sub);line-height:1.6;margin-top:6px}.legacy-content .kv-meter-row {display:flex;justify-content:space-between;gap:8px;font-size:12px;color:var(--text);margin-top:10px;padding-top:10px;box-shadow:0 -1px 0 var(--border)}.legacy-content .kv-meter-row b {font-family:ui-monospace,Menlo,monospace}.legacy-content .kv-caption {display:flex;gap:9px;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:64px}.legacy-content .kv-caption svg {flex:0 0 auto;color:var(--accent);margin-top:2px}@media(max-width:760px){.legacy-content .facts {grid-template-columns:1fr}.legacy-content .kv-stage {grid-template-columns:1fr}.legacy-content .kv-mode {margin-left:0;width:100%}.legacy-content .kv-mode button {flex:1}.legacy-content .source-head {flex-direction:column}.legacy-content .objective {grid-template-columns:1fr}.legacy-content .lesson-header:after {display:none}.legacy-content .kv-btn {flex:1 1 auto;justify-content:center}.legacy-content .kv-ribbon {height:44px}}

.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)}