@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,.24);border-radius:50%;box-shadow:0 0 0 26px rgba(77,107,254,.05),0 0 0 52px rgba(77,107,254,.028)}.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 .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 .core-visual {background:var(--card);border:1px solid rgba(77,107,254,.25);border-radius:18px;padding:24px;margin:24px 0;box-shadow:var(--shadow-card)}.legacy-content .core-visual 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 .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}.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 h4 {display:flex;align-items:center;gap:8px;margin:0 0 10px;font-size:15px;color:var(--text)}.legacy-content .cmp-card h4 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,#f0f3ff,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,.28);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 {background:var(--card);border:1px solid rgba(77,107,254,.25);border-radius:18px;padding:28px;box-shadow:var(--shadow-card)}.legacy-content .demo-bar {display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:20px}.legacy-content .demo-scenarios, .legacy-content .demo-ctrl {display:flex;gap:12px;flex-wrap:wrap}.legacy-content .demo button {display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:44px;padding:8px 14px;border-radius:10px;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:background .2s,border-color .2s,color .2s}.legacy-content .demo button.active, .legacy-content .demo button:active {background:var(--accent);border-color:var(--accent);color:#fff}.legacy-content .demo button svg {flex:none}.legacy-content .demo-stage {display:grid;grid-template-columns:1.35fr 1fr;gap:18px;align-items:start}.legacy-content .sp-outslot {min-height:64px;margin-bottom:12px}.legacy-content .oc {border:1px solid rgba(77,107,254,.35);background:var(--accent-soft);border-radius:12px;padding:10px 14px;display:flex;align-items:center;gap:10px;opacity:0;transform:translateY(-8px);transition:opacity .4s,transform .4s}.legacy-content .oc.show {opacity:1;transform:none}.legacy-content .oc svg {color:var(--accent);flex:none}.legacy-content .oc .oc-name {font:700 13px/1.4 ui-monospace,Menlo,monospace;color:var(--text)}.legacy-content .oc .oc-size {margin-left:auto;font:800 13px/1 ui-monospace,Menlo,monospace;color:var(--accent-deep);background:#fff;border:1px solid rgba(77,107,254,.3);border-radius:999px;padding:5px 10px}.legacy-content .oc.big .oc-size {color:var(--danger);border-color:rgba(220,38,38,.4)}.legacy-content .lanes {display:grid;grid-template-columns:1fr 1fr;gap:12px}.legacy-content .lane {border:1.5px dashed rgba(77,107,254,.3);border-radius:12px;background:var(--bg);min-height:170px;padding:10px}.legacy-content .lane-title {font:700 11px/1.5 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;color:var(--sub);letter-spacing:.04em;margin-bottom:8px;display:flex;align-items:center;gap:6px}.legacy-content .lane-title svg {color:var(--accent);flex:none}.legacy-content .cc {background:#fff;border:1px solid var(--border);border-radius:9px;padding:8px 10px;margin-bottom:7px;font:11.5px/1.55 ui-monospace,Menlo,monospace;color:var(--text);opacity:0;transform:translateY(6px);transition:opacity .4s,transform .4s;overflow-wrap:anywhere}.legacy-content .cc.show {opacity:1;transform:none}.legacy-content .cc.hint {border-color:rgba(77,107,254,.45);background:var(--accent-soft)}.legacy-content .cc.hint b {color:var(--accent-deep)}.legacy-content .cc.cut {border-color:rgba(217,119,6,.45);background:rgba(217,119,6,.07)}.legacy-content .cc.fat {border-color:rgba(217,119,6,.45);background:rgba(217,119,6,.07)}.legacy-content .cc .dim {color:var(--sub)}.legacy-content .fc {background:#fff;border:1px solid rgba(22,163,74,.4);border-radius:9px;padding:8px 10px;margin-bottom:7px;font:11.5px/1.55 ui-monospace,Menlo,monospace;color:var(--text);display:flex;gap:8px;align-items:center;opacity:0;transform:translateY(6px);transition:opacity .4s,transform .4s;overflow-wrap:anywhere}.legacy-content .fc.show {opacity:1;transform:none}.legacy-content .fc svg {color:var(--success);flex:none}.legacy-content .lane-empty {font:12px/1.6 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;color:var(--sub);text-align:center;padding:22px 6px}.legacy-content .sp-ret {margin-top:12px;min-height:56px}.legacy-content .rb {display:flex;gap:8px;align-items:flex-start;margin-bottom:8px;opacity:0;transform:translateY(6px);transition:opacity .4s,transform .4s}.legacy-content .rb.show {opacity:1;transform:none}.legacy-content .rb .who {flex:none;font:800 11px/1 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;color:#fff;background:var(--accent);border-radius:8px;padding:6px 8px;margin-top:2px}.legacy-content .rb.res .who {background:var(--success)}.legacy-content .rb.bad .who {background:var(--danger)}.legacy-content .rb .txt {font:12px/1.6 ui-monospace,Menlo,monospace;color:var(--text);background:#fff;border:1px solid var(--border);border-radius:9px;padding:7px 10px;overflow-wrap:anywhere}.legacy-content .checkpane {border:1px solid var(--border);border-radius:14px;background:var(--bg);padding:14px}.legacy-content .cp-title {font:700 11px/1.4 -apple-system,BlinkMacSystemFont,"PingFang SC",sans-serif;color:var(--sub);margin-bottom:10px;letter-spacing:.05em}.legacy-content .chk {display:flex;gap:9px;align-items:flex-start;padding:7px 8px;border-radius:8px;transition:background .25s}.legacy-content .chk .chk-ico {flex:none;width:18px;height:18px;border-radius:50%;border:2px solid rgba(77,107,254,.35);margin-top:2px;display:grid;place-items:center;background:#fff;transition:border-color .25s,background .25s}.legacy-content .chk .chk-ico svg {display:none}.legacy-content .chk b {display:block;font-size:12.5px;color:var(--text)}.legacy-content .chk small {font:11px/1.5 ui-monospace,Menlo,monospace;color:var(--sub)}.legacy-content .chk.on {background:rgba(77,107,254,.12)}.legacy-content .chk.on .chk-ico {border-color:var(--accent);background:var(--accent)}.legacy-content .chk.pass .chk-ico {border-color:var(--success);background:var(--success)}.legacy-content .chk.fail {background:rgba(220,38,38,.08)}.legacy-content .chk.fail .chk-ico {border-color:var(--danger);background:var(--danger)}.legacy-content .chk.pass .chk-ico svg.ok, .legacy-content .chk.fail .chk-ico svg.no, .legacy-content .chk.on .chk-ico svg.dot {display:block}.legacy-content .sp-status {margin-top:16px;min-height:56px;padding:16px 18px;border-radius:10px;background:var(--accent-soft);border:1px solid rgba(77,107,254,.22);font-size:14px;line-height:1.8;color:var(--text)}.legacy-content .demo-note {font-size:12px;color:var(--sub);margin-top:12px;line-height:1.7}.legacy-content .demo .flash-ok {animation:spok 1.2s ease}@keyframes spok{0%,100%{box-shadow:none}30%{box-shadow:0 0 0 3px rgba(22,163,74,.25)}}.legacy-content .demo .shake {animation:spshk .5s ease}@keyframes spshk{0%,100%{transform:translateX(0)}25%{transform:translateX(-5px)}50%{transform:translateX(5px)}75%{transform:translateX(-2px)}}@media(max-width:760px){.legacy-content .facts {grid-template-columns:1fr}.legacy-content .compare {grid-template-columns:1fr}.legacy-content .demo-stage {grid-template-columns:1fr}.legacy-content .lanes {grid-template-columns:1fr}.legacy-content .objective {grid-template-columns:1fr}.legacy-content .lesson-header:after {display:none}.legacy-content .demo-bar {flex-direction:column;align-items:stretch}.legacy-content .demo button {flex:1}}

.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)}