@keyframes _si{to{opacity:1}}

.legacy-content .lesson-header {position:relative;overflow:hidden;padding:42px 38px;border:1px solid rgba(217,149,24,.24);border-radius:24px;background:radial-gradient(circle at 88% 12%,rgba(244,185,66,.23),transparent 34%),linear-gradient(145deg,#fffaf0,var(--card));box-shadow:0 18px 50px rgba(100,64,7,.09)}.legacy-content .lesson-header:after {content:"79";position:absolute;right:28px;bottom:-26px;font-size:140px;font-weight:900;color:rgba(217,149,24,.07);line-height:1}.legacy-content .kicker {letter-spacing:.14em}.legacy-content .subtitle {max-width:760px;position:relative;z-index:1}.legacy-content .goal-strip, .legacy-content .snapshot, .legacy-content .takeaway {margin-top:18px;border:1px solid rgba(217,149,24,.22);background:var(--soft);border-radius:16px;padding:16px 20px;line-height:1.7}.legacy-content .goal-strip {display:grid;grid-template-columns:auto 1fr;gap:14px;align-items:start}.legacy-content .goal-strip b, .legacy-content .snapshot b, .legacy-content .takeaway b {color:var(--accent)}.legacy-content .icon {width:28px;height:28px;color:var(--accent);flex:none}.legacy-content .section-title {margin:34px 0 14px;font-size:13px;font-weight:800;letter-spacing:.12em;color:var(--accent);text-transform:uppercase}.legacy-content .arch {padding:24px;border:1px solid var(--border);border-radius:20px;background:var(--card);box-shadow:var(--shadow-card)}.legacy-content .arch svg {display:block;width:100%;height:auto;min-height:240px}.legacy-content .arch text {font-family:ui-monospace,SFMono-Regular,Menlo,monospace}.legacy-content .axis {display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:14px}.legacy-content .card {padding:19px;border:1px solid var(--border);border-radius:16px;background:var(--card);box-shadow:var(--shadow-card)}.legacy-content .card .num {font-size:30px;line-height:1;font-weight:900;color:var(--accent)}.legacy-content .card h3 {font-size:15px;margin:8px 0 6px}.legacy-content .card p, .legacy-content .snapshot {font-size:13px;color:var(--sub)}.legacy-content .evidence {display:grid;grid-template-columns:1fr 1fr;gap:16px}.legacy-content .path {font:700 11px/1.5 ui-monospace,monospace;color:var(--accent);overflow-wrap:anywhere}.legacy-content .code {margin-top:9px;padding:15px;border-radius:12px;background:var(--surface-soft);color:var(--muted);overflow:auto;font:12px/1.65 ui-monospace,monospace}.legacy-content .code .cm {color:#aa9570}.legacy-content .code .kw {color:#ffc85a}.legacy-content .exercise {display:grid;grid-template-columns:52px 1fr;gap:14px;align-items:start;padding:20px;border:1px dashed rgba(217,149,24,.45);border-radius:18px;background:linear-gradient(120deg,var(--soft),transparent)}.legacy-content .exercise strong {display:grid;place-items:center;width:44px;height:44px;border-radius:50%;background:var(--accent);color:white}.legacy-content .exercise h3 {margin:0 0 6px;font-size:16px}.legacy-content .exercise p {margin:0;color:var(--sub);line-height:1.7}.legacy-content .takeaway {display:flex;gap:12px;align-items:flex-start;font-size:15px;color:var(--text)}@media(max-width:760px){.legacy-content .lesson-header {padding:30px 22px}.legacy-content .lesson-header:after {font-size:92px}.legacy-content .axis, .legacy-content .evidence {grid-template-columns:1fr}.legacy-content .arch {padding:12px;overflow-x:auto}.legacy-content .arch svg {min-width:650px}.legacy-content .goal-strip {grid-template-columns:1fr}.legacy-content .exercise {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)}