#lesson{margin:28px 0;border:1px solid var(--line);border-radius:14px;background:#fbfaf6}#lesson summary{padding:22px 24px;cursor:pointer;font-size:20px;font-weight:600}#lesson summary span{font-size:13px;font-weight:400;color:var(--muted);margin-left:16px}.lesson-body{padding:0 24px 22px}.lesson-tabs{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 22px}.lesson-tabs button[aria-pressed=true]{background:var(--accent);color:white;border-color:var(--accent)}.lesson-grid{display:grid;grid-template-columns:1.2fr 1fr;gap:30px;align-items:start}#lesson-canvas{height:350px;background:#101c25;border-radius:10px;touch-action:auto}.lesson-copy h2{font-size:24px;margin:0 0 12px;letter-spacing:-.03em}.lesson-copy p{font-size:14px;line-height:1.7;margin:0 0 16px;color:var(--muted)}.lesson-copy .eyebrow{font-size:11px;color:var(--accent)}.lesson-copy pre{white-space:pre-wrap;overflow-wrap:anywhere;background:#edf1ea;padding:16px;border-radius:8px;font:13px/1.8 ui-monospace,Consolas,monospace;min-height:100px;font-variant-numeric:tabular-nums}.lesson-buttons{display:flex;gap:8px;margin:12px 0}.lesson-note{border-top:1px solid var(--line);padding-top:18px;font-size:12px;line-height:1.7;color:var(--muted);margin-bottom:0}.lesson-copy #lesson-result{color:var(--accent)}#frequency-control{margin:16px 0}#lesson-position-label{margin-top:16px}
@media(max-width:800px){.lesson-grid{grid-template-columns:1fr;gap:20px}#lesson-canvas{height:290px}#lesson summary span{display:block;margin:8px 0 0}.lesson-body{padding:0 16px 18px}.lesson-tabs button{flex:1;padding:9px 7px;font-size:12px}.lesson-copy pre{font-size:12px}}