.lesson-body section{margin-bottom:48px;scroll-margin-top:24px}.lesson-body p,.lesson-body dd{color:var(--muted)}.lesson-body h2{font-size:30px}.lesson-body h3{font-size:24px}.lesson-body .eyebrow{font-size:14px;color:var(--teal)}.lesson-body figure{margin:20px 0}.lesson-body img{display:block;max-width:100%;width:auto;max-height:580px;margin:auto;border-radius:8px}.lesson-body figcaption,.reference{font-size:14px;color:var(--muted);margin-top:10px}.axes-grid,.surface-intro{display:grid;grid-template-columns:1fr 1fr;gap:28px;align-items:start}.axes-grid figure{margin:0}.surface-intro{grid-template-columns:1.1fr 1fr}.surface-intro h3{font-size:32px;margin:12px 0}.surface-panel{padding:28px;background:white;border:1px solid var(--line);border-radius:14px;margin-top:18px}.surface-panel[hidden]{display:none}.surface-picker{display:flex;flex-wrap:wrap;gap:10px}.surface-picker button{padding:12px 16px;border:1px solid #a9bdc6;border-radius:8px;color:var(--navy);background:white;cursor:pointer;font-weight:600}.surface-picker button[aria-pressed=true]{background:var(--navy);color:white;border-color:var(--navy)}dt{font-weight:700;margin-top:20px;color:var(--ink)}dd{margin:5px 0 16px}.key-point{padding:16px;border-left:3px solid var(--teal);background:var(--paper);font-weight:600}.deeper{border-top:1px solid var(--line);padding:18px 0;margin-top:18px}.deeper summary{color:var(--teal);cursor:pointer;font-weight:700;line-height:1.6}.deeper p{margin-top:16px}.spoiler-diagram{width:100%;height:auto;margin:18px 0}.concept-checks{padding:0 24px;background:white;border:1px solid var(--line);border-radius:12px}.concept-checks .deeper:first-child{border-top:0;margin-top:0}#sources li{margin:18px 0}#sources li p{font-size:15px}.lesson-body{min-width:0}.lesson-body a{overflow-wrap:anywhere}@media(max-width:650px){.axes-grid,.surface-intro{grid-template-columns:1fr}.surface-panel{padding:20px}.surface-picker button{flex:1 1 140px}.lesson-body h2{font-size:27px}.surface-intro h3{font-size:28px}.lesson-body img{max-height:600px}.lesson-body section{margin-bottom:36px}}