/* Shared chapter/lab composition contract extracted from the established M2.5 component baseline. */
.chapter-page{overflow-x:hidden}.chapter-page main{overflow:visible}.chapter-links .is-current{color:var(--accent);border-color:var(--accent);background:var(--bg-soft)}.chapter-hero,.chapter-section,.chapter-pagination{width:min(var(--max),calc(100% - 2rem));margin-inline:auto}.chapter-hero{padding:clamp(2rem,5vw,4.5rem) 0 clamp(3rem,7vw,6rem)}.chapter-kicker{display:flex;flex-wrap:wrap;gap:.55rem;align-items:center;margin-bottom:1.5rem;color:var(--muted);font-size:.78rem}.chapter-kicker a{color:var(--muted);text-decoration:none}.chapter-kicker strong{color:var(--accent)}.chapter-hero-grid{display:grid;grid-template-columns:.86fr 1.14fr;align-items:center;gap:clamp(2rem,5vw,5rem)}.chapter-hero h1{margin:0;font-size:clamp(3.1rem,6.6vw,6.8rem);line-height:.9;letter-spacing:-.055em}.chapter-hero h1 span{color:var(--accent)}.chapter-lede{max-width:760px;margin:1.4rem 0 0;color:var(--muted);font-size:clamp(1rem,1.3vw,1.16rem)}.assumption-row{display:flex;flex-wrap:wrap;gap:.45rem;margin-top:1.5rem}.assumption-row span{padding:.45rem .65rem;border:1px solid var(--line);border-radius:999px;color:var(--muted);background:var(--panel);font:700 .7rem ui-monospace,monospace}.chapter-concept{margin:0;padding:.65rem;border:1px solid var(--line);border-radius:22px;background:var(--panel)}.chapter-concept img{width:100%;border-radius:16px}.chapter-section{padding:clamp(3.5rem,7vw,6.5rem) 0;border-top:1px solid var(--line)}.concept-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1rem;margin-top:2rem}.concept-card{padding:1.1rem;border:1px solid var(--line);border-radius:var(--radius);background:var(--panel)}.concept-card h3{margin:.45rem 0}.concept-card p{color:var(--muted);font-size:.9rem}.formula{padding:.75rem;border:1px solid var(--line);border-radius:10px;background:var(--bg-soft);color:var(--accent);font:700 .84rem ui-monospace,monospace}.lab-shell{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:1rem;margin-top:2rem}.lab-main,.control-panel{border:1px solid var(--line);border-radius:var(--radius);background:var(--panel)}.lab-main{overflow:hidden}.lab-toolbar{display:flex;justify-content:space-between;align-items:center;padding:.8rem 1rem;border-bottom:1px solid var(--line)}.lab-toolbar-title{display:grid;grid-template-columns:auto 1fr;column-gap:.55rem;align-items:center}.lab-toolbar-title small{grid-column:2;color:var(--muted);font-size:.68rem}.status-dot{width:9px;height:9px;border-radius:50%;background:var(--accent)}.lab-button{padding:.45rem .7rem;border:1px solid var(--line);border-radius:9px;background:var(--bg-soft);color:var(--text);cursor:pointer}.plot-grid{display:grid;gap:.7rem;padding:.75rem}.plot-card{border:1px solid var(--line);border-radius:14px;background:var(--nav-bg);overflow:hidden}.plot-card header{display:flex;justify-content:space-between;padding:.6rem .75rem;border-bottom:1px solid var(--line);font-size:.78rem}.plot-card header span{color:var(--muted);font-size:.65rem}.plot-card svg{width:100%;display:block}.plot-bg{fill:var(--nav-bg)}.grid-line{stroke:var(--line);stroke-width:1}.control-panel{padding:1rem}.control{padding:.8rem 0;border-top:1px solid var(--line)}.control label{display:flex;justify-content:space-between;color:var(--muted);font-size:.75rem}.control input{width:100%;accent-color:var(--accent)}.control-note{padding:.8rem;border:1px solid var(--line);border-radius:10px;background:var(--bg-soft)}.control-note p{margin:.35rem 0 0;color:var(--muted);font-size:.72rem}.metric-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:.65rem;margin-top:.7rem}.metric-grid article{padding:.8rem;border:1px solid var(--line);border-radius:12px;background:var(--panel)}.metric-grid span,.metric-grid small{display:block;color:var(--muted);font-size:.66rem}.metric-grid strong{display:block;margin:.3rem 0}.interpretation-panel{display:grid;grid-template-columns:.75fr 1.25fr;gap:1.5rem;margin-top:.7rem;padding:1rem;border:1px solid var(--line);border-radius:var(--radius);background:var(--bg-soft)}.interpretation-panel p{margin:0;color:var(--muted)}.module-equation{display:flex;flex-wrap:wrap;gap:.55rem;justify-content:center;margin-top:1rem;padding:1rem;border:1px solid var(--line);border-radius:var(--radius);background:var(--panel)}.chapter-pagination{display:grid;grid-template-columns:1fr 1fr;gap:1rem;padding:0 0 4rem}.chapter-pagination a{display:grid;padding:1rem;border:1px solid var(--line);border-radius:13px;background:var(--panel);text-decoration:none}.chapter-pagination a:last-child{text-align:right}.chapter-pagination span{color:var(--muted);font-size:.7rem}@media(max-width:1000px){.chapter-hero-grid,.lab-shell{grid-template-columns:1fr}}@media(max-width:760px){.chapter-hero,.chapter-section,.chapter-pagination{width:min(100% - 1.2rem,var(--max))}.chapter-hero h1{font-size:clamp(2.9rem,14vw,4.8rem)}.concept-grid,.chapter-pagination,.interpretation-panel{grid-template-columns:1fr}.chapter-pagination a:last-child{text-align:left}.plot-card{overflow-x:auto}.plot-card svg{min-width:680px}}