.course-heading{display:grid;grid-template-columns:1fr 260px;gap:48px;padding:52px var(--gutter) 48px}.course-heading h1{font-size:clamp(48px,6vw,88px);margin-bottom:24px}.course-heading p{max-width:60ch}.course-resources{font-size:var(--small);align-self:end}.course-resources p{margin-bottom:20px}.course-main{display:grid;grid-template-columns:270px minmax(0,1fr);gap:48px;padding:0 var(--gutter)}#nav{position:sticky;top:24px;align-self:start;max-height:calc(100vh - 48px);overflow:auto;padding:10px 0}#nav button{display:block;width:100%;text-align:left;font-size:var(--small);padding:12px 16px;background:transparent;margin-bottom:4px;line-height:1.35}#nav button[aria-current=true]{background:var(--surface);font-weight:600}#content{min-width:0}#content section{padding:32px;background:var(--surface);margin-bottom:28px}#content section:nth-child(even){background:transparent}#content h2{font-size:38px;max-width:36ch;margin:0 0 28px}#content h3{font-size:var(--lead);margin:16px 0}#content p{margin:18px 0;max-width:65ch}#content details{padding:16px 0;margin:12px 0}#content summary{font-weight:600;min-height:44px;font-size:var(--body);line-height:1.4}#content details[open] summary{margin-bottom:16px}.method{background:var(--bg);padding:24px}.source,.note,.formula-key{font-size:var(--small);color:var(--muted)}.formula-key{margin:20px 0}.formula-row{padding:18px 0;overflow:auto}.formula-row p{font-size:var(--small);color:var(--muted)}math{font-size:1.12em;text-align:left;margin:12px 0;font-family:'Cambria Math',serif}.controls{display:flex;gap:28px;flex-wrap:wrap;margin:28px 0;background:var(--surface);padding:24px}.controls label{flex:1;min-width:170px;font-size:var(--small)}.controls output{float:right;font-variant-numeric:tabular-nums}#fig{width:100%;height:auto;display:block;background:var(--surface);margin:24px 0}#fig text{font:16px Erode,Georgia,serif;fill:var(--ink)}.readout{background:var(--surface);padding:24px;font-size:var(--body);font-variant-numeric:tabular-nums}#time{display:block;width:100%}#play{background:var(--ink);color:var(--bg);margin-top:20px}.task{padding:28px 0}.task+.task{margin-top:28px}.answer{font-weight:600}.pager{display:flex;justify-content:space-between;gap:20px}.pager button{background:var(--ink);color:var(--bg);font-size:var(--small)}button:disabled{opacity:.35;cursor:default}.mobile-topics{display:none}.formula-view{padding:52px var(--gutter) 0}.formula-title h1{font-size:clamp(48px,6vw,88px);max-width:15ch;line-height:1}.formula-title p{margin:28px 0}.formula-view section{margin:80px auto 0;max-width:960px;background:var(--surface);padding:24px}.formula-view h2{font-size:var(--lead);margin:0 0 24px}.formula-view section img{background:white}.formula-view section a{display:block}
@media(max-width:1000px){.course-main{grid-template-columns:220px minmax(0,1fr);gap:28px}#content section{padding:24px}#content h2{font-size:32px}.course-heading{grid-template-columns:1fr 190px}}
@media(max-width:700px){.course-heading{display:block;padding-top:28px;padding-bottom:28px}.course-heading h1{font-size:52px}.course-resources{margin-top:24px;display:flex;gap:24px;align-items:center}.course-resources p{margin:0}.course-main{display:block}#nav{display:none}.mobile-topics{display:block;padding:0 var(--gutter) 28px}.mobile-topics label{display:block;font-size:var(--small);margin-bottom:10px}.mobile-topics select{font:inherit;font-size:var(--small);background:var(--surface);color:var(--ink);border:0;min-height:48px;width:100%;padding:12px}#content section{padding:24px 20px}#content h2{font-size:28px}#content h3{font-size:24px}#content p{font-size:18px}#content .source,#content .note,#content .formula-row p{font-size:16px}.controls{padding:20px;gap:20px}.controls label{min-width:100%}.method{padding:18px}#fig text{font-size:18px}math{font-size:1em}.formula-view{padding-top:28px}.formula-title h1{font-size:48px}.formula-view section{padding:12px;margin-top:48px}.formula-view h2{padding:12px}.pager button{padding:12px;min-width:0}.task{padding:20px 0}}
@media print{.site-nav,.site-footer,.formula-title,.formula-view h2{display:none}.formula-view{padding:0}.formula-view section{margin:0;padding:0;max-width:none;background:none;break-after:page}.formula-view section img{height:270mm;width:auto;max-width:100%;margin:auto}.course-heading,.mobile-topics,#nav,.controls,#play,.pager{display:none}.course-main{display:block;padding:0}#content section{background:none;break-inside:avoid}details>*{display:block!important}@page{size:A4;margin:8mm}}