/* Shared course UI. Physics is the baseline for both subjects. */
.course-interface .course-return{display:block;margin-bottom:25px;font:400 12px/1.6 Inter,sans-serif;color:#1557c7;text-decoration:none}
.course-interface .directory-course{font:700 15px/1.5 Inter,sans-serif;color:#0b2545}
.course-interface .directory-course small{display:block;margin-top:5px;font:400 11px/1.5 Inter,sans-serif;color:#5a7396}
.course-interface .directory-label{font:400 10px/1.5 Inter,sans-serif;letter-spacing:1.5px;color:#5a7396;margin:30px 0 12px}
.course-interface .physics-course-header{display:block;position:relative;padding:24px 18px 0;background:transparent;border:0}
.course-interface .physics-course-header .sidebar-close-x-btn{position:absolute;top:22px;right:18px}
.course-interface .physics-course-header+.directory-topics-list{padding:0 18px 15px}
@font-face{font-family:Inter;src:url('../assets/fonts/Inter-Variable.ttf') format('truetype');font-style:normal;font-weight:100 900;font-display:swap}
@font-face{font-family:Outfit;src:url('../assets/fonts/Outfit-Variable.ttf') format('truetype');font-style:normal;font-weight:100 900;font-display:swap}
body.course-interface{--course-paper:#fff;--course-ink:#0b2545;--course-muted:#42597a;--course-line:#e4ebf5;--course-side:#f8fbff;--course-content:1130px;background:var(--course-paper);color:var(--course-ink);font-family:Inter,system-ui,-apple-system,sans-serif;font-size:16px}
.course-interface .lab-top-navbar,.course-interface .site-header{height:64px!important;background:#fff!important;border-bottom:1px solid var(--course-line)!important}
.course-interface .header-inner{padding:0 40px;max-width:none}
.course-interface .site-brand,.course-interface .physics-brand{font-family:Outfit,Inter,sans-serif;font-size:15px;font-weight:800;letter-spacing:-.5px;text-transform:uppercase}
.course-interface .topic-workspace,.course-interface .workspace{--directory-width:280px;min-height:calc(100vh - 64px);max-width:none}
.course-interface .directory-collapsed{--directory-width:30px}
.course-interface .course-directory{background:var(--course-side);height:calc(100vh - 64px);font-family:Inter,system-ui,sans-serif}
.course-interface .minimal-topic-title{font-family:Inter,system-ui,sans-serif;font-size:15.2px;font-weight:800}
.course-interface .minimal-topic-header{padding:8px 12px}
.course-interface .minimal-subtopic-item{font-family:Inter,system-ui,sans-serif;font-size:13px;line-height:1.5;color:#5a7396}
.course-interface .minimal-subtopic-item.current{background:#cfe0fa;color:#0a2f73;font-weight:800}
.course-interface .overview,.course-interface .lesson-body{width:100%;max-width:1192px;margin:0 auto;padding:24px 31px 40px;background:white;min-width:0}
.course-interface .cognito-study-console{max-width:var(--course-content)}
.course-interface .overview-head h1,.course-interface .lesson-header h1,.course-interface .lesson-title-row h1{font:850 26px/1.3 Outfit,Inter,sans-serif;color:var(--course-ink);letter-spacing:-.5px}
.course-interface .overview-head .eyebrow,.course-interface .lesson-header .eyebrow,.course-interface .spec-tier-pill{font:800 11px/1.5 Inter,sans-serif;letter-spacing:.6px;text-transform:uppercase;background:#f2f7fe;color:#1b6ef3;padding:3px 8px;border-radius:6px;width:fit-content}
.course-interface .lesson-header .intro-text,.course-interface .overview-head .intro-text{font:400 16px/1.65 Inter,system-ui,sans-serif;color:var(--course-muted)}
.course-interface .maths-study-map,.course-interface .note-section,.course-interface .nb-block{background:#fff;border:1px solid var(--course-line);border-radius:14px;box-shadow:none;color:var(--course-ink)}
.course-interface .maths-study-map{padding:16px}
.course-interface .section-head{padding:18px 20px 12px 24px;background:#fff;border-color:var(--course-line)}
.course-interface .section-head h2,.course-interface #notes-content-1-1 .nb-block-title{font:800 18px/1.4 Outfit,Inter,sans-serif;color:var(--course-ink)}
.course-interface .section-head p{font:400 14px/1.65 Inter,sans-serif;color:var(--course-muted)}
.course-interface .note-grid{padding:6px 20px 18px 24px;gap:22px;align-items:start}
.course-interface .note-copy,.course-interface #notes-content-1-1 .nb-block-desc{font:400 16px/1.65 Inter,system-ui,sans-serif;color:var(--course-muted)}
.course-interface .note-copy .formula{font:22px/1.6 Georgia,serif;color:var(--course-ink)}
.course-interface .diagram{background:#f8fbff;border:1px solid var(--course-line);border-radius:11px;padding:16px}
.course-interface .diagram.green{background:#f8fbff;border-color:var(--course-line)}
.course-interface .callout{background:#f2f7fe;border-top:1px solid #cfe0fa;font:400 15px/1.65 Inter,sans-serif;color:var(--course-muted)}
.course-interface .minimal-topic-chevron{border:0;background:transparent;color:#5a7396;width:24px;min-width:24px;height:24px;padding:0;display:grid;place-items:center;cursor:pointer;font:11px Inter,sans-serif}
.course-interface .canvas-narration{font:400 15px/1.65 Inter,sans-serif;min-height:50px}
.course-interface .canvas-transport label{font-size:12px}
@media(max-width:760px){
 .course-interface .header-inner{padding:0 16px}
 .course-interface .course-directory{top:64px;height:calc(100dvh - 64px)}
 .course-interface .directory-backdrop{top:64px;height:calc(100dvh - 64px)}
 .course-interface .overview,.course-interface .lesson-body{padding:18px 12px 30px}
 .course-interface .section-head{padding:16px 15px 10px;gap:10px}
 .course-interface .note-grid{padding:8px 15px 16px;gap:16px}
 .course-interface .note-copy{font-size:16px}
 .course-interface .canvas-narration{font-size:14px}
 .course-interface .diagram{padding:12px}
}
.course-interface .course-directory,.course-interface .directory-left-sidebar,.course-interface .maths-study-map,.course-interface .nb-block{font-family:Inter,system-ui,-apple-system,sans-serif;font-size:16px;font-weight:400;line-height:1.5}
.course-interface .maths-study-map .map-canvas{min-width:960px}
.course-interface .topic1-study-map .note-node h2{font-family:Outfit,Inter,sans-serif;font-size:16px;font-weight:600}
.course-interface .nb-block:hover,.course-interface .note-section:hover{box-shadow:none;transform:none}

/* Keep the path and reading controls visible on topic and lesson pages. */
.course-interface .course-reading-toolbar,
.course-interface .topic1-overview-toolbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;margin:0 auto 20px;padding:10px 0;position:relative;top:auto;z-index:2}
.course-interface .course-reading-toolbar .lesson-breadcrumbs,
.course-interface .topic1-overview-toolbar .lesson-breadcrumbs{display:flex;flex-wrap:wrap;align-items:center;gap:6px;min-width:0;white-space:normal;font:600 13px/1.6 Inter,sans-serif;color:#5a7396;margin:0}
.course-interface .course-reading-toolbar .lesson-breadcrumbs{flex:1 1 300px}
.course-interface .course-reading-toolbar .breadcrumb>span{padding:0}
.course-interface .lesson-breadcrumbs a,
.course-interface .topic1-overview-toolbar .lesson-breadcrumbs button{border:0;background:transparent;padding:0;color:#1557c7;font:inherit;text-decoration:none;cursor:pointer}
.course-interface .lesson-breadcrumbs a:hover,
.course-interface .topic1-overview-toolbar .lesson-breadcrumbs button:hover{text-decoration:underline}
.course-interface .course-reading-controls{display:flex;align-items:center;gap:4px;flex-shrink:0;border:1px solid #e4ebf5;border-radius:8px;padding:2px 4px;background:#f3f7fd}
.course-interface .course-reading-controls .font-zoom-btn{min-width:32px;min-height:32px;border:0;border-radius:6px;background:transparent;color:#42597a;font:800 12px Outfit,Inter,sans-serif;cursor:pointer;padding:3px 8px}
.course-interface .course-reading-controls .font-zoom-label{min-width:38px;text-align:center;color:#1557c7;font:800 12px Outfit,Inter,sans-serif}
.course-interface .course-reading-controls button:hover:not(:disabled){background:#fff;color:#0b2545}
.course-interface .course-reading-controls button:disabled{opacity:.4;cursor:default}
.course-interface .course-reading-controls button:focus-visible,
.course-interface .lesson-breadcrumbs a:focus-visible,
.course-interface .topic1-overview-toolbar .lesson-breadcrumbs button:focus-visible{outline:2px solid #1557c7;outline-offset:3px}
@media(max-width:760px){
 .course-interface .course-reading-toolbar,
 .course-interface .topic1-overview-toolbar{gap:8px;padding:4px 0 10px}
 .course-interface .course-reading-toolbar .lesson-breadcrumbs{flex-basis:100%}
 .course-interface .topic1-overview-toolbar .lesson-header-left{width:100%;min-width:0}
 .course-interface .topic1-overview-toolbar .lesson-header-right{flex-wrap:wrap;gap:8px}
 .course-interface .course-reading-controls .font-zoom-btn{min-height:36px;min-width:36px}
}