/* Brand chrome only. Do not override formula applicability, plots, diagrams,
   task feedback, laboratory controls or lesson-specific typography. */
.energy-course{--brand-navy:#102c60;--brand-blue:#2351b5;--brand-turquoise:#72e0cc;--brand-text:#16345e;--brand-muted:#536980;--brand-line:#d6e1eb;--brand-paper:#f6f9fc;background:var(--brand-paper)}
.energy-course .workspace{background:var(--brand-paper)}
.energy-course .sidebar{background:#f0f5fa;border-right-color:var(--brand-line);color:var(--brand-text)}
.energy-course .brand{font-family:Inter,"Segoe UI",Arial,sans-serif;font-size:19px;line-height:1.18;letter-spacing:-.55px;margin-left:8px;margin-right:4px;gap:11px;color:var(--brand-navy)}
.energy-course .brand-mark{flex:0 0 42px;width:42px;height:42px;background:var(--brand-turquoise);color:var(--brand-navy);font-family:Inter,"Segoe UI",Arial,sans-serif;font-size:24px;font-weight:700;border-radius:12px}
.energy-course .brand-sub{font-size:9px;letter-spacing:.08em;color:var(--brand-muted);line-height:1.4;margin-top:6px}
.energy-course .search-button{background:#fff;border-color:#b9cbdc;color:var(--brand-muted)}
.energy-course .search-button kbd{border-color:#c5d4e1;color:#526a82}
.energy-course .nav-label{color:#526b84}
.energy-course .nav-link:hover{background:#e3edf7}
.energy-course .nav-link.active{background:#dce8fa;color:#163f8d}
.energy-course .nav-number{color:#526b84}
.energy-course .nav-dot{background:#5b7591}
.energy-course .nav-children{border-color:#cad9e7}
.energy-course .expand-button{color:#426281}
.energy-course .expand-button:hover{background:#dce8f4}
.energy-course .sidebar-note{border-color:var(--brand-line);color:#536980}
.energy-course .sidebar-note strong{color:#294968}
.energy-course .sidebar-note .status-dot{background:#357a6e}
.energy-course .bank-nav-link{background:#dff5f0;border-color:#a9d9cf;color:var(--brand-navy);box-shadow:none}
.energy-course .bank-nav-link:hover,.energy-course .bank-nav-link.active{background:#bdebe0;border-color:#76b9aa;color:var(--brand-navy)}
.energy-course .bank-nav-link small{color:#42675f}
.energy-course .topbar{background:var(--brand-navy);border-bottom-color:#294573;color:#fff}
.energy-course .topbar-title{color:#edf4ff;font-family:Inter,"Segoe UI",Arial,sans-serif;font-size:14px;font-weight:600;letter-spacing:-.2px}
.energy-course .topbar .draft-badge{color:#c2d6ed}
.energy-course .topbar .draft-badge>span{background:var(--brand-turquoise)}
.energy-course .topbar .owner-mark{background:#284a78;color:#fff}
.energy-course .topbar .menu-toggle{color:#fff}
.energy-course .topbar .menu-toggle:hover{background:#284a78}
.energy-course .bank-top-link{background:#183e76;color:#fff;border-color:#6c88b0}
.energy-course .bank-top-link:hover,.energy-course .bank-top-link.active{background:var(--brand-turquoise);color:var(--brand-navy);border-color:var(--brand-turquoise)}
.energy-course .topbar a:focus-visible,.energy-course .topbar button:focus-visible,.energy-course .brand-home-hero a:focus-visible{outline:3px solid #fff4da;outline-offset:4px}
.energy-course .sidebar a:focus-visible,.energy-course .sidebar button:focus-visible,.energy-course .page-head a:focus-visible,.energy-course .section-card:focus-visible,.energy-course .extra-card:focus-visible,.energy-course .bank-home-link:focus-visible{outline:3px solid #2351b5;outline-offset:4px}
.energy-course .edition-note{background:#edf3fa;border-bottom-color:var(--brand-line);color:#294968;font-size:12px}
.energy-course .edition-note span{color:#536980}
.energy-course .edition-note a{color:#204b8f}
.energy-course .page-head{color:var(--brand-text)}
.energy-course .page-head .eyebrow,.energy-course .page-head .page-label{color:#526b84}
.energy-course .page-head .tiny-square{background:#248875}
.energy-course .brand-home-hero{position:relative;isolation:isolate;overflow:hidden;display:grid;grid-template-columns:1fr;align-items:center;gap:30px;min-height:0;padding:clamp(28px,3.5vw,48px);background:var(--brand-navy);color:#fff;border:1px solid #193d72;border-radius:20px}
.energy-course .brand-home-hero.has-portrait{grid-template-columns:minmax(0,1.03fr) minmax(0,1fr)}
.energy-course .brand-home-copy{position:relative;z-index:1;min-width:0}
.energy-course .brand-home-eyebrow{display:flex;align-items:center;gap:10px;color:#c2d6ed;text-transform:uppercase;letter-spacing:.1em;font-size:10px;line-height:1.6;margin:0 0 20px}
.energy-course .brand-home-eyebrow>span{width:23px;height:1px;background:var(--brand-turquoise);flex-shrink:0}
.energy-course .brand-home-hero h1{font-family:Inter,"Segoe UI",Arial,sans-serif;font-size:clamp(33px,3.2vw,52px);font-weight:700;line-height:1.1;letter-spacing:-1.8px;color:#fff;margin:0;max-width:570px;overflow-wrap:normal}
.energy-course .brand-home-hero h1 em{display:block;font-family:inherit;font-size:inherit;font-weight:700;font-style:normal;color:var(--brand-turquoise);letter-spacing:inherit}
.energy-course .brand-home-welcome{font-size:14px;line-height:1.75;color:#c2d6ed;max-width:440px;margin:24px 0 28px}
.energy-course .brand-home-actions{display:flex;align-items:center;gap:22px;flex-wrap:wrap}
.energy-course .brand-home-primary{display:inline-flex;align-items:center;justify-content:space-between;gap:26px;padding:14px 20px;background:var(--brand-turquoise);color:var(--brand-navy);border:1px solid var(--brand-turquoise);border-radius:30px;font-size:13px;line-height:1.4;font-weight:650}
.energy-course .brand-home-primary:hover{background:#9aebdc;border-color:#9aebdc}
.energy-course .brand-home-secondary{display:inline-flex;align-items:center;gap:16px;color:#f3f8ff;font-size:13px;line-height:1.4;border-bottom:1px solid #7998bd;padding:9px 0}
.energy-course .brand-home-secondary:hover{color:var(--brand-turquoise)}
.energy-course .brand-home-portrait{position:relative;z-index:1;margin:0;min-width:0;padding:9px 9px 0;border:1px solid #ffffff36;border-radius:18px;background:#ffffff0a}
.energy-course .brand-home-portrait>img{display:block;width:100%;height:auto;max-width:100%;aspect-ratio:2048/1365;object-fit:contain;border-radius:11px}
.energy-course .brand-home-portrait figcaption{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:13px 3px;font-size:10px;line-height:1.5;color:#fff}
.energy-course .brand-home-portrait figcaption strong{font-weight:600}
.energy-course .brand-home-portrait figcaption span{max-width:125px;text-align:right;font-size:8px;color:#c2d6ed}
.energy-course .brand-home-orbits{position:absolute;width:430px;height:430px;right:-190px;top:-160px;border:1px solid #72e0cc2e;border-radius:50%;z-index:0;pointer-events:none}
.energy-course .brand-home-orbits>span{position:absolute;inset:45px;border:1px solid #72e0cc2e;border-radius:50%}
.energy-course .brand-home-orbits>span+span{inset:90px}
.energy-course .bank-home-link{background:#dff5f0;border-color:#a9d9cf;color:var(--brand-navy)}
.energy-course .bank-home-link:hover{background:#c8eee5}
.energy-course .bank-home-link small{color:#42675f}
.energy-course .course-stats{border-color:var(--brand-line);color:var(--brand-muted)}
.energy-course .course-stats span+span{border-color:var(--brand-line)}
.energy-course .course-stats strong{color:var(--brand-text);font-weight:650}
.energy-course .section-heading h2{color:var(--brand-text);font-weight:650;letter-spacing:-.5px}
.energy-course .section-heading .eyebrow,.energy-course .section-heading .subtle{color:var(--brand-muted)}
.energy-course .section-card{background:#fff;border-color:var(--brand-line);border-radius:13px;color:var(--brand-text)}
.energy-course .section-card:hover{border-color:#90b1da;box-shadow:0 8px 24px #16345e0c}
.energy-course .section-card h3{font-weight:600}
.energy-course .section-card p,.energy-course .section-card .section-number,.energy-course .section-card .card-bottom{color:var(--brand-muted)}
.energy-course .section-card .card-bottom{border-color:#e3eaf1}
.energy-course .section-card .card-icon{background:#e6f5f1;color:#267966}
.energy-course .extra-card{background:#fff;border-color:var(--brand-line);color:#244875}
.energy-course .extra-card strong{color:#244875}
.energy-course .extra-card small{color:var(--brand-muted)}
.energy-course .extra-card:hover{background:#edf4fc;border-color:#adc4e0}
.energy-course .construction-note{background:#eef3f9;border-color:var(--brand-line);color:#536980}
.energy-course .construction-note strong,.energy-course .construction-note a{color:#294e7c}
.energy-course .breadcrumbs{color:#586e85}
.energy-course .breadcrumbs a{color:#2d5790}
.energy-course .breadcrumbs [aria-current]{color:#28496d}
.energy-course .detail-hero{background:#edf4fb;border-color:#cddfed;border-radius:14px;color:var(--brand-text)}
.energy-course .detail-hero>p,.energy-course .detail-hero .eyebrow,.energy-course .detail-hero .detail-stat{color:#536980}
.energy-course .detail-hero h1{color:var(--brand-text);font-family:Inter,"Segoe UI",Arial,sans-serif;font-weight:650}
.energy-course .detail-hero .outline-badge{background:#fff;border-color:#adc5dd;color:#355b85}
.energy-course .topic-row{border-color:var(--brand-line);color:var(--brand-text)}
.energy-course .topic-row:hover{background:#f0f6fc}
.energy-course .topic-row p,.energy-course .topic-index,.energy-course .row-state{color:#536980}
.energy-course .material-tabs{border-bottom-color:var(--brand-line);background:#fbfdff;border-radius:12px 12px 0 0}
.energy-course .material-tab{color:#526b84}
.energy-course .material-tab.selected{color:#194993;border-color:#2351b5;font-weight:650}
.energy-course .sequence{border-color:var(--brand-line);color:#28496d}
.energy-course .sequence small{color:#536980}
.energy-course .sequence a:hover strong{color:#2351b5}
.energy-course .footer{border-color:var(--brand-line);color:#536980;background:#f0f5fa;font-size:11px}
.energy-course #search-dialog{background:#f8fbff;border-color:#bed0e2;color:var(--brand-text)}
.energy-course #search-input{border-color:#b6cada;color:var(--brand-text)}
.energy-course #search-input::placeholder{color:#62758a}
.energy-course .search-result:hover{background:#e7f0fb}
.energy-course .search-result small,.energy-course .result-count,.energy-course .search-hint,.energy-course .search-empty p{color:#536980}
.energy-course .search-empty strong{color:#294e7c}
.energy-course #course-sections{scroll-margin-top:90px}
@media(min-width:1500px){.energy-course .brand-home-hero{gap:44px;padding:48px}.energy-course .brand-home-hero h1{font-size:55px}}
@media(max-width:1150px){.energy-course .brand{font-size:18px;margin-left:3px;gap:9px}.energy-course .brand-mark{flex-basis:38px;width:38px;height:38px;font-size:22px}.energy-course .brand-home-hero{padding:30px;gap:24px}.energy-course .brand-home-hero h1{font-size:36px;letter-spacing:-1.2px}.energy-course .brand-home-welcome{font-size:13px;margin:20px 0 24px}.energy-course .brand-home-actions{gap:14px}.energy-course .brand-home-primary,.energy-course .brand-home-secondary{font-size:12px}.energy-course .brand-home-portrait figcaption span{display:none}}
@media(min-width:851px) and (max-width:1030px){.energy-course .brand-home-hero.has-portrait{grid-template-columns:1fr}.energy-course .brand-home-portrait{max-width:600px;width:100%;justify-self:center}.energy-course .brand-home-portrait figcaption span{display:block}.energy-course .brand-home-hero h1{max-width:600px}.energy-course .brand-home-welcome{max-width:520px}}
@media(max-width:700px){.energy-course .brand-home-hero.has-portrait{grid-template-columns:1fr}.energy-course .brand-home-hero{padding:28px;gap:28px}.energy-course .brand-home-hero h1{font-size:40px}.energy-course .brand-home-portrait{max-width:600px;width:100%;justify-self:center}.energy-course .brand-home-portrait figcaption span{display:block}.energy-course .brand-home-welcome{max-width:490px;font-size:14px}}
@media(max-width:570px){.energy-course .topbar-title{display:block;max-width:100px;font-size:11px;line-height:1.25;white-space:normal}.energy-course .topbar .owner-mark{display:none}.energy-course .topbar-right{gap:0}.energy-course .topbar{gap:10px}.energy-course .brand-home-hero{padding:26px 21px;gap:25px;border-radius:16px}.energy-course .brand-home-hero h1{font-size:35px;line-height:1.12;letter-spacing:-1.3px}.energy-course .brand-home-eyebrow{font-size:9px;margin-bottom:18px}.energy-course .brand-home-welcome{font-size:13px;margin:20px 0 23px}.energy-course .brand-home-actions{gap:16px}.energy-course .brand-home-primary{padding:13px 17px;gap:20px}.energy-course .brand-home-secondary{font-size:12px}.energy-course .brand-home-portrait{padding:7px 7px 0;border-radius:13px}.energy-course .brand-home-portrait>img{border-radius:7px}.energy-course .brand-home-portrait figcaption{font-size:9px;padding:10px 1px}.energy-course .brand-home-portrait figcaption span{font-size:8px;max-width:112px}.energy-course .edition-note{font-size:11px}.energy-course .bank-home-link{padding:20px}.energy-course .bank-home-link strong{font-size:19px}.energy-course .bank-home-link small{font-size:12px}.energy-course .bank-home-link>span:last-child{font-size:13px}.energy-course .footer{font-size:10px}.energy-course .detail-hero h1{font-size:29px}}
@media(max-width:360px){.energy-course .brand-home-hero{padding:23px 18px}.energy-course .brand-home-hero h1{font-size:31px}.energy-course .brand-home-actions{align-items:flex-start;flex-direction:column;gap:12px}.energy-course .topbar-title{max-width:78px}.energy-course .bank-top-link{font-size:11px;padding-left:10px;padding-right:10px}}
@media(prefers-reduced-motion:reduce){.energy-course .section-card{transition:none}}