@import url('/assets/fonts/satoshi.css');
:root{--font-display:'Satoshi',Arial,sans-serif;--font-text:'Satoshi',Arial,sans-serif;--bg:#f4f4f0;--surface:#e7e7e2;--ink:#111;--muted:#51514d;--accent:#e61919;--field:#f4f4f0;--field-ink:#111}
[data-theme=dark]{--bg:#121212;--surface:#252525;--ink:#f0f0ec;--muted:#b9b9b3;--accent:#ff5148;--field:#121212;--field-ink:#f0f0ec}
body,button,input,select,textarea{font-family:var(--font-text)}h1,.brand,.footer-wordmark,.atlas-course .course-title,.section-opening h2,.formula-set h2,.course-heading h1,#math-content h1,.sheet h1{font-family:var(--font-display);font-weight:900;letter-spacing:-.055em}.brand,h1,.footer-wordmark,.atlas-course .course-title,.section-opening h2,.formula-set h2{text-transform:uppercase}.brand{font-weight:900;letter-spacing:-.045em}.atlas-hero>h1{font-weight:900;font-size:clamp(100px,17.7vw,280px);line-height:1;overflow:visible;margin:0}.atlas-hero{padding-top:12px;row-gap:20px}.atlas-home .footer-wordmark{font-size:clamp(100px,17.7vw,280px);font-weight:900;line-height:1;overflow:visible}.footer-wordmark{font-weight:900;line-height:1;overflow:hidden}.site-nav{border-bottom:2px solid var(--ink)}.atlas-courses{border-top:2px solid var(--ink);border-bottom:2px solid var(--ink)}.atlas-course{border-top:1px solid var(--ink)}.atlas-course+.atlas-course{padding-top:36px}.atlas-courses .section-opening{margin-bottom:44px}.atlas-live{border:1px solid var(--ink);background:var(--bg)}.atlas-live h2,.method-sequence h3{font-weight:700}.atlas-method{background:var(--bg);border-top:2px solid var(--ink)}.site-footer{background:var(--bg);color:var(--ink);border-top:2px solid var(--ink)}.section-opening h2{line-height:1.02}.atlas-sheets{position:relative}.sheet-strip figure{background:var(--surface)}.sheet-strip figcaption{padding:12px;margin:0;border-top:1px solid var(--ink);font-size:15px}.sheet-strip a{overflow:hidden}.sheet-strip img{transition:transform .6s cubic-bezier(.16,1,.3,1)}.sheet-strip a:hover img{transform:scale(1.025)}.course-title{transition:color .2s}.course-title:hover{color:var(--accent)}.atlas-course-copy{min-width:0}.atlas-course .course-title{font-size:clamp(42px,6vw,84px)}.topic-ticker{overflow:hidden;border-top:1px solid var(--ink);border-bottom:1px solid var(--ink);padding:18px 0;display:block}.topic-ticker-track{display:flex;gap:42px;width:max-content;font-size:15px;font-weight:700;white-space:nowrap}.topic-ticker-track span{display:flex;gap:42px}.topic-ticker-track b{font:inherit;color:var(--accent)}.inline-sheet{display:inline-block;width:1.05em;height:.7em;overflow:hidden;vertical-align:baseline;margin-left:.12em;background:white;border:1px solid var(--ink)}.inline-sheet img{width:100%;height:100%;object-fit:cover;object-position:top}.resource-row{border-bottom:1px solid var(--ink)}.resource-filters{border:1px solid var(--ink);background:var(--bg)}.resource-filters input,.resource-filters select{border-bottom:1px solid var(--ink);background:var(--surface)}.subject-filter{border-bottom:1px solid var(--ink);padding-bottom:24px}.formula-set{border-top:1px solid var(--ink)}.math-sidebar{border-right:1px solid var(--surface)}#math-content{border-left:0}#math-content h1{font-size:40px;font-weight:900;text-transform:none;letter-spacing:-.04em;max-width:32ch}.portal-heading h1{font-weight:900;font-size:clamp(52px,7vw,100px);line-height:1.05;overflow:visible}.math-app .site-footer .footer-wordmark{font-size:clamp(72px,15vw,220px)}.course-heading h1{font-weight:900}.math-app p,#content p{font-weight:400}#math-content h2,#math-content h3,#content h2,#content h3{font-family:var(--font-text);font-weight:700;text-transform:none;letter-spacing:-.025em}.sheet h1{font-family:var(--font-display)!important;font-weight:900!important;letter-spacing:-.04em}.sheet h2{font-family:var(--font-text);font-weight:700}.lab,.worked{border:0;background:var(--surface)}.english-note{border:0}.atlas-home .arrived{animation:none}.atlas-home .atlas-live,.atlas-home .atlas-hero>h1{animation:none}.atlas-home .sheet-strip figure:nth-child(2) img{animation:none}
@media(prefers-reduced-motion:no-preference){.topic-ticker-track{animation:topics-travel 35s linear infinite}.topic-ticker:hover .topic-ticker-track{animation-play-state:paused}@keyframes topics-travel{to{transform:translateX(-50%)}}}
@media(max-width:750px){.atlas-hero>h1{font-size:17.6vw;margin-bottom:30px}.atlas-home .footer-wordmark{font-size:17.6vw}.atlas-course{padding:28px 0}.atlas-course-copy{margin-top:24px}.section-opening h2{font-size:42px}.portal-heading h1{font-size:14vw}#math-content h1{font-size:30px}.atlas-live{padding:18px}.atlas-intro .text-link{margin:18px 0 0}.sheet-strip figcaption{font-size:14px;padding:10px}.topic-ticker{padding:14px 0}.atlas-home .atlas-intro p{font-size:20px}}
@media(prefers-reduced-motion:reduce){.topic-ticker-track{animation:none}.sheet-strip img{transform:none!important}.pin-spacer{height:auto!important}.atlas-sheets .section-opening{position:static!important;transform:none!important}}
@media print{.sheet{font-size:12px;font-family:var(--font-text)}.sheet h1{font-family:var(--font-display)!important}.tools,.topic-ticker{display:none}}
.atlas-sheets{display:grid;grid-template-columns:minmax(0,.7fr) minmax(0,1.3fr);gap:48px;align-items:start}.atlas-sheets .section-opening{display:block;margin:0}.atlas-sheets .section-opening h2{font-size:clamp(42px,5vw,72px);margin-bottom:28px}.atlas-sheets .section-opening p{font-size:20px}.atlas-sheets .sheet-strip{grid-template-columns:1fr 1fr;gap:24px}.atlas-course[open] 
@media(max-width:750px){.atlas-sheets{display:block}.atlas-sheets .section-opening{margin-bottom:30px}.atlas-sheets .section-opening h2{font-size:42px}.atlas-sheets .sheet-strip{gap:22px 14px}}

/* Shared subject disclosure; course descriptions remain permanently visible. */
.site-nav{position:relative;z-index:50}.subjects-menu{position:relative}.subjects-menu>summary{display:flex;align-items:center;gap:8px;min-height:44px;cursor:pointer;list-style:none}.subjects-menu>summary::-webkit-details-marker{display:none}.subjects-menu>summary svg{transition:transform .15s}.subjects-menu[open]>summary svg{transform:rotate(180deg)}.subjects-menu-panel{position:absolute;top:calc(100% + 12px);left:-16px;width:230px;padding:8px;background:var(--bg);border:2px solid var(--ink);z-index:60}.subjects-menu-panel>a{display:flex;align-items:center;min-height:48px;padding:10px 14px;text-decoration:none;white-space:nowrap;font-size:17px;font-weight:600}.subjects-menu-panel>a:hover,.subjects-menu-panel>a:focus-visible{background:var(--ink);color:var(--bg)}.subjects-menu>summary:focus-visible{outline:2px solid var(--accent);outline-offset:4px}.atlas-course-heading{margin:0;font:inherit}.atlas-course-heading .course-title{text-decoration:none;line-height:1.05}.atlas-course-heading .course-title:focus-visible{outline:2px solid var(--accent);outline-offset:6px}@media(max-width:750px){.subjects-menu-panel{left:0;top:calc(100% + 8px);width:220px}}

.prose-fraction{font-size:1em;vertical-align:baseline;margin:0 .1em;line-height:normal}.prose-fraction mtext{font-family:var(--font-text);font-size:inherit}#content p,#content li,.resource-description{line-height:1.95}.math-app .katex{font-size:1.06em}.math-app p:has(.mfrac),.math-app li:has(.mfrac){line-height:2.15}
@media print{.sheet{font-size:11px;line-height:1.4}.sheet h2{font-size:15px}.sheet section{margin-bottom:12px}.sheet .katex-display{margin:5px 0}}