:root{color-scheme:light;--ink:#263238;--muted:#5b6870;--teal:#006c80;--rule:#dce3e6;--soft:#f4f7f7}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:24px}body{margin:0;background:#fff;color:var(--ink);font:16px/1.5 -apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}a{color:inherit;text-decoration:none}button,input{font:inherit}button,a,input,summary{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--teal);outline-offset:4px}a:hover{color:var(--teal)}.page{max-width:1440px;margin:0 auto;padding:0 48px}.skip-link{position:absolute;left:16px;top:-100px;z-index:5;background:#fff;padding:12px}.skip-link:focus{top:16px}.sr-only{position:absolute;width:1px;height:1px;margin:-1px;overflow:hidden;clip:rect(0,0,0,0)}.masthead{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:108px;border-bottom:1px solid var(--rule)}.brand{display:block;line-height:0}.brand img{display:block;width:220px;height:auto;max-width:100%}.masthead 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80px;margin-top:2px;background:var(--soft)}.topic-row-text{min-width:0;flex:1}.eyebrow{display:block;color:var(--teal);font-size:10px;font-weight:650;letter-spacing:.055em;line-height:1.4}.topic-row h3{font-size:23px;margin:5px 0 8px}.topic-row p{font-size:14px;line-height:1.5;color:var(--muted);display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.topic-row small{display:block;color:var(--muted);font-size:12px;margin-top:9px}.row-arrow{color:var(--teal);align-self:center;flex:0 0 14px}.browse-all{display:flex;justify-content:space-between;border-top:1px solid var(--rule);color:var(--teal);font-weight:600;font-size:14px;padding:16px 0}.library-utilities{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:32px;border-top:1px solid var(--rule);margin-top:8px;padding:20px 0}.library-utilities>a{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 12px;font-size:15px;font-weight:600}.library-utilities>a 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p{flex-basis:100%;max-width:100ch;font-size:11px;line-height:1.6}
@media(max-width:900px){.page{padding:0 28px}.categories{gap:0 18px}.topic-rows{column-gap:24px}.topic-row{gap:13px}.topic-image{width:64px;height:64px;flex-basis:64px}.topic-row h3{font-size:21px}.topic-row p{-webkit-line-clamp:3}.library-utilities{gap:24px}}
@media(max-width:680px){.page{padding:0 20px}.masthead{min-height:88px;gap:16px}.brand img{width:176px}.masthead nav{gap:18px;font-size:13px}.intro{padding-top:24px}.intro-label{font-size:10px}.intro>p{font-size:14px}.search{min-height:52px;margin-top:18px}.search input{padding:12px;font-size:14px}.search button{padding:12px 16px;font-size:14px}.search button span{display:none}.categories{gap:0 18px;margin-bottom:22px}.categories a{font-size:13px;padding:9px 0}.section-heading h2{font-size:25px}.topic-rows{grid-template-columns:1fr}.topic-row{padding:18px 0;gap:16px}.topic-image{width:72px;height:72px;flex-basis:72px}.topic-row h3{font-size:23px}.topic-row p{-webkit-line-clamp:2}.library-utilities{grid-template-columns:1fr;gap:18px}.topic-panel{padding:20px 16px;margin-bottom:24px}.topic-panel-heading h2{font-size:29px}.resource-list,.source-list{grid-template-columns:1fr}.resource-row{padding:13px 0}.teacher-links{flex-direction:column;gap:12px}.preview-label{white-space:nowrap}.intro-label{gap:12px}footer{padding-bottom:24px}}
.topic-image-space{width:80px;flex:0 0 80px}.search-result-links{display:flex;flex-wrap:wrap;gap:12px 24px}
@media(max-width:900px){.topic-image-space{width:64px;flex-basis:64px}}
@media(max-width:680px){.topic-image-space{width:72px;flex-basis:72px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}