/* Subject pages and navigation share the existing HB Science visual system. */
.subjects-section{width:min(1200px,calc(100% - 40px));margin:0 auto;padding:62px 0 50px;scroll-margin-top:84px}.subjects-section .section-heading{margin-bottom:24px}.subjects-section h2{font-size:clamp(28px,3.3vw,40px);margin:0 0 10px;line-height:1.18}.subjects-section .section-heading p{max-width:570px}.subject-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px}.subject-card{display:flex;flex-direction:column;overflow:hidden;border:1px solid #dce7f3;border-radius:20px;background:white;box-shadow:0 10px 28px #0f254009;transition:transform .2s,box-shadow .2s}.subject-card:hover{transform:translateY(-3px);box-shadow:0 16px 30px #0f254012}.subject-visual{position:relative;background:var(--subject-tint);aspect-ratio:1.9;overflow:hidden}.subject-art{width:100%;height:100%;display:block}.subject-card-body{padding:22px;display:flex;flex:1;flex-direction:column;gap:12px}.subject-card h3{margin:0;font-size:25px;line-height:1.2}.subject-card p{font-size:14px;line-height:1.65;color:#51677c;margin:0}.subject-status{display:inline-flex;align-items:center;gap:6px;width:fit-content;font-size:11px;font-weight:800;letter-spacing:.035em;padding:5px 9px;border-radius:999px;color:#45576b;background:#edf2f7}.subject-status.available{color:#116743;background:#e6f6ed}.subject-card .subject-status{position:absolute;left:15px;top:14px;background:#ffffffed;box-shadow:0 1px 5px #0f25400a}.subject-card .button{width:100%;margin-top:auto;min-height:44px}.subject-hero-link{display:inline-flex;align-items:center;gap:10px;color:#125aaf;font-weight:800;text-decoration:none;margin-top:20px;font-size:14px}.subject-hero-link:hover{text-decoration:underline}.subject-switch{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 26px}.subject-switch a{padding:9px 16px;border:1px solid #d4dfed;border-radius:999px;text-decoration:none;color:#52687e;background:#fff;font-size:13px;font-weight:750}.subject-switch a[aria-current=page]{background:var(--subject-accent);border-color:var(--subject-accent);color:white}.subject-page .subject-main{width:min(1200px,calc(100% - 40px));margin:0 auto;padding:36px 0 64px}.subject-breadcrumb{margin:0 0 24px;font-size:12px;color:#567085}.subject-breadcrumb a{color:#1864af;text-decoration:none}.subject-breadcrumb a:hover{text-decoration:underline}.subject-hero{display:grid;grid-template-columns:1.25fr .75fr;align-items:center;gap:45px;padding:38px 42px;border:1px solid #dce7f3;border-radius:24px;background:linear-gradient(120deg,#fff,var(--subject-tint))}.subject-hero h1{font-size:clamp(34px,4.2vw,51px);line-height:1.12;letter-spacing:-.025em;margin:16px 0 18px}.subject-hero p{color:#50667b;line-height:1.75;font-size:16px;max-width:650px;margin:0 0 20px}.subject-hero-art{width:100%;max-width:360px;justify-self:center;aspect-ratio:1.4}.subject-hero .button{min-height:44px;min-width:160px}.subject-overview{display:flex;flex-wrap:wrap;gap:8px;margin:22px 0 0}.subject-overview span{font-size:12px;color:#466078;font-weight:650;padding:7px 10px;border:1px solid #dce7f3;border-radius:8px;background:#ffffffb0}.subject-release-note{display:flex;gap:16px;align-items:start;padding:20px 24px;border:1px solid #d6e3f1;border-left:4px solid var(--subject-accent);border-radius:12px;background:#f7faff;margin:26px 0 45px}.subject-release-note p{margin:4px 0 0;color:#52697f;font-size:14px;line-height:1.65}.subject-release-note strong{font-size:15px;color:#183a58}.subject-library h2{font-size:30px;margin:0 0 8px}.subject-library-intro{font-size:14px;color:#586d81;line-height:1.7;margin:0 0 20px;max-width:760px}.subject-filter{display:flex;flex-wrap:wrap;align-items:end;gap:12px;padding:18px;border:1px solid #dbe5f0;border-radius:13px;background:#f5f8fc}.subject-filter label{display:grid;gap:6px;font-size:12px;font-weight:800;color:#314c64}.subject-filter label:first-child{flex:1;min-width:180px}.subject-filter input,.subject-filter select{min-height:44px;width:100%;font:14px 'DM Sans',system-ui,sans-serif;border:1px solid #b9cadd;border-radius:8px;padding:9px 12px;background:white;color:#173650}.subject-filter button{min-height:44px;border:1px solid #b9cadd;border-radius:8px;padding:9px 14px;color:#254e72;background:white;font:700 13px 'DM Sans',system-ui,sans-serif;cursor:pointer}.subject-filter-status{margin:14px 2px 18px;min-height:20px;font-size:12px;color:#587087}.subject-topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.subject-topic{border:1px solid #dce6f0;border-radius:15px;padding:22px;background:white;box-shadow:0 3px 12px #0f254004}.subject-topic[hidden]{display:none}.subject-topic-top{display:flex;align-items:center;gap:12px;margin-bottom:12px}.subject-topic-number{display:grid;place-items:center;flex:none;width:36px;height:36px;border-radius:10px;background:var(--subject-tint);color:var(--subject-accent);font:750 14px 'Poppins',sans-serif}.subject-topic h3{font-size:18px;line-height:1.4;margin:0}.subject-topic p{font-size:13px;line-height:1.75;color:#536b80;margin:0 0 13px}.subject-topic-meta{display:flex;align-items:center;flex-wrap:wrap;gap:7px;font-size:11px;color:#49657d}.subject-topic-meta span{padding:4px 7px;border-radius:5px;background:#f1f5fa}.subject-topic-meta .topic-count{color:var(--subject-accent);font-weight:800;background:var(--subject-tint)}.subject-topic details{margin-top:16px;padding-top:14px;border-top:1px solid #e4ebf4}.subject-topic summary{font-size:12px;font-weight:800;color:#315e87;cursor:pointer;min-height:24px}.subject-topic ul{font-size:12px;line-height:1.8;color:#526b81;padding-left:18px;margin:10px 0 0}.subject-topic li+li{margin-top:5px}.subject-no-results{padding:26px;text-align:center;border:1px dashed #c4d4e5;border-radius:12px;color:#506a81;font-size:14px}.subject-no-results[hidden]{display:none}.subject-next{margin-top:42px;padding:28px;border:1px solid #dce7f3;border-radius:16px;background:#f6f9fd;display:flex;align-items:center;justify-content:space-between;gap:22px}.subject-next h2{font-size:21px;margin:0 0 8px}.subject-next p{font-size:13px;line-height:1.65;margin:0;color:#52697e;max-width:650px}.subject-next .button{white-space:nowrap}.subject-page .footer-links{flex-wrap:wrap}.subject-page :focus-visible,.subjects-section :focus-visible{outline:3px solid #2075dc;outline-offset:4px}.subject-page [hidden]{display:none!important}.subject-jump-links{display:flex;gap:12px;flex-wrap:wrap;font-size:13px;margin:14px 0}.subject-jump-links a{color:#2268ad;text-decoration:none}.subject-jump-links a:hover{text-decoration:underline}
@media(max-width:960px){.subject-card-body{padding:18px}.subject-grid{gap:15px}.subject-hero{padding:30px;gap:20px}.subject-hero-art{max-width:280px}.subject-card h3{font-size:22px}}
@media(max-width:700px){.subjects-section{padding:36px 0;width:calc(100% - 28px)}.subject-grid{grid-template-columns:1fr}.subject-visual{aspect-ratio:2.3}.subject-card-body{padding:22px}.subject-card .button{width:auto;align-self:start;min-width:180px}.subject-page .subject-main{width:calc(100% - 28px);padding-top:24px}.subject-hero{grid-template-columns:1fr;padding:25px;gap:18px}.subject-hero-art{display:none}.subject-hero h1{font-size:37px}.subject-hero p{font-size:14px}.subject-overview{gap:6px}.subject-overview span{font-size:11px}.subject-release-note{padding:18px;margin-bottom:30px}.subject-topic-grid{grid-template-columns:1fr}.subject-library h2{font-size:26px}.subject-filter label{flex:1;min-width:130px}.subject-filter label:first-child{flex-basis:100%}.subject-next{align-items:start;flex-direction:column;padding:22px}.subject-next .button{width:100%;white-space:normal}.subject-page .header-inner{gap:10px}.subject-page .brand{font-size:14px;gap:8px}.subject-page .brand-mark{width:32px;height:32px}.subject-page .header-actions>.nav-cta{display:none}.subject-switch{gap:7px}.subject-switch a{font-size:12px;padding:8px 13px}}
@media(prefers-reduced-motion:reduce){.subject-card{transition:none}.subject-card:hover{transform:none}}