:root {
  --paper: #f3f6f7;
  --ink: #18262c;
  --lagoon: #2c7a85;
  --mist: #d9ebee;
  --deep: #173a42;
  --card: #2b5860;
  --display: 'Lora', Georgia, serif;
  --body: 'Albert Sans', Arial, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 400 18px/1.6 var(--body); }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-underline-offset: .25em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, summary:focus-visible { outline: 3px solid var(--lagoon); outline-offset: 6px; }
.subject-index a:focus-visible, .article-introduction a:focus-visible, .site-footer a:focus-visible { outline-color: var(--mist); }
button, summary { font: inherit; }
h1, h2, h3 { font-family: var(--display); font-weight: 500; line-height: 1.16; letter-spacing: -.015em; text-wrap: balance; }
h1, h2 { font-weight: 600; }
h1, h2, h3, p, figure { margin: 0; }
.compound-name { white-space: nowrap; }
p + p { margin-top: 22px; }
.skip-to-text { position: absolute; top: 8px; left: 24px; padding: 10px 18px; background: var(--paper); z-index: 20; transform: translateY(-160%); }
.skip-to-text:focus { transform: translateY(0); }
.site-notice { min-height: 40px; padding: 8px 24px; text-align: center; font-size: 15px; line-height: 24px; background: var(--mist); color: var(--deep); }
.site-notice a { text-decoration: none; }
.masthead { position: absolute; inset: 40px 0 auto; z-index: 5; padding: 25px 32px; display: flex; align-items: center; gap: 30px; color: var(--ink); background: var(--mist); }
.brand-unit { flex: 1 1 auto; }
.brand-name { display: inline-block; font: 600 24px/1.2 var(--display); text-decoration: none; }
.brand-line { font-size: 16px; line-height: 1.4; letter-spacing: normal; max-width: 430px; margin-top: 5px; }
.topic-navigation { display: flex; gap: 28px; align-items: center; font-size: 16px; }
.topic-navigation a { text-decoration: none; padding-block: 9px; }
.topic-navigation a:hover, .topic-navigation a[aria-current] { text-decoration: underline; }
.pill { display: inline-flex; min-height: 50px; padding: 12px 25px; align-items: center; justify-content: center; gap: 18px; border: 1px solid transparent; border-radius: 100px; background: var(--deep); color: var(--paper); font-size: 16px; font-weight: 500; line-height: 1.4; text-decoration: none; }
.pill:hover { background: var(--ink); text-decoration: none; }
.pill-light { background: var(--paper); color: var(--deep); }
.pill-light:hover { background: var(--mist); }
.quiet-link { display: inline-flex; align-items: center; gap: 12px; font-size: 16px; font-weight: 500; }
.actions { display: flex; gap: 28px; align-items: center; flex-wrap: wrap; margin-top: 30px; }
.mobile-navigation { display: none; }
.page-index main { background: var(--deep); }
.opening { min-height: max(844px, calc(100svh - 40px)); position: relative; padding: 210px 56px 150px; display: flex; align-items: flex-start; background: var(--paper); isolation: isolate; border-radius: 0 0 40px 40px; overflow: hidden; }
.photo-surface { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.opening > .photo-surface { z-index: -2; object-position: 50% 58%; }
.opening::after { content: ''; position: absolute; inset: 0; z-index: -1; background: linear-gradient(90deg, rgba(243,246,247,.24), rgba(217,235,238,.08) 48%, transparent 70%); }
.opening-copy { width: 58%; max-width: 760px; text-align: left; }
.opening h1 { font-size: clamp(60px, 4.9vw, 76px); line-height: 1.065; text-wrap: pretty; }
.opening p { max-width: 535px; margin-top: 28px; font-size: 19px; line-height: 1.55; }
.opening .actions { justify-content: flex-start; margin-top: 32px; }
.subject-index { padding: 98px 32px 112px; background: var(--deep); color: var(--paper); }
.index-introduction { display: grid; grid-template-columns: 1fr 1fr; gap: 7%; align-items: end; margin-bottom: 54px; }
.index-introduction h2 { font-size: 48px; max-width: 510px; }
.index-introduction p { max-width: 580px; font-size: 17px; }
.topic-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.topic-card { min-width: 0; min-height: 462px; padding: 34px 24px 32px; border-radius: 24px; background: var(--card); display: flex; flex-direction: column; align-items: center; text-align: center; }
.topic-card h3 { font-size: 28px; min-height: 65px; }
.topic-card .topic-art { width: 100%; max-width: 270px; height: 144px; object-fit: contain; margin: 12px auto 24px; }
.topic-card p { margin-top: 20px; font-size: 16px; line-height: 1.5; }
.topic-card .pill { min-height: 46px; padding: 10px 22px; }
.feature-area { position: relative; padding: 112px 32px 120px; border-radius: 40px 40px 0 0; background: var(--paper); }
.feature-introduction { display: grid; grid-template-columns: 1fr 1fr; align-items: end; gap: 7%; margin-bottom: 48px; }
.feature-introduction h2 { max-width: 580px; font-size: 48px; }
.feature-introduction p { max-width: 580px; font-size: 17px; }
.two-features { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.feature-photo { width: 100%; height: 410px; object-fit: cover; border-radius: 24px; object-position: 68% 70%; }
.feature-copy { padding: 28px 8px 0 0; max-width: 570px; }
.feature-copy h3 { font-size: 30px; }
.feature-copy p { font-size: 17px; margin: 18px 0 22px; }
.study-band { position: relative; isolation: isolate; min-height: 760px; display: flex; align-items: center; padding: 88px 32px 128px; background: var(--mist); }
.study-band > .photo-surface { z-index: -1; object-position: 60% 50%; }
.frosted-panel { width: min(48%, 660px); border: 1px solid rgba(243,246,247,.55); border-radius: 32px; padding: 44px; background: rgba(243,246,247,.9); backdrop-filter: blur(22px); }
.frosted-panel h2 { font-size: 44px; max-width: 550px; }
.frosted-panel p { font-size: 17px; margin-top: 22px; max-width: 590px; }
.study-question { margin-top: 30px; padding: 18px 24px; border: 1px solid #a2c0c6; border-radius: 16px; font-size: 16px; }
.study-question strong { display: block; font: 500 28px/1.2 var(--display); margin-top: 5px; }
.evidence-split { position: relative; margin-top: -40px; border-radius: 40px 40px 0 0; background: var(--paper); padding: 110px 32px; display: grid; grid-template-columns: 1fr 1fr; align-items: center; gap: 7%; }
.evidence-split h2 { font-size: 48px; max-width: 550px; }
.evidence-split p { max-width: 570px; font-size: 17px; margin-top: 24px; }
.evidence-figure { display: grid; place-items: center; min-height: 485px; padding: 40px 20px; border-radius: 32px; background: #e6eef0; }
.evidence-figure svg { width: 100%; max-width: 440px; height: auto; }
.evidence-figure figcaption { font-size: 16px; line-height: 1.5; text-align: center; max-width: 38ch; }
.closing-note { padding: 50px 24px 116px; text-align: center; background: var(--paper); }
.closing-note h2 { font-size: 44px; max-width: 810px; margin: auto; }
.closing-note p { margin: 25px auto 0; font-size: 17px; max-width: 760px; }
.inner-opening { position: relative; isolation: isolate; padding: 182px 48px 56px; min-height: 490px; background: var(--mist); }
.inner-opening h1 { max-width: 880px; font-size: 58px; }
.inner-opening .lead { max-width: 660px; margin-top: 22px; font-size: 19px; line-height: 1.5; }
.inner-opening .photo-surface { z-index: -2; object-position: 70% 50%; }
.inner-opening.photo-opening::after { content: ''; position: absolute; inset: 0; z-index: -1; background: linear-gradient(90deg, rgba(243,246,247,.3), rgba(217,235,238,.08) 52%, transparent 75%); }
.photo-opening { min-height: 550px; padding-bottom: 86px; border-radius: 0 0 40px 40px; overflow: hidden; }
.page-bpc-157 main, .page-tb-500 main, .page-ghk-cu main, .page-compare main { background: var(--deep); }
.photo-opening .lead, .photo-opening h1 { max-width: 710px; }
.photo-opening h1 { max-width: 700px; }
.image-note { position: absolute; right: 32px; bottom: 22px; width: min(310px, 32%); font-size: 15px; line-height: 1.45; padding: 16px 20px; border-radius: 16px; color: var(--ink); background: rgba(243,246,247,.94); backdrop-filter: blur(20px); }
.article-introduction { background: var(--deep); color: var(--paper); padding: 32px; }
.intro-feature { background: var(--card); border-radius: 28px; padding: 54px 48px; display: grid; grid-template-columns: 1fr 1.8fr; gap: 8%; align-items: start; }
.intro-feature h2 { font-size: 36px; }
.intro-feature p { font-size: 18px; }
.breadcrumb-line { display: flex; gap: 10px; padding: 26px 32px; border-bottom: 1px solid #c9d9dc; font-size: 15px; flex-wrap: wrap; background: var(--paper); }
.breadcrumb-line a { text-decoration: none; }
.article-sections { padding: 32px max(32px, calc((100% - 1376px)/2)); margin: auto; border-radius: 40px 40px 0 0; background: var(--paper); }
.article-section { display: grid; grid-template-columns: 1fr 1.8fr; gap: 8%; padding: 66px 48px; border-bottom: 1px solid #c9d9dc; }
.article-section:last-child { border: 0; padding-bottom: 95px; }
.article-section h2 { font-size: 32px; max-width: 340px; }
.section-prose { min-width: 0; max-width: 780px; }
.text-section { row-gap: 22px; }
.text-section > h2 { grid-column: 1; grid-row: 1 / span 3; }
.text-section > p { grid-column: 2; margin: 0; max-width: 780px; }
.article-photo { width: 100%; max-height: 450px; object-fit: cover; border-radius: 20px; margin-top: 30px; }
.material-drawing { width: 100%; max-width: 600px; height: auto; padding: 32px 48px; margin-top: 30px; border-radius: 24px; background: var(--deep); }
.article-caption { font-size: 15px; margin-top: 13px; }
.article-table { border-collapse: collapse; width: 100%; margin-top: 28px; font-size: 16px; line-height: 1.5; }
.article-table th, .article-table td { text-align: left; vertical-align: top; padding: 18px 14px; border-bottom: 1px solid #b4cbd0; }
.article-table th { background: var(--mist); font-weight: 500; }
.article-table th:first-child, .article-table td:first-child { padding-left: 0; }
.article-table th:first-child { padding-left: 14px; }
.source-records .article-section { padding-block: 38px; }
.source-records .article-section h2 { font-size: 25px; line-height: 1.3; }
.source-records .article-section p { font-size: 17px; }
.source-records .source-link { display: inline-block; margin-top: 16px; font-size: 16px; }
.related-pages { margin: 0 32px 70px; padding: 40px 48px; background: var(--mist); display: flex; align-items: center; justify-content: space-between; gap: 28px; border-radius: 24px; }
.related-pages h2 { font-size: 28px; }
.related-pages nav { display: flex; gap: 24px; flex-wrap: wrap; font-size: 16px; }
.site-footer { background: var(--deep); color: var(--paper); padding: 64px 32px 28px; }
.footer-top { display: flex; justify-content: space-between; gap: 56px; padding-bottom: 45px; }
.footer-name { font: 500 27px/1.25 var(--display); }
.footer-top p { margin-top: 18px; max-width: 530px; font-size: 16px; }
.footer-navigation { display: flex; align-items: flex-start; gap: 35px; font-size: 16px; }
.footer-bottom { padding-top: 23px; border-top: 1px solid #4f737b; display: flex; justify-content: space-between; gap: 24px; font-size: 15px; }
.not-found { min-height: 650px; padding: 230px 32px 100px; }
.not-found h1 { font-size: 52px; }
.not-found p { margin-top: 24px; max-width: 620px; }
@media (min-width: 1600px) {
  .masthead, .subject-index, .feature-area, .evidence-split { padding-inline: max(32px, calc((100vw - 1440px)/2)); }
}
@media (max-width: 1100px) {
  .masthead { gap: 20px; }
  .brand-name { font-size: 22px; }
  .brand-line { max-width: 360px; }
  .topic-navigation { gap: 18px; }
  .topic-grid { grid-template-columns: 1fr 1fr; gap: 18px; }
  .topic-card { min-height: 410px; }
  .feature-photo { height: 300px; }
  .intro-feature, .article-section { padding-inline: 28px; gap: 5%; grid-template-columns: 1fr 1.7fr; }
  .image-note { width: 280px; max-width: 38%; }
}
@media (max-width: 1000px) {
  .opening { padding: 200px 32px 160px; }
  .opening-copy { width: 78%; max-width: 620px; }
  .opening h1 { font-size: 60px; }
  .opening p { max-width: 485px; }
  .topic-navigation, .masthead > .pill { display: none; }
  .mobile-navigation { display: block; flex: 0 0 auto; }
  .mobile-navigation summary { list-style: none; display: flex; gap: 10px; align-items: center; cursor: pointer; font-size: 16px; padding: 12px 0 12px 12px; }
  .mobile-navigation summary::-webkit-details-marker { display: none; }
  .mobile-navigation summary svg { width: 24px; height: 24px; }
  .mobile-navigation nav { position: absolute; right: 24px; left: 24px; top: calc(100% - 12px); padding: 18px 24px; background: var(--paper); border: 1px solid #b4cbd0; border-radius: 20px; display: grid; gap: 4px; }
  .mobile-navigation nav a { padding: 9px 0; font-size: 17px; }
  .index-introduction h2, .feature-introduction h2, .evidence-split h2 { font-size: 42px; }
  .feature-area, .evidence-split { padding-block: 80px; }
  .frosted-panel { width: min(78%, 640px); padding: 36px; }
  .evidence-split { gap: 32px; grid-template-columns: 1fr; }
  .evidence-figure { min-height: 380px; }
}
@media (max-width: 700px) {
  body { font-size: 17px; }
  .site-notice { padding-inline: 16px; font-size: 15px; }
  .masthead { padding: 22px 20px; gap: 12px; align-items: flex-start; }
  .brand-unit { min-width: 0; }
  .brand-name { font-size: 21px; line-height: 1.25; }
  .brand-line { max-width: 280px; margin-top: 7px; line-height: 1.4; }
  .mobile-navigation summary { padding-top: 0; }
  .mobile-navigation summary span { display: none; }
  .mobile-navigation nav { right: 16px; left: 16px; }
  .opening { min-height: max(940px, calc(100svh - 40px)); padding: 166px 24px 280px; border-radius: 0 0 32px 32px; }
  .opening-copy { width: 100%; max-width: 520px; }
  .opening h1 { font-size: 42px; line-height: 1.08; }
  .opening p { font-size: 18px; margin-top: 26px; }
  .opening > .photo-surface { object-position: 65% 50%; }
  .opening::after { background: linear-gradient(180deg, rgba(243,246,247,.86), rgba(243,246,247,.8) 52%, rgba(243,246,247,0) 68%); }
  .actions { gap: 20px; }
  .opening .actions { flex-wrap: nowrap; gap: 20px; }
  .opening .pill { padding-inline: 21px; }
  .subject-index { padding: 72px 20px 80px; }
  .index-introduction, .feature-introduction { grid-template-columns: 1fr; gap: 24px; margin-bottom: 34px; }
  .index-introduction h2, .feature-introduction h2 { font-size: 36px; }
  .topic-grid { grid-template-columns: 1fr; gap: 16px; }
  .topic-card { padding: 30px 28px; min-height: auto; }
  .topic-card h3 { min-height: 0; font-size: 28px; }
  .topic-card .topic-art { height: 150px; margin-block: 22px; }
  .topic-card p { max-width: 350px; }
  .feature-area { padding: 72px 20px 80px; border-radius: 32px 32px 0 0; }
  .two-features { grid-template-columns: 1fr; gap: 40px; }
  .feature-photo { height: 290px; }
  .feature-copy { padding-top: 23px; }
  .study-band { min-height: 930px; padding: 58px 20px 100px; align-items: flex-start; }
  .study-band > .photo-surface { object-position: 76% 50%; }
  .frosted-panel { width: 100%; border-radius: 24px; padding: 28px 24px; }
  .frosted-panel h2 { font-size: 35px; }
  .study-question { padding: 18px; }
  .study-question strong { font-size: 25px; }
  .evidence-split { grid-template-columns: 1fr; padding: 75px 20px 60px; gap: 38px; border-radius: 32px 32px 0 0; margin-top: -32px; }
  .evidence-split h2 { font-size: 36px; }
  .evidence-figure { min-height: 340px; border-radius: 24px; padding: 24px 8px; }
  .closing-note { padding: 35px 24px 75px; }
  .closing-note h2 { font-size: 34px; }
  .inner-opening { padding: 195px 24px 48px; min-height: 450px; }
  .inner-opening h1 { font-size: 40px; line-height: 1.12; }
  .inner-opening .lead { font-size: 18px; margin-top: 22px; }
  .photo-opening { min-height: 820px; padding-bottom: 240px; border-radius: 0 0 32px 32px; }
  .inner-opening.photo-opening::after { background: linear-gradient(180deg, rgba(243,246,247,.3), rgba(217,235,238,.08) 52%, transparent 72%); }
  .photo-opening .photo-surface { object-position: 67% 50%; }
  .image-note { right: 20px; bottom: 20px; left: 20px; width: auto; max-width: none; padding: 14px 18px; }
  .article-introduction { padding: 20px; }
  .intro-feature { grid-template-columns: 1fr; gap: 22px; border-radius: 24px; padding: 32px 24px; }
  .intro-feature h2 { font-size: 30px; }
  .intro-feature p { font-size: 17px; }
  .breadcrumb-line { padding: 22px 24px; }
  .article-sections { padding: 0 24px; border-radius: 32px 32px 0 0; }
  .article-section { grid-template-columns: 1fr; gap: 22px; padding: 42px 0; }
  .article-section h2 { font-size: 29px; max-width: 100%; }
  .text-section > h2 { grid-row: auto; }
  .text-section > p { grid-column: 1; }
  .article-section:last-child { padding-bottom: 55px; }
  .article-photo { margin-top: 25px; }
  .material-drawing { padding: 24px; }
  .article-table { font-size: 15px; table-layout: fixed; }
  .article-table th, .article-table td { padding: 14px 7px; overflow-wrap: break-word; }
  .article-table th:first-child { padding-left: 7px; }
  .source-records .article-section { padding-block: 32px; gap: 15px; }
  .source-records .article-section h2 { font-size: 25px; }
  .related-pages { margin: 0 20px 50px; padding: 30px 24px; display: block; }
  .related-pages nav { margin-top: 24px; gap: 14px 25px; }
  .site-footer { padding: 48px 24px 24px; }
  .footer-top { flex-direction: column; gap: 32px; padding-bottom: 35px; }
  .footer-name { font-size: 25px; }
  .footer-navigation { gap: 25px; flex-wrap: wrap; }
  .footer-bottom { flex-direction: column; gap: 12px; }
  .not-found { padding: 215px 24px 75px; }
  .not-found h1 { font-size: 38px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }