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/* Mobile header: preserve the photograph without a white overlay. */
@media(max-width:760px){.ao-hero{display:flex;flex-direction:column;align-items:stretch;min-height:0;background:transparent;overflow:hidden}.ao-hero>img{position:relative;inset:auto;width:100%;height:170px;object-fit:cover;object-position:center 65%;z-index:auto;transform:none!important}.ao-hero .heading{background:transparent;padding:22px 0 8px;max-width:none}.ao-hero h1{margin-top:0}}

.ao-polar-feature{margin:48px 0}.ao-polar-feature h2{font-size:clamp(30px,4vw,48px);line-height:1.12;letter-spacing:-1px;margin:12px 0}.ao-polar-feature>img{object-position:center 65%}.founder-note+#ao-life-intro{margin-top:40px}

.ao-polar-feature .heading{display:block;width:100%}.ao-polar-feature .ao-jumps a{white-space:nowrap}

@media(max-width:760px){.ao-hero>img{border-radius:8px}}

/* Editorial opening; scientific controls retain their existing layout. */
.ao-hero .heading{display:block;width:100%}
.ao-observe-start h2{font-size:clamp(25px,3vw,34px);color:#173e4c;margin:0 0 14px}
.ao-polar-feature h2{color:inherit}
@media(max-width:760px){
 .ao-polar-feature{background:#17313d;border-radius:12px}
 .ao-polar-feature .heading{background:#17313d;color:#fff;padding:25px 22px 28px}
 .ao-polar-feature>img{border-radius:12px 12px 0 0}
 .ao-polar-feature .ao-jumps a{white-space:normal;text-align:center}
 .ao-hero h1{letter-spacing:-.04em}
}

/* Atlantic Explore deeper introductions: one shared label and consistent layout. */
body.ao-main #ao-deeper-label{margin:36px 0 16px}
body.ao-main :is(#ao-life-intro,#ao-seabed-intro,#ao-history-intro){margin:32px 0 16px;gap:24px;align-items:center}
body.ao-main #ao-life-intro{margin-top:0}
body.ao-main :is(#ao-life-intro,#ao-seabed-intro,#ao-history-intro) .ao-photo{min-height:0;aspect-ratio:2.6 / 1}
body.ao-main :is(#ao-life-intro,#ao-seabed-intro,#ao-history-intro) h2{margin-top:0}
@media(max-width:760px){
 body.ao-main #ao-deeper-label{margin-top:28px}
 body.ao-main :is(#ao-life-intro,#ao-seabed-intro,#ao-history-intro){grid-template-columns:1fr;gap:16px;margin-bottom:16px}
}

/* One shared photographic opening, followed by tools and a plain history opening. */
body.ao-main #ao-history-intro.ao-history-opening{display:block;margin:40px 0 16px;padding:0}
body.ao-main #ao-history-intro.ao-history-opening #atlantic-history-title{font-size:var(--ao-type-chapter)!important;font-weight:600;line-height:1.2;margin:0 0 12px}
body.ao-main #ao-history-intro.ao-history-opening p{max-width:66ch;line-height:1.7}
#ao-seabed-intro{scroll-margin-top:28px}
@media(max-width:760px){body.ao-main #ao-history-intro.ao-history-opening{margin-top:32px}}

/* Contained finishing pass: quieter closing label and aligned exploration rows. */
body.ao-main #amoc .amoc-related>h3{font-size:16px!important;font-weight:600;line-height:1.5;margin-bottom:8px}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section){margin:12px 0 0;padding-top:0}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section)>summary{display:grid;grid-template-columns:12px 22px minmax(0,1fr);align-items:center;column-gap:8px;padding:16px 0;min-height:56px;box-sizing:border-box;list-style:none}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section)>summary::-webkit-details-marker{display:none}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section)>summary::before{content:'▶';font-size:11px;line-height:1}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section)[open]>summary::before{content:'▼'}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section)>summary .ao-icon{width:22px;height:22px;margin:0;align-self:center}

/* Match the Atlantic support heading to the shared chapter-title size. */
body.ao-main #support-title{font-size:var(--ao-type-chapter)!important}
body.ao-main #ao-life-intro h2{font-size:var(--ao-type-chapter)!important}

/* Atlantic section labels share the geographic-opening text size. */
body.ao-main :is(#amoc>.eyebrow,#ao-deeper-label,#atlantic-records .history-card>.eyebrow,#nao-history .eyebrow,#whole-atlantic>.eyebrow,#rapid-title+p>strong){font-size:16px!important}
@media(max-width:430px){body.ao-main :is(#amoc>.eyebrow,#ao-deeper-label,#atlantic-records .history-card>.eyebrow,#nao-history .eyebrow,#whole-atlantic>.eyebrow,#rapid-title+p>strong){font-size:15px!important}}

/* Atlantic spacing pass: one divider per disclosure row. */
body.ao-main #amoc-record-methods{margin-top:24px}
body.ao-main #amoc-record-methods>details{margin:0;padding:0;border:0}
body.ao-main #amoc-record-methods>details>summary{padding:16px 0;min-height:48px;box-sizing:border-box;border-top:1px solid var(--line)}
body.ao-main #amoc-record-methods>details[open]{padding-bottom:16px}
body.ao-main #amoc-record-methods>p{margin:16px 0 0}
body.ao-main #amoc-record-methods>details p{margin:12px 0}
body.ao-main #ao-maps>section>:is(#explorer-settings,.plain-explainer){margin-top:16px;padding:0}
body.ao-main #ao-maps>section>:is(#explorer-settings,.plain-explainer)>summary{padding:16px 0;min-height:48px;box-sizing:border-box}
body.ao-main :is(#bio-explorer,#mercator-explorer,#seabed-section){border-top-color:var(--line)}
body.ao-main #atlantic-records .history-card{margin-top:16px;padding:24px 0 0}
body.ao-main #atlantic-records .history-card>details{margin-top:20px;padding-top:0}
body.ao-main #atlantic-records .history-card>details>summary{padding:16px 0;min-height:48px;box-sizing:border-box}
body.ao-main #nao-history{margin-top:32px;padding-top:0}
body.ao-main #nao-history>.history-summary{padding:20px 0}
body.ao-main #whole-atlantic>details{margin-top:20px;padding-top:0}
body.ao-main #whole-atlantic>details>summary{padding:16px 0;min-height:48px;box-sizing:border-box}
body.ao-main .observatory-support{margin-top:32px!important;padding-top:24px}