/* "About the Centre" text pages (objectives, history) — Meridian design language.
   Requires news-article.css on the same page for the --na-* tokens and fonts.
   Prefix: ab-. The hero mirrors the research-staff banner so the section reads as one. */

.ab-page {
    --ab-accent: var(--na-azure);
    background: var(--na-paper);
    font-family: var(--na-font-body);
    color: var(--na-ink);
    padding: 26px 0 72px;
    -webkit-font-smoothing: antialiased;
}
.ab-wrap { max-width: 1140px; margin: 0 auto; padding: 0 clamp(20px, 5vw, 32px); }

/* ---- Hero: navy banner with breadcrumb, title and the building photo ------- */
.ab-hero {
    position: relative;
    isolation: isolate;
    overflow: hidden;
    border-radius: 20px;
    padding: 16px 28px 0;
    color: #fff;
    background:
        radial-gradient(720px 360px at 92% -30%, color-mix(in srgb, var(--ab-accent) 55%, transparent), transparent 70%),
        radial-gradient(420px 260px at 0% 110%, color-mix(in srgb, var(--ab-accent) 22%, transparent), transparent 70%),
        linear-gradient(135deg, #10345c 0%, #0a2340 100%);
}
.ab-hero::before {
    content: "";
    position: absolute; inset: 0; z-index: -1;
    background-image: radial-gradient(rgba(255, 255, 255, .13) 1px, transparent 1.3px);
    background-size: 22px 22px;
    -webkit-mask-image: linear-gradient(105deg, transparent 42%, #000 100%);
    mask-image: linear-gradient(105deg, transparent 42%, #000 100%);
    pointer-events: none;
}
.ab-hero .article-breadcrumb { margin-bottom: 14px; }
.ab-hero .article-breadcrumb a,
.ab-hero .article-breadcrumb .sep { color: rgba(255, 255, 255, .6); }
.ab-hero .article-breadcrumb a:hover { color: #fff; }
.ab-hero .article-breadcrumb .current { color: rgba(255, 255, 255, .92); }
.ab-hero-body { display: grid; grid-template-columns: minmax(0, 1fr); align-items: center; min-height: 212px; padding: 0 46% 22px 0; }
.ab-title {
    font-family: var(--na-font-display);
    font-size: clamp(28px, 3vw, 36px);
    font-weight: 700;
    line-height: 1.08;
    letter-spacing: -.015em;
    color: #fff;
    max-width: 760px;
    margin: 0;
    text-wrap: balance;
}
.ab-hero-photo {
    position: absolute; top: 0; right: 0; bottom: 0; z-index: -1;
    width: 50%;
    -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 42%);
    mask-image: linear-gradient(90deg, transparent 0%, #000 42%);
}
.ab-hero-photo img {
    display: block; width: 100%; height: 100%;
    object-fit: cover; object-position: 62% 58%;
    filter: saturate(.78) contrast(1.04);
}
.ab-hero-photo::before {
    content: "";
    position: absolute; inset: 0;
    background: var(--ab-accent);
    mix-blend-mode: color; opacity: .42;
}
.ab-hero-photo::after {
    content: "";
    position: absolute; inset: 0;
    background:
        linear-gradient(0deg, rgba(8, 28, 52, .72) 0%, rgba(8, 28, 52, .18) 42%, transparent 70%),
        linear-gradient(90deg, rgba(10, 35, 64, .5) 0%, transparent 55%);
}

/* ---- Tabs: the other pages of the section --------------------------------- */
.ab-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0 0; }
.ab-tab {
    display: inline-flex; align-items: center;
    min-height: 38px; padding: 0 16px;
    border: 1px solid var(--na-hair); border-radius: 999px;
    font-family: var(--na-font-display); font-size: 14px; font-weight: 600; letter-spacing: -.005em;
    color: var(--na-navy); background: var(--na-paper);
    text-decoration: none;
    transition: border-color .18s ease, background .18s ease, color .18s ease;
}
.ab-tab:hover { border-color: var(--na-navy); color: var(--na-navy); }
.ab-tab.is-active { background: var(--na-navy); border-color: var(--na-navy); color: #fff; }

/* ---- Reading column ------------------------------------------------------- */
.ab-content { max-width: 820px; margin: 34px auto 0; }

.ab-toc {
    margin: 0 0 32px; padding: 18px 20px;
    border: 1px solid var(--na-hair); border-radius: 14px;
    background: var(--na-mist);
}
.ab-toc-label { display: block; margin-bottom: 10px; font-size: 11px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--na-slate); }
.ab-toc-list {
    list-style: none; margin: 0; padding: 0;
    display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 7px 22px;
    counter-reset: toc;
}
.ab-toc-list li { counter-increment: toc; display: grid; grid-template-columns: 28px minmax(0, 1fr); align-items: baseline; }
.ab-toc-list li::before { content: counter(toc, decimal-leading-zero); font-family: var(--na-font-display); font-size: 12px; font-weight: 700; color: var(--ab-accent); }
.ab-toc-list a { font-size: 15.5px; font-weight: 600; line-height: 1.35; color: var(--na-navy); text-decoration: none; }
.ab-toc-list a:hover { color: var(--ab-accent); text-decoration: underline; text-underline-offset: 3px; }

/* Body: numbered chapters, lists with accent markers (overrides news-article-body) */
.ab-body { counter-reset: chapter; }
.ab-body h2 {
    display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 0 14px; align-items: baseline;
    margin: 2.1em 0 .8em; padding-top: 1.1em;
    border-top: 1px solid var(--na-hair);
    font-size: 1.4em;
    scroll-margin-top: 24px;
}
.ab-body h2::before {
    counter-increment: chapter;
    content: counter(chapter, decimal-leading-zero);
    font-family: var(--na-font-display); font-size: 13px; font-weight: 700; letter-spacing: .08em;
    color: var(--ab-accent);
}
.ab-body > h2:first-child { margin-top: 0; padding-top: 0; border-top: 0; }
.ab-body ul { list-style: none; margin: 0 0 1.4em; padding: 0; display: grid; gap: 10px; }
.ab-body ul li { position: relative; margin: 0; padding-left: 26px; text-align: left; hyphens: manual; }
.ab-body ul li::before { content: ""; position: absolute; left: 0; top: .78em; width: 14px; height: 2px; border-radius: 2px; background: var(--ab-accent); }

/* Objectives: every task as a numbered card */
.ab-body--tasks ul { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; counter-reset: task; }
.ab-body--tasks ul li {
    counter-increment: task;
    padding: 16px 18px;
    border: 1px solid var(--na-hair); border-radius: 14px;
    background: var(--na-paper);
    font-size: 16px; line-height: 1.55;
}
.ab-body--tasks ul li::before {
    content: counter(task, decimal-leading-zero);
    position: static; display: block; width: auto; height: auto; margin-bottom: 8px;
    background: none;
    font-family: var(--na-font-display); font-size: 12px; font-weight: 700; letter-spacing: .08em;
    color: var(--ab-accent);
}

/* ---- Responsive ----------------------------------------------------------- */
@media (max-width: 860px) {
    .ab-hero-body { min-height: 0; padding: 0 0 18px; }
    .ab-hero-photo {
        position: relative; z-index: 0; width: auto; height: 190px; margin: 4px -28px -18px;
        -webkit-mask-image: linear-gradient(180deg, transparent 0%, #000 38%);
        mask-image: linear-gradient(180deg, transparent 0%, #000 38%);
    }
    .ab-hero-photo img { object-position: 50% 62%; }
    .ab-body--tasks ul { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
    .ab-page { padding-top: 16px; }
    .ab-hero { padding: 16px 18px 0; border-radius: 16px; }
    .ab-hero-photo { height: 160px; margin: 4px -18px -18px; }
    .ab-tabs { gap: 6px; }
    .ab-tab { min-height: 34px; padding: 0 13px; font-size: 13px; }
    .ab-content { margin-top: 26px; }
    .ab-toc { padding: 14px 16px; margin-bottom: 26px; }
    .ab-toc-list { grid-template-columns: 1fr; }
    .ab-body p { text-align: left; hyphens: manual; }
}
@media (prefers-reduced-motion: reduce) {
    .ab-tab { transition: none; }
}

/* ---- Dark theme (tokens come from dark.css) ------------------------------- */
html[data-theme=dark] .ab-hero {
    border: 1px solid var(--dk-border);
    background:
        radial-gradient(720px 360px at 92% -30%, color-mix(in srgb, var(--ab-accent) 38%, transparent), transparent 70%),
        linear-gradient(135deg, #132b4a 0%, var(--dk-surface) 100%);
}
html[data-theme=dark] .ab-tab { background: var(--dk-surface); border-color: var(--dk-border); color: var(--dk-text); }
html[data-theme=dark] .ab-tab:hover { border-color: var(--dk-accent); color: var(--dk-accent); }
html[data-theme=dark] .ab-tab.is-active { background: var(--dk-accent); border-color: var(--dk-accent); color: var(--dk-bg); }
html[data-theme=dark] .ab-toc { background: var(--dk-surface); border-color: var(--dk-border); }
html[data-theme=dark] .ab-toc-list a { color: var(--dk-text); }
html[data-theme=dark] .ab-toc-list a:hover { color: var(--dk-accent); }
html[data-theme=dark] .ab-body h2 { border-top-color: var(--dk-border); }
html[data-theme=dark] .ab-body--tasks ul li { background: var(--dk-surface); border-color: var(--dk-border); }