/* Shared theme, loaded after page layouts. Content and page geometry stay local. */
:root {
  --brand-blue: #1197d5;
  --brand-green: #74a534;
  --river: #006f9b;
  --river-deep: #073d52;
  --leaf: #4e7225;
  --teal: var(--leaf);
  --gold: var(--leaf);
  --ink: #193640;
  --muted: #536a73;
  --paper: #f6f9f7;
  --surface: #ffffff;
  --line: #d4e2e1;
  --blue-wash: #eaf4f9;
  --green-wash: #eff5e8;
  --radius: 8px;
  --panel-padding: clamp(22px, 3vw, 40px);
  --panel-shadow: 0 8px 28px -22px #073d5255;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
  --serif: Georgia, "Source Han Serif SC", "Noto Serif SC", "Songti SC", "SimSun", serif;
}
body { background: var(--paper); color: var(--ink); line-height: 1.75; }
a { color: var(--river); text-decoration-color: #92bdcc; text-underline-offset: 4px; }
a:hover { color: var(--river-deep); text-decoration-color: var(--brand-blue); }
a:focus-visible, button:focus-visible, summary:focus-visible { outline: 2px solid var(--river); outline-offset: 4px; }
.prose strong { color: inherit; font-weight: 650; }
.prose h2, .prose h3, .prose h4 { color: var(--river-deep); }
.inner-page .prose { padding-block: 44px 88px; }
.prose > h2, .prose .symposium-overview h2, .prose .conference-schedule h2,
.page-program .program-section > h2, .page-field-trip .prose h2,
.historical-page .prose .previous-articles h2,
.page-registration .registration-section-heading h2, .page-registration .registration-information h2 {
  font-size: clamp(1.7rem, 2.4vw, 2.15rem); line-height: 1.25; letter-spacing: -.025em;
}
.prose > h2 { margin-top: 64px; padding-bottom: 18px; border-bottom-color: var(--line); }
.prose > h2:first-child { margin-top: 0; }
.prose p { text-wrap: pretty; }
.prose figure figcaption { color: var(--muted); line-height: 1.6; }
.prose .symposium-overview__figure img, .prose .announcement-figure img,
.page-program .program-figure img, .page-field-trip .excursion-figure img,
.page-about .prose .history-gallery img, .historical-page .prose .historical-report__photo img {
  border-radius: var(--radius);
}
.table-wrap { border-radius: var(--radius); border-color: var(--line); box-shadow: var(--panel-shadow); }
.prose th { background: var(--blue-wash); color: var(--river-deep); }
.prose blockquote, .notice { background: var(--green-wash); border-left-color: var(--brand-green); }

/* Primary navigation: stable tabs, precise underlines, and a persistent home header. */
.site-header { background: #f6f9f7f7; border-bottom-color: var(--line); transition: background .22s ease, box-shadow .22s ease; }
.site-header.is-scrolled { box-shadow: 0 4px 24px #073d5212; }
.home-page > .site-header { position: fixed; inset: 0 0 auto; background: transparent; }
.home-page .site-header.is-scrolled { background: #f6f9f7fa; backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.home-page .site-header.is-scrolled .site-header__inner { border-bottom-color: transparent; }
.home-page .site-header.is-scrolled .brand__wordmark--blue { display: block; }
.home-page .site-header.is-scrolled .brand__wordmark--white { display: none; }
.site-nav { gap: 4px; }
.site-nav a { position: relative; padding: 13px 12px; border-radius: var(--radius); color: var(--ink); font-size: .9rem; line-height: 1.5; transition: color .2s ease, background .2s ease, box-shadow .2s ease; }
.site-nav a:hover, .site-nav a:focus-visible { color: var(--river-deep); background: var(--blue-wash); transform: none; }
.site-nav a::after { left: 12px; right: 12px; bottom: 6px; height: 2px; background: linear-gradient(90deg, var(--brand-blue), var(--brand-green)); opacity: 1; }
.site-nav a[aria-current=page] { color: #fff; background: linear-gradient(120deg, var(--river-deep), #075b7b); box-shadow: 0 4px 12px #073d521c; }
.site-nav a[aria-current=page]::after { background: #afcf7e; }
.home-page .site-header:not(.is-scrolled) .site-nav a { color: #fff; }
.home-page .site-header:not(.is-scrolled) .site-nav a:hover,
.home-page .site-header:not(.is-scrolled) .site-nav a:focus-visible { color: #fff; background: #ffffff16; transform: none; }
.home-page .site-header:not(.is-scrolled) .site-nav a[aria-current=page] { color: #fff; background: #ffffff20; box-shadow: inset 0 0 0 1px #ffffff40; }
.home-page .site-header:not(.is-scrolled) .site-nav a[aria-current=page]::after { background: #cbe5a7; }
.home-page .site-header:not(.is-scrolled) .nav-toggle span { background: #fff; }
.home-page .site-header.is-scrolled .site-nav a { color: var(--ink); }
.home-page .site-header.is-scrolled .site-nav a:hover,
.home-page .site-header.is-scrolled .site-nav a:focus-visible { color: var(--river-deep); background: var(--blue-wash); transform: none; }
.home-page .site-header.is-scrolled .site-nav a[aria-current=page] { color: #fff; background: linear-gradient(120deg, var(--river-deep), #075b7b); box-shadow: 0 4px 12px #073d521c; }
.home-page .site-header.is-scrolled .site-nav a[aria-current=page]::after { background: #afcf7e; }
.home-page .site-header:not(.is-scrolled) a:focus-visible { outline-color: #fff; }

/* River contours give every inner-page title the same restrained identity. */
.inner-page .page-hero { background-color: var(--river-deep); background-image: url('../images/river-contours.svg'), linear-gradient(120deg, var(--river-deep), #084e63); background-repeat: no-repeat; background-size: auto 100%, cover; background-position: right center, center; border-bottom: 3px solid; border-image: linear-gradient(90deg, var(--brand-blue), var(--brand-green)) 1; }
.inner-page .page-hero .eyebrow { color: #d6edbd; }
.inner-page .page-hero .page-hero__description { color: #dcebf0; }
.inner-page .page-hero .history-back { border-radius: 6px; border-color: #c7e0e66e; background: #ffffff06; }
.inner-page .page-hero .history-back:hover { background: #ffffff16; border-color: #d6edbd; }

/* Home: a clear announcement panel and a light conference facts strip. */
.home-page .hero-announcement { padding: 26px 28px; margin-top: 20px; gap: 0 36px; grid-template-columns: minmax(0,.65fr) minmax(0,2fr); border: 1px solid #d6e7eb35; border-left: 3px solid var(--brand-green); border-radius: var(--radius); background: #052c3c8c; }
.home-page .hero-announcement h2 { font-size: 1.14rem; line-height: 1.4; }
.home-page .hero-announcement .announcement-download { color: #dbefc7; border-bottom-color: #a8cf74; }
.home-page .hero-announcement .announcement-download:hover { color: #fff; }
.home-page .fact-grid { margin-bottom: 64px; background: var(--surface); border-radius: 0 0 var(--radius) var(--radius); box-shadow: var(--panel-shadow); }
.home-page .fact-card, .home-page .fact-card:first-child { padding: 26px 24px; }
.home-page .fact-card small { color: var(--river); font-size: .7rem; letter-spacing: .1em; }
.home-page .fact-card strong { font-size: 1.12rem; }
.prose .symposium-format li { border-top-width: 3px; border-top-color: #aad0dd; }
.prose .symposium-format li:nth-child(2) { border-top-color: #b1ca90; }
.home-page .organization-columns--updated { margin-top: 64px; }
.home-page .organization-column h2 { min-height: 54px; }

/* One surface, border and corner treatment across cards and status panels. */
.committee-member, .organization, .contact-panel, .page-program .program-at-a-glance {
  background-color: var(--surface); border-color: var(--line); border-radius: var(--radius); box-shadow: var(--panel-shadow);
}
.committee-member { background-image: linear-gradient(90deg, var(--brand-blue), var(--brand-green)); background-size: 52px 3px; background-position: 24px 0; background-repeat: no-repeat; }
.committee-member__portrait { outline: 3px solid var(--green-wash); outline-offset: 3px; }
.committee-member:focus-within { border-color: #8ab9c9; }
.organization { transition: border-color .2s ease, box-shadow .2s ease; }
a.organization:hover, a.organization:focus-visible { border-color: #91bccc; box-shadow: 0 8px 24px -16px #073d523d; }
.organization[href="https://english.ecnu.edu.cn/"] { background-color: #fff; }
.contact-person { position: relative; }
.contact-person::before { content: ""; display: block; width: 40px; height: 3px; margin-bottom: 18px; border-radius: 2px; background: linear-gradient(90deg, var(--brand-blue), var(--brand-green)); }
.page-registration .registration-status, .page-award .award-status {
  padding: var(--panel-padding); border: 1px solid var(--line); border-top: 3px solid var(--brand-blue); border-radius: var(--radius); background: linear-gradient(110deg, var(--blue-wash), var(--green-wash));
}
.page-registration .registration-status__details, .page-award .award-status__details { border-left-color: #bfd4d6; }
.page-registration .registration-status__details li, .page-award .award-status__details li { border-bottom-color: #cbdddd; }
.page-registration .registration-eyebrow, .page-award .award-eyebrow { display: inline-flex; align-items: center; gap: 9px; font-size: .72rem; color: var(--leaf); letter-spacing: .075em; }
.registration-eyebrow::before, .award-eyebrow::before { content: ""; width: 8px; height: 8px; flex-shrink: 0; border: 2px solid var(--leaf); border-radius: 50%; }
.page-registration .registration-deadlines { gap: 24px; }
.page-registration .registration-deadlines > div { padding: 24px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.page-registration .registration-deadlines > div:first-child { border-top: 3px solid var(--brand-blue); }
.page-registration .registration-deadlines__day { color: var(--river); }

/* The contents index remains a reading aid, visually distinct from primary tabs. */
.page-program .program-nav { padding: 20px 14px; border: 1px solid var(--line); border-radius: var(--radius); background: #ffffffb8; }
.page-program .program-nav__summary { padding-bottom: 16px; }
.page-program .program-nav__title { font-size: 1.1rem; }
.page-program .program-nav a { padding-left: 12px; border-radius: 0; background: transparent; }
.page-program .program-nav a[aria-current=location]::before { background: var(--brand-green); }
.page-program .program-nav a[aria-current=location] .program-nav__number { color: var(--leaf); }
.page-program .program-at-a-glance { border-top: 3px solid var(--brand-blue); }
.page-program .program-kicker, .page-field-trip .excursion-kicker { font-size: .7rem; letter-spacing: .09em; }
.page-program .program-theme, .page-program .program-information, .page-program .participation-deadlines,
.page-field-trip .excursion-route, .page-field-trip .excursion-arrangements {
  border-radius: var(--radius); background: linear-gradient(110deg, var(--blue-wash), var(--green-wash));
}
.page-program .program-theme { border-left-color: var(--brand-blue); }
.page-program .program-topic__number, .page-field-trip .excursion-stop__number { color: var(--leaf); }
.page-program .participation-panel { padding: 26px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--panel-shadow); }
.page-program .participation-panel p { line-height: 1.8; }
.page-program .program-contact { border-radius: var(--radius); background: linear-gradient(120deg, var(--river-deep), #084e63); }
.page-program .program-contact .contact-person::before { margin-bottom: 16px; }
.page-program .program-contact h2, .page-program .program-contact .contact-person h3 { color: #fff; }

/* Document controls share icon spacing and a legible format label. */
.announcement-download__type { padding: 2px 6px; border-radius: 4px; font-size: .66rem; letter-spacing: .06em; }
.page-program .prose .announcement-download { margin-top: 12px; color: var(--river); line-height: 1.6; }
.announcement-download__icon { width: 24px; height: 24px; }

/* Deadlines stay blue, programme nodes green, and the nearest deadline stays white. */
.prose .conference-timeline__item { border-radius: var(--radius); box-shadow: var(--panel-shadow); border-color: var(--line); }
.prose .conference-timeline__item--event { --milestone-color: var(--leaf); border-top-color: #adc890; }
.prose .conference-timeline__item--featured { --milestone-color: var(--river); background: linear-gradient(145deg, var(--river-deep), #075b7b); border-color: var(--river-deep); }
.conference-timeline__item--featured .conference-timeline__type { color: #fff; }
.conference-timeline__item--featured .conference-timeline__date,
.prose .conference-timeline__item--featured .conference-timeline__title { color: #fff; }
.conference-timeline::before { background: linear-gradient(90deg, #a5d2e3 0%, #a5d2e3 50%, #b6ce95 50%, #b6ce95 100%); }
.page-field-trip .excursion-transfer::before { background: linear-gradient(90deg, #99c9da, #b6ce95); }
.page-field-trip .excursion-transfer li::before { border-color: var(--blue-wash); }
.page-field-trip .excursion-transfer li:nth-child(n+3)::before { background: var(--leaf); box-shadow: 0 0 0 1px var(--leaf); }
.page-field-trip .excursion-reaches { border-top-color: #c7dcd7; }
.page-field-trip .excursion-reaches .excursion-kicker { color: var(--leaf); }

/* Keep historical meetings chronological, with consistent scholarly references. */
.page-about .history-entry__year { border-left-color: var(--brand-blue); border-image: linear-gradient(var(--brand-blue), var(--brand-green)) 1; }
.page-about .history-entry__year strong { color: var(--river-deep); }
.page-about .history-entry__theme { color: var(--river); }
.historical-page .previous-article::before { display: grid; place-items: center; width: 28px; height: 28px; top: 25px; background: var(--blue-wash); color: var(--river); border-radius: 6px; font-size: .73rem; }
.historical-page .previous-article__links a { text-decoration-color: #a3c2ce; }
.historical-page .previous-article__citation { color: var(--muted); }
.page-archive .prose > img { width: 100%; max-width: 960px; margin: 28px 0; border-radius: var(--radius); box-shadow: none; }
.archive-link { padding-block: 18px; gap: 18px; }
.archive-link span { text-align: right; }

/* Finish with the same blue and green identity as the title banners. */
.river-index { background: linear-gradient(90deg, var(--blue-wash), var(--green-wash)); border-color: var(--line); }
.river-index .container { color: var(--muted); padding-block: 20px; }
.site-footer { background: var(--river-deep); border-top: 3px solid; border-image: linear-gradient(90deg, var(--brand-blue), var(--brand-green)) 1; }
.footer-grid h2 { color: #d7edc1; }
.footer-grid > div > a:not(.brand) { color: #d4e7eb; text-underline-offset: 4px; }
.footer-grid > div > a:not(.brand):hover { color: #fff; }
.footer-bottom { color: #b2cbd3; border-top-color: #ffffff26; }
.site-footer a:focus-visible, .hero a:focus-visible { outline-color: #d7edc1; }

@media(max-width:1199px) {
  .page-program .program-nav { padding: 0; border-radius: 6px; background: var(--paper); }
  .page-program .program-nav__summary { padding: 12px 16px; }
  .page-program .program-nav__title { font-family: var(--sans); font-size: .82rem; }
  .page-program .program-nav__links { background: var(--surface); border-color: var(--line); border-radius: 0 0 6px 6px; }
}
@media(max-width:1120px) {
  .site-nav, .home-page .site-nav { border-radius: var(--radius); background: var(--surface); border-color: var(--line); box-shadow: 0 16px 40px #073d5226; }
  .site-nav a { padding: 16px; }
  .site-nav a::after { left: 16px; right: 16px; }
  .home-page .site-header:not(.is-scrolled) .site-nav a { color: var(--ink); }
  .home-page .site-header:not(.is-scrolled) .site-nav a:hover,
  .home-page .site-header:not(.is-scrolled) .site-nav a:focus-visible { color: var(--river-deep); background: var(--blue-wash); }
  .home-page .site-header:not(.is-scrolled) .site-nav a[aria-current=page] { color: #fff; background: var(--river-deep); box-shadow: none; }
  .home-page .site-header:not(.is-scrolled) .site-nav a:focus-visible { outline-color: var(--river); }
}
@media(max-width:1100px) {
  .conference-timeline::before { background: linear-gradient(#a5d2e3 0%, #a5d2e3 50%, #b6ce95 50%, #b6ce95 100%); }
}
@media(max-width:800px) {
  .home-page .hero-announcement { grid-template-columns: 1fr; gap: 12px; padding: 24px; }
}
@media(max-width:700px) {
  .inner-page .prose { padding-block: 32px 56px; }
  .inner-page .page-hero { background-position: 65% center, center; }
  .prose > h2 { margin-top: 44px; }
  .home-page .hero-announcement { padding: 22px 20px; margin-top: 0; }
  .home-page .fact-grid { margin-bottom: 44px; }
  .home-page .fact-card, .home-page .fact-card:first-child { padding: 20px; }
  .home-page .organization-columns--updated { margin-top: 44px; }
  .page-registration .registration-status, .page-award .award-status { padding: 26px 22px; }
  .page-registration .registration-status__details, .page-award .award-status__details { border-top-color: #bfd4d6; }
  .page-registration .registration-deadlines > div { padding: 20px; }
  .page-program .participation-panel { padding: 22px; }
  .page-field-trip .excursion-route { padding: 24px 20px; }
  .page-field-trip .excursion-transfer::before { background: linear-gradient(#99c9da, #b6ce95); }
  .archive-link { flex-wrap: wrap; gap: 4px 18px; }
  .archive-link span { text-align: left; }
}
@media(prefers-reduced-motion:reduce) {
  .site-header, .site-nav a, .site-nav a::after, .organization { transition: none; }
  .site-nav.is-open { animation: none; }
}