/* =============================================================
   ICDM 2026 — Main Stylesheet
   修改 :root 中的 CSS 变量可快速更换整站配色
   ============================================================= */

/* ---- 颜色 & 主题变量 ---------------------------------------- */
:root {
  --color-primary:    #0d3880;   /* 深蓝 - 主色 */
  --color-primary-dk: #082060;   /* 更深的蓝 - hover */
  --color-accent:     #c8960c;   /* 金色 - 强调 */
  --color-accent-lt:  #f5c842;   /* 浅金 */
  --color-bg:         #ffffff;
  --color-surface:    #f4f6fb;   /* 浅灰蓝背景 */
  --color-border:     #dde3ef;
  --color-text:       #1a1f36;
  --color-text-muted: #5f6b8a;
  --color-white:      #ffffff;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-serif: 'Merriweather', Georgia, serif;

  --radius:    8px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.05);
  --shadow-md: 0 4px 16px rgba(13,56,128,.10);
  --shadow-lg: 0 8px 32px rgba(13,56,128,.14);

  --nav-height: 64px;
  --container:  1140px;
}

/* ---- Reset & base ------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { color: var(--color-primary-dk); }
ul { list-style: none; }

/* ---- Layout helpers ---------------------------------------- */
.container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 24px;
}
.section { padding-block: 72px; }
.section-alt { background: var(--color-surface); }

/* ---- Typography -------------------------------------------- */
h1, h2, h3, h4 { line-height: 1.25; font-weight: 700; }
h2.section-title {
  font-size: 1.75rem;
  color: var(--color-primary);
  margin-bottom: 8px;
}
.section-subtitle {
  color: var(--color-text-muted);
  font-size: 1rem;
  margin-bottom: 40px;
}
.section-divider {
  width: 48px; height: 4px;
  background: var(--color-accent);
  border-radius: 2px;
  margin-bottom: 16px;
}

/* ---- Buttons ----------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all .2s;
  border: 2px solid transparent;
}
.btn-primary {
  background: var(--color-accent);
  color: var(--color-primary-dk);
}
.btn-primary:hover {
  background: var(--color-accent-lt);
  color: var(--color-primary-dk);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn-outline {
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.btn-outline:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-primary);
  height: var(--nav-height);
  transition: box-shadow .3s;
}
.navbar.scrolled { box-shadow: var(--shadow-lg); }

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--nav-height);
}

.nav-brand {
  display: flex;
  align-items: baseline;
  gap: 4px;
  color: var(--color-white);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -.5px;
}
.nav-brand:hover { color: var(--color-accent-lt); }
.nav-brand-abbr { font-family: var(--font-serif); }
.nav-brand-year { font-size: 1rem; color: var(--color-accent-lt); font-weight: 600; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-links a {
  color: rgba(255,255,255,.85);
  font-size: .875rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius);
  transition: all .15s;
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--color-white);
  background: rgba(255,255,255,.15);
}
.nav-links a.active {
  background: rgba(255,255,255,.2);
  color: var(--color-accent-lt);
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-toggle span {
  display: block;
  width: 22px; height: 2px;
  background: var(--color-white);
  border-radius: 1px;
  transition: .2s;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  /* Brisbane Story Bridge at golden hour (Pexels, free license) */
  background: url('../images/brisbane-hero.jpg') center 78% / cover no-repeat var(--color-primary-dk);
  color: var(--color-white);
  padding-block: 100px 170px;
  overflow: hidden;
}
.hero-overlay {
  position: absolute; inset: 0;
  /* 中性压暗保证文字可读，不改变照片色调 */
  background: linear-gradient(90deg, rgba(15,18,28,.55) 0%, rgba(15,18,28,.25) 55%, rgba(15,18,28,0) 85%);
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-content { position: relative; z-index: 1; max-width: 780px; text-shadow: 0 1px 3px rgba(10,15,25,.5), 0 4px 18px rgba(10,15,25,.35); }

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.15);
  border: 1px solid rgba(255,255,255,.3);
  color: var(--color-accent-lt);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  padding: 4px 14px;
  border-radius: 99px;
  margin-bottom: 20px;
}
.hero-title {
  font-family: var(--font-serif);
  font-size: clamp(2.8rem, 7vw, 5rem);
  color: var(--color-white);
  line-height: 1;
  margin-bottom: 12px;
}
.hero-title span { color: var(--color-accent-lt); }
.hero-full-name {
  font-size: 1.15rem;
  font-weight: 500;
  opacity: .9;
  margin-bottom: 12px;
}
.hero-tagline {
  font-size: 1rem;
  opacity: .75;
  max-width: 520px;
  margin-bottom: 32px;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 36px;
}
.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: .95rem;
  font-weight: 500;
  opacity: .9;
}
.hero-meta-item .icon {
  width: 18px; height: 18px;
  stroke: var(--color-accent-lt);
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex-shrink: 0;
}

/* ============================================================
   PAGE HEADER (inner pages)
   ============================================================ */
.page-header {
  background: linear-gradient(135deg, var(--color-primary-dk), #1a4da8);
  color: var(--color-white);
  padding-block: 52px 48px;
  border-bottom: 3px solid var(--color-accent);
}
.page-header-title {
  font-family: var(--font-serif);
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 700;
}
.page-header-subtitle {
  opacity: .8;
  margin-top: 8px;
  font-size: 1rem;
}

/* ============================================================
   MAIN CONTENT
   ============================================================ */
.main-content { padding-block: 64px; }

/* Generic prose inside markdown pages */
.main-content p { margin-bottom: 1em; color: var(--color-text); }
.main-content h2 { font-size: 1.5rem; color: var(--color-primary); margin: 2em 0 .6em; }
.main-content h3 { font-size: 1.15rem; color: var(--color-primary); margin: 1.5em 0 .5em; }
.main-content ul, .main-content ol { padding-left: 1.4em; margin-bottom: 1em; }
.main-content li { margin-bottom: .4em; list-style: disc; }
.main-content strong { color: var(--color-primary-dk); }

/* ============================================================
   HOMEPAGE SECTIONS
   ============================================================ */

/* ---- Quick highlights grid (homepage) ---- */
.highlights {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px;
  margin-top: 16px;
}
.highlight-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform .2s, box-shadow .2s;
}
.highlight-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.highlight-icon { font-size: 2rem; margin-bottom: 12px; }
.highlight-label { font-size: .8rem; font-weight: 600; letter-spacing: 1px; text-transform: uppercase; color: var(--color-text-muted); margin-bottom: 6px; }
.highlight-value { font-size: 1.25rem; font-weight: 700; color: var(--color-primary); }

/* ---- Dates preview (homepage) ---- */
.dates-list { display: flex; flex-direction: column; gap: 12px; }
.date-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 20px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color .2s;
}
.date-item.highlight {
  border-left-color: var(--color-accent);
  background: #fffbf0;
}
.date-item.passed {
  opacity: .5;
  border-left-color: #ccc;
}
.date-item.passed .date-event { text-decoration: line-through; }
.date-event { font-weight: 500; font-size: .95rem; }
.date-value {
  font-size: .9rem;
  font-weight: 600;
  color: var(--color-primary);
  white-space: nowrap;
}
.date-item.highlight .date-value { color: var(--color-accent); }

/* ============================================================
   COMMITTEE PAGE
   ============================================================ */
.major-section-title {
  font-family: var(--font-serif);
  font-size: 2rem;
  color: var(--color-primary);
  padding-bottom: 12px;
  border-bottom: 3px solid var(--color-accent);
  margin-bottom: 36px;
}
.committee-section { margin-bottom: 56px; }
.committee-section-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-primary);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-border);
  margin-bottom: 24px;
}
.committee-subsection { margin-bottom: 28px; }
.committee-subsection-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: 14px;
}
.committee-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(480px, 1fr));
  gap: 16px;
}
.committee-card {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 18px;
  padding: 18px 20px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: box-shadow .2s, transform .2s;
  min-width: 0;
}
.committee-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.committee-avatar {
  width: 160px; height: 160px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-primary), #4c7acc);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-weight: 700;
  font-size: 3rem;
  flex-shrink: 0;
}
.committee-photo {
  width: 160px; height: 160px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  border: 3px solid var(--color-border);
}
.committee-info { min-width: 0; }
.committee-name { font-size: 1.3rem; font-weight: 600; color: var(--color-text); line-height: 1.3; }
.committee-name a { color: var(--color-primary); }
.committee-name a:hover { text-decoration: underline; }
.committee-affiliation { font-size: 1.1rem; color: var(--color-text-muted); margin-top: 6px; }

/* ============================================================
   KEYNOTE SPEAKERS PAGE
   ============================================================ */
.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 28px;
  margin-top: 16px;
}
.speaker-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow .2s, transform .2s;
}
.speaker-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.speaker-photo {
  width: 100%; height: 200px;
  object-fit: cover;
  background: var(--color-surface);
}
.speaker-photo-placeholder {
  width: 100%; height: 200px;
  background: linear-gradient(135deg, var(--color-primary), #4c7acc);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: rgba(255,255,255,.5);
}
.speaker-body { padding: 20px; }
.speaker-name { font-size: 1.1rem; font-weight: 700; color: var(--color-text); }
.speaker-affiliation { font-size: .875rem; color: var(--color-text-muted); margin-top: 2px; margin-bottom: 12px; }
.speaker-talk { font-size: .875rem; color: var(--color-primary); font-style: italic; font-weight: 500; }
.speaker-placeholder-msg {
  text-align: center;
  color: var(--color-text-muted);
  padding: 60px 20px;
  font-size: 1rem;
}

/* ============================================================
   CALL FOR PAPERS / CFP PAGE
   ============================================================ */
.cfp-topics {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 12px;
  margin: 16px 0 32px;
}
.cfp-topic {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 16px;
  background: var(--color-surface);
  border-radius: var(--radius);
  font-size: .9rem;
}
.cfp-topic::before {
  content: '▸';
  color: var(--color-accent);
  font-size: .85rem;
  flex-shrink: 0;
  margin-top: 2px;
}

/* ============================================================
   NOTICE / ALERT BOXES
   ============================================================ */
.notice {
  padding: 16px 20px;
  border-radius: var(--radius);
  border-left: 4px solid;
  margin-bottom: 24px;
  font-size: .9rem;
}
.notice-info {
  background: #eff6ff;
  border-color: #3b82f6;
  color: #1e3a8a;
}
.notice-warning {
  background: #fffbeb;
  border-color: var(--color-accent);
  color: #78350f;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--color-primary-dk);
  color: rgba(255,255,255,.75);
  padding-block: 48px 36px;
  margin-top: auto;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 32px;
}
.footer-name {
  display: block;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 6px;
}
.footer-desc { font-size: .85rem; opacity: .8; }
.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.footer-links a {
  color: rgba(255,255,255,.7);
  font-size: .875rem;
  transition: color .15s;
}
.footer-links a:hover { color: var(--color-accent-lt); }
.footer-copy { font-size: .82rem; line-height: 1.9; opacity: .65; }
.footer-copy a { color: rgba(255,255,255,.8); text-decoration: underline; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0; right: 0;
    background: var(--color-primary-dk);
    flex-direction: column;
    align-items: stretch;
    padding: 12px 16px 20px;
    gap: 2px;
    box-shadow: var(--shadow-lg);
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 10px 14px; font-size: .95rem; }
  .nav-toggle { display: flex; }

  .hero { padding-block: 64px 56px; }
  .hero-title { font-size: 2.6rem; }

  .footer-inner { grid-template-columns: 1fr; gap: 24px; }

  .committee-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .highlights { grid-template-columns: 1fr 1fr; }
  .date-item { flex-direction: column; align-items: flex-start; gap: 4px; }
}

/* ---- About Brisbane page: BEDA promo video ----------------- */
.video-wrap {
  max-width: 960px;
  margin: 32px auto 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  background: #000;
}
.video-wrap video {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
}
.video-credit {
  max-width: 960px;
  margin: 12px auto 48px;
  text-align: center;
  font-size: .85rem;
  color: var(--color-text-muted);
}

/* ============================================================
   ABOUT BRISBANE PAGE — attraction cards
   ============================================================ */
.attractions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
  margin: 24px 0 8px;
}
.attraction-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform .2s, box-shadow .2s;
  display: flex;
  flex-direction: column;
}
.attraction-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.attraction-card img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  display: block;
}
.attraction-card-body { padding: 20px 22px 22px; }
.attraction-card-body h3 { margin: 0 0 8px !important; }
.attraction-card-body p { margin-bottom: 0 !important; font-size: .95rem; color: var(--color-text-muted); }