@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700&display=swap');

/* ============================================
   CSS Variables
   ============================================ */
:root {
  --text-color: #1a1a1a;
  --text-muted: #555;
  --border-color: #e0e0e0;
  --bg-light: #f7f7f7;
  --topbar-height: 56px;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-serif: Georgia, "Times New Roman", serif;
}

/* ============================================
   Reset & Base (Mobile-first)
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-color);
  background: #fff;
}

/* Rheo inserts a default header — hide it */
.header {
  display: none;
}

h1, h2 {
  text-transform: uppercase;
}

a {
  color: var(--text-color);
  text-decoration: underline;
}

a:hover {
  opacity: 0.7;
}

/* ============================================
   Hero
   ============================================ */
.hero {
  position: relative;
  height: 70vh;
  width: 100%;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}

.hero-overlay {
  position: relative;
  z-index: 1;
  color: #fff;
  padding: 1rem;
}

.hero-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 0 0 0.5rem 0;
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.7);
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.1rem;
  margin: 0 0 0.3rem 0;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.6);
  font-weight: 400;
}

.hero-location {
  font-size: 0.9rem;
  margin: 0;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.6);
  font-weight: 300;
  opacity: 0.9;
}

/* ============================================
   Sticky Topbar
   ============================================ */
.topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--topbar-height);
  background-size: cover;
  background-position: center 30%;
  z-index: 100;
  transform: translateY(-100%);
  transition: transform 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.topbar::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
}

.topbar.visible {
  transform: translateY(0);
}

.topbar-link {
  text-decoration: none;
}

.topbar-link:hover {
  opacity: 1;
}

.topbar-title {
  position: relative;
  z-index: 1;
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  margin: 0;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.5);
  white-space: nowrap;
}

/* On subpages (no hero), add top padding so content isn't hidden behind fixed topbar */
body:not(:has(.hero)) .main-content {
  padding-top: calc(var(--topbar-height) + 2rem);
}

/* ============================================
   Main Content
   ============================================ */
.main-content {
  position: relative;
  max-width: 48em;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.intro {
  margin-bottom: 2rem;
}

.intro p {
  margin: 0 0 1rem 0;
}

.contact-info {
  font-style: italic;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ============================================
   Schedule
   ============================================ */
.schedule-section h2 {
  font-family: var(--font-body);
  font-size: 1.1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 2.5rem 0 0.5rem 0;
  color: var(--text-muted);
}

.schedule-location {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0 0 1.5rem 0;
}

.day-heading {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 2rem 0 0.5rem 0;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--text-color);
}

.schedule-row {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--border-color);
}

.schedule-time {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
  white-space: nowrap;
}

.schedule-speaker {
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 0.15rem;
}

.schedule-talk-title {
  font-style: italic;
  margin-bottom: 0.25rem;
}

.schedule-discussant {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.schedule-abstract {
  margin: 0.75rem 0;
  font-size: 0.95rem;
  line-height: 1.65;
}

.schedule-bio {
  font-size: 0.88rem;
  color: var(--text-muted);
  border-left: 3px solid var(--border-color);
  padding-left: 1rem;
  margin: 0.75rem 0 0 0;
  line-height: 1.55;
}

.schedule-row.break-row {
  background: var(--bg-light);
  border-radius: 4px;
  padding: 0.75rem 1rem;
  margin: 0.25rem 0;
}

.schedule-row.break-row .schedule-content {
  color: var(--text-muted);
  font-style: italic;
}

.roundtable-chair {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ============================================
   Footer
   ============================================ */
.site-footer {
  margin-top: 3rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-muted);
  font-style: italic;
}

/* ============================================
   Tablet+ (min-width: 600px)
   ============================================ */
@media (min-width: 600px) {
  .hero {
    height: 100vh;
  }

  .hero-title {
    font-size: 2.4rem;
  }

  .hero-subtitle {
    font-size: 1.3rem;
  }

  .hero-location {
    font-size: 1rem;
  }

  .main-content {
    padding: 3rem 2rem;
  }

  .schedule-row {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 1rem;
  }

  .schedule-row.break-row {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 1rem;
  }

  .schedule-time {
    margin-bottom: 0;
    padding-top: 0.15rem;
  }
}

/* ============================================
   Desktop (min-width: 900px)
   ============================================ */
@media (min-width: 900px) {
  .hero-title {
    font-size: 3rem;
  }

  .topbar-title {
    font-size: 1.1rem;
  }

  .schedule-row {
    grid-template-columns: 160px 1fr;
  }

  .schedule-row.break-row {
    grid-template-columns: 160px 1fr;
  }
}