/* ===== CSS Custom Properties ===== */
:root {
  --navy-deep: #0d1b2a;
  --navy-mid: #1a2e4a;
  --navy-light: #243b55;
  --blue-accent: #3b82f6;
  --blue-light: #60a5fa;
  --teal-accent: #06b6d4;
  --bg-white: #ffffff;
  --bg-light: #f1f5f9;
  --bg-lighter: #f8fafc;
  --text-primary: #1e293b;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --card-shadow: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -1px rgba(0,0,0,0.04);
  --card-shadow-hover: 0 20px 25px -5px rgba(0,0,0,0.12), 0 8px 10px -5px rgba(0,0,0,0.06);
}

/* ===== Base ===== */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  color: var(--text-primary);
  padding-top: 64px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; }

p { text-align: justify; margin-bottom: 1rem; }

a {
  color: var(--blue-accent);
  text-decoration: none;
  transition: color 0.15s;
}
a:hover { color: var(--blue-light); text-decoration: underline; }

*::selection { background: var(--blue-accent); color: #fff; }

/* ===== Navbar ===== */
#mainNav {
  background: var(--navy-deep);
  padding: 0;
  height: 64px;
  box-shadow: 0 1px 0 rgba(255,255,255,0.06);
}

#mainNav .container-xl {
  height: 100%;
  display: flex;
  align-items: center;
}

#mainNav .navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.85) !important;
  letter-spacing: -0.01em;
}
#mainNav .navbar-brand:hover { color: #fff !important; text-decoration: none; }
#mainNav .navbar-brand img { height: 26px; }

#mainNav .nav-link {
  color: rgba(255,255,255,0.7) !important;
  font-size: 0.88rem;
  font-weight: 500;
  padding: 0.4rem 0.9rem !important;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
}
#mainNav .nav-link:hover {
  color: #fff !important;
  background: rgba(255,255,255,0.09);
  text-decoration: none;
}

#mainNav .navbar-toggler {
  border-color: rgba(255,255,255,0.2);
  padding: 0.3rem 0.6rem;
}
#mainNav .navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255%2C255%2C255%2C0.75%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ===== Hero ===== */
#hero {
  background: linear-gradient(145deg, var(--navy-deep) 0%, var(--navy-mid) 65%, var(--navy-light) 100%);
  color: white;
  padding: 96px 0 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

#hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 70% 25%, rgba(59,130,246,0.13) 0%, transparent 55%),
    radial-gradient(ellipse at 25% 75%, rgba(6,182,212,0.09) 0%, transparent 55%);
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  background: rgba(59,130,246,0.18);
  border: 1px solid rgba(59,130,246,0.38);
  color: var(--blue-light);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.35rem 1rem;
  border-radius: 100px;
  margin-bottom: 1.5rem;
}

#hero h1 {
  font-size: clamp(1.7rem, 3.5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.22;
  color: #fff;
  margin: 0 auto 2rem;
  max-width: 960px;
  letter-spacing: -0.025em;
}

.event-badges {
  display: flex;
  gap: 0.65rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 3.25rem;
}

.event-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: rgba(255,255,255,0.09);
  border: 1px solid rgba(255,255,255,0.18);
  color: rgba(255,255,255,0.88);
  padding: 0.45rem 1.1rem;
  border-radius: 100px;
  font-size: 0.88rem;
  font-weight: 500;
}

.hero-image-wrap {
  max-width: 700px;
  margin: 0 auto;
}
.hero-image-wrap img {
  width: 100%;
  border-radius: 14px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.45);
  border: 1px solid rgba(255,255,255,0.08);
}

/* ===== Sections ===== */
.site-section { padding: 80px 0; }
.site-section.bg-alt { background: var(--bg-light); }

.section-header { text-align: center; margin-bottom: 2.75rem; }

.section-title {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.section-divider {
  width: 48px;
  height: 4px;
  background: linear-gradient(90deg, var(--blue-accent), var(--teal-accent));
  border-radius: 2px;
  margin: 0 auto;
}

/* ===== Overview ===== */
.overview-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--blue-accent);
  border-radius: 0 12px 12px 0;
  padding: 2rem 2.25rem;
  box-shadow: var(--card-shadow);
}
.overview-card p { color: var(--text-primary); }
.overview-card p:last-child { margin-bottom: 0; }

/* ===== Speaker Cards ===== */
.speaker-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 2rem 1.25rem 1.5rem;
  text-align: center;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.speaker-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--card-shadow-hover);
  border-color: var(--blue-accent);
}

.speaker-photo-wrap {
  width: 120px;
  height: 120px;
  margin: 0 auto 1.25rem;
}
.speaker-photo-wrap img {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  transition: border-color 0.2s;
}
.speaker-card:hover .speaker-photo-wrap img { border-color: var(--blue-accent); }

.speaker-monogram {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--navy-mid), var(--navy-light));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  font-weight: 700;
  color: #fff;
  border: 3px solid var(--border-color);
  transition: border-color 0.2s;
  margin: 0 auto 1.25rem;
}
.speaker-card:hover .speaker-monogram { border-color: var(--blue-accent); }

.speaker-name {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}
.speaker-name a { color: var(--text-primary); }
.speaker-name a:hover { color: var(--blue-accent); text-decoration: none; }

.speaker-affil {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--blue-accent);
  background: rgba(59,130,246,0.08);
  padding: 0.2rem 0.65rem;
  border-radius: 100px;
  margin-bottom: 0.75rem;
  letter-spacing: 0.01em;
}

.speaker-talk {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.5;
  flex-grow: 1;
  font-style: italic;
}

/* ===== Schedule ===== */
.schedule-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-white);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  border: 1px solid var(--border-color);
}
.schedule-table thead th {
  background: var(--navy-deep);
  color: rgba(255,255,255,0.85);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.9rem 1.25rem;
  border: none;
}
.schedule-table tbody tr {
  border-bottom: 1px solid var(--border-color);
  transition: background 0.15s;
}
.schedule-table tbody tr:last-child { border-bottom: none; }
.schedule-table tbody tr:nth-child(even) { background: var(--bg-lighter); }
.schedule-table tbody tr:hover { background: rgba(59,130,246,0.04); }
.schedule-table tbody td {
  padding: 1.1rem 1.25rem;
  vertical-align: middle;
  font-size: 0.93rem;
}

.time-badge {
  display: inline-block;
  background: rgba(59,130,246,0.1);
  color: var(--blue-accent);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.3rem 0.75rem;
  border-radius: 100px;
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.talk-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
  line-height: 1.4;
}

.talk-meta {
  font-size: 0.83rem;
  color: var(--text-muted);
}

/* ===== Organizers ===== */
.organizer-card {
  text-align: center;
  padding: 1.25rem 0.75rem 1.5rem;
  border-radius: 12px;
  transition: background 0.2s;
}
.organizer-card:hover { background: var(--bg-white); }

.organizer-photo {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border-color);
  margin: 0 auto 0.85rem;
  display: block;
  transition: border-color 0.2s, transform 0.2s;
}
.organizer-card:hover .organizer-photo {
  border-color: var(--blue-accent);
  transform: scale(1.04);
}

.organizer-name {
  font-size: 0.93rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}
.organizer-name a { color: var(--text-primary); }
.organizer-name a:hover { color: var(--blue-accent); text-decoration: none; }

.organizer-affil {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ===== Publications ===== */
.pub-list {
  list-style: none;
  padding: 0;
  margin: 0 0 1.5rem;
}
.pub-list li {
  padding: 0.85rem 1.1rem 0.85rem 1.25rem;
  border-left: 3px solid var(--border-color);
  margin-bottom: 0.6rem;
  border-radius: 0 8px 8px 0;
  background: var(--bg-white);
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--text-primary);
  transition: border-color 0.15s, background 0.15s;
  text-align: left;
}
.pub-list li:hover {
  border-left-color: var(--blue-accent);
  background: var(--bg-lighter);
}
.pub-list li a { color: var(--blue-accent); }

.resource-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 2rem;
}

.resource-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: rgba(59,130,246,0.08);
  border: 1px solid rgba(59,130,246,0.22);
  padding: 0.45rem 1rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--blue-accent);
  transition: background 0.15s, border-color 0.15s;
}
.resource-btn:hover {
  background: rgba(59,130,246,0.15);
  border-color: var(--blue-accent);
  text-decoration: none;
  color: var(--blue-accent);
}

/* ===== Footer ===== */
#footer {
  background: var(--navy-deep);
  color: rgba(255,255,255,0.45);
  padding: 1.5rem 0;
  font-size: 0.8rem;
  border-top: 1px solid rgba(255,255,255,0.06);
}
#footer a { color: rgba(255,255,255,0.55); }
#footer a:hover { color: rgba(255,255,255,0.9); text-decoration: none; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  body { font-size: 16px; }
  .site-section { padding: 56px 0; }
  #hero { padding: 64px 0 56px; }
  #hero h1 { font-size: 1.55rem; }
  .section-title { font-size: 1.4rem; }
  .overview-card { padding: 1.5rem; }
  .schedule-table tbody td { padding: 0.8rem; font-size: 0.88rem; }
  .time-badge { font-size: 0.74rem; }
}

@media (max-width: 480px) {
  #hero h1 { font-size: 1.35rem; }
  .event-badge { font-size: 0.8rem; padding: 0.38rem 0.85rem; }
}