* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --primary:      #4338ca;
  --primary-dark: #3730a3;
  --hero-top:     #1e1b4b;
  --hero-bot:     #1d4ed8;
  --text:         #1e293b;
  --text-muted:   #475569;
  --border:       #e2e8f0;
  --bg:           #ffffff;
  --bg-alt:       #f8fafc;
  --radius:       14px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Header ── */
.site-header {
  background: linear-gradient(140deg, var(--hero-top) 0%, #312e81 55%, var(--hero-bot) 100%);
  color: #fff;
  padding: 2.75rem 0 2.25rem;
  position: relative;
  overflow: hidden;
}

.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255,255,255,0.06) 1px, transparent 1px);
  background-size: 28px 28px;
  pointer-events: none;
}

.site-header::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(600px 300px at 15% -10%, rgba(129,140,248,0.35), transparent 70%),
    radial-gradient(700px 400px at 90% 110%, rgba(56,189,248,0.22), transparent 70%);
  pointer-events: none;
}

.header-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 1.15rem;
}

.header-logo {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  flex-shrink: 0;
  border: 1px solid rgba(255,255,255,0.18);
  box-shadow: 0 6px 18px rgba(0,0,0,0.3);
}

.site-title h1 {
  font-family: 'Fraunces', Georgia, 'Times New Roman', serif;
  font-size: 1.7rem;
  font-weight: 600;
  color: #fff;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.site-title .event-info {
  font-size: 0.875rem;
  color: #c7d2fe;
  margin-top: 0.45rem;
}

/* ── Nav ── */
nav {
  background: rgba(255,255,255,0.96);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
}

nav a {
  display: block;
  padding: 0.8rem 1.1rem;
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

nav a:hover {
  color: var(--primary);
}

nav a.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}

/* ── Main content ── */
.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 3rem 1.5rem 4.5rem;
}

section {
  margin-bottom: 3.5rem;
}

section:last-child {
  margin-bottom: 0;
}

h2 {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  position: relative;
}

h2::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 2.5rem;
  height: 3px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--primary), #a5b4fc);
}

h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.35rem;
}

p {
  color: var(--text-muted);
  margin-bottom: 1rem;
  font-size: 0.97rem;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--primary);
}

/* ── Hero / intro ── */
.intro-block {
  background: #eef2ff;
  border-left: 4px solid var(--primary);
  border-radius: 0 10px 10px 0;
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
  font-style: italic;
  color: var(--primary-dark);
  font-size: 1rem;
}

/* ── CTA button ── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  background: linear-gradient(135deg, #4f46e5, #2563eb);
  color: #fff;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.75rem 1.7rem;
  border-radius: 999px;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(67,56,202,0.35);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(67,56,202,0.45);
}

/* ── Data tables (program, dates) ── */
.data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  font-size: 0.92rem;
  margin-top: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 1px 2px rgba(15,23,42,0.04);
  background: var(--bg);
}

.data-table th {
  background: #eef2ff;
  color: var(--primary-dark);
  text-align: left;
  padding: 0.65rem 1.1rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.data-table td {
  padding: 0.7rem 1.1rem;
  border-top: 1px solid #eef1f6;
  color: #334155;
}

.data-table tr:first-child td {
  border-top: none;
}

.data-table th + th,
.data-table td + td {
  border-left: 1px solid #eef1f6;
}

.data-table tbody tr:nth-child(even) td {
  background: #f8fafc;
}

.data-table .time {
  white-space: nowrap;
  color: #64748b;
  font-variant-numeric: tabular-nums;
  width: 11rem;
}

/* ── Topic cards ── */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.1rem;
  margin-top: 1rem;
}

.topic-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.2rem 1.35rem;
  background: var(--bg);
  box-shadow: 0 1px 2px rgba(15,23,42,0.04);
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.topic-card:hover {
  box-shadow: 0 10px 30px rgba(67,56,202,0.10);
  border-color: #c7d2fe;
  transform: translateY(-3px);
}

.topic-card h3 {
  font-size: 0.9rem;
  color: var(--primary);
  margin-bottom: 0.4rem;
}

.topic-card ul {
  padding-left: 1.1rem;
  font-size: 0.83rem;
  color: #4b5563;
}

.topic-card ul li {
  margin-bottom: 0.2rem;
}

/* ── Organizer cards ── */
.organizer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1rem;
}

.organizer-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.9rem 1.4rem;
  text-align: center;
  min-width: 160px;
  background: var(--bg);
  box-shadow: 0 1px 2px rgba(15,23,42,0.04);
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.organizer-card:hover {
  box-shadow: 0 10px 28px rgba(67,56,202,0.10);
  border-color: #c7d2fe;
  transform: translateY(-3px);
}

.organizer-card .name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text);
}

.organizer-card .affil {
  font-size: 0.78rem;
  color: #64748b;
  margin-top: 0.2rem;
}

/* ── Speaker cards ── */
.speaker-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1.25rem;
  margin-top: 1rem;
}

.speaker-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  text-align: center;
  background: var(--bg);
  box-shadow: 0 1px 2px rgba(15,23,42,0.04);
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
}

.speaker-card:hover {
  box-shadow: 0 10px 28px rgba(67,56,202,0.12);
  border-color: #c7d2fe;
  transform: translateY(-3px);
}

.speaker-photo {
  width: 100%;
  aspect-ratio: 1;
  background: #e0e7ff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: #6366f1;
}

.speaker-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.speaker-info {
  padding: 0.8rem 0.6rem;
}

.speaker-info .name {
  font-weight: 700;
  font-size: 0.88rem;
  color: var(--text);
}

.speaker-info .affil {
  font-size: 0.78rem;
  color: #64748b;
  margin-top: 0.15rem;
}

.speaker-info .tag {
  display: inline-block;
  margin-top: 0.35rem;
  font-size: 0.72rem;
  padding: 0.1rem 0.5rem;
  border-radius: 999px;
  background: #e0e7ff;
  color: var(--primary);
}

/* ── Coming soon ── */
.coming-soon {
  text-align: center;
  padding: 5rem 2rem;
  color: #94a3b8;
}

.coming-soon .icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.coming-soon p {
  color: #64748b;
  font-size: 1rem;
}

/* ── Footer ── */
footer {
  background: var(--hero-top);
  color: #c7d2fe;
  padding: 2.25rem 1.5rem;
  text-align: center;
  font-size: 0.83rem;
  line-height: 1.7;
  border-top: 3px solid transparent;
  border-image: linear-gradient(90deg, #6366f1, #38bdf8) 1;
}

/* ── Responsive ── */
@media (max-width: 600px) {
  .site-title h1 {
    font-size: 1.25rem;
  }
  nav a {
    padding: 0.7rem 0.75rem;
    font-size: 0.82rem;
  }
  .topic-grid {
    grid-template-columns: 1fr;
  }
  .data-table .time {
    width: auto;
  }
}