:root {
  --bg: #0b0f19;
  --bg-alt: #0f1524;
  --surface: #131a2b;
  --surface-border: #232c42;
  --text: #e7ebf5;
  --text-muted: #9aa4bd;
  --accent: #4fd1c5;
  --accent-2: #8b5cf6;
  --accent-gradient: linear-gradient(120deg, #4fd1c5 0%, #6366f1 55%, #8b5cf6 100%);
  --radius: 14px;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, 0.55);
  --max-width: 1120px;
  --font-heading: 'Space Grotesk', 'Inter', sans-serif;
  --font-body: 'Inter', system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: 1.2;
  margin: 0 0 0.5em;
}

p {
  margin: 0 0 1em;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  padding-left: 1.2em;
  margin: 0 0 1em;
}

li {
  margin-bottom: 0.4em;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header / Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(11, 15, 25, 0.8);
  border-bottom: 1px solid var(--surface-border);
}

.navbar {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-mark {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.35rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: 0.5px;
}

.brand-mark.small {
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.2s ease;
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 100%;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

/* Hero */
.hero {
  position: relative;
  padding: 120px 0 90px;
  overflow: hidden;
  text-align: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(79, 209, 197, 0.18), transparent 45%),
    radial-gradient(circle at 80% 10%, rgba(139, 92, 246, 0.18), transparent 45%),
    radial-gradient(circle at 50% 100%, rgba(99, 102, 241, 0.12), transparent 55%);
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 18px;
}

.hero h1 {
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--text);
  max-width: 720px;
  margin: 0 auto 18px;
}

.hero-tagline {
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 36px;
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 56px;
}

.btn {
  display: inline-block;
  padding: 13px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #05070d;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px -8px rgba(99, 102, 241, 0.5);
}

.btn-ghost {
  border: 1px solid var(--surface-border);
  color: var(--text);
  background: rgba(255, 255, 255, 0.02);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.hero-meta {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.hero-meta-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.hero-meta-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
}

.hero-meta-value {
  font-weight: 600;
  font-size: 1rem;
}

/* Sections */
.section {
  padding: 90px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 10px;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 28px;
}

.lead {
  color: var(--text-muted);
  max-width: 820px;
  font-size: 1.05rem;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-top: 36px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--surface-border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}

.soft-card h3 {
  font-size: 1.15rem;
}

.soft-card .mt {
  margin-top: 24px;
}

.check-list {
  list-style: none;
  padding-left: 0;
}

.check-list li {
  position: relative;
  padding-left: 26px;
  color: var(--text-muted);
}

.check-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.badge {
  display: inline-block;
  margin-top: 18px;
  padding: 8px 16px;
  border-radius: 999px;
  background: rgba(79, 209, 197, 0.12);
  color: var(--accent);
  font-size: 0.82rem;
  font-weight: 600;
}

.badge-muted {
  background: rgba(154, 164, 189, 0.12);
  color: var(--text-muted);
}

/* Topics */
.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.topic-card {
  display: flex;
  flex-direction: column;
}

.topic-index {
  display: inline-block;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--accent-2);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 10px;
}

.topic-card h3 {
  font-size: 1.2rem;
  margin-bottom: 14px;
}

.topic-card ul {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Schedule */
.schedule-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--surface-border);
}

.schedule-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  min-width: 640px;
}

.schedule-table th,
.schedule-table td {
  padding: 18px 20px;
  text-align: left;
  border-bottom: 1px solid var(--surface-border);
  vertical-align: top;
}

.schedule-table th {
  background: rgba(79, 209, 197, 0.08);
  color: var(--accent);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.schedule-table tbody tr:last-child td {
  border-bottom: none;
}

.schedule-table tbody tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

.time-cell {
  white-space: nowrap;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.time-tbd {
  font-size: 0.78rem;
  font-weight: 400;
  color: var(--text-muted);
}

.break-row td {
  background: rgba(139, 92, 246, 0.06);
  font-weight: 600;
  color: var(--text-muted);
  text-align: center;
}

.table-sublist {
  margin: 10px 0 0;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.note {
  margin-top: 18px;
  color: var(--text-muted);
  font-size: 0.9rem;
  font-style: italic;
}

/* Presenters */
.presenters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.presenters-grid-secondary {
  margin-top: 24px;
}

.presenters-grid-trio {
  grid-template-columns: repeat(3, 1fr);
}

.presenter-card {
  display: flex;
  flex-direction: column;
}

.presenter-card-compact {
  flex-direction: row;
  align-items: flex-start;
  gap: 18px;
}

.avatar {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #05070d;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.2rem;
  margin-bottom: 18px;
  flex-shrink: 0;
}

.avatar-sm {
  width: 48px;
  height: 48px;
  font-size: 1rem;
  margin-bottom: 0;
}

.presenter-role {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.presenter-bio {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 0;
}

.presenter-bio-muted {
  font-style: italic;
  font-size: 0.88rem;
}

/* Resources */
.resources-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 36px;
}

.resource-card {
  text-align: center;
}

.resource-icon {
  font-size: 2rem;
  margin-bottom: 14px;
}

.resource-card h3 {
  font-size: 1.05rem;
}

.resource-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Footer */
.site-footer {
  padding: 48px 0;
  border-top: 1px solid var(--surface-border);
  background: var(--bg-alt);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-text {
  margin: 4px 0;
  font-size: 0.9rem;
}

.footer-text.muted {
  color: var(--text-muted);
}

/* Responsive */
@media (max-width: 860px) {
  .two-col,
  .topics-grid,
  .presenters-grid {
    grid-template-columns: 1fr;
  }

  .resources-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--surface-border);
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .presenter-card-compact {
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  .resources-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 100px 0 70px;
  }
}