:root {
  color-scheme: light dark;
  --bg: #05060f;
  --bg-alt: rgba(15, 19, 45, 0.65);
  --surface: rgba(25, 30, 64, 0.55);
  --card: rgba(255, 255, 255, 0.08);
  --text: #f4f7ff;
  --muted: rgba(244, 247, 255, 0.7);
  --accent: #66f7c5;
  --accent-strong: #4ce3f5;
  --shadow: rgba(4, 8, 36, 0.6);
  --border: rgba(102, 247, 197, 0.25);
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Space Grotesk', var(--font-sans);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--text);
  background: radial-gradient(circle at top right, rgba(102, 247, 197, 0.2), transparent 45%),
    radial-gradient(circle at 10% 20%, rgba(76, 227, 245, 0.2), transparent 40%),
    var(--bg);
  min-height: 100vh;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.hero {
  padding: 2.5rem clamp(1.5rem, 4vw + 1rem, 4.5rem) 4rem;
  position: relative;
  overflow: hidden;
}

.top-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-display);
  font-weight: 600;
  letter-spacing: 0.02em;
}

.brand-mark {
  padding: 0.4rem 0.7rem;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #05060f;
  font-weight: 700;
  font-size: 0.9rem;
}

.brand-name {
  font-size: clamp(1rem, 2vw + 0.5rem, 1.3rem);
}

.cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  border: 1px solid transparent;
  padding: 0.55rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 500;
  background: rgba(244, 247, 255, 0.1);
  color: var(--text);
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
}

.cta.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #05060f;
  font-weight: 600;
}

.cta:hover,
.cta:focus-visible {
  transform: translateY(-1px);
  background: rgba(244, 247, 255, 0.18);
  border-color: var(--accent);
}

.cta.primary:hover,
.cta.primary:focus-visible {
  background: linear-gradient(135deg, var(--accent-strong), var(--accent));
  color: #05060f;
}

.hero-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(2rem, 4vw, 4.5rem);
  align-items: center;
  margin-top: 3rem;
}

.hero-text h1 {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 5vw + 1rem, 4.5rem);
  line-height: 1.05;
  margin-bottom: 1rem;
}

.hero-text .lead {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 520px;
}

.hero-text .eyebrow {
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: rgba(244, 247, 255, 0.6);
}

.meta {
  display: grid;
  gap: 1rem;
  margin: 2rem 0;
}

.meta-item {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding-left: 1.1rem;
  border-left: 2px solid rgba(102, 247, 197, 0.35);
}

.meta-label {
  font-size: 0.8rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(244, 247, 255, 0.5);
}

.meta-value {
  font-size: 1rem;
  font-weight: 500;
}

.hero-visual {
  position: relative;
  min-height: 320px;
  display: grid;
  place-items: center;
}

.orb {
  width: clamp(240px, 20vw + 180px, 360px);
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.6), rgba(76, 227, 245, 0.1), transparent 75%),
    linear-gradient(145deg, rgba(76, 227, 245, 0.45), rgba(102, 247, 197, 0.2));
  filter: drop-shadow(0 18px 45px rgba(76, 227, 245, 0.35));
  position: relative;
}

.grid {
  position: absolute;
  inset: 12% 8%;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: repeat(2, 1fr);
  gap: 1.4rem;
  z-index: -1;
}

.grid-line {
  border: 1px solid rgba(102, 247, 197, 0.2);
  border-radius: 12px;
  backdrop-filter: blur(12px);
}

.section {
  padding: 4.5rem clamp(1.5rem, 4vw + 1rem, 4.5rem);
}

.section-intro {
  max-width: 720px;
  margin-bottom: 2.5rem;
}

.section h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3vw + 1rem, 3rem);
  margin-bottom: 1rem;
}

.section p {
  color: var(--muted);
  line-height: 1.6;
  font-size: 1.05rem;
}

.schedule {
  background: rgba(5, 6, 15, 0.5);
}

.schedule-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.schedule-controls label {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: rgba(244, 247, 255, 0.6);
}

.schedule-controls select {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.6rem 0.9rem;
  font-size: 1rem;
  font-family: inherit;
}

.schedule-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.session-card {
  background: var(--surface);
  border-radius: 20px;
  padding: 1.5rem;
  border: 1px solid var(--border);
  box-shadow: 0 20px 45px var(--shadow);
  display: grid;
  gap: 0.75rem;
}

.session-card.upcoming {
  border-color: rgba(102, 247, 197, 0.65);
  box-shadow: 0 28px 60px rgba(102, 247, 197, 0.35);
  position: relative;
}

.session-card.upcoming::after {
  content: 'Next up';
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  background: rgba(102, 247, 197, 0.2);
  color: var(--accent);
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  border: 1px solid rgba(102, 247, 197, 0.4);
}

.session-date {
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(244, 247, 255, 0.65);
}

.session-speakers {
  display: grid;
  gap: 0.6rem;
}

.speaker {
  background: rgba(5, 6, 15, 0.35);
  border-radius: 14px;
  padding: 0.75rem 1rem;
  border: 1px solid transparent;
  transition: border-color 150ms ease;
}

.speaker:hover {
  border-color: rgba(102, 247, 197, 0.4);
}

.speaker-name {
  font-weight: 600;
}

.speaker-affiliation {
  font-size: 0.95rem;
  color: rgba(244, 247, 255, 0.6);
}

.footer {
  padding: 3rem clamp(1.5rem, 4vw + 1rem, 4.5rem) 3.5rem;
  background: rgba(5, 6, 15, 0.7);
  border-top: 1px solid rgba(102, 247, 197, 0.2);
}

.footer-content {
  display: grid;
  gap: 1rem;
  justify-items: flex-start;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
  font-size: 0.95rem;
}

.footer-note {
  color: rgba(244, 247, 255, 0.5);
  margin: 0;
}

@media (max-width: 720px) {
  .hero {
    padding-top: 1.8rem;
  }

  .hero-content {
    margin-top: 2.2rem;
  }

  .top-nav {
    gap: 0.9rem;
  }

  .cta {
    width: 100%;
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .footer-content {
    justify-items: stretch;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

.empty-state {
  grid-column: 1 / -1;
  background: rgba(5, 6, 15, 0.35);
  border: 1px dashed rgba(102, 247, 197, 0.35);
  border-radius: 18px;
  padding: 2rem;
  text-align: center;
  color: rgba(244, 247, 255, 0.7);
}