/* ============================================================
   Fortium Conference 2026 — Cinematic Gradient Theme
   ============================================================ */

/* --- Root Variables --- */
:root {
  /* Fortium Brand Colors */
  --fortium-emerald: #15D16C;
  --fortium-spring-green: #2AE280;
  --fortium-blue: #2046B5;
  --fortium-prussian: #083161;
  --fortium-baby-blue: #A6BFFF;
  --fortium-cultured: #F6F8F9;

  /* Theme — built from Fortium palette */
  --bg-deep: #041a38;
  --bg-mid: #083161;
  --bg-surface: #0C4A92;
  --bg-card: rgba(255, 255, 255, 0.05);
  --border-subtle: rgba(255, 255, 255, 0.1);
  --border-accent: rgba(21, 209, 108, 0.35);
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.75);
  --text-muted: rgba(255, 255, 255, 0.45);
  --accent: #15D16C;
  --accent-glow: rgba(21, 209, 108, 0.15);
  --accent-light: rgba(42, 226, 128, 0.1);
  --accent-blue: #2046B5;
  --accent-blue-glow: rgba(32, 70, 181, 0.2);
  --font-display: Georgia, 'Times New Roman', serif;
  --font-body: system-ui, -apple-system, sans-serif;
}

/* --- Reset & Body --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background: linear-gradient(135deg, var(--bg-deep) 0%, var(--bg-mid) 50%, var(--bg-surface) 100%);
  background-attachment: fixed;
  line-height: 1.6;
  min-height: 100vh;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.25s ease, opacity 0.25s ease;
}

a:hover {
  color: #2AE280;
}

/* --- Typography --- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h1 {
  font-size: clamp(2.25rem, 5vw, 4rem);
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.75rem);
}

h3 {
  font-size: clamp(1.25rem, 2.5vw, 1.75rem);
}

p {
  color: var(--text-secondary);
  max-width: 65ch;
}

/* --- Layout --- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* --- Navigation --- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: rgba(15, 12, 41, 0.75);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-brand {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  gap: 1.75rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.25s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
}

/* --- Hero --- */
.hero {
  position: relative;
  text-align: center;
  padding: 6rem 2rem 4rem;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

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

.hero-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 1rem;
  padding: 0.35rem 1rem;
  border: 1px solid var(--border-accent);
  border-radius: 100px;
  background: var(--accent-glow);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
  background: linear-gradient(135deg, #ffffff 0%, rgba(255, 255, 255, 0.75) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: clamp(1.1rem, 2vw, 1.5rem);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
  line-height: 1.5;
}

.hero-meta {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.hero-meta span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* --- Section --- */
.section {
  padding: 4rem 0;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  margin-bottom: 2rem;
  position: relative;
  padding-bottom: 0.75rem;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

/* --- Session Cards --- */
.sessions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.session-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1),
              border-color 0.3s ease,
              box-shadow 0.3s ease;
  cursor: pointer;
}

.session-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-accent);
  box-shadow: 0 12px 40px rgba(21, 209, 108, 0.12),
              0 0 0 1px var(--border-accent);
}

.session-card-thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--bg-surface);
}

.session-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.session-card:hover .session-card-thumb img {
  transform: scale(1.05);
}

.session-card-thumb .play-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.35);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.session-card:hover .play-overlay {
  opacity: 1;
}

.play-overlay svg,
.play-overlay .play-icon {
  width: 48px;
  height: 48px;
  color: white;
  filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
}

.session-card-body {
  padding: 1.25rem;
}

.session-card-label {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.session-card-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.session-card-presenter {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

.session-card-duration {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- Sponsors --- */
.sponsors {
  border-top: 1px solid var(--border-subtle);
  padding: 4rem 0;
  text-align: center;
}

.sponsors .section-title::after {
  left: 50%;
  transform: translateX(-50%);
}

.sponsor-tier-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  margin-top: 2.5rem;
}

.sponsor-tier-label:first-of-type {
  margin-top: 0;
}

.sponsor-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
  margin-bottom: 2rem;
}

.sponsor-grid img {
  height: 40px;
  opacity: 0.6;
  filter: brightness(0) invert(1);
  transition: opacity 0.3s ease;
}

.sponsor-grid img:hover {
  opacity: 1;
}

/* --- Video Player --- */
.video-wrapper {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 */
  background: #000;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

.video-wrapper iframe,
.video-wrapper video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

/* --- Chapters --- */
.chapters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1.5rem;
}

.chapter-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  font-family: var(--font-body);
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  cursor: pointer;
  transition: background 0.25s ease,
              border-color 0.25s ease,
              color 0.25s ease;
}

.chapter-btn:hover {
  background: var(--accent-glow);
  border-color: var(--border-accent);
  color: var(--text-primary);
}

.chapter-btn.active {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--text-primary);
}

.chapter-btn .chapter-time {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
}

/* --- Transcript --- */
.transcript-section {
  margin-top: 2rem;
}

.transcript-search {
  width: 100%;
  padding: 0.75rem 1.25rem;
  font-size: 0.9rem;
  font-family: var(--font-body);
  color: var(--text-primary);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  outline: none;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
  margin-bottom: 1rem;
}

.transcript-search::placeholder {
  color: var(--text-muted);
}

.transcript-search:focus {
  border-color: var(--border-accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.transcript-body {
  max-height: 400px;
  overflow-y: auto;
  padding-right: 0.5rem;
}

/* Custom scrollbar */
.transcript-body::-webkit-scrollbar {
  width: 6px;
}

.transcript-body::-webkit-scrollbar-track {
  background: transparent;
}

.transcript-body::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.12);
  border-radius: 3px;
}

.transcript-body::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.2);
}

.transcript-segment {
  display: flex;
  gap: 1rem;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.transcript-segment:hover {
  background: rgba(255, 255, 255, 0.04);
}

.transcript-segment.active {
  background: var(--accent-glow);
}

.transcript-timestamp {
  flex-shrink: 0;
  font-size: 0.8rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  min-width: 52px;
  padding-top: 2px;
}

.transcript-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-secondary);
}

.transcript-text mark {
  background: rgba(21, 209, 108, 0.35);
  color: var(--text-primary);
  padding: 0.1em 0.25em;
  border-radius: 3px;
}

/* --- Clips Gallery --- */
.clips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.clip-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  overflow: hidden;
  transition: transform 0.3s cubic-bezier(0.22, 1, 0.36, 1),
              border-color 0.3s ease;
  cursor: pointer;
}

.clip-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-accent);
}

.clip-card-thumb {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--bg-surface);
}

.clip-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.clip-card-body {
  padding: 1rem;
}

.clip-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}

.clip-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.clip-description {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* --- Filter Chips --- */
.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
}

.filter-chip {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 1rem;
  font-size: 0.82rem;
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 100px;
  cursor: pointer;
  transition: background 0.25s ease,
              border-color 0.25s ease,
              color 0.25s ease;
}

.filter-chip:hover {
  background: var(--accent-glow);
  border-color: var(--border-accent);
  color: var(--text-primary);
}

.filter-chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #ffffff;
}

/* --- Auth Gate --- */
.auth-gate {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 80vh;
  padding: 2rem;
}

.auth-box {
  width: 100%;
  max-width: 420px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  padding: 3rem 2.5rem;
  text-align: center;
  box-shadow: 0 16px 64px rgba(0, 0, 0, 0.3);
}

.auth-box h2 {
  font-family: var(--font-display);
  margin-bottom: 0.75rem;
}

.auth-box p {
  color: var(--text-secondary);
  margin: 0 auto 2rem;
  font-size: 0.95rem;
}

.auth-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  width: 100%;
  padding: 0.85rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  font-family: var(--font-body);
  color: #ffffff;
  background: var(--accent);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.25s ease,
              box-shadow 0.25s ease,
              transform 0.15s ease;
}

.auth-btn:hover {
  background: #4f46e5;
  box-shadow: 0 4px 20px rgba(21, 209, 108, 0.35);
  transform: translateY(-1px);
}

.auth-btn:active {
  transform: translateY(0);
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2.5rem 2rem;
  text-align: center;
}

.footer p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0 auto;
}

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

.footer a:hover {
  color: var(--text-primary);
}

/* --- Utility --- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --- Responsive: Tablet (768px) --- */
@media (max-width: 768px) {
  .hero {
    padding: 4rem 1.5rem 3rem;
  }

  .container {
    padding: 0 1.25rem;
  }

  .sessions-grid {
    grid-template-columns: 1fr;
  }

  .clips-grid {
    grid-template-columns: 1fr;
  }

  .hero-meta {
    gap: 1rem;
  }

  .section {
    padding: 3rem 0;
  }

  .sponsor-grid {
    gap: 1.5rem;
  }

  .auth-box {
    padding: 2rem 1.5rem;
  }
}

/* --- Responsive: Mobile (480px) --- */
@media (max-width: 480px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding: 3rem 1rem 2rem;
  }

  .hero::before {
    width: 300px;
    height: 300px;
  }

  .container {
    padding: 0 1rem;
  }

  .chapters {
    flex-direction: column;
  }

  .chapter-btn {
    width: 100%;
    justify-content: space-between;
  }

  .hero-meta {
    flex-direction: column;
    gap: 0.5rem;
  }

  .sponsor-grid img {
    height: 28px;
  }

  .transcript-segment {
    flex-direction: column;
    gap: 0.25rem;
  }
}