/* =========================================
   Introduction Page (About)
   ========================================= */

.intro-page {
  position: relative;
  overflow: hidden;
  background-color: var(--bg-body);
  background-image:
    linear-gradient(160deg, var(--intro-glow-primary), transparent 55%),
    linear-gradient(330deg, var(--intro-glow-accent), transparent 50%);
  --intro-glow-primary: rgba(9, 105, 218, 0.14);
  --intro-glow-accent: rgba(142, 136, 199, 0.14);
}

[data-theme="dark"] .intro-page {
  --intro-glow-primary: rgba(88, 166, 255, 0.22);
  --intro-glow-accent: rgba(142, 136, 199, 0.2);
}

.intro-page::before {
  display: none;
}

.intro-about .site-header {
  background-color: rgba(14, 22, 36, 0.78);
  border-bottom-color: rgba(255, 255, 255, 0.06);
}

html:not([data-theme="dark"]) .intro-about .site-header {
  background-color: rgba(246, 249, 252, 0.9);
  border-bottom-color: rgba(36, 41, 47, 0.08);
}

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

.intro-step {
  padding: 120px 0;
  scroll-margin-top: 110px;
}

.intro-hero {
  padding-top: 140px;
  padding-bottom: 120px;
}

.intro-hero-grid,
.intro-grid,
.intro-join-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 64px;
  align-items: center;
}

.intro-grid.reverse .intro-media,
.intro-grid.reverse .intro-join-media {
  order: -1;
}

.intro-copy {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.intro-hero .intro-copy {
  gap: 14px;
}

.intro-brand-mark {
  position: relative;
  width: min(420px, 100%);
  margin-bottom: 2px;
}

.intro-brand-svg {
  display: block;
  width: min(76vw, 360px);
  aspect-ratio: 3 / 2;
  background-image: linear-gradient(135deg, var(--text-primary), var(--color-primary));
  -webkit-mask: url("../../resources/title.svg") center / contain no-repeat;
  mask: url("../../resources/title.svg") center / contain no-repeat;
  filter:
    drop-shadow(0 10px 24px rgba(12, 20, 32, 0.24))
    drop-shadow(0 0 16px rgba(120, 190, 255, 0.24));
}

.intro-brand-text {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.intro-title {
  font-size: clamp(2.6rem, 4vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 0;
  background: linear-gradient(120deg, var(--text-primary), var(--color-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.intro-heading {
  font-size: clamp(2rem, 3vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}

.intro-lead {
  font-size: 1.2rem;
  color: var(--text-secondary);
}

.intro-sub,
.intro-text {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.intro-cta-group {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.intro-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-primary);
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-primary);
  background-color: transparent;
  transition: all var(--duration-fast);
}

.intro-btn--primary {
  background: linear-gradient(120deg, var(--color-primary), var(--color-primary-light));
  color: #fff;
  border-color: transparent;
  box-shadow: var(--shadow-sm);
}

.intro-btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.intro-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
  margin-top: 8px;
}

.intro-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-default);
  background-color: var(--bg-card);
  min-width: 120px;
}

.stat-number {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.intro-media,
.intro-hero-media,
.intro-join-media {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.intro-hero-media {
  align-items: stretch;
}

.media-card {
  min-height: 200px;
  border-radius: var(--radius-md);
  border: 1px dashed var(--border-default);
  background-color: var(--bg-card);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: 16px;
}

.media-card--tall {
  grid-row: span 2;
  min-height: 420px;
}

.media-card--wide {
  grid-column: span 2;
  min-height: 240px;
}

.intro-points {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 12px;
}

.intro-points li,
.intro-list li {
  position: relative;
  padding-left: 18px;
  color: var(--text-secondary);
}

.intro-points li::before,
.intro-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-primary);
}

.intro-org-grid,
.intro-feature-grid,
.intro-adv-grid {
  display: grid;
  gap: 16px;
  margin-top: 16px;
}

.intro-org-grid,
.intro-feature-grid {
  grid-template-columns: repeat(3, 1fr);
}

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

.intro-card {
  border-radius: var(--radius-md);
  border: 1px solid var(--border-default);
  background-color: var(--bg-card);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.intro-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
}

.intro-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.intro-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 4px;
}

.intro-join {
  padding-bottom: 140px;
}

.intro-join-grid {
  align-items: start;
}

.intro-join-content {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.intro-join-media {
  grid-template-columns: repeat(3, 1fr);
}

/* Stream text characters */
.stream-char {
  transition: opacity 0.4s ease;
}

/* Animations */
.intro-animate {
  transition: opacity 0.8s var(--ease-in-out), transform 0.8s var(--ease-in-out);
  transition-delay: var(--delay, 0s);
}

body.has-intro-animations .intro-animate {
  opacity: 0;
  transform: translateY(30px);
}

body.has-intro-animations .intro-step.is-active .intro-animate {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .intro-animate {
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

/* Responsive */
@media (max-width: 1100px) {
  .intro-hero-grid,
  .intro-grid,
  .intro-join-grid {
    grid-template-columns: 1fr;
  }

  .intro-grid.reverse .intro-media,
  .intro-grid.reverse .intro-join-media {
    order: 0;
  }

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

  .intro-adv-grid {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 768px) {
  .intro-step {
    padding: 80px 0;
  }

  .intro-hero {
    padding-top: 110px;
  }

  .intro-brand-svg {
    width: min(86vw, 320px);
  }

  .intro-title {
    font-size: 2.2rem;
  }

  .intro-cta-group {
    flex-direction: column;
    align-items: flex-start;
  }

  .intro-org-grid,
  .intro-feature-grid,
  .intro-join-media {
    grid-template-columns: 1fr;
  }
}