/* ============================================================
   SPACE FROM EARTH — Animations & Transitions
   Keyframes, entrance reveals, star twinkle, hover effects
   ============================================================ */

/* ── Page Entrance ── */
.fade-in {
  opacity: 0;
  animation: fadeIn 0.7s var(--ease-out) forwards;
}

.fade-up {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.7s var(--ease-out) forwards;
}

.fade-up-sm {
  opacity: 0;
  transform: translateY(10px);
  animation: fadeUp 0.5s var(--ease-out) forwards;
}

/* Staggered delays */
.delay-1 { animation-delay: 0.05s; }
.delay-2 { animation-delay: 0.12s; }
.delay-3 { animation-delay: 0.2s; }
.delay-4 { animation-delay: 0.3s; }
.delay-5 { animation-delay: 0.42s; }
.delay-6 { animation-delay: 0.56s; }

@keyframes fadeIn {
  to { opacity: 1; }
}

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-left {
  opacity: 0;
  transform: translateX(-24px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.reveal-left.revealed {
  opacity: 1;
  transform: translateX(0);
}

.reveal-right {
  opacity: 0;
  transform: translateX(24px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.reveal-right.revealed {
  opacity: 1;
  transform: translateX(0);
}

/* Stagger for children */
.stagger-children > *:nth-child(1) { transition-delay: 0s; }
.stagger-children > *:nth-child(2) { transition-delay: 0.1s; }
.stagger-children > *:nth-child(3) { transition-delay: 0.2s; }
.stagger-children > *:nth-child(4) { transition-delay: 0.3s; }
.stagger-children > *:nth-child(5) { transition-delay: 0.4s; }
.stagger-children > *:nth-child(6) { transition-delay: 0.5s; }

/* ── Canvas Star Background ── */
#stars-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  opacity: 0.6;
}

/* ── Articles Page Grid ── */
.articles-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  grid-template-rows: auto auto;
  gap: 1.5rem;
}

.article-card {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
  cursor: pointer;
  transition: transform 0.4s var(--ease-out), border-color var(--transition), box-shadow var(--transition);
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-border);
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
}

/* Featured card spans 2 rows */
.article-card--featured {
  grid-row: span 2;
}

.article-card-img {
  width: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.6s var(--ease-out);
}

.article-card--featured .article-card-img {
  height: 520px;
}

.article-card:not(.article-card--featured) .article-card-img {
  height: 200px;
}

.article-card:hover .article-card-img {
  transform: scale(1.04);
}

.article-card-body {
  padding: var(--space-lg);
}

.article-card-tag {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid var(--accent-border);
  border-radius: 100px;
  padding: 0.25rem 0.75rem;
  margin-bottom: var(--space-sm);
}

.article-card-title {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
  line-height: 1.3;
  margin-bottom: var(--space-sm);
  transition: color var(--transition);
}

.article-card--featured .article-card-title {
  font-size: 1.55rem;
  line-height: 1.2;
  margin-bottom: var(--space-md);
}

.article-card:hover .article-card-title {
  color: var(--accent);
}

.article-card-excerpt {
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text-secondary);
  max-width: none;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--space-md);
}

.article-card--featured .article-card-excerpt {
  -webkit-line-clamp: 4;
}

.article-card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
  transition: gap var(--transition);
}

.article-card-link:hover {
  gap: 0.65rem;
}

.article-card-link svg {
  transition: transform var(--transition);
}

.article-card:hover .article-card-link svg {
  transform: translateX(3px);
}

/* ── Article Detail Layout ── */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-xl);
  align-items: start;
}

.article-main {}

.article-sidebar {
  position: sticky;
  top: calc(var(--nav-height) + var(--space-lg));
}

.sidebar-section {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-md);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.03);
}

.sidebar-section h4 {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  margin-bottom: var(--space-sm);
}

.sidebar-article-link {
  display: block;
  padding: 0.625rem 0;
  border-bottom: 1px solid var(--border-subtle);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition), padding-left var(--transition);
}

.sidebar-article-link:last-child { border-bottom: none; }

.sidebar-article-link:hover {
  color: var(--accent);
  padding-left: 4px;
}

.sidebar-article-link.current {
  color: var(--accent);
  font-weight: 600;
}

/* ── Planet highlight badge ── */
.highlight-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  background: var(--accent-dim);
  border: 1px solid var(--accent-border);
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--accent);
  transition: background var(--transition), transform var(--transition);
}

.highlight-badge:hover {
  background: rgba(0,217,255,0.2);
  transform: translateY(-1px);
}

.highlight-badge svg { flex-shrink: 0; }

/* ── Shimmer skeleton ── */
@keyframes shimmer {
  0%   { background-position: -400px 0; }
  100% { background-position: 400px 0; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--bg-secondary) 25%,
    rgba(45,53,97,0.5) 50%,
    var(--bg-secondary) 75%
  );
  background-size: 800px 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 4px;
}

/* ── Copy success flash ── */
.copy-flash {
  animation: copyFlash 0.4s var(--ease-out);
}

@keyframes copyFlash {
  0%   { background: var(--accent-dim); }
  100% { background: transparent; }
}

/* ── Accent pulse dot ── */
.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulseDot 2s ease-in-out infinite;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.4; transform: scale(0.7); }
}

/* ── Gradient border ── */
.gradient-border {
  position: relative;
}

.gradient-border::before {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, var(--accent), var(--accent-sec));
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* ── Responsive Articles Grid ── */
@media (max-width: 900px) {
  .articles-grid {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }

  .article-card--featured {
    grid-row: span 1;
  }

  .article-card--featured .article-card-img {
    height: 300px;
  }

  .article-card:not(.article-card--featured) .article-card-img {
    height: 180px;
  }

  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    position: static;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
  }
}

@media (max-width: 600px) {
  .article-sidebar {
    grid-template-columns: 1fr;
  }
}