/* ============================================
   MindrianOS SnapshotHub - Shared Stylesheet
   De Stijl Design System - Dark Theme
   Mobile-first responsive: 375px -> 1440px
   ============================================ */

/* -- Design Tokens -- */
:root {
  /* Backgrounds */
  --ds-bg: #1a1a1a;
  --ds-surface: #2d2d2d;
  --ds-elevated: #3a3a3a;
  /* Text */
  --ds-cream: #f5f1e8;
  --ds-muted: #a8a39f;
  --ds-text: #d4cfc7;
  /* Borders */
  --ds-border: #404040;
  /* Mondrian palette */
  --ds-red: #A63D2F;
  --ds-blue: #1E3A6E;
  --ds-yellow: #C8A43C;
  --ds-green: #2D6B4A;
  --ds-teal: #2A6B5E;
  --ds-sienna: #B5602A;
  --ds-gray: #5C5A56;
  --ds-amethyst: #6B4E8B;
  /* Text variants */
  --ds-red-text: #C95A4A;
  --ds-blue-text: #4A7BC8;
  --ds-yellow-text: #C8A43C;
  --ds-green-text: #4A9B72;
  --ds-teal-text: #4A9B8E;
  --ds-sienna-text: #D4804A;
  --ds-amethyst-text: #9B7EB5;
  /* Shadows */
  --ds-shadow-flat: 0 0 0 1px var(--ds-border);
  --ds-shadow-lifted: 4px 4px 0 #0a0a0f;
  /* Motion */
  --ds-transition: 150ms ease;
  --ds-transition-slow: 200ms ease-out;
  /* Typography */
  --ds-font-display: 'Bebas Neue', sans-serif;
  --ds-font-body: 'Inter', system-ui, sans-serif;
  --ds-font-mono: 'JetBrains Mono', monospace;
  /* Layout */
  --ds-max-width: 1200px;
  --ds-sidebar-width: 280px;
}

/* -- Reset + Base -- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; }
body {
  font-family: var(--ds-font-body);
  background: var(--ds-bg);
  color: var(--ds-cream);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* Zero border-radius - De Stijl mandate */
* { border-radius: 0 !important; }

/* No italic */
em, i { font-style: normal; font-weight: 600; }

/* -- Typography Scale -- */
h1 {
  font-family: var(--ds-font-display);
  font-size: 2rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ds-cream);
}
h2 {
  font-family: var(--ds-font-display);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ds-cream);
}
h3 {
  font-family: var(--ds-font-body);
  font-size: 1rem;
  font-weight: 600;
  color: var(--ds-cream);
}
p {
  font-size: 0.875rem;
  color: var(--ds-text);
  line-height: 1.6;
}
code {
  font-family: var(--ds-font-mono);
  font-size: 0.8125rem;
  color: var(--ds-teal-text);
  background: var(--ds-bg);
  padding: 2px 6px;
}
a {
  color: var(--ds-blue-text);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* -- Header -- */
.snap-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--ds-bg);
  border-bottom: 1px solid var(--ds-border);
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}
.snap-header-left {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}
.snap-header-title {
  font-family: var(--ds-font-display);
  font-size: 1.25rem;
  font-weight: 400;
  letter-spacing: 0.03em;
  color: var(--ds-cream);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.snap-header-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}
.snap-header-nav a {
  font-family: var(--ds-font-mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ds-muted);
  padding: 6px 10px;
  border: 1px solid transparent;
  text-decoration: none;
  transition: color var(--ds-transition), border-color var(--ds-transition);
}
.snap-header-nav a:hover,
.snap-header-nav a.active {
  color: var(--ds-cream);
  border-color: var(--ds-border);
}
.snap-header-nav a.active {
  border-color: var(--ds-blue);
  color: var(--ds-blue-text);
}

/* -- Accent Bar (Mondrian) -- */
.accent-bar {
  display: flex;
  height: 4px;
  width: 100%;
}
.accent-bar span { flex: 1; }
.accent-bar-red { background: var(--ds-red); }
.accent-bar-blue { background: var(--ds-blue); }
.accent-bar-yellow { background: var(--ds-yellow); }
.accent-bar-cream { background: var(--ds-cream); }
.accent-bar-black { background: #1a1a1a; }

/* -- Stats Bar -- */
.stats-bar {
  display: flex;
  justify-content: center;
  gap: 24px;
  padding: 16px;
  background: var(--ds-surface);
  border-bottom: 1px solid var(--ds-border);
  flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-value {
  font-family: var(--ds-font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--ds-cream);
}
.stat-label {
  font-size: 0.625rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ds-muted);
  margin-top: 2px;
}

/* -- Container -- */
.container {
  max-width: var(--ds-max-width);
  margin: 0 auto;
  padding: 0 16px;
}

/* -- Section -- */
.section {
  padding: 32px 0;
  border-top: 1px solid var(--ds-border);
}
.section:first-child { border-top: none; }
.section-alt { background: var(--ds-surface); }
.section-header {
  font-family: var(--ds-font-display);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.04em;
  color: var(--ds-cream);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.section-header::before {
  content: '';
  display: inline-block;
  width: 4px;
  height: 24px;
  background: var(--ds-blue);
  flex-shrink: 0;
}

/* -- Card Grid -- */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
.card {
  background: var(--ds-surface);
  border: 1px solid var(--ds-border);
  padding: 16px;
  transition: border-color var(--ds-transition), box-shadow var(--ds-transition);
}
.card:hover {
  filter: brightness(1.25);
  box-shadow: var(--ds-shadow-lifted);
}

/* -- Tag -- */
.tag {
  display: inline-block;
  font-size: 0.625rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ds-muted);
  margin-bottom: 6px;
}

/* -- Version History Sidebar -- */
.version-sidebar {
  position: fixed;
  top: 68px;
  right: 0;
  width: var(--ds-sidebar-width);
  height: calc(100vh - 68px);
  background: var(--ds-surface);
  border-left: 1px solid var(--ds-border);
  overflow-y: auto;
  z-index: 90;
  transform: translateX(100%);
  transition: transform var(--ds-transition-slow);
  padding: 16px;
}
.version-sidebar.open {
  transform: translateX(0);
}
.version-sidebar-toggle {
  position: fixed;
  top: 80px;
  right: 12px;
  z-index: 91;
  background: var(--ds-surface);
  border: 1px solid var(--ds-border);
  color: var(--ds-muted);
  font-family: var(--ds-font-mono);
  font-size: 0.6875rem;
  padding: 6px 10px;
  cursor: pointer;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.version-sidebar-toggle:hover {
  color: var(--ds-cream);
  border-color: var(--ds-blue);
}
.version-entry {
  padding: 10px 0;
  border-bottom: 1px solid var(--ds-border);
}
.version-entry:last-child { border-bottom: none; }
.version-date {
  font-family: var(--ds-font-mono);
  font-size: 0.75rem;
  color: var(--ds-cream);
}
.version-metric {
  font-size: 0.6875rem;
  color: var(--ds-muted);
  margin-top: 2px;
}

/* -- Signature Footer -- */
.signature-footer {
  border-top: 1px solid var(--ds-border);
  padding: 20px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.signature-footer-left {
  display: flex;
  align-items: center;
  gap: 12px;
}
.signature-footer-brand {
  font-size: 0.75rem;
  color: var(--ds-muted);
  letter-spacing: 0.04em;
}
.signature-footer-brand a {
  color: var(--ds-muted);
  text-decoration: none;
}
.signature-footer-brand a:hover {
  color: var(--ds-cream);
}
.signature-footer-meta {
  font-family: var(--ds-font-mono);
  font-size: 0.6875rem;
  color: var(--ds-muted);
}
.mondrian-bar {
  display: flex;
  height: 4px;
  width: 100%;
}
.mondrian-bar span { flex: 1; }

/* -- Utility -- */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ============================================
   RESPONSIVE BREAKPOINTS (mobile-first)
   375px base -> 768px tablet -> 1024px desktop -> 1440px wide
   ============================================ */

/* Tablet (768px+) */
@media (min-width: 768px) {
  .snap-header { padding: 0 24px; }
  .container { padding: 0 24px; }
  .stats-bar { gap: 40px; padding: 20px 24px; }
  .stat-value { font-size: 1.75rem; }
  .section { padding: 40px 0; }
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .signature-footer { padding: 24px; }
  .snap-header-title { font-size: 1.5rem; }
  h1 { font-size: 2.5rem; }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
  .snap-header { padding: 0 32px; }
  .container { padding: 0 32px; }
  .stats-bar { gap: 48px; padding: 24px 32px; }
  .section { padding: 48px 0; }
  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }
  .signature-footer { padding: 24px 32px; }
}

/* Wide (1440px+) */
@media (min-width: 1440px) {
  .card-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  :root {
    --ds-max-width: 1320px;
  }
}

/* Small mobile (<375px) - graceful degradation */
@media (max-width: 374px) {
  .snap-header { height: 56px; }
  .snap-header-nav { display: none; }
  .stats-bar { gap: 16px; }
  .stat-value { font-size: 1.25rem; }
}

/* -- Reduced Motion -- */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}