:root {
  --font-body: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --color-bg: #f8f9fb;
  --color-surface: #ffffff;
  --color-border: #e4e7ec;
  --color-text: #1f2933;
  --color-muted: #52606d;
  --color-accent: #3b82f6;
  --color-accent-strong: #2156c3;
  --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.05);
  --radius-lg: 14px;
  --radius-md: 10px;
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 18px;
  --space-lg: 28px;
  --space-xl: 48px;
}

[data-theme="dark"] {
  --color-bg: #0f1720;
  --color-surface: #0f1a26;
  --color-border: #1f2a38;
  --color-text: #e5ecf5;
  --color-muted: #9fb0c6;
  --color-accent: #7aa2ff;
  --color-accent-strong: #9cb8ff;
  --shadow-soft: 0 12px 34px rgba(0, 0, 0, 0.35);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

a:hover {
  color: var(--color-accent-strong);
}

.page-content {
  max-width: 1100px;
  margin: 0 auto;
  padding: calc(var(--space-xl) + 56px) var(--space-lg) var(--space-xl);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  border-bottom: 1px solid var(--color-border);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-sm) var(--space-lg);
}

.brand {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: var(--space-sm);
  align-items: center;
}

.brand-mark {
  height: 56px;
  width: 56px;
  display: grid;
  place-items: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--color-accent);
  box-shadow: var(--shadow-soft);
}

.brand-title {
  margin: 0;
  font-weight: 700;
}

.brand-subtitle {
  margin: 2px 0 0;
  color: var(--color-muted);
  font-size: 0.9rem;
}

.top-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.top-nav a {
  padding: 8px 12px;
  border-radius: 8px;
  color: var(--color-text);
  border: 1px solid transparent;
}

.top-nav a:hover {
  border-color: var(--color-border);
  background: var(--color-surface);
}

.header-actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: flex-end;
  flex-wrap: wrap;
}

button {
  font: inherit;
  border: none;
  cursor: pointer;
}

.primary-btn,
.ghost-btn {
  padding: 10px 14px;
  border-radius: 10px;
  transition: transform 0.1s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.primary-btn {
  background: var(--color-accent);
  color: #ffffff;
  box-shadow: var(--shadow-soft);
}

.primary-btn:hover {
  transform: translateY(-1px);
}

.ghost-btn {
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
}

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

.hero {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.hero h1 {
  margin-top: 0;
  margin-bottom: var(--space-sm);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
}

.hero p {
  margin: 0;
  color: var(--color-muted);
}

section {
  margin-bottom: var(--space-xl);
}

section h2 {
  margin-top: 0;
  font-size: 1.6rem;
}

.grid {
  display: grid;
  gap: var(--space-md);
}

.grid.cards {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: var(--shadow-soft);
}

.card h3 {
  margin-top: 0;
}

.meta {
  color: var(--color-muted);
  margin: 0 0 var(--space-xs);
  font-size: 0.95rem;
}

.callout {
  border-left: 4px solid var(--color-accent);
  padding: var(--space-sm) var(--space-md);
  background: color-mix(in srgb, var(--color-accent) 8%, var(--color-surface) 92%);
  border-radius: var(--radius-md);
}

.diagram {
  width: 100%;
  height: auto;
  margin-top: var(--space-md);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

th, td {
  padding: 12px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

th {
  background: color-mix(in srgb, var(--color-accent) 10%, var(--color-surface) 90%);
}

tbody tr:hover {
  background: color-mix(in srgb, var(--color-accent) 6%, var(--color-surface) 94%);
}

.site-footer {
  text-align: center;
  padding: var(--space-lg);
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-bg) 90%, transparent);
}

.badge {
  display: inline-block;
  background: color-mix(in srgb, var(--color-accent) 12%, var(--color-surface) 88%);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 4px 10px;
  font-size: 0.85rem;
}

.stack-card .meta {
  margin-bottom: var(--space-sm);
}

.list-compact {
  padding-left: 18px;
  margin: 6px 0;
  color: var(--color-muted);
}

.list-compact li {
  margin-bottom: 4px;
}

.actions-inline {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
  margin-top: var(--space-sm);
}

.print-note {
  color: var(--color-muted);
  margin-top: var(--space-xs);
}

@media (max-width: 900px) {
  .site-header {
    position: sticky;
    grid-template-columns: 1fr;
    align-items: start;
  }

  .header-actions {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .page-content {
    padding: calc(var(--space-lg) + 56px) var(--space-sm) var(--space-xl);
  }

  table, thead, tbody, th, td, tr {
    display: block;
  }

  thead {
    display: none;
  }

  td {
    padding: 10px;
    border: none;
    border-bottom: 1px solid var(--color-border);
    position: relative;
  }

  td::before {
    content: attr(data-label);
    font-weight: 600;
    display: block;
    color: var(--color-muted);
    margin-bottom: 4px;
  }
}

@media print {
  :root {
    --color-bg: #ffffff;
    --color-surface: #ffffff;
    --color-text: #111111;
    --color-muted: #333333;
    --color-border: #d1d5db;
    --color-accent: #1f2937;
    --shadow-soft: none;
  }

  html, body {
    background: #ffffff !important;
    color: #111111 !important;
  }

  .site-header,
  .header-actions,
  .top-nav,
  #theme-toggle,
  #print-btn,
  .actions-inline button {
    display: none !important;
  }

  a {
    color: #111111 !important;
    text-decoration: none;
  }

  .page-content {
    padding: 12px;
  }

  section, .card, table {
    box-shadow: none !important;
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .diagram {
    filter: none !important;
  }
}