:root {
  color-scheme: light dark;
  --text: #1a1a1a;
  --bg: #ffffff;
  --muted: #555555;
  --border: #dddddd;
  --link: #0969da;
  --code-bg: #f4f4f5;
  --blockquote-bg: #f8f8f8;
  --max-width: 42rem;
  --line-height: 1.65;
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 2.5rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --text: #e6e6e6;
    --bg: #111111;
    --muted: #aaaaaa;
    --border: #333333;
    --link: #58a6ff;
    --code-bg: #1c1c1e;
    --blockquote-bg: #1a1a1a;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 1rem;
  line-height: var(--line-height);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

header {
  border-bottom: 1px solid var(--border);
  padding: var(--space-md);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
}

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

nav a:hover,
nav a:focus {
  color: var(--link);
  text-decoration: underline;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-md) 3rem;
  overflow-wrap: break-word;
}

/* --- Heading hierarchy --- */

main h1 {
  margin: 0 0 var(--space-lg);
  font-size: clamp(1.875rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

main h2 {
  margin: var(--space-2xl) 0 var(--space-sm);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--border);
  font-size: clamp(1.375rem, 3vw, 1.625rem);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

main h3 {
  margin: var(--space-xl) 0 var(--space-sm);
  font-size: clamp(1.125rem, 2.5vw, 1.3125rem);
  font-weight: 600;
  line-height: 1.35;
}

main h4 {
  margin: var(--space-lg) 0 var(--space-xs);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text);
}

/* Legal pages: first paragraph is the document title (no leading h1). */
main > p:first-child {
  margin: 0 0 var(--space-xs);
  font-size: clamp(1.875rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

/* "Last updated" / metadata line on legal pages. */
main > p:first-child + p {
  margin: 0 0 var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9375rem;
  line-height: 1.5;
}

/* --- Body text --- */

main p {
  margin: 0 0 var(--space-md);
}

main p:last-child {
  margin-bottom: 0;
}

main strong {
  font-weight: 600;
}

/* --- Lists --- */

main ul,
main ol {
  margin: 0 0 var(--space-md);
  padding-left: 1.625rem;
}

main ul {
  list-style-type: disc;
}

main ol {
  list-style-type: decimal;
}

main li {
  margin: 0 0 var(--space-xs);
  line-height: var(--line-height);
  padding-left: 0.25rem;
}

main li:last-child {
  margin-bottom: 0;
}

main li > ul,
main li > ol {
  margin-top: var(--space-xs);
  margin-bottom: 0;
}

main ul ul {
  list-style-type: circle;
}

/* --- Links --- */

main a {
  color: var(--link);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
}

main a:hover,
main a:focus {
  text-decoration-thickness: 2px;
}

a {
  color: var(--link);
}

a:hover,
a:focus {
  text-decoration-thickness: 2px;
}

/* --- Blockquotes --- */

main blockquote {
  margin: var(--space-md) 0;
  padding: var(--space-sm) var(--space-md);
  border-left: 4px solid var(--border);
  background: var(--blockquote-bg);
  color: var(--text);
}

main blockquote p {
  margin: 0 0 var(--space-sm);
}

main blockquote p:last-child {
  margin-bottom: 0;
}

/* --- Tables --- */

main table {
  width: 100%;
  margin: var(--space-md) 0 var(--space-lg);
  border-collapse: collapse;
  font-size: 0.9375rem;
  line-height: 1.5;
}

main thead {
  border-bottom: 2px solid var(--border);
}

main th,
main td {
  padding: 0.625rem 0.75rem;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--border);
}

main th {
  font-weight: 600;
}

main tbody tr:last-child td {
  border-bottom: 0;
}

/* Tab-separated rows rendered as paragraphs (legal source format). */
main p:has(+ p) {
  tab-size: 1.5rem;
}

main > p:first-child ~ p {
  white-space: pre-wrap;
}

/* --- Code --- */

main code {
  font-family: ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, monospace;
  font-size: 0.9em;
  padding: 0.15em 0.35em;
  border-radius: 0.25rem;
  background: var(--code-bg);
  word-break: break-word;
}

main pre {
  margin: var(--space-md) 0;
  padding: var(--space-md);
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: var(--code-bg);
  font-size: 0.875rem;
  line-height: 1.55;
  -webkit-overflow-scrolling: touch;
}

main pre code {
  padding: 0;
  border-radius: 0;
  background: transparent;
  font-size: inherit;
  word-break: normal;
}

/* --- Horizontal rules --- */

main hr {
  margin: var(--space-xl) 0;
  border: 0;
  border-top: 1px solid var(--border);
}

@media (max-width: 600px) {
  nav {
    flex-direction: column;
    gap: var(--space-xs);
  }

  main {
    padding: var(--space-lg) var(--space-md) 2.5rem;
  }

  main table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    max-width: 100%;
  }

  main th,
  main td {
    padding: 0.5rem 0.625rem;
  }
}