/* Shared by every page: colours, header, sections, buttons and footer. */

:root {
  --fg: #18181b;
  --muted: #5f5f67;
  --bg: #fafaf9;
  --surface: #ffffff;
  --line: #e4e4e7;
  --accent: #0f766e;
  --accent-fg: #ffffff;
  --ok: #16a34a;
  --warn: #d97706;
  --danger: #dc2626;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", Menlo, Consolas, monospace;
  color-scheme: light;
}

/* Light by default. The header switch sets data-theme="dark" on <html>,
   and the choice is remembered in the browser. */
:root[data-theme="dark"] {
  --fg: #ededef;
  --muted: #a1a1aa;
  --bg: #0c0c0e;
  --surface: #141417;
  --line: #27272a;
  --accent: #2dd4bf;
  --accent-fg: #042f2e;
  --ok: #4ade80;
  --warn: #fbbf24;
  --danger: #f87171;
  color-scheme: dark;
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-underline-offset: 0.2em;
}

a:focus-visible,
button:focus-visible,
canvas:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.wrap {
  max-width: 68rem;
  margin: 0 auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* Header */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-top: 1.5rem;
  padding-bottom: 1.5rem;
}

.brand {
  font-weight: 650;
  text-decoration: none;
  white-space: nowrap;
}

.brand-role {
  color: var(--muted);
  font-weight: 400;
}

.site-header nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.95rem;
}

.site-header nav a {
  color: var(--muted);
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--fg);
}

.lang {
  font-family: var(--mono);
  font-size: 0.8rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.1rem 0.6rem;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.95rem;
  line-height: 1;
  cursor: pointer;
}

.theme-toggle:hover {
  border-color: var(--muted);
  color: var(--fg);
}

/* Stays hidden without JS, since the switch does nothing without it. */
.theme-toggle[hidden] {
  display: none;
}

/* Sections */

section {
  padding-top: 4.5rem;
  padding-bottom: 4.5rem;
}

section + section {
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 2rem;
  font-size: 1.6rem;
  font-weight: 650;
  letter-spacing: -0.02em;
}

h3 {
  letter-spacing: -0.01em;
}

.intro {
  max-width: 38rem;
  margin: 0 0 2rem;
  color: var(--muted);
}

.case-meta,
.when {
  margin: 0;
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}

.button {
  display: inline-block;
  padding: 0.7rem 1.2rem;
  border: 1px solid var(--accent);
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-fg);
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}

.button.ghost {
  border-color: var(--line);
  background: transparent;
  color: var(--fg);
}

.button.ghost:hover {
  border-color: var(--muted);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin: 2rem 0 0;
  padding: 0;
  list-style: none;
}

/* Demo pages: title, hint and the line under the demo */

h1 {
  margin: 0;
  font-family: var(--mono);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.1;
  text-transform: uppercase;
}

.hint {
  margin: 0.25rem 0 0;
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--muted);
}

.stack {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.stack p {
  margin: 0;
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
}

.site-footer {
  padding-top: 2rem;
  padding-bottom: 3rem;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
}

@media (max-width: 40rem) {
  .site-header nav .section-link,
  .brand-role {
    display: none;
  }
}