:root {
  --dark-surface: #24271d;
  --dark-visited-color: #bac49d;
  --visited-color: var(--dark-surface);
  --link-color: var(--visited-color);
  color-scheme: light dark;
}

/* Keep the system dark theme working without JavaScript. */
@media (prefers-color-scheme: dark) {
  :root {
    --background-color: var(--dark-surface);
    --visited-color: var(--dark-visited-color);
  }
}

:root[data-theme="light"] {
  color-scheme: light;
  --background-color: #fff;
  --heading-color: #222;
  --text-color: #444;
  --visited-color: var(--dark-surface);
  --blockquote-color: #222;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --background-color: var(--dark-surface);
  --heading-color: #eee;
  --text-color: #ddd;
  --visited-color: var(--dark-visited-color);
  --blockquote-color: #ccc;
}

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

.theme-toggle {
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: transparent;
}

.theme-toggle-track {
  position: relative;
  display: block;
  width: 32px;
  height: 20px;
  margin: auto;
  border-radius: 999px;
  background: var(--dark-surface);
  transition: background-color 180ms ease-in-out;
}

.theme-toggle-track::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px #0003;
  transition: transform 180ms ease-in-out, background-color 180ms ease-in-out;
}

.theme-toggle[aria-checked="true"] .theme-toggle-track {
  background: #fff;
}

.theme-toggle[aria-checked="true"] .theme-toggle-track::before {
  background: var(--dark-surface);
  transform: translateX(12px);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--link-color);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .theme-toggle-track,
  .theme-toggle-track::before {
    transition: none;
  }
}