:root {
  --bg: #ffffff;
  --fg: #000000;
  --link: #1a0dab;
  --heading: #004c99;
  --code-bg: #f0f0f0;
}

body.dark {
  --bg: #121212;
  --fg: #e0e0e0;
  --link: #8ab4f8;
  --heading: #7baaf7;
  --code-bg: #1e1e1e;
}

body {
  font-family: sans-serif;
  max-width: 700px;
  margin: 2rem auto;
  padding: 1rem;
  line-height: 1.6;
  background-color: var(--bg);
  color: var(--fg);
  transition: background-color 0.3s, color 0.3s;
}

h1, h2, h3 {
  color: var(--heading);
}

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

a:hover {
  text-decoration: underline;
}

pre, code {
  background: var(--code-bg);
  padding: 0.2em 0.4em;
  border-radius: 4px;
  font-family: monospace;
}

/* Toggle button */
#theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  padding: 0.4em 0.8em;
  background: var(--code-bg);
  border: none;
  border-radius: 5px;
  cursor: pointer;
}