:root {
  --line-height: 1.75;
  --font-family: 'PT Serif', Georgia, Cambria, 'Times New Roman', Times, serif;
  --color-text: #212121;
  --color-text-secondary: #bdbdbd;
  --color-text-visited: #757575;
  --color-background: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #fafafa;
    --color-text-secondary: #bdbdbd;
    --color-text-visited: #757575;
    --color-background: #212121;
  }
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { font-family: var(--font-family); }
body { background: var(--color-background); color: var(--color-text); line-height: var(--line-height); padding: 0 2rem 2rem 2rem; }
footer { margin-top: 2rem; font-style: italic; color: var(--color-text-secondary); }
h2 { margin: 2rem 0 1rem 0; }
ul, li { list-style: none; padding: 0; }
a { cursor: pointer; color: var(--text-color); text-decoration: none; }
em { padding: 0 0.5rem; color: var(--color-text-secondary); }
a:visited, a:visited em { color: var(--color-text-visited); }