@font-face {
  font-family: RobotoWeb;
  src: local('Roboto'), url('fonts/Roboto-Regular.ttf');
  font-display: swap;
}

@font-face {
  font-family: RobotoWeb;
  src: local('Roboto Italic'), url('fonts/Roboto-Italic.ttf');
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: RobotoWeb;
  src: local('Roboto Bold'), url('fonts/Roboto-Bold.ttf');
  font-weight: bold;
  font-display: swap;
}

@font-face {
  font-family: RobotoWeb;
  src: local('Roboto Bold Italic'), url('fonts/Roboto-BoldItalic.ttf');
  font-style: italic;
  font-weight: bold;
  font-display: swap;
}

html {
  color-scheme: dark light;
}

body {
  margin: 0;

  --text-on-primary-color: white;
  --opposite-text-on-primary-color: black;

  --color: #e0e0e0;
  --color-half: #707070;
  --high-contrast: #fff;
  --primary: #b82828;
  --primary-active: hsl(0, 64%, 48%);
  --primary-hover: hsl(0, 64%, 40%);
  --primary-half: rgba(184, 40, 40, 0.5);
  --primary-shaded: hsl(0, 64%, 30%);
  --secondary: hsl(180, 67%, 38%);
  --secondary-active: hsl(180, 67%, 42%);
  --secondary-hover: hsl(180, 67%, 34%);
  --background-color: #000000;
  --form-background-color: #383838;
  --form-border-color: #b0b0b0;
  --letter-background-color: #202020;

  color: var(--color);
  background-color: var(--background-color);

  font-family: RobotoWeb, Roboto, Arial, sans-serif;
}

@media (prefers-color-scheme: light) {
  body:not(.dark) {
    color-scheme: light;

    --color: #1a1a1a;
    --color-half: #8c8c8c;
    --high-contrast: #000;
    --background-color: #fff;
    --form-background-color: #ccc;
    --form-border-color: #444;
    --form-disabled-border-color: rgba(140, 140, 140, 0.3);
    --letter-background-color: #e0e0e0;
  }
}

header {
  background-color: var(--primary);
  padding-bottom: 0.25em;
}

header, header a {
  color: var(--text-on-primary-color) !important;
}

header a {
  display: block;
  text-align: center;
  text-decoration: none;
  font-size: 2em;
}

main {
  font-size: 1em;
  padding: 12px;
  max-width: 900px;
  margin: 0 auto;
}

main > h1:first-child {
  margin-top: 0.25em;
}

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

a:hover {
  color: var(--primary-hover);
}

a:active {
  color: var(--primary-active);
}

code {
  background-color: var(--letter-background-color);
  margin: 0 1em;
  text-align: center;
  display: block;
  font-size: 1.2em;
  padding: 0.5em;
}

p, li {
  line-height: 1.4;
}

p.img {
  text-align: center;
}

img.grid {
  /* Show 2x image at half resolution. */
  width: 280px;
  /* Don't extend past page width. */
  max-width: 100%;
}

li > dt:first-child {
  display: inline;
}