:root {
  --font-family: "Fira Code", monospace;
  --line-height: 1.25rem;
  --border-thickness: 2px;
  --bold-weight: 700;
  --text-color: #000;
  --background-color: #fff;

  font-family: var(--font-family);
  font-optical-sizing: auto;
  font-weight: 500;
  font-style: normal;
  font-variant-numeric: tabular-nums lining-nums;
  font-size: 16px;
}

* {
  box-sizing: border-box;
}


*:first-child {
  margin: 0;
}

* + * {
  margin-top: var(--line-height);
}

html {
  display: flex;
  width: 100%;
  margin: 0;
  padding: 0;
  flex-direction: column;
  align-items: center;
  background: var(--background-color);
  color: var(--text-color);
}

body {
  position: relative;
  width: 100%;
  margin: 0;
  padding: var(--line-height) 2ch;
  max-width: calc(min(80ch, round(down, 100%, 1ch)));
  line-height: var(--line-height);
}

@media screen and (max-width: 480px) {
  :root {
    font-size: 14px;
  }
  body {
    padding: var(--line-height) 1ch;
  }
}

h1, h2, h3, h4, h5, h6 {
  font-weight: var(--bold-weight);
  margin: calc(var(--line-height) * 2) 0 0;
  line-height: var(--line-height);
}

h1 {
  font-size: 2rem;
  line-height: calc(2 * var(--line-height));
  text-transform: uppercase;
}
h2 {
  font-size: 1rem;
  text-transform: uppercase;
}

hr {
  position: relative;
  display: block;
  height: var(--line-height);
  margin: calc(var(--line-height) * 1.5) 0;
  border: none;
  color: var(--text-color);
}
hr:after {
  display: block;
  content: "";
  position: absolute;
  top: calc(var(--line-height) / 2 - var(--border-thickness));
  left: 0;
  width: 100%;
  border-top: calc(var(--border-thickness) * 3) double var(--text-color);
  height: 0;
}

a {
  text-decoration-thickness: var(--border-thickness);
}

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

p {
  margin-top: var(--line-height);
}

strong {
  font-weight: var(--bold-weight);
}
em {
  font-style: italic;
}

sub {
  position: relative;
  display: inline-block;
  margin: 0;
  vertical-align: sub;
  line-height: 0;
  width: calc(1ch / 0.75);
  font-size: .75rem;
}

table {
  position: relative;
  top: calc(var(--line-height) / 2);
  width: calc(round(down, 100%, 1ch));
  border-collapse: collapse;
  margin: var(--line-height) 0 calc(var(--line-height) * 3);
}

th, td {
  border: var(--border-thickness) solid var(--text-color);
  padding: 
    calc((var(--line-height) / 2))
    calc(1ch - var(--border-thickness) / 2)
    calc((var(--line-height) / 2) - (var(--border-thickness)))
  ;
  line-height: var(--line-height);
  vertical-align: top;
  text-align: left;
}
table tbody tr:first-child > * {
  padding-top: calc((var(--line-height) / 2) - var(--border-thickness));
}


th {
  font-weight: 600;
}
.width-min {
  width: 0%;
}
.width-auto {
  width: 100%;
}

header {
  padding: 0;
}

p {
  word-break: break-word;
  word-wrap: break-word;
  hyphens: auto;
}

img, video {
  --real-height: 100% / var(--ratio);

  display: block;
  width: 100%;
  padding-bottom: calc(
    round(
      down, 
      var(--line-height) - (
        var(--real-height) - round(down, var(--real-height), var(--line-height))
      ),
      1px
    )
  );
  object-fit: contain;
}

pre, code {
  font-family: var(--font-family);
}

code {
  font-weight: 600;
}

figure {
  margin: calc(var(--line-height) * 2) 3ch;
  overflow-x: auto;
}

figcaption {
  display: block;
  font-style: italic;
  margin-top: var(--line-height);
}

ul, ol {
  padding: 0;
  margin: var(--line-height) 0;
}

ul {
  list-style-type: square;
  padding: 0 0 0 2ch;
}

li {
  margin: 0;
  padding: 0;
}

::marker {
  line-height: 0;
}

.tree, .tree ul {
  position: relative;
  padding-left: 0;
  list-style-type: none;
  line-height: var(--line-height);
}
.tree ul {
  margin: 0;
}
.tree ul li {
  position: relative;
  padding-left: 1.5ch;
  margin-left: 1.5ch;
  border-left: var(--border-thickness) solid var(--text-color);
}
.tree ul li:before {
  position: absolute;
  display: block;
  top: calc(var(--line-height) / 2);
  left: 0;
  content: "";
  width: 1ch;
  border-bottom: var(--border-thickness) solid var(--text-color);
}
.tree ul li:last-child {
  border-left: none;
}
.tree ul li:last-child:after {
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  content: "";
  height: calc(var(--line-height) / 2);
  border-left: var(--border-thickness) solid var(--text-color);
}

/* DEBUG UTILITIES */

.grid {
  --color: color-mix(in srgb, var(--text-color) 10%, var(--background-color) 90%);
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: -1;
  background-image:
    repeating-linear-gradient(var(--color) 0 1px, transparent 1px 100%),
    repeating-linear-gradient(90deg, var(--color) 0 1px, transparent 1px 100%);
  background-size: 1ch var(--line-height);
  margin: 0;

  /*display: none;*/
}

body :not(.grid) {
  /*background: rgba(255, 0, 0, 0.1);*/
}

@media (prefers-color-scheme: dark) {
  :root {
    --text-color: #fff;
    --background-color: #000;
  }
}