:root {
    --font-family: "JetBrains Mono", monospace;
    --line-height: 1.20rem;
    --border-thickness: 2px;
    --text-color: #000;
    --text-color-alt: #666;
    --background-color: #fff;
    --background-color-alt: #eee;
  
    --font-weight-normal: 500;
    --font-weight-medium: 600;
    --font-weight-bold: 800;
  
    font-family: var(--font-family);
    font-optical-sizing: auto;
    font-weight: var(--font-weight-normal);
    font-style: normal;
    font-variant-numeric: tabular-nums lining-nums;
    font-size: 16px;
  }
  
  @media (prefers-color-scheme: dark) {
    :root {
      --text-color: #fff;
      --text-color-alt: #aaa;
      --background-color: #000;
      --background-color-alt: #111;
    }
  }
  
  * {
    box-sizing: border-box;
  }
  
  
  * + * {
    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);
    overflow-x: hidden;
  }
  
  @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(--font-weight-bold);
    margin: calc(var(--line-height) * 2) 0 var(--line-height);
    line-height: var(--line-height);
  }
  
  h1 {
    font-size: 2rem;
    line-height: calc(2 * var(--line-height));
    margin-bottom: calc(var(--line-height) * 2);
    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-bottom: var(--line-height);
  }
  
  strong {
    font-weight: var(--font-weight-bold);
  }
  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: 0 0 calc(var(--line-height) * 2);
  }
  
  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: 700;
  }
  .width-min {
    width: 0%;
  }
  .width-auto {
    width: 100%;
  }
  
  .header {
    margin-bottom: calc(var(--line-height) * 2);
  }
  .header h1 {
    margin: 0;
  }
  .header tr td:last-child {
    text-align: right;
  }
  
  p {
    word-break: break-word;
    word-wrap: break-word;
    hyphens: auto;
  }
  
  img, video {
    display: block;
    width: 100%;
    object-fit: contain;
    overflow: hidden;
  }
  img {
    font-style: italic;
    color: var(--text-color-alt);
  }
  
  details {
    border: var(--border-thickness) solid var(--text-color);
    padding: calc(var(--line-height) - var(--border-thickness)) 1ch;
    margin-bottom: var(--line-height);
  }
  
  summary {
    font-weight: var(--font-weight-medium);
    cursor: pointer;
  }
  details[open] summary {
    margin-bottom: var(--line-height);
  }
  
  details ::marker {
    display: inline-block;
    content: '▶';
    margin: 0;
  }
  details[open] ::marker {
    content: '▼';
  }
  
  details :last-child {
    margin-bottom: 0;
  }
  
  pre {
    white-space: pre;
    overflow-x: auto;
    margin: var(--line-height) 0;
    overflow-y: hidden;
  }
  figure pre {
    margin: 0;
  }
  
  pre, code {
    font-family: var(--font-family);
  }
  
  code {
    font-weight: var(--font-weight-medium);
  }
  
  figure {
    margin: calc(var(--line-height) * 2) 3ch;
    overflow-x: auto;
    overflow-y: hidden;
  }
  
  figcaption {
    display: block;
    font-style: italic;
    margin-top: var(--line-height);
  }
  
  ul, ol {
    padding: 0;
    margin: 0 0 var(--line-height);
  }
  
  ul {
    list-style-type: square;
    padding: 0 0 0 2ch;
  }
  ol {
    list-style-type: none;
    counter-reset: item;
    padding: 0;
  }
  ol ul,
  ol ol,
  ul ol,
  ul ul {
    padding: 0 0 0 3ch;
    margin: 0;
  }
  ol li:before { 
    content: counters(item, ".") ". ";
    counter-increment: item;
    font-weight: var(--font-weight-medium);
  }
  
  li {
    margin: 0;
    padding: 0;
  }
  
  li::marker {
    line-height: 0;
  }
  
  ::-webkit-scrollbar {
      height: var(--line-height);
  }
  
  input, button, textarea {
    border: var(--border-thickness) solid var(--text-color);
    padding: 
      calc(var(--line-height) / 2 - var(--border-thickness))
      calc(1ch - var(--border-thickness));
    margin: 0;
    font: inherit;
    font-weight: inherit;
    height: calc(var(--line-height) * 2);
    width: auto;
    overflow: visible;
    background: var(--background-color);
    color: var(--text-color);
    line-height: normal;
    -webkit-font-smoothing: inherit;
    -moz-osx-font-smoothing: inherit;
    -webkit-appearance: none;
  }
  
  input[type=checkbox],
  input[type=radio] {
    display: inline-grid;
    place-content: center;
    vertical-align: top;
    width: 2ch;
    height: var(--line-height);
    cursor: pointer;
  }
  input[type=checkbox]:checked:before,
  input[type=radio]:checked:before {
    content: "";
    width: 1ch;
    height: calc(var(--line-height) / 2);
    background: var(--text-color);
  }
  input[type=radio],
  input[type=radio]:before {
    border-radius: 100%;
  }
  
  button:focus, input:focus {
    --border-thickness: 3px;
    outline: none;
  }
  
  input {
    width: calc(round(down, 100%, 1ch));
  }
  ::placeholder {
    color: var(--text-color-alt);
    opacity: 1;
  }
  ::-ms-input-placeholder {
    color: var(--text-color-alt);
  }
  button::-moz-focus-inner {
    padding: 0;
    border: 0
  }
  
  button {
    text-transform: uppercase;
    font-weight: var(--font-weight-medium);
    cursor: pointer;
  }
  
  button:hover {
    background: var(--background-color-alt);
  }
  button:active {
    transform: translate(2px, 2px);
  }
  
  label {
    display: block;
    width: calc(round(down, 100%, 1ch));
    height: auto;
    line-height: var(--line-height);
    font-weight: var(--font-weight-medium);
    margin: 0;
  }
  
  label input {
    width: 100%;
  }
  
  .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);
  }
  
  .grid {
    --grid-cells: 0;
    display: flex;
    gap: 1ch;
    width: calc(round(down, 100%, (1ch * var(--grid-cells)) - (1ch * var(--grid-cells) - 1)));
    margin-bottom: var(--line-height);
  }
  
  .grid > *,
  .grid > input {
    flex: 0 0 calc(round(down, (100% - (1ch * (var(--grid-cells) - 1))) / var(--grid-cells), 1ch));
  }
  .grid:has(> :last-child:nth-child(1)) { --grid-cells: 1; }
  .grid:has(> :last-child:nth-child(2)) { --grid-cells: 2; }
  .grid:has(> :last-child:nth-child(3)) { --grid-cells: 3; }
  .grid:has(> :last-child:nth-child(4)) { --grid-cells: 4; }
  .grid:has(> :last-child:nth-child(5)) { --grid-cells: 5; }
  .grid:has(> :last-child:nth-child(6)) { --grid-cells: 6; }
  .grid:has(> :last-child:nth-child(7)) { --grid-cells: 7; }
  .grid:has(> :last-child:nth-child(8)) { --grid-cells: 8; }
  .grid:has(> :last-child:nth-child(9)) { --grid-cells: 9; }
  
  /* DEBUG UTILITIES */
  
  .debug .debug-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;
  }
  
  .debug .off-grid {
    background: rgba(255, 0, 0, 0.1);
  }
  
  .debug-toggle-label {
    text-align: right;
  }