:root {
  --panel: #0b0b0b;
  --dot-off: #1e1e1e;
  --dot-on: #f2e200;
  --page: #141414;
  --text: #9a9a9a;
  --text-link: #c9c9c9;
  --dot-fill: 0.82; /* disc diameter as a fraction of the dot pitch */
  --gutter: 16px;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  display: flex;
  flex-direction: column;
  background: var(--page);
  color: var(--text);
  font: 14px/1.4 system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
}

/* The stage takes all the room the footer leaves; main.js fits the board into its content box. */
#stage {
  flex: 1 1 0;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--gutter);
}

.board {
  display: grid;
  grid-template-columns: repeat(var(--columns), var(--pitch, 4px));
  grid-auto-rows: var(--pitch, 4px);
  background: var(--panel);
  border-radius: calc(var(--pitch, 4px) * 1.5);
  contain: layout paint;
  box-shadow: 0 0 0 1px #000, 0 6px 24px rgba(0, 0, 0, 0.5);
}

.board i {
  width: calc(var(--pitch, 4px) * var(--dot-fill));
  height: calc(var(--pitch, 4px) * var(--dot-fill));
  place-self: center;
  border-radius: 50%;
  background: var(--dot-off);
}

.board i.on {
  background: var(--dot-on);
}

footer {
  flex: none;
  padding: 0 var(--gutter) 12px;
  text-align: center;
  font-size: 12px;
}

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

noscript {
  padding: var(--gutter);
}