:root {
  font-size: 18px;

  @media print {
    font-size: 10pt;
  }

  --color-foreground: #000;
  --color-unchecked: #FFF;
  --color-checked: #CCC;

  @media(prefers-color-scheme: dark) {
    --color-foreground: #FFF;
    --color-unchecked: #111;
    --color-checked: #444;
  }
}

* {
  box-sizing: border-box;
}

body {
  width: 100vw;
  height: 100vmin;
  margin: 0;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;

  background: var(--color-unchecked);
  color: var(--color-foreground);
  font-family: system-ui, sans-serif;
  font-size: 1rem;

  header {
    flex: 0;
    height: 1.2rem;
    line-height: 1.2rem;
    text-align: center;
  }

  main {
    flex: 1;
    contain: size;
    container-type: size;

    table {
      width: 100cqmin;
      aspect-ratio: 1 / 1;
      margin: 0 auto;

      table-layout: fixed;
      border-collapse: collapse;

      tr {
        td {
          width: 20%;
          height: 20%;
          border: 2px solid var(--color-foreground);
          padding: 0.5rem;
          text-align: center;
          cursor: pointer;
          hyphens: auto;

            &.checked {
              background: var(--color-checked);
            }
        }
      }
    }
  }
}