<div class="row gap align-top">
  Dark Mode Setting:
  <label><input name="color-scheme" type="radio" value="light dark" checked> System</label>
  <label><input name="color-scheme" type="radio" value="light"> Forced Light</label>
  <label><input name="color-scheme" type="radio" value="dark"> Forced Dark</label>
</div>

<p>Use your operating system’s preferences to <mark>switch between light and dark mode</mark>, or use one of the options to force a mode</p>

:root {
  color-scheme: light dark;
  --primary-color: light-dark(#333, #fafafa);
  --primary-background: light-dark(#e4e4e4, #121212);
  --highlight-color: light-dark(hotpink, lime);
}

:root {
  &:has(input[name="color-scheme"][value="light dark"]:checked) {
    color-scheme: light dark;
  }
  &:has(input[name="color-scheme"][value="light"]:checked) {
    color-scheme: light;
  }
  &:has(input[name="color-scheme"][value="dark"]:checked) {
    color-scheme: dark;
  }
}

body {
  color: var(--primary-color);
  background-color: var(--primary-background);
  transition: color 0.4s, background-color 0.4s;
}

mark {
  background: var(--highlight-color);
  transition: color 0.4s, background-color 0.4s;
}

@layer reset {
  *,
  *:after,
  *:before {
    box-sizing: border-box;
  }

  html,
  body {
    margin: 0;
    padding: 0;
  }

  ul[class] {
    list-style: none;
  }

  label {
    cursor: pointer;
    max-width: max-content;
    user-select: none;
  }
}

@layer baselayout {
  html {
    margin: auto;
    line-height: 1.5;
    font-size: 24px;
    font-family: "Syne", sans-serif;
    height: 100%;
    background: white;
  }

  body {
    width: 100%;
    height: 100%;
    margin: 0 auto;
    min-height: 100dvh;
    padding: 2em;
    display: grid;
    place-content: center;
  }

  footer {
    text-align: center;
    font-style: italic;
    margin-top: 2rem;
  }

  h1,
  h2,
  summary {
    font-family: "Anybody", sans-serif;

    text-decoration: underline;
    text-decoration-color: hsl(156deg 100% 50% / 50%);
    text-decoration-thickness: 0.2rem;
    text-decoration-style: wavy;
    text-decoration-skip-ink: none;
  }

  h2 {
    margin: 2em 0 0.5em 0;
    text-wrap: balance;
  }

  a {
    color: inherit;
  }

  button,
  input,
  textarea {
    font-family: inherit;
    font-size: inherit;
  }
}

@layer components {
  @layer forms {
    label {
      text-align: center;
    }
  }
}

@layer utilities {
  .float-right {
    float: right;
    margin-left: 0.5em;
  }
  .float-left {
    float: left;
    margin-right: 0.5em;
  }
  *:has(> .float-right, > .float-left) {
    display: flow-root;
  }

  .row {
    display: flex;
    flex-direction: row;
  }

  .align-top {
    align-items: top;
  }

  .column {
    display: flex;
    flex-direction: column;
  }

  .gap {
    gap: 1rem;
  }

  .sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
  }
}