style.css

@layer reset, tokens, syntax-highlight-element, layout;

@layer layout {
  :root {
    font-family: var(--fonts-sans);
    line-height: 1.5;
    font-weight: 400;

    color-scheme: light dark;
    color: light-dark(var(--light-canvas-text), var(--dark-canvas-text));
    background-color: light-dark(var(--light-canvas), var(--dark-canvas));

    font-synthesis: none;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }

  body {
    display: grid;
    gap: var(--spacing-24);
    min-height: 100vh;
  }

  :focus-visible {
    outline-color: light-dark(var(--light-accent), var(--dark-accent));
  }

  a {
    color: inherit;
    text-underline-offset: var(--spacing-1);
    transition: text-decoration-color .3s;
    text-decoration-line: underline;
  }

  a:not(:is(:hover, :focus)) {
    text-decoration-color: color-mix(in srgb, currentColor, transparent 75%);
  }

  button,
  .button {
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    border: 1px solid transparent;
    padding: 0.6em 1.2em;
    font-weight: 500;
    font-family: inherit;
    background-color: light-dark(var(--light-button-face), var(--dark-button-face));
    cursor: pointer;
    user-select: none;
    transition-duration: 0.25s;
    transition-property: border-color, opacity, scale;
  }
  button:hover,
  .button:hover {
    border-color: currentColor;
    color: light-dark(var(--light-accent), var(--dark-accent));
    scale: 1.1;
  }

  code {
    background-color: light-dark(var(--light-button-face), var(--dark-button-face));
    border-radius: 0.25rem;
    padding: var(--spacing-0\.5) var(--spacing-1);
  }

  header {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: var(--spacing-5);
    border-radius: 1rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    background-color: light-dark(var(--light-button-face-muted), var(--dark-button-face-muted));
    padding: var(--spacing-4);
    margin: var(--spacing-6) var(--spacing-4);

    color-scheme-switch.button {
      padding: var(--spacing-2);
      aspect-ratio: 1;
      align-self: flex-start;
      user-select: none;
    }
  }

  .header-links {
    font-size: 0.9rem;
    display: flex;
    flex-wrap: wrap;
    flex: 1;
    gap: var(--spacing-5);
    container-type: inline-size;

    a {
      color: inherit;
      display: inline-flex;
      align-items: center;
      gap: var(--spacing-2);
      text-wrap: nowrap;
      width: 100%;
    }

    a:first-of-type {
      margin-inline-end: auto;
    }

    svg {
      display: none;
    }
  }

  @container (min-width: 400px) {
    .header-links a {
      width: auto;
    }

    .header-links svg {
      display: initial;
    }
  }

  main {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-10);
    margin-inline: auto;
    max-inline-size: var(--sizes-3xl);
    inline-size: var(--sizes-full);
    padding: var(--spacing-4);
  }

  footer {
    border-block-start: 1px solid light-dark(var(--light-button-face), var(--dark-button-face));
    text-align: center;
    margin-inline: auto;
    margin-block-start: auto;
    inline-size: var(--sizes-full);
    padding: var(--spacing-8) var(--spacing-4);

    p {
      margin: 0;
    }
  }

  .copy-code {
    display: flex;
    position: relative;
    inline-size: 0;
    min-inline-size: 100%;

    syntax-highlight {
      flex: 1;
      border-radius: 0.6rem;
      padding: var(--spacing-4);
    }

    .button {
      /* color: inherit; */
      opacity: 0;
      position: absolute;
      inset-inline-end: var(--spacing-2);
      inset-block-start: var(--spacing-2);
      padding: var(--spacing-2);
      aspect-ratio: 1;
    }
  }

  .copy-code:hover .button,
  .copy-code:focus-within .button {
    opacity: 1;
  }

  /* Intro */
  [data-section="intro"] {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-4);
    text-align: center;
    text-wrap: balance;
    padding-block-end: var(--spacing-24);

    .emoji {
      font-size: clamp(2rem, 2vw + 1.6rem, 5rem);
      line-height: 1;
    }

    .heading {
      /* color: light-dark(var(--light-accent), var(--dark-accent)); */
      font-size: clamp(1.5rem, 2vw + 1.3rem, 3rem);
      font-weight: bold;
      line-height: 1.1;
      display: flex;
      flex-direction: column;
      margin: 0;
    }

    .tagline {
      font-size: clamp(1rem, 2vw, 1.25rem);
      font-weight: normal;
      margin: 0;
    }

    .badges {
      display: flex;
      justify-content: center;
      flex-wrap: wrap;
      gap: .5rem;
      font-size: 0;
      padding-block-start: var(--spacing-6);
    }

    .copy-code-container {
      text-align: initial;
      max-inline-size: var(--sizes-md);
      inline-size: var(--sizes-full);
      padding-block-start: var(--spacing-6);
    }
  }

  /* Content */
  [data-section="content"] {
    h1,
    h2 {
      margin-block-start: var(--spacing-6);
      margin-block-end: var(--spacing-4);
    }

    h1 {
      font-size: clamp(1.5rem, 2vw + 1rem, 2rem);
      line-height: 1.1;
    }

    h2 {
      font-size: clamp(1rem, 2vw + .75rem, 1.5rem);
    }

    p,
    li {
      text-wrap: balance;
    }

    li + li {
      margin-block-start: var(--spacing-2);
    }

    p,
    ul,
    .copy-code {
      margin-block-start: 0;
      margin-block-end: var(--spacing-4);
    }

    b {
      font-weight: 600;
    }
  }

  /* Exmaple */
  [data-section="example"] {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4);
    text-align: center;

    syntax-highlight {
      text-align: initial;
    }

    h1 {
      font-size: clamp(1.5rem, 2vw + 1rem, 2rem);
      line-height: 1.1;
      margin: 0;
    }

    figcaption {
      color: light-dark(var(--light-canvas-text-faded), var(--dark-canvas-text-faded));
    }
  }

  progressive-image {
    background-color: light-dark(var(--light-button-face-muted), var(--dark-button-face-muted));
  }

  progressive-image.loadable:before,
  progressive-image.loading:before {
    content: "";
    cursor: pointer;
    display: block;
    z-index: 1;
    position: absolute;
    top: 0;
    left: 0;
  }

  progressive-image.loadable:before {
    right: 0;
    bottom: 0;
    background-repeat: no-repeat;
    background-position: 16px 16px;
    background-size: 24px;
    background-image: url('data:image/svg+xml,\<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor">\<path d="M0 0h24v24H0z" fill="none"/>\<path d="M12 4.5C7 4.5 2.73 7.61 1 12c1.73 4.39 6 7.5 11 7.5s9.27-3.11 11-7.5c-1.73-4.39-6-7.5-11-7.5zM12 17c-2.76 0-5-2.24-5-5s2.24-5 5-5 5 2.24 5 5-2.24 5-5 5zm0-8c-1.66 0-3 1.34-3 3s1.34 3 3 3 3-1.34 3-3-1.34-3-3-3z"/>\</svg>');
  }

  progressive-image.loading:before {
    background-color: #000;
    animation: running-progress 2s cubic-bezier(0.4, 0, 0.2, 1) infinite;
    height: 3px;
    width: 100%;
  }

  progressive-image > img {
    opacity: 0;
    transition: opacity 400ms ease 0ms;
  }

  progressive-image > img[alt]:first-of-type {
    filter: blur(100px);
  }

  progressive-image > img.loaded {
    opacity: 1;
  }

  @keyframes running-progress {
    0% {
      margin-left: 0px;
      margin-right: 100%;
    }
    50% {
      margin-left: 25%;
      margin-right: 0%;
    }
    100% {
      margin-left: 100%;
      margin-right: 0;
    }
  }
}

@layer reset {
  *,
  :after,
  :before {
    box-sizing: border-box;
  }
  body {
    margin: 0;
  }
  [hidden] {
    display: none !important;
  }
}

@layer tokens {
  :where(:root) {
    --spacing-0: 0rem;
    --spacing-0\.5: 0.125rem;
    --spacing-1: 0.25rem;
    --spacing-1\.5: 0.375rem;
    --spacing-2: 0.5rem;
    --spacing-2\.5: 0.625rem;
    --spacing-3: 0.75rem;
    --spacing-3\.5: 0.875rem;
    --spacing-4: 1rem;
    --spacing-5: 1.25rem;
    --spacing-6: 1.5rem;
    --spacing-7: 1.75rem;
    --spacing-8: 2rem;
    --spacing-9: 2.25rem;
    --spacing-10: 2.5rem;
    --spacing-11: 2.75rem;
    --spacing-12: 3rem;
    --spacing-14: 3.5rem;
    --spacing-16: 4rem;
    --spacing-20: 5rem;
    --spacing-24: 6rem;
    --spacing-28: 7rem;
    --spacing-32: 8rem;

    --sizes-xs: 20rem;
    --sizes-sm: 24rem;
    --sizes-md: 28rem;
    --sizes-lg: 32rem;
    --sizes-xl: 36rem;
    --sizes-2xl: 42rem;
    --sizes-3xl: 48rem;
    --sizes-4xl: 56rem;
    --sizes-5xl: 64rem;
    --sizes-6xl: 72rem;
    --sizes-7xl: 80rem;
    --sizes-8xl: 90rem;
    --sizes-full: 100%;

    --fonts-sans:
      ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --fonts-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono",
      "Courier New", monospace;

    --dark-accent: #ffc300;
    --dark-canvas: #111;
    --dark-canvas-text: #f3f4f6;
    --dark-canvas-text-faded: hsla(0, 0%, 100%, 0.5);
    --dark-button-face: hsla(0, 0%, 100%, 0.1);
    --dark-button-face-muted: rgba(255, 255, 255, 0.1);

    --light-accent: #ffc300;
    --light-canvas: #ffffff;
    --light-canvas-text: black;
    --light-canvas-text-faded: hsla(0, 0%, 0%, 0.6);
    --light-button-face: #f6f8fa;
    --light-button-face-muted: hsla(0, 0%, 0%, 0.04);
  }
}

@layer syntax-highlight-element {
  :root {
    --she-token-constant: #e06c75;
    --she-token-string: #d19a66;
    --she-token-comment: #7f848e;
    --she-token-keyword: #98c379;
    --she-token-parameter: #1a1a1a;
    --she-token-function: #61afef;
    --she-token-string-expression: #c678dd;
    --she-token-punctuation: #abb2bf;
    --she-token-link: #c1cff1;
  }

  syntax-highlight {
    display: block;
    font-family: var(--fonts-mono);
    white-space: pre;
    tab-size: 2;
    hyphens: none;
    line-height: 1.6;
    overflow: auto;
    background-color: #292929;
    color: #abb2bf;
  }

  ::highlight(parameter) {
    color: var(--she-token-parameter);
  }

  ::highlight(comment),
  ::highlight(prolog),
  ::highlight(doctype),
  ::highlight(cdata) {
    color: var(--she-token-comment);
  }

  ::highlight(comment) {
    font-style: italic;
  }

  ::highlight(punctuation) {
    color: var(--she-token-punctuation);
  }

  ::highlight(property),
  ::highlight(tag),
  ::highlight(boolean),
  ::highlight(number),
  ::highlight(constant),
  ::highlight(symbol),
  ::highlight(class-name) {
    color: var(--she-token-constant);
  }

  ::highlight(selector),
  ::highlight(attr-name),
  ::highlight(string),
  ::highlight(char),
  ::highlight(builtin) {
    color: var(--she-token-string);
  }

  ::highlight(operator),
  ::highlight(entity),
  ::highlight(url) {
    color: var(--she-token-link);
    background: hsla(0, 0%, 100%, 0.5);
  }

  ::highlight(atrule),
  ::highlight(attr-value),
  ::highlight(keyword) {
    color: var(--she-token-keyword);
  }

  ::highlight(function) {
    color: var(--she-token-function);
  }

  ::highlight(regex),
  ::highlight(important),
  ::highlight(variable) {
    color: var(--she-token-string-expression);
  }
}