/* Tokens */
:root {
  --inline-space: 1ch;
  --block-space: 1rem;
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 2rem;
  --space-lg: 4rem;
  --space-xl: 6rem;

  --font-sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", Ubuntu, "Helvetica Neue", sans-serif;

  --leading-tight: 1.25;
  --leading-snug: 1.4;
  --leading-normal: 1.6;

  --content-width: 72ch;
  --page-width: 108ch;

  --radius-sm: 0.25rem;
  --transition-fast: 150ms ease;

  --lch-paper: 98% 0.005 96;
  --lch-ink: 5% 0.005 96;
  --lch-mid-gray: 54% 0.005 96;
  --lch-blue: 54% 0.23 255;

  --color-canvas: color-mix(in oklab, oklch(var(--lch-blue)) 5%, oklch(var(--lch-paper)));
  --color-ink: color-mix(in oklab, oklch(var(--lch-blue)) 5%, oklch(var(--lch-ink)));
  --color-border: color-mix(in oklab, oklch(var(--lch-blue)) 12%, var(--color-canvas));
  --color-subtle: color-mix(in oklab, oklch(var(--lch-mid-gray)) 15%, var(--color-ink));
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-canvas: color-mix(in oklab, oklch(var(--lch-blue)) 5%, oklch(var(--lch-ink)));
    --color-ink: color-mix(in oklab, oklch(var(--lch-blue)) 5%, oklch(var(--lch-paper)));
  }
}

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

  html {
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
  }

  body {
    margin: 0;
  }

  img,
  svg {
    display: block;
    max-width: 100%;
  }

  input,
  button,
  textarea,
  select {
    font: inherit;
  }

  p {
    margin: 0;
  }

  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    margin: 0;
  }

  ol,
  ul {
    list-style: none;
    margin: 0;
    padding: 0;
  }
}

@layer base {
  html {
    scroll-behavior: smooth;
  }

  @media (prefers-reduced-motion: reduce) {
    html {
      scroll-behavior: auto;
    }

    a {
      transition: none;
    }
  }

  body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: var(--leading-normal);
    color: var(--color-ink);
    background-color: var(--color-canvas);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
  }

  h1 {
    font-size: clamp(1.75rem, 4vw + 0.5rem, 2.75rem);
    line-height: var(--leading-tight);
    letter-spacing: -0.02em;
    font-weight: 600;
  }

  h2 {
    font-size: clamp(1.25rem, 3vw + 0.25rem, 1.75rem);
    line-height: var(--leading-tight);
    letter-spacing: -0.01em;
    font-weight: 600;
  }

  h3 {
    font-size: clamp(1rem, 2vw + 0.25rem, 1.25rem);
    line-height: var(--leading-snug);
    font-weight: 600;
  }

  p {
    max-width: var(--content-width);
  }

  a {
    color: currentColor;
    text-decoration-thickness: 1px;
    text-underline-offset: 0.15em;
    transition: color var(--transition-fast);
  }

  a:focus-visible {
    outline: 2px solid var(--color-ink);
    outline-offset: 0.2em;
  }

  @media (any-hover: hover) {
    a:hover {
      text-decoration-thickness: 2px;
    }
  }

  hr {
    border: none;
    height: 1px;
    background-color: var(--color-border);
    margin: var(--space-lg) 0;
  }
}

@layer layout {
  .skip-link {
    position: absolute;
    inset-inline-start: var(--space-md);
    inset-block-start: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-canvas);
    color: var(--color-ink);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    z-index: 1;
    transform: translateY(-200%);
  }

  .skip-link:focus {
    transform: translateY(0);
  }

  .page {
    max-width: var(--page-width);
    margin-inline: auto;
    padding-inline: var(--space-md);
  }

  .nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-block: var(--space-sm);
    border-bottom: 1px solid var(--color-border);
    margin-block-end: var(--space-xl);
  }

  .nav__brand {
    font-weight: 600;
    font-size: 1.1rem;
    letter-spacing: -0.01em;
    text-decoration: none;
  }

  .nav__links {
    display: flex;
    gap: var(--space-md);
    align-items: center;
  }

  .nav a {
    color: var(--color-subtle);
    font-size: 0.9rem;
  }

  @media (any-hover: hover) {
    .nav a:hover {
      color: var(--color-ink);
    }
  }

  .hero {
    padding-block: var(--space-xl);
  }

  .hero__brand {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    margin-block-end: var(--space-sm);
  }

  .hero__subtitle {
    font-size: 1.15rem;
    color: var(--color-subtle);
    line-height: var(--leading-snug);
    margin-block-start: var(--space-sm);
  }

  .hero__cta {
    margin-block-start: var(--space-md);
    font-size: 1rem;
  }

  .section {
    padding-block: var(--space-lg);
  }

  .section__title {
    margin-block-end: var(--space-md);
  }

  .features {
    display: grid;
    gap: 1px;
    background-color: var(--color-border);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
  }

  .features--grid {
    grid-template-columns: repeat(4, 1fr);
  }

  @media (max-width: 70ch) {
    .features--grid {
      grid-template-columns: repeat(2, 1fr);
    }
  }

  @media (max-width: 36ch) {
    .features--grid {
      grid-template-columns: 1fr;
    }
  }

  .feature {
    background-color: var(--color-canvas);
    padding: var(--space-md);
  }

  .feature__title {
    margin-block-end: var(--space-xs);
  }

  .feature__desc {
    font-size: 0.95rem;
    color: var(--color-subtle);
    line-height: var(--leading-snug);
  }

  .about__text {
    font-size: 0.95rem;
    color: var(--color-subtle);
    line-height: var(--leading-snug);
    max-width: var(--content-width);
  }

  .footer {
    padding-block: var(--space-lg);
    margin-block-start: var(--space-xl);
    border-top: 1px solid var(--color-border);
    font-size: 0.85rem;
    color: var(--color-subtle);
  }

  .footer__credit {
    margin-block-start: var(--space-xs);
  }

  .footer a {
    font-size: 0.85rem;
    color: var(--color-subtle);
  }

  @media (any-hover: hover) {
    .footer a:hover {
      color: var(--color-ink);
    }
  }
}