/* ————————————————————————————————————————————————————————————————
   Design Primitives — shared theme
   Every rule lives in @layer theme, so any unlayered per-page CSS
   always wins the cascade regardless of specificity. Pages remain
   free to override or extend anything here.
   Never style raw interactive/content elements (button, input,
   select, table, bare a, …) in this file — they are the subject
   matter of the specimens.
   ———————————————————————————————————————————————————————————————— */
@layer theme;

@layer theme {
  :root {
    --fg: #1a1a1a;
    --fg-muted: #6b6b6b;
    --fg-faint: #999;
    --bg: #fafaf8;
    --bg-specimen: #f2f1ed;
    --bg-specimen-alt: #eae8e3;
    --border: #d4d2cc;
    --border-light: #e8e6e1;
    --accent: #1a1a1a;
    --serif: 'DM Serif Display', 'Georgia', serif;
    --sans: 'DM Sans', -apple-system, sans-serif;
    --mono: 'IBM Plex Mono', monospace;
    --instrument: 'Instrument Serif', serif;
    --max-w: 820px;
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 32px;
    --space-xl: 48px;
    --space-2xl: 72px;
    --space-3xl: 120px;
  }

  * { margin: 0; padding: 0; box-sizing: border-box; }

  body {
    font-family: var(--sans);
    background: var(--bg);
    color: var(--fg);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
  }

  ::selection {
    background: var(--fg);
    color: var(--bg);
  }

  .container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 var(--space-lg);
  }

  header {
    padding: var(--space-3xl) 0 var(--space-2xl);
    border-bottom: 1px solid var(--border);
  }

  header .overline {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--fg-muted);
    margin-bottom: var(--space-md);
  }

  header h1 {
    font-family: var(--serif);
    font-size: clamp(36px, 5vw, 54px);
    font-weight: 400;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-md);
  }

  header .subtitle {
    font-family: var(--instrument);
    font-style: italic;
    font-size: 20px;
    color: var(--fg-muted);
    max-width: 560px;
    line-height: 1.5;
  }

  section {
    padding: var(--space-2xl) 0;
    border-bottom: 1px solid var(--border-light);
  }

  section:last-of-type {
    border-bottom: none;
  }

  h2 {
    font-family: var(--serif);
    font-size: 28px;
    font-weight: 400;
    line-height: 1.2;
    margin-bottom: var(--space-lg);
    letter-spacing: -0.01em;
  }

  h3 {
    font-family: var(--sans);
    font-size: 14px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--fg-muted);
    margin-bottom: var(--space-md);
    margin-top: var(--space-xl);
  }

  h3:first-child { margin-top: 0; }

  p {
    max-width: 620px;
    margin-bottom: var(--space-md);
    color: var(--fg);
  }

  p.muted {
    color: var(--fg-muted);
    font-size: 15px;
  }

  .lead {
    font-size: 18px;
    line-height: 1.65;
    color: var(--fg-muted);
    max-width: 600px;
  }

  .callout {
    border-left: 2px solid var(--fg);
    padding-left: var(--space-md);
    margin: var(--space-lg) 0;
    font-family: var(--instrument);
    font-style: italic;
    font-size: 17px;
    color: var(--fg-muted);
    line-height: 1.6;
    max-width: 560px;
  }

  .specimen {
    background: var(--bg-specimen);
    border-radius: 12px;
    padding: var(--space-xl) var(--space-lg);
    margin: var(--space-lg) 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
    position: relative;
  }

  .specimen-row {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    align-items: center;
    justify-content: center;
    width: 100%;
  }

  .specimen-label {
    font-family: var(--mono);
    font-size: 10px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--fg-faint);
    text-align: center;
    width: 100%;
    margin-top: var(--space-sm);
  }

  .specimen-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
  }

  .specimen-group .specimen-label {
    margin-top: 0;
  }

  /* ——— Chrome: shared nav + footer, swapped in by htmx ——— */

  html {
    scroll-padding-top: 56px;
  }

  .chrome-nav {
    min-height: 43px;
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg);
    background: color-mix(in srgb, var(--bg) 86%, transparent);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
  }

  .chrome-nav .container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: var(--space-md);
  }

  .chrome-nav a {
    font-family: var(--mono);
    font-size: 11px;
    line-height: 19px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--fg-muted);
    text-decoration: none;
    padding: 12px 0;
    display: inline-block;
  }

  .chrome-nav a:hover { color: var(--fg); }

  .chrome-nav-crumbs {
    display: inline-flex;
    align-items: baseline;
    gap: 10px;
  }

  .chrome-nav-sep {
    font-family: var(--mono);
    font-size: 11px;
    color: var(--fg-faint);
  }

  .chrome-nav-note {
    font-family: var(--instrument);
    font-style: italic;
    font-size: 13px;
    color: var(--fg-faint);
  }

  .colophon {
    padding: var(--space-2xl) 0 var(--space-xl);
    text-align: center;
    font-size: 13px;
    color: var(--fg-faint);
    max-width: 100%;
    margin: 0 auto;
  }

  .chrome-footer {
    min-height: 140px;
    padding-bottom: var(--space-3xl);
  }

  .chrome-pager {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    gap: var(--space-md);
    border-top: 1px solid var(--border-light);
    padding-top: var(--space-md);
  }

  .chrome-pager a {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--fg-muted);
    text-decoration: none;
  }

  .chrome-pager a:hover { color: var(--fg); }

  .chrome-colophon {
    font-family: var(--mono);
    font-size: 10px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--fg-faint);
    text-align: center;
    max-width: 100%;
    margin: var(--space-lg) auto 0;
  }

  /* ——— Chrome: author / attribution module ———
     Footer module by default; fixed bottom-left rail at ≥1360px.
     The placeholder div must stay empty — :empty hides it pre-swap. */

  .chrome-author:empty {
    display: none;
  }

  .chrome-author {
    margin-top: var(--space-xl);
  }

  .chrome-author-card {
    border-top: 1px solid var(--border-light);
    padding-top: var(--space-md);
  }

  .chrome-author-overline {
    font-family: var(--mono);
    font-size: 10px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--fg-faint);
    margin-bottom: var(--space-sm);
  }

  .chrome-author-blurb {
    font-family: var(--sans);
    font-size: 13px;
    line-height: 1.6;
    color: var(--fg-muted);
    max-width: 480px;
    margin-bottom: var(--space-sm);
  }

  .chrome-author-blurb a {
    color: var(--fg);
    text-decoration: none;
    border-bottom: 1px solid var(--border);
  }

  .chrome-author-blurb a:hover {
    border-bottom-color: var(--fg);
  }

  .chrome-author-links {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs) var(--space-lg);
  }

  .chrome-author-links a {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--fg-muted);
    text-decoration: none;
  }

  .chrome-author-links a:hover {
    color: var(--fg);
  }

  @media (min-width: 1360px) {
    .chrome-author {
      position: fixed;
      bottom: var(--space-xl);
      left: max(var(--space-lg), calc(50% - 650px));
      width: 200px;
      margin: 0;
      z-index: 90;
    }

    .chrome-author .container {
      max-width: none;
      padding: 0;
    }

    .chrome-author-card {
      border-top: none;
      padding-top: 0;
    }

    .chrome-author-blurb {
      font-size: 12px;
    }

    .chrome-author-links {
      flex-direction: column;
      gap: var(--space-xs);
    }

    .chrome-author-links a {
      font-size: 10px;
    }
  }

  @media (max-width: 640px) {
    .container { padding: 0 var(--space-md); }
    header { padding: var(--space-2xl) 0 var(--space-xl); }
    .specimen { padding: var(--space-lg) var(--space-md); }
    .chrome-nav-note { display: none; }
  }
}