/* ─── global.css ─────────────────────────────────────────────────────────────
   Shared across all refueler.io pages.
   Token reference: REFUELER-BRIDGE.md § Design system
   Theme detection: document.documentElement.dataset.theme === 'carbon'
   Theme persistence: cookie rs-theme scoped to .refueler.io
   ─────────────────────────────────────────────────────────────────────────── */

/* ─── Brand tokens — Paper default ──────────────────────────────────────── */
:root {
  --carbon:  #1A1A1A;
  --paper:   #F5F0E8;

  --bg:             var(--paper);
  --fg:             var(--carbon);
  --fg-muted:       #5A5550;
  --fg-subtle:      #9A9590;
  --border:         rgba(26,26,26,0.12);
  --nav-bg:         #F5F0E8;
  --input-bg:       #FFFFFF;
  --input-border:   rgba(26,26,26,0.18);
  --divider-color:  rgba(26,26,26,0.14);
  --metric-block-bg: rgba(26,26,26,0.04);
  --submit-bg:      var(--carbon);
  --submit-fg:      var(--paper);

  /* REFUELER-BRIDGE canonical surface tokens */
  --surface:        #EDEAE4;
  --surface-raised: #E4E1DA;
  --text-primary:   #3D3A36;
  --text-secondary: #5A5751;
  --text-tertiary:  #9A948D;
  --accent:         #C8A96E;
  --accent-hover:   #E0C48A;
  --accent-action:  #D4690A;

  /* Structural */
  --radius-card:    10px;
  --radius-btn:     8px;
  --radius-modal:   12px;
  --border-weight:  0.5px;
  --theme-transition: 0.35s;
}

/* ─── Carbon override ────────────────────────────────────────────────────── */
[data-theme="carbon"] {
  --bg:             var(--carbon);
  --fg:             var(--paper);
  --fg-muted:       #B0AAA2;
  --fg-subtle:      #6A6560;
  --border:         rgba(245,240,232,0.10);
  --nav-bg:         #1A1A1A;
  --input-bg:       #252525;
  --input-border:   rgba(245,240,232,0.18);
  --divider-color:  rgba(245,240,232,0.14);
  --metric-block-bg: rgba(245,240,232,0.04);
  --submit-bg:      var(--paper);
  --submit-fg:      var(--carbon);

  /* REFUELER-BRIDGE canonical surface tokens */
  --surface:        #26282C;
  --surface-raised: #2E3035;
  --text-primary:   #E4E2DC;
  --text-secondary: #8A8680;
  --text-tertiary:  #5A5751;
  --accent:         #C8A96E;
  --accent-hover:   #E0C48A;
  --accent-action:  #F5820A;
}

/* ─── Reset ──────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  font-family: 'DM Sans', sans-serif;
  font-weight: 300;
  background-color: var(--bg);
  color: var(--fg);
  min-height: 100vh;
  transition: background-color var(--theme-transition) ease, color 0.25s ease;
  -webkit-font-smoothing: antialiased;
}

/* ─── Nav ────────────────────────────────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  border-bottom: var(--border-weight) solid var(--border);
  padding: 0 clamp(1.25rem, 4vw, 3rem);
  transition: background var(--theme-transition) ease, border-color 0.25s ease;
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.wordmark {
  font-family: 'Satoshi', 'DM Sans', sans-serif;
  font-weight: 600;
  font-size: 0.875rem;
  letter-spacing: 0.06em;
  color: var(--fg);
  text-decoration: none;
  white-space: nowrap;
}
.wordmark-divider {
  font-weight: 300;
  opacity: 0.3;
  margin: 0 0.5rem;
}
.wordmark-section {
  font-weight: 400;
  letter-spacing: 0.08em;
  opacity: 0.55;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.site-nav a {
  font-family: 'Satoshi', 'DM Sans', sans-serif;
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--fg-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.site-nav a:hover { color: var(--fg); }
.site-nav a.active { color: var(--fg); }

.theme-pill {
  font-family: 'Satoshi', 'DM Sans', sans-serif;
  font-size: 0.65rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border: var(--border-weight) solid var(--border);
  border-radius: 100px;
  padding: 0.35rem 0.85rem;
  background: transparent;
  color: var(--fg-muted);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
  white-space: nowrap;
  user-select: none;
}
.theme-pill:hover {
  border-color: var(--fg-muted);
  color: var(--fg);
}

/* ─── Footer ─────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: var(--border-weight) solid var(--border);
  padding: 2rem clamp(1.25rem, 4vw, 3rem);
  transition: border-color 0.25s;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-note,
.footer-links a {
  font-family: 'Satoshi', 'DM Sans', sans-serif;
  font-size: 0.6375rem;
  letter-spacing: 0.06em;
  color: var(--fg-subtle);
  text-decoration: none;
}
.footer-links {
  display: flex;
  gap: 1.5rem;
}
.footer-links a:hover { color: var(--fg-muted); }

/* ─── Responsive nav ─────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .site-header { padding: 0 24px; }
  .site-nav a:not(.active):not(button) { display: none; }
}