/* ── Fuel Smarter — Shared Stylesheet ───────────────────────────────────────
   Applied to every page. Controls header, nav, logo, and footer.
   To update the nav/logo across the whole site, edit this file only.
────────────────────────────────────────────────────────────────────────── */

/* ── Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* ── CSS Variables ── */
:root {
  --bg: #F4F1EA;
  --card: #FDFCFA;
  --border: rgba(0,0,0,0.08);
  --text: #1C1917;
  --text-secondary: #6B6560;
  --text-tertiary: #A8A29E;
  --accent: #2D6A4F;
  --accent-light: #EAF4EE;
  --accent-border: #95C9A8;
  --accent-text: #1A4731;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 16px rgba(0,0,0,0.04);
  --radius: 10px;
  --radius-lg: 16px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #171512;
    --card: #1F1E1B;
    --border: rgba(255,255,255,0.08);
    --text: #E8E4DC;
    --text-secondary: #9B9690;
    --text-tertiary: #6B6560;
    --accent: #40916C;
    --accent-light: #1A2E22;
    --accent-border: #2D6A4F;
    --accent-text: #95C9A8;
  }
}

/* ── Base ── */
*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}

/* ── Header ── */
header {
  background: var(--card);
  border-bottom: 1px solid var(--border);
  padding: 0 1.5rem;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 12px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
  width: 100%;
  overflow-x: hidden;
}

/* ── Logo ── */
.logo-mark { display: none; }

.logo-text {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text);
  text-decoration: none;
  white-space: nowrap;
  font-family: var(--font);
}

.logo-text span {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* For pages using the older .logo class */
a.logo {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.5px;
  font-family: var(--font);
  white-space: nowrap;
}

a.logo .fuel { color: var(--text); }
a.logo .smarter {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* ── Nav ── */
header nav, nav {
  margin-left: auto;
  display: flex;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
  flex-shrink: 1;
}

header nav::-webkit-scrollbar, nav::-webkit-scrollbar { display: none; }

header nav a, nav a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  padding: 0 10px;
  height: 60px;
  display: flex;
  align-items: center;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
  white-space: nowrap;
  flex-shrink: 0;
  font-family: var(--font);
}

header nav a:hover, nav a:hover { color: var(--text); }

header nav a.active, nav a.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 500;
}

/* ── Footer ── */
footer {
  text-align: center;
  padding: 2rem 1rem;
  font-size: 12px;
  color: var(--text-tertiary);
  border-top: 1px solid var(--border);
  background: var(--card);
  font-family: var(--font);
}

footer a { color: inherit; text-decoration: none; }
footer a:hover { color: var(--text); }

.footer-smarter {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* ── Mobile ── */
@media (max-width: 600px) {
  header { padding: 0 1rem; }
  header nav a, nav a { padding: 0 8px; font-size: 12px; }
  .logo-text { font-size: 15px; }
  a.logo { font-size: 15px; }
}