:root {
  --bg-base:       #f0f5fb;
  --bg-card:       #ffffff;
  --bg-card-hover: #f7f9ff;
  --border:        #dde5f0;
  --accent:        #1e40af;
  --accent2:       #6d28d9;
  --text-primary:  #0f172a;
  --text-muted:    #64748b;
  --text-faint:    #94a3b8;
}

* { box-sizing: border-box; }

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  line-height: 1.6;
}

/* ── Gradient text helper ── */
.grad-text {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Calculator cards ── */
.calc-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 1rem;
  box-shadow: 0 1px 3px rgba(15,23,42,0.06), 0 1px 2px rgba(15,23,42,0.04);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}
.calc-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 8px 28px rgba(30,64,175,0.13);
  background: var(--bg-card-hover);
}

/* ── Section headers ── */
.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: 9999px;
}

/* ── AdSense slots ── */
.ad-slot {
  background: #e8eef8;
  border: 1px dashed #b0c0d8;
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-faint);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
}

/* ── Nav ── */
.nav-link {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.15s;
}
.nav-link:hover { color: var(--accent); }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: #c7d4e8; border-radius: 3px; }