/* Shared styles for BuildCalc Pro guide pages — matches landing aesthetic */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #0a0a0a;
  --surface: #141414;
  --surface-2: #1e1e1e;
  --surface-3: #252525;
  --border: #2a2a2a;
  --border-light: #333;
  --text: #fafafa;
  --text-secondary: #b0b0b0;
  --text-tertiary: #8a8a8a;
  --accent: #f59e0b;
  --accent-hover: #d97706;
  --accent-glow: rgba(245, 158, 11, 0.15);
  --green: #22c55e;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* Nav */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 10, 10, 0.9);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 18px;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
}

.logo span { color: var(--accent); }

.nav-cta {
  padding: 8px 18px;
  background: var(--accent);
  color: #000;
  border-radius: 8px;
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s;
}

.nav-cta:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

/* Article */
article {
  max-width: 760px;
  margin: 0 auto;
  padding: 60px 24px 80px;
}

.breadcrumb {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 24px;
}

.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}

.breadcrumb a:hover { color: var(--accent); }

h1 {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.lead {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  line-height: 1.7;
}

h2 {
  font-size: 26px;
  font-weight: 800;
  margin-top: 48px;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 19px;
  font-weight: 700;
  margin-top: 28px;
  margin-bottom: 12px;
  color: var(--accent);
}

p {
  color: var(--text-secondary);
  margin-bottom: 16px;
}

strong { color: var(--text); font-weight: 600; }

ul, ol {
  margin: 0 0 20px 24px;
  color: var(--text-secondary);
}

li { margin-bottom: 8px; }

code {
  background: var(--surface-2);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'SF Mono', Menlo, monospace;
  font-size: 0.9em;
  color: var(--accent);
}

.formula {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  padding: 16px 20px;
  border-radius: 8px;
  margin: 20px 0;
  font-family: 'SF Mono', Menlo, monospace;
  color: var(--text);
  font-size: 15px;
}

.callout {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 24px;
  margin: 28px 0;
}

.callout strong { color: var(--accent); }

.step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px;
  margin-bottom: 16px;
}

.step-num {
  display: inline-block;
  background: var(--accent);
  color: #000;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  text-align: center;
  line-height: 28px;
  font-weight: 800;
  font-size: 14px;
  margin-right: 10px;
}

.step h3 {
  display: inline;
  margin: 0;
  color: var(--text);
  font-size: 18px;
}

.step p {
  margin-top: 12px;
  margin-bottom: 0;
}

.cta-box {
  background: linear-gradient(135deg, var(--surface-2), var(--surface));
  border: 1px solid var(--border-light);
  border-radius: 14px;
  padding: 32px;
  margin: 48px 0 24px;
  text-align: center;
}

.cta-box h3 {
  color: var(--text);
  font-size: 22px;
  margin-bottom: 8px;
}

.cta-box p {
  margin-bottom: 20px;
}

.cta-btn {
  display: inline-block;
  padding: 12px 28px;
  background: var(--accent);
  color: #000;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 700;
  transition: all 0.2s;
}

.cta-btn:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--accent-glow);
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  color: var(--text-tertiary);
  font-size: 13px;
}

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

footer a:hover { color: var(--accent); }

footer .sep {
  margin: 0 10px;
  color: var(--border-light);
}

@media (max-width: 640px) {
  article { padding: 40px 20px 60px; }
  h1 { font-size: 32px; }
  h2 { font-size: 22px; }
}