/* RVWaterHeaterParts.com - Industrial RV Plumbing & Electrical Design System */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  --bg-primary: #090d16;
  --bg-secondary: #0f172a;
  --bg-tertiary: #1e293b;
  --bg-card: rgba(15, 23, 42, 0.85);
  --bg-card-hover: rgba(30, 41, 59, 0.95);
  --border-subtle: rgba(148, 163, 184, 0.12);
  --border-accent: rgba(45, 212, 191, 0.35);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --teal-primary: #0d9488;
  --teal-bright: #2dd4bf;
  --red-critical: #ef4444;
  --green-verified: #10b981;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-subtle: 0 4px 20px -2px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px -5px rgba(45, 212, 191, 0.25);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', "SF Mono", Consolas, Menlo, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-family: var(--font-sans); background-color: var(--bg-primary); color: var(--text-main); line-height: 1.6; }
body { min-height: 100vh; display: flex; flex-direction: column; background-image: radial-gradient(rgba(45, 212, 191, 0.04) 1px, transparent 1px), linear-gradient(to bottom, #090d16, #0c1322); background-size: 24px 24px, 100% 100%; }

.container { width: 100%; max-width: 1240px; margin: 0 auto; padding: 0 1.5rem; position: relative; z-index: 1; }
h1, h2, h3, h4 { color: #ffffff; font-weight: 700; line-height: 1.25; letter-spacing: -0.02em; }

.mono-tag { font-family: var(--font-mono); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.06em; padding: 0.2rem 0.55rem; border-radius: var(--radius-sm); background: rgba(45, 212, 191, 0.1); color: var(--teal-bright); border: 1px solid rgba(45, 212, 191, 0.25); display: inline-flex; align-items: center; gap: 0.35rem; }
.mono-tag.success { background: rgba(16, 185, 129, 0.1); color: #34d399; border-color: rgba(16, 185, 129, 0.25); }
.mono-tag.critical { background: rgba(239, 68, 68, 0.1); color: #f87171; border-color: rgba(239, 68, 68, 0.25); }

.gradient-text { background: linear-gradient(135deg, #ffffff 40%, var(--teal-bright) 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

/* Disclosure Banner */
.affiliate-banner { background: #070b13; border-bottom: 1px solid var(--border-subtle); font-size: 0.78rem; color: var(--text-muted); padding: 0.45rem 0; position: sticky; top: 0; z-index: 50; }
.banner-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 0.5rem; }
.banner-badge { font-family: var(--font-mono); font-size: 0.65rem; background: rgba(45, 212, 191, 0.15); color: var(--teal-bright); padding: 0.1rem 0.4rem; border-radius: 2px; }

/* Header & Nav */
.site-header { background: rgba(9, 13, 22, 0.95); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border-subtle); padding: 0.85rem 0; position: sticky; top: 29px; z-index: 40; }
.nav-inner { display: flex; justify-content: space-between; align-items: center; }
.brand-logo { display: flex; align-items: center; gap: 0.75rem; text-decoration: none; }
.brand-icon { width: 36px; height: 36px; border-radius: var(--radius-sm); background: var(--bg-tertiary); border: 1px solid var(--border-accent); display: flex; align-items: center; justify-content: center; }
.brand-title { font-size: 1.15rem; font-weight: 800; color: #ffffff; letter-spacing: -0.03em; }
.brand-title span { color: var(--teal-bright); }
.brand-subtitle { font-family: var(--font-mono); font-size: 0.62rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.08em; display: block; }

.nav-links { display: flex; align-items: center; list-style: none; gap: 1.5rem; }
.nav-link { color: var(--text-muted); text-decoration: none; font-size: 0.88rem; font-weight: 500; transition: color 0.15s ease; }
.nav-link:hover { color: #ffffff; }
.nav-cta-btn { background: var(--teal-primary); color: #fff; font-weight: 700; font-size: 0.82rem; padding: 0.45rem 0.95rem; border-radius: var(--radius-sm); text-decoration: none; transition: all 0.2s ease; display: inline-flex; align-items: center; gap: 0.4rem; border: none; cursor: pointer; }
.nav-cta-btn:hover { background: var(--teal-bright); color: #000; box-shadow: var(--shadow-glow); }
.mobile-toggle { display: none; background: none; border: none; color: #fff; cursor: pointer; }

/* Hero */
.hero-section { padding: 3.5rem 0 2.5rem 0; position: relative; }
.hero-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 2.5rem; align-items: center; }
.hero-headline { font-size: 2.75rem; margin: 0.75rem 0; letter-spacing: -0.03em; }
.hero-subhead { font-size: 1.05rem; color: var(--text-muted); line-height: 1.6; margin-bottom: 1.75rem; }
.hero-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin-top: 2rem; padding-top: 1.5rem; border-top: 1px solid var(--border-subtle); }
.stat-val { display: block; font-family: var(--font-mono); font-size: 1.25rem; font-weight: 700; color: #ffffff; }
.stat-label { font-size: 0.78rem; color: var(--text-dim); text-transform: uppercase; }

/* Schematic Card */
.schematic-box, .hero-schematic-card { background: var(--bg-card); border: 1px solid var(--border-subtle); border-radius: var(--radius-md); padding: 1.5rem; box-shadow: var(--shadow-subtle); }
.schematic-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.schematic-title { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.05em; }

/* Fitment Table & Matrix */
.matrix-section, .diagnostic-section { padding: 4rem 0; }
.section-header { margin-bottom: 2rem; }
.section-title { font-size: 2rem; margin: 0.5rem 0; }
.section-desc { font-size: 0.95rem; color: var(--text-muted); max-width: 780px; }

.matrix-search-box { position: relative; flex: 1; }
.matrix-search-box input { width: 100%; background: var(--bg-secondary); border: 1px solid var(--border-subtle); border-radius: var(--radius-sm); padding: 0.75rem 1rem 0.75rem 2.5rem; color: #ffffff; font-family: var(--font-sans); font-size: 0.9rem; }
.matrix-search-box input:focus { outline: none; border-color: var(--teal-primary); }
.search-icon { position: absolute; left: 0.85rem; top: 50%; transform: translateY(-50%); color: var(--text-dim); }

.table-wrapper { overflow-x: auto; border: 1px solid var(--border-subtle); border-radius: var(--radius-md); background: var(--bg-card); margin-top: 1.5rem; }
.fitment-table { width: 100%; border-collapse: collapse; text-align: left; font-size: 0.88rem; }
.fitment-table th { background: rgba(15, 23, 42, 0.95); padding: 0.85rem 1rem; font-family: var(--font-mono); font-size: 0.75rem; text-transform: uppercase; color: var(--text-muted); border-bottom: 1px solid var(--border-subtle); }
.fitment-table td { padding: 1rem; border-bottom: 1px solid var(--border-subtle); vertical-align: middle; }
.fitment-table tr:hover { background: rgba(30, 41, 59, 0.5); }

/* Buttons & Links */
.cta-amazon-link { display: inline-flex; align-items: center; gap: 0.4rem; padding: 0.55rem 0.95rem; background: rgba(45, 212, 191, 0.15); color: var(--teal-bright); border: 1px solid var(--border-accent); border-radius: var(--radius-sm); text-decoration: none; font-size: 0.82rem; font-weight: 600; transition: all 0.2s ease; }
.cta-amazon-link:hover { background: var(--teal-primary); color: #fff; box-shadow: var(--shadow-glow); }

/* Calculator */
.calc-card { background: var(--bg-card); border: 1px solid var(--border-accent); border-radius: var(--radius-md); padding: 1.75rem; }
.calc-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 1rem; margin-bottom: 1.5rem; }
.calc-display { background: var(--bg-secondary); border: 1px solid var(--border-subtle); border-radius: var(--radius-sm); padding: 1.25rem; text-align: center; }
.calc-display-val { font-family: var(--font-mono); font-size: 2.2rem; font-weight: 800; color: var(--teal-bright); display: block; line-height: 1.1; }
.calc-display-label { font-size: 0.75rem; color: var(--text-muted); text-transform: uppercase; font-family: var(--font-mono); }

/* Guide prose */
.guide-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 2.5rem; margin-top: 1.5rem; }
.guide-prose h3 { font-size: 1.3rem; margin: 1.25rem 0 0.5rem 0; }
.guide-prose h4 { font-size: 1.05rem; margin: 1rem 0 0.4rem 0; color: var(--teal-bright); }
.guide-prose p, .guide-prose li { color: var(--text-muted); font-size: 0.92rem; line-height: 1.6; margin-bottom: 0.75rem; }
.guide-prose ol, .guide-prose ul { padding-left: 1.25rem; }
.technical-callout { background: rgba(45, 212, 191, 0.08); border-left: 3px solid var(--teal-primary); padding: 1rem; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 1rem 0; font-size: 0.88rem; }
.technical-callout.critical { background: rgba(239, 68, 68, 0.08); border-left-color: var(--red-critical); color: #fca5a5; }

/* Footer */
.site-footer { background: #060910; border-top: 1px solid var(--border-subtle); padding: 3rem 0 1.5rem 0; margin-top: auto; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 2rem; margin-bottom: 2rem; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
.footer-links a { color: var(--text-muted); text-decoration: none; font-size: 0.85rem; }
.footer-links a:hover { color: var(--teal-bright); }
.footer-disclaimer-card { background: rgba(15, 23, 42, 0.6); border: 1px solid var(--border-subtle); padding: 1rem; border-radius: var(--radius-sm); font-size: 0.75rem; color: var(--text-dim); margin-bottom: 1.5rem; line-height: 1.5; }
.footer-bottom { display: flex; justify-content: space-between; font-size: 0.75rem; color: var(--text-dim); font-family: var(--font-mono); padding-top: 1rem; border-top: 1px solid rgba(255,255,255,0.05); }

/* Media Queries */
@media (max-width: 900px) {
  .hero-grid, .guide-grid, .footer-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .mobile-toggle { display: block; }
}