/* HotTubHeatingElements.com - Industrial Technical 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(6, 182, 212, 0.35);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --cyan-primary: #06b6d4;
  --cyan-bright: #22d3ee;
  --cyan-glow: rgba(6, 182, 212, 0.2);
  --amber-warning: #f59e0b;
  --red-critical: #ef4444;
  --green-verified: #10b981;
  --steel-surface: #334155;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --shadow-subtle: 0 4px 20px -2px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px -5px rgba(6, 182, 212, 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;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background-image: 
    radial-gradient(rgba(6, 182, 212, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, #090d16, #0c1322);
  background-size: 24px 24px, 100% 100%;
}

/* Technical Grid Overlay */
.technical-grid-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 600px;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 40%, rgba(0,0,0,0) 100%);
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 40%, rgba(0,0,0,0) 100%);
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  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(6, 182, 212, 0.1);
  color: var(--cyan-bright);
  border: 1px solid rgba(6, 182, 212, 0.25);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.mono-tag.warning {
  background: rgba(245, 158, 11, 0.1);
  color: var(--amber-warning);
  border-color: rgba(245, 158, 11, 0.3);
}

.mono-tag.success {
  background: rgba(16, 185, 129, 0.1);
  color: var(--green-verified);
  border-color: rgba(16, 185, 129, 0.3);
}

/* Global Top Advisory Bar */
.compliance-banner {
  background: #060b14;
  border-bottom: 1px solid var(--border-subtle);
  padding: 0.5rem 1rem;
  font-size: 0.78rem;
  color: var(--text-muted);
  text-align: center;
  position: relative;
  z-index: 50;
}
.compliance-banner a {
  color: var(--cyan-bright);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* Navigation Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(9, 13, 22, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.25rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-icon {
  width: 2.25rem;
  height: 2.25rem;
  background: linear-gradient(135deg, #0284c7, #06b6d4);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.4);
  border: 1px solid rgba(255,255,255,0.2);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 0.2rem;
}

.brand-title span {
  color: var(--cyan-bright);
}

.brand-subtitle {
  font-size: 0.68rem;
  font-family: var(--font-mono);
  color: var(--text-dim);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  transition: color 0.15s ease;
  position: relative;
}

.nav-link:hover {
  color: #ffffff;
}

.nav-link.active {
  color: var(--cyan-bright);
}

.nav-cta-btn {
  background: linear-gradient(135deg, #0e7490, #0891b2);
  color: #ffffff;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 600;
  font-family: var(--font-mono);
  text-decoration: none;
  border: 1px solid rgba(34, 211, 238, 0.3);
  box-shadow: 0 2px 8px rgba(6, 182, 212, 0.2);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: all 0.2s ease;
}

.nav-cta-btn:hover {
  background: linear-gradient(135deg, #0891b2, #06b6d4);
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.4);
  transform: translateY(-1px);
}

/* Mobile Menu Toggle */
.mobile-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  padding: 0.5rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

/* Hero Section */
.hero-section {
  padding: 3.5rem 0 3rem 0;
  border-bottom: 1px solid var(--border-subtle);
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 2.5rem;
  align-items: center;
}

.hero-badge-wrap {
  margin-bottom: 1rem;
}

.hero-headline {
  font-size: 2.65rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.25rem;
  color: #ffffff;
}

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

.hero-subhead {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  max-width: 580px;
  line-height: 1.6;
}

.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-item {
  display: flex;
  flex-direction: column;
}

.stat-val {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--cyan-bright);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* Interactive Schematic Hero Card */
.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);
  position: relative;
  overflow: hidden;
}

.hero-schematic-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan-bright), transparent);
}

.schematic-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-subtle);
}

.schematic-title {
  font-size: 0.85rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.schematic-svg-wrap {
  width: 100%;
  background: #070b13;
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  padding: 1rem;
  display: flex;
  justify-content: center;
}

.schematic-legend {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  font-size: 0.72rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.legend-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan-bright);
}
.legend-dot.amber { background: var(--amber-warning); }
.legend-dot.red { background: var(--red-critical); }
.legend-dot.green { background: var(--green-verified); }

/* Section Headers */
.section-header {
  margin-bottom: 2rem;
}

.section-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

.section-title {
  font-size: 1.85rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: #ffffff;
  margin-bottom: 0.5rem;
}

.section-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  max-width: 720px;
}

/* Fitment Matrix Section */
.matrix-section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-subtle);
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  background: var(--bg-card);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  align-items: center;
  justify-content: space-between;
}

.search-input-wrap {
  position: relative;
  flex: 1;
  min-width: 240px;
}

.search-input-wrap svg {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-dim);
}

.matrix-search-input {
  width: 100%;
  background: #0a0f1d;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.75rem 0.5rem 2.25rem;
  color: #fff;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  outline: none;
  transition: border-color 0.15s ease;
}

.matrix-search-input:focus {
  border-color: var(--cyan-primary);
  box-shadow: 0 0 0 1px var(--cyan-primary);
}

.filter-chips {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 0.35rem 0.75rem;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
}

.filter-btn:hover {
  border-color: var(--cyan-primary);
  color: #fff;
}

.filter-btn.active {
  background: rgba(6, 182, 212, 0.15);
  border-color: var(--cyan-primary);
  color: var(--cyan-bright);
}

/* Responsive Table Wrapper */
.matrix-table-container {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow-x: auto;
  box-shadow: var(--shadow-subtle);
}

.matrix-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  text-align: left;
}

.matrix-table th {
  background: #0c1322;
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  white-space: nowrap;
}

.matrix-table td {
  padding: 0.9rem 1rem;
  border-bottom: 1px solid rgba(148, 163, 184, 0.08);
  color: #e2e8f0;
  vertical-align: middle;
}

.matrix-table tbody tr:hover {
  background: rgba(30, 41, 59, 0.5);
}

.matrix-table tbody tr:last-child td {
  border-bottom: none;
}

.matrix-oem-col {
  font-weight: 600;
  color: #ffffff;
}

.oem-sub {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  display: block;
}

.matrix-specs-col {
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.matrix-material-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.15rem 0.45rem;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.05);
  color: #cbd5e1;
  display: inline-block;
}

.matrix-material-badge.ti {
  background: rgba(6, 182, 212, 0.15);
  color: var(--cyan-bright);
  border: 1px solid rgba(6, 182, 212, 0.3);
}

.cta-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  align-items: flex-end;
}

.cta-amazon-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  background: #0284c7;
  color: #ffffff;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: all 0.15s ease;
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.cta-amazon-link:hover {
  background: #0ea5e9;
  box-shadow: 0 0 12px rgba(14, 165, 233, 0.4);
  transform: translateY(-1px);
}

.cta-assembly-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  background: rgba(30, 41, 59, 0.7);
  color: #22d3ee;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: all 0.15s ease;
  border: 1px solid rgba(34, 211, 238, 0.3);
}

.cta-assembly-link:hover {
  background: rgba(6, 182, 212, 0.18);
  border-color: #22d3ee;
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.25);
  color: #ffffff;
  transform: translateY(-1px);
}

.card-cta-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.6rem;
  width: 100%;
  margin-top: 0.75rem;
}

.card-cta-group .cta-amazon-link,
.card-cta-group .cta-assembly-link {
  width: 100%;
  text-align: center;
  padding: 0.55rem 0.5rem;
}


/* Top 5 Essential Elements Section */
.top5-section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-subtle);
  background: linear-gradient(180deg, transparent, rgba(15, 23, 42, 0.4) 100%);
}

.elements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 1.5rem;
}

.element-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.element-card:hover {
  border-color: rgba(6, 182, 212, 0.4);
  transform: translateY(-2px);
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5), 0 0 15px -3px rgba(6, 182, 212, 0.15);
}

.element-card-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
}

.element-schematic-mini {
  background: #080d17;
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
  padding: 0.5rem;
}

.element-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
  color: #fff;
}

.element-compat {
  font-size: 0.78rem;
  color: var(--cyan-bright);
  font-family: var(--font-mono);
  margin-bottom: 1rem;
}

.specs-list {
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  margin-bottom: 1.25rem;
  background: rgba(0, 0, 0, 0.2);
  padding: 0.75rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.specs-list li {
  display: flex;
  justify-content: space-between;
  padding: 0.25rem 0;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
}

.specs-list li:last-child {
  border-bottom: none;
}

.specs-list .label {
  color: var(--text-dim);
}

.specs-list .val {
  color: #e2e8f0;
  font-weight: 600;
}

.element-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1.25rem;
  flex: 1;
}

.card-cta-wrap {
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.price-notice {
  font-size: 0.72rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* Diagnostic & Educational Hub */
.diagnostic-section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-subtle);
}

.diagnostic-tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
  overflow-x: auto;
}

.tab-btn {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tab-btn:hover {
  color: #fff;
}

.tab-btn.active {
  color: var(--cyan-bright);
  border-bottom-color: var(--cyan-bright);
}

.diagnostic-panel {
  display: none;
}

.diagnostic-panel.active {
  display: block;
}

.guide-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 2.5rem;
  align-items: flex-start;
}

.guide-prose {
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.7;
}

.guide-prose h3 {
  font-size: 1.35rem;
  margin: 1.5rem 0 0.75rem 0;
  color: #fff;
}

.guide-prose h3:first-child {
  margin-top: 0;
}

.guide-prose p {
  margin-bottom: 1rem;
}

.guide-prose ul, .guide-prose ol {
  margin: 0 0 1.25rem 1.5rem;
}

.guide-prose li {
  margin-bottom: 0.4rem;
}

.technical-callout {
  background: rgba(6, 182, 212, 0.06);
  border-left: 3px solid var(--cyan-primary);
  padding: 1rem 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 1.25rem 0;
  font-size: 0.88rem;
  color: #e2e8f0;
}

.technical-callout.warning {
  background: rgba(245, 158, 11, 0.08);
  border-left-color: var(--amber-warning);
}

.technical-callout.critical {
  background: rgba(239, 68, 68, 0.08);
  border-left-color: var(--red-critical);
}

.schematic-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.schematic-box h4 {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Interactive Multimeter Diagnostic Calculator */
.calc-card {
  background: #080d17;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.calc-display {
  background: #020617;
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: var(--radius-sm);
  padding: 1rem;
  margin-bottom: 1.25rem;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.8);
}

.lcd-screen {
  font-family: var(--font-mono);
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.lcd-label {
  font-size: 0.7rem;
  color: var(--text-dim);
  text-transform: uppercase;
}

.lcd-value {
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--cyan-bright);
  text-shadow: 0 0 10px rgba(6, 182, 212, 0.5);
}

.lcd-unit {
  font-size: 1rem;
  color: var(--text-muted);
  margin-left: 0.25rem;
}

.calc-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.calc-field label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
}

.calc-select, .calc-input {
  width: 100%;
  background: #0f172a;
  border: 1px solid var(--border-subtle);
  color: #fff;
  padding: 0.5rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
  outline: none;
}

.calc-select:focus, .calc-input:focus {
  border-color: var(--cyan-primary);
}

.calc-status {
  padding: 0.75rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: rgba(16, 185, 129, 0.1);
  color: var(--green-verified);
  border: 1px solid rgba(16, 185, 129, 0.2);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* FAQ Accordion */
.faq-section {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border-subtle);
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  overflow: hidden;
  transition: border-color 0.15s ease;
}

.faq-item:hover {
  border-color: rgba(6, 182, 212, 0.3);
}

.faq-question {
  width: 100%;
  background: transparent;
  border: none;
  text-align: left;
  padding: 1.25rem 1.5rem;
  color: #fff;
  font-size: 1.02rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-chevron {
  transition: transform 0.2s ease;
  color: var(--cyan-bright);
}

.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  display: none;
  padding: 0 1.5rem 1.25rem 1.5rem;
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.65;
  border-top: 1px solid rgba(148, 163, 184, 0.06);
  padding-top: 1rem;
}

.faq-item.open .faq-answer {
  display: block;
}

/* Footer */
.site-footer {
  background: #050811;
  border-top: 1px solid var(--border-subtle);
  padding: 3.5rem 0 2rem 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-brand p {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-top: 0.75rem;
  max-width: 360px;
}

.footer-col h4 {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  color: #fff;
  letter-spacing: 0.06em;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: var(--cyan-bright);
}

.footer-disclaimer-card {
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  padding: 1.25rem;
  margin-bottom: 2rem;
  font-size: 0.78rem;
  color: var(--text-dim);
  line-height: 1.6;
}

.footer-disclaimer-card strong {
  color: var(--text-muted);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.75rem;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

/* Modals for Legal / Contact */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
  z-index: 100;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal-overlay.open {
  display: flex;
}

.modal-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  max-width: 680px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 2rem;
  position: relative;
  box-shadow: 0 20px 40px rgba(0,0,0,0.8);
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0.25rem;
}

.modal-close-btn:hover {
  color: #fff;
}

/* Error Code Decoder Section */
.error-code-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.error-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: all 0.2s ease;
  display: flex;
  flex-direction: column;
}

.error-card:hover {
  border-color: var(--cyan-primary);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  transform: translateY(-2px);
}

.error-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.75rem;
}

.error-code-badge {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.3);
  letter-spacing: 0.05em;
}

.error-code-badge.warning {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border-color: rgba(245, 158, 11, 0.3);
}

.error-brand-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  color: var(--text-dim);
  padding: 0.2rem 0.5rem;
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
}

.error-card-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 0.5rem;
}

.error-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.error-diag-box {
  background: rgba(15, 23, 42, 0.7);
  border-left: 3px solid var(--cyan-primary);
  padding: 0.75rem;
  font-size: 0.82rem;
  color: #cbd5e1;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 1rem;
  font-family: var(--font-mono);
}

.error-diag-box strong {
  color: var(--cyan-bright);
  display: block;
  margin-bottom: 0.25rem;
  font-family: var(--font-sans);
}

.error-action-row {
  display: flex;
  gap: 0.5rem;
  margin-top: auto;
}

.error-action-btn {
  flex: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
  text-decoration: none;
  background: rgba(6, 182, 212, 0.12);
  color: var(--cyan-bright);
  border: 1px solid var(--border-accent);
  transition: all 0.15s ease;
}

.error-action-btn:hover {
  background: var(--cyan-primary);
  color: #041018;
}

/* OEM Subpage Specialized Components */
.breadcrumb-trail {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 1.5rem;
}

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

.breadcrumb-trail a:hover {
  color: var(--cyan-bright);
}

.oem-header-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.75rem;
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--cyan-bright);
  margin-bottom: 1rem;
}

.spec-matrix-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0;
}

.spec-matrix-cell {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
}

.spec-matrix-cell .cell-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  color: var(--text-dim);
  display: block;
  margin-bottom: 0.25rem;
}

.spec-matrix-cell .cell-value {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
}

.spec-matrix-cell .cell-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

/* Lead Capture & Waitlist Modal */
.waitlist-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-group label {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.form-input {
  background: rgba(9, 13, 22, 0.8);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  color: #ffffff;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  transition: border-color 0.15s ease;
}

.form-input:focus {
  outline: none;
  border-color: var(--cyan-primary);
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.2);
}

.form-submit-btn {
  background: var(--cyan-primary);
  color: #041018;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: all 0.2s ease;
}

.form-submit-btn:hover {
  background: var(--cyan-bright);
  box-shadow: 0 0 15px rgba(34, 211, 238, 0.4);
}

.waitlist-success-banner {
  display: none;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.35);
  color: #34d399;
  padding: 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  margin-top: 1rem;
  line-height: 1.5;
}

/* Print-Ready Field Guide Styling */
@media print {
  /* Hide interactive, commercial, and navigation clutter */
  .site-header,
  .footer-links,
  .footer-disclaimer-card,
  .footer-bottom,
  .mobile-toggle,
  .nav-cta-btn,
  .filter-bar,
  .tab-btn,
  .cta-amazon-link,
  .cta-assembly-link,
  .error-action-row,
  .modal-overlay,
  .no-print {
    display: none !important;
  }

  body {
    background: #ffffff !important;
    color: #000000 !important;
    font-size: 10pt;
    line-height: 1.35;
  }

  .container {
    max-width: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
  }

  .print-only-header {
    display: block !important;
    border-bottom: 2pt solid #000;
    padding-bottom: 8pt;
    margin-bottom: 12pt;
  }

  .print-only-header h1 {
    color: #000 !important;
    font-size: 16pt;
    margin: 0 0 4pt 0;
  }

  .print-only-header p {
    color: #444 !important;
    font-size: 9pt;
    margin: 0;
  }

  .guide-grid, .error-code-grid, .spec-matrix-grid {
    display: block !important;
  }

  .guide-prose h3, .guide-prose h4 {
    color: #000 !important;
    page-break-after: avoid;
    margin-top: 10pt;
  }

  .guide-prose p, .guide-prose li {
    color: #222 !important;
  }

  .technical-callout {
    background: #f4f4f4 !important;
    border-left: 3pt solid #333 !important;
    color: #000 !important;
    page-break-inside: avoid;
    margin: 8pt 0;
    padding: 6pt;
  }

  .schematic-box, .hero-schematic-card {
    background: #ffffff !important;
    border: 1pt solid #ccc !important;
    page-break-inside: avoid;
    margin: 8pt 0;
  }

  table {
    width: 100% !important;
    border-collapse: collapse !important;
    margin: 8pt 0 !important;
    page-break-inside: avoid;
  }

  th, td {
    border: 1pt solid #999 !important;
    padding: 4pt 6pt !important;
    color: #000 !important;
    font-size: 8.5pt !important;
  }

  th {
    background: #e6e6e6 !important;
    font-weight: bold !important;
  }

  svg text {
    fill: #000 !important;
  }
}

/* Hide print header in screen mode */
.print-only-header {
  display: none;
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .hero-grid, .guide-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .mobile-toggle {
    display: block;
  }
  .mobile-menu-open .nav-links {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-subtle);
    padding: 1.5rem;
    gap: 1rem;
  }
  .hero-headline {
    font-size: 2rem;
  }
  .hero-stats {
    grid-template-columns: 1fr;
  }
  .error-code-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 0.5rem;
    text-align: center;
  }
}