/* ============================================
   Carmtek Official Website - Main Stylesheet
   Supports: Light/Dark mode, Responsive, i18n
   ============================================ */

/* --- CSS Custom Properties (Light Theme) --- */
:root {
  /* Brand Colors */
  --color-primary: #F6A42E;
  --color-primary-dark: #E8900D;
  --color-primary-light: #FEF3E5;
  --color-primary-bg: #FDEFD0;

  /* Neutral Colors */
  --color-bg: #FFFFFF;
  --color-bg-secondary: #F8F9FA;
  --color-bg-tertiary: #F0EEF1;
  --color-surface: #FFFFFF;
  --color-text: #1A1A2E;
  --color-text-secondary: #555555;
  --color-text-muted: #8F8F8F;
  --color-border: #E0E0E0;
  --color-border-light: #EEEEEE;

  /* Semantic Colors */
  --color-success: #9CDA1E;
  --color-warning: #ECDC05;
  --color-danger: #FB2A37;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Layout */
  --max-width: 1200px;
  --header-height: 64px;
}

/* --- Dark Theme --- */
[data-theme="dark"] {
  --color-bg: #0F0F1A;
  --color-bg-secondary: #1A1A2E;
  --color-bg-tertiary: #252540;
  --color-surface: #1E1E32;
  --color-text: #EAEAEA;
  --color-text-secondary: #B0B0B0;
  --color-text-muted: #787878;
  --color-border: #333350;
  --color-border-light: #2A2A45;
  --color-primary-light: #2A2215;
  --color-primary-bg: #1F1A10;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.6);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* --- Utility Classes --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-4xl) 0;
}

.section-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  text-align: center;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.section-subtitle {
  font-size: var(--font-size-lg);
  text-align: center;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-3xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  border: none;
  border-radius: var(--radius-md);
  font-size: var(--font-size-base);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  font-family: var(--font-family);
}

.btn-primary {
  background-color: var(--color-primary);
  color: #FFFFFF;
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: #FFFFFF;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: #FFFFFF;
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: var(--font-size-lg);
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: 8px 18px;
  font-size: var(--font-size-sm);
}

/* --- Header / Navigation --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border-light);
  z-index: 1000;
  transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

.header.scrolled {
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

.logo img {
  height: 36px;
  width: auto;
}

.nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-primary);
  border-radius: 1px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

/* Theme Toggle Button */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: all var(--transition-fast);
  color: var(--color-text);
}

.theme-toggle:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

/* Language Toggle Button */
.lang-toggle {
  padding: 6px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  cursor: pointer;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  transition: all var(--transition-fast);
  font-family: var(--font-family);
}

.lang-toggle:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}

/* Mobile Menu Button */
.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border: none;
  background: none;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 1px;
  transition: all var(--transition-fast);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Hero Section --- */
.hero {
  padding-top: calc(var(--header-height) + var(--space-4xl));
  padding-bottom: var(--space-4xl);
  background: linear-gradient(135deg, var(--color-primary-bg) 0%, var(--color-bg) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(246, 164, 46, 0.15) 0%, transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content {
  max-width: 520px;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background-color: var(--color-primary-light);
  color: var(--color-primary);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
  margin-bottom: var(--space-lg);
  border: 1px solid rgba(246, 164, 46, 0.3);
}

.hero-title {
  font-size: var(--font-size-5xl);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--space-lg);
  color: var(--color-text);
}

.hero-title .highlight {
  color: var(--color-primary);
}

.hero-desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xl);
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.hero-image-wrapper {
  position: relative;
  width: 320px;
  height: 560px;
  background: linear-gradient(145deg, #2A2A2A, #1A1A1A);
  border-radius: 40px;
  padding: 12px;
  box-shadow: var(--shadow-xl), 0 0 80px rgba(246, 164, 46, 0.2);
  overflow: hidden;
}

.hero-image-wrapper::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 28px;
  background: #1A1A1A;
  border-radius: 0 0 16px 16px;
  z-index: 2;
}

.hero-phone-screen {
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, #F6A42E 0%, #FFFFFF 30%);
  border-radius: 30px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
  position: relative;
  overflow: hidden;
}

.hero-phone-screen .app-logo-hero {
  width: 80px;
  height: 80px;
  border-radius: 20px;
  margin-bottom: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.hero-phone-screen .gauge-mockup {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 8px solid #F6A42E;
  border-top-color: #9CDA1E;
  position: relative;
  margin: 20px 0;
  background: rgba(255, 255, 255, 0.9);
}

.hero-phone-screen .gauge-mockup::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-15deg);
  width: 4px;
  height: 80px;
  background: linear-gradient(to top, #F6A42E, #FB2A37);
  border-radius: 2px;
  transform-origin: bottom center;
}

.hero-phone-screen .gauge-value {
  font-size: 24px;
  font-weight: 700;
  color: #333;
  margin-top: 8px;
}

.hero-phone-screen .gauge-labels {
  display: flex;
  justify-content: space-between;
  width: 200px;
  margin-top: 12px;
  font-size: 12px;
  font-weight: 600;
  color: #666;
}

.hero-phone-screen .status-bar {
  display: flex;
  gap: 16px;
  margin-top: 20px;
}

.hero-phone-screen .status-item {
  padding: 6px 16px;
  background: rgba(246, 164, 46, 0.15);
  border-radius: 20px;
  font-size: 12px;
  font-weight: 600;
  color: #333;
}

/* --- Features Section --- */
.features {
  background-color: var(--color-bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
}

.feature-card {
  padding: var(--space-xl);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border-light);
  transition: all var(--transition-base);
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.feature-icon {
  width: 64px;
  height: 64px;
  background: var(--color-primary-bg);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-lg);
  font-size: 28px;
}

.feature-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.feature-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --- RV Types Section --- */
.rv-types {
  background-color: var(--color-bg-secondary);
}

.rv-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-lg);
}

.rv-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-md);
  text-align: center;
  border: 2px solid transparent;
  transition: all var(--transition-base);
}

.rv-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.rv-card img {
  width: 100%;
  max-width: 140px;
  height: 80px;
  object-fit: contain;
  margin: 0 auto var(--space-md);
}

.rv-card h3 {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
}

/* --- How It Works Section --- */
.how-it-works {
  background: var(--color-bg);
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-xl);
  position: relative;
}

.steps::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 12.5%;
  right: 12.5%;
  height: 2px;
  background: var(--color-border);
  z-index: 0;
}

.step {
  text-align: center;
  position: relative;
  z-index: 1;
}

.step-number {
  width: 80px;
  height: 80px;
  background: var(--color-primary);
  color: #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-2xl);
  font-weight: 800;
  margin: 0 auto var(--space-lg);
  box-shadow: 0 4px 20px rgba(246, 164, 46, 0.4);
}

.step-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-text);
}

.step-desc {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* --- Download / CTA Section --- */
.cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #FFFFFF;
  text-align: center;
}

.cta .section-title {
  color: #FFFFFF;
}

.cta .section-subtitle {
  color: rgba(255, 255, 255, 0.85);
}

.cta-buttons {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

.btn-white {
  background: #FFFFFF;
  color: var(--color-primary);
  font-weight: 700;
}

.btn-white:hover {
  background: #F5F5F5;
  color: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-ghost {
  background: transparent;
  color: #FFFFFF;
  border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #FFFFFF;
  color: #FFFFFF;
}

/* --- Footer --- */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
}

.footer-brand p {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin-top: var(--space-md);
  max-width: 280px;
  line-height: 1.6;
}

.footer h4 {
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border-light);
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-bottom p {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
}

/* --- Support Page --- */
.page-header {
  padding-top: calc(var(--header-height) + var(--space-3xl));
  padding-bottom: var(--space-2xl);
  background: linear-gradient(135deg, var(--color-primary-bg) 0%, var(--color-bg) 100%);
  text-align: center;
}

.page-header h1 {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  margin-bottom: var(--space-md);
}

.page-header p {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  max-width: 500px;
  margin: 0 auto;
}

/* FAQ Accordion */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-base);
}

.faq-item:hover {
  border-color: var(--color-primary);
}

.faq-question {
  width: 100%;
  padding: var(--space-lg) var(--space-xl);
  background: none;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  font-weight: 600;
  color: var(--color-text);
  text-align: left;
}

.faq-question .icon {
  font-size: 20px;
  color: var(--color-primary);
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

.faq-item.active .faq-question .icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-answer-inner {
  padding: 0 var(--space-xl) var(--space-lg);
  color: var(--color-text-secondary);
  line-height: 1.7;
  font-size: var(--font-size-sm);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

/* Contact Cards */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  max-width: 800px;
  margin: 0 auto;
}

.contact-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  text-align: center;
  transition: all var(--transition-base);
}

.contact-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.contact-icon {
  width: 56px;
  height: 56px;
  background: var(--color-primary-bg);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
  font-size: 24px;
}

.contact-card h3 {
  font-size: var(--font-size-base);
  font-weight: 700;
  margin-bottom: var(--space-xs);
}

.contact-card p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

/* Troubleshooting Cards */
.troubleshoot-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
  max-width: 900px;
  margin: 0 auto;
}

.troubleshoot-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-base);
}

.troubleshoot-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.troubleshoot-card h3 {
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.troubleshoot-card h3 .icon {
  color: var(--color-primary);
}

.troubleshoot-card p {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.troubleshoot-card ol {
  padding-left: var(--space-lg);
  margin-top: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* --- Privacy Policy Page --- */
.legal-content {
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-lg);
}

.legal-content h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.legal-content h2:first-child {
  margin-top: 0;
}

.legal-content p {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

.legal-content ul {
  padding-left: var(--space-xl);
  margin-bottom: var(--space-md);
}

.legal-content li {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-xs);
}

.legal-content strong {
  color: var(--color-text);
}

.legal-meta {
  display: flex;
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border-light);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

/* --- Responsive Design --- */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    order: -1;
  }

  .hero-image-wrapper {
    width: 260px;
    height: 460px;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .rv-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps::before {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2.25rem;
    --font-size-4xl: 1.875rem;
    --font-size-3xl: 1.5rem;
  }

  .nav {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    flex-direction: column;
    padding: var(--space-lg);
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-lg);
    gap: var(--space-md);
  }

  .nav.open {
    display: flex;
  }

  .menu-toggle {
    display: flex;
  }

  .hero {
    padding-top: calc(var(--header-height) + var(--space-2xl));
    padding-bottom: var(--space-2xl);
  }

  .hero-image-wrapper {
    width: 220px;
    height: 400px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .rv-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .troubleshoot-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .section {
    padding: var(--space-2xl) 0;
  }
}

@media (max-width: 480px) {
  .hero-image-wrapper {
    width: 200px;
    height: 360px;
  }

  .hero-phone-screen .gauge-mockup {
    width: 140px;
    height: 140px;
  }

  .rv-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
  }

  .step-number {
    width: 60px;
    height: 60px;
    font-size: var(--font-size-xl);
  }
}

/* --- Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-in {
  animation: fadeInUp 0.6s ease forwards;
  opacity: 0;
}

.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }
.animate-in:nth-child(5) { animation-delay: 0.4s; }

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}