:root {
  --bg-primary: #f8fafc;
  --bg-secondary: #eef2f7;
  --card-bg: #ffffff;
  --accent-primary: #2563eb;
  --accent-secondary: #10b981;
  --accent-tertiary: #f59e0b;
  --accent-gradient: linear-gradient(135deg, #2563eb, #10b981);
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --border-color: #e2e8f0;
  
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 100px;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  
  --transition-fast: 0.2s ease;
  --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (max-width: 1024px) {
  :root { --spacing-lg: 70px; }
}

@media (max-width: 768px) {
  :root { --spacing-lg: 50px; }
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

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

/* Layout Utilities */
.container {
  max-width: 1360px;
  margin: 0 auto;
  padding: 0 2rem;
}

.grid {
  display: grid;
  gap: var(--spacing-md);
}

.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

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

.text-center {
  text-align: center;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }

.bg-white { background-color: var(--card-bg); }
.bg-secondary { background-color: var(--bg-secondary); }
.text-secondary { color: var(--text-secondary); }
.text-primary { color: var(--accent-primary); }
.text-green { color: var(--accent-secondary); }

/* Typography */
h1, h2, h3, h4, h5 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

.subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-top: 1rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--accent-gradient);
  color: white;
  box-shadow: var(--shadow-sm);
}

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

.btn-secondary {
  background: white;
  color: var(--accent-primary);
  border: 1px solid var(--accent-primary);
}

.btn-secondary:hover {
  background: var(--bg-secondary);
  transform: translateY(-2px);
}

.btn-block {
  width: 100%;
}

/* Header & Navigation */
.header {
  background: var(--card-bg);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
  padding: 1rem 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-primary);
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-icon {
  width: 28px;
  height: 28px;
  background: var(--accent-gradient);
  border-radius: 6px;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-weight: 500;
  color: var(--text-primary);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--accent-primary);
  transition: width var(--transition-fast);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-links a.active {
  color: var(--accent-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-primary);
}

/* Hero Section */
.hero {
  padding: var(--spacing-lg) 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-content h1 span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
}

.hero-image-wrapper {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-hover);
}

.hero-image-wrapper img {
  width: 100%;
  height: auto;
  object-fit: cover;
  transition: transform var(--transition-smooth);
}

.hero-image-wrapper:hover img {
  transform: scale(1.02);
}

/* Features / Trust Section */
.features-grid {
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background: var(--card-bg);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: transform var(--transition-fast);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 64px;
  height: 64px;
  background: var(--bg-secondary);
  color: var(--accent-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin: 0 auto 1.5rem;
}

/* Marketplace Grid */
.marketplace-layout {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 2rem;
  align-items: start;
}

.filters-sidebar {
  background: var(--card-bg);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 100px;
}

.filter-group {
  margin-bottom: 1.5rem;
}

.filter-group h4 {
  margin-bottom: 0.75rem;
  font-size: 1rem;
}

.filter-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  cursor: pointer;
  color: var(--text-secondary);
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

/* Product Card */
.product-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-fast);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
  border-color: var(--accent-primary);
}

.product-image {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-bottom: 1px solid var(--border-color);
  padding: 1rem;
  background: var(--bg-primary);
}

.product-info {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.product-badges {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
}

.badge-new { background: #dbeafe; color: var(--accent-primary); }
.badge-used { background: #fef3c7; color: var(--accent-tertiary); }
.badge-refurbished { background: #d1fae5; color: var(--accent-secondary); }

.product-title {
  font-size: 1.125rem;
  margin-bottom: 0.5rem;
}

.product-price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  margin-top: auto;
}

.product-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
}

/* Forms (Sell / Trade / Contact) */
.form-container {
  max-width: 600px;
  margin: 0 auto;
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.trade-split-container {
  max-width: 1000px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.5rem;
}

.form-control {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color var(--transition-fast);
  background: var(--bg-primary);
}

.form-control:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

/* Value Estimator Box */
.estimate-box {
  background: var(--bg-secondary);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  text-align: center;
  margin-bottom: 1.5rem;
  border: 1px dashed var(--accent-primary);
}

.estimate-value {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent-primary);
  margin: 0.5rem 0;
}

/* Footer */
.footer {
  background: var(--card-bg);
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem;
  margin-top: var(--spacing-lg);
}

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

.footer-col h4 {
  margin-bottom: 1.5rem;
  font-size: 1.125rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: var(--text-secondary);
}

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

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* Page Headers */
.page-header {
  background: var(--card-bg);
  padding: 4rem 0;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 3rem;
}

/* Legal Pages */
.legal-content {
  max-width: 800px;
  margin: 0 auto;
  background: var(--card-bg);
  padding: 3rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.legal-content h2 {
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.legal-content p, .legal-content li {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn var(--transition-smooth) forwards;
}

@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive */
@media (max-width: 1024px) {
  .marketplace-layout {
    grid-template-columns: 1fr;
  }
  .trade-split-container {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-actions {
    justify-content: center;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--card-bg);
    flex-direction: column;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    text-align: center;
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .header-cta {
    display: none;
  }
  
  .mobile-menu-btn {
    display: block;
  }
}