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

:root {
  --background: #0a0f14;
  --foreground: #e8eaed;
  --card: #111820;
  --card-foreground: #e8eaed;
  --primary: #14b8a6;
  --primary-foreground: #042f2e;
  --secondary: #1a2332;
  --secondary-foreground: #e8eaed;
  --muted: #1a2332;
  --muted-foreground: #8b949e;
  --border: #21303d;
  --ring: #14b8a6;
  --radius: 0.75rem;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--background);
  color: var(--foreground);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: inherit;
  text-decoration: none;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }
  h3 { font-size: 1.25rem; }
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(10, 15, 20, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.25rem;
}

.logo-icon {
  width: 2rem;
  height: 2rem;
  background: linear-gradient(135deg, var(--primary), #0d9488);
  border-radius: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.logo-icon svg {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--primary-foreground);
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--muted-foreground);
  transition: color 0.2s;
  font-size: 0.875rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--foreground);
}

.cart-button {
  position: relative;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  color: var(--foreground);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s;
}

.cart-button:hover {
  background-color: var(--secondary);
  border-color: var(--primary);
}

.cart-button svg {
  width: 1.25rem;
  height: 1.25rem;
}

.cart-count {
  position: absolute;
  top: -0.5rem;
  right: -0.5rem;
  background-color: var(--primary);
  color: var(--primary-foreground);
  font-size: 0.75rem;
  font-weight: 600;
  width: 1.25rem;
  height: 1.25rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mobile-menu-button {
  display: none;
  background: transparent;
  border: none;
  color: var(--foreground);
  cursor: pointer;
  padding: 0.5rem;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .mobile-menu-button {
    display: block;
  }
  
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 4rem;
    left: 0;
    right: 0;
    background-color: var(--card);
    padding: 1rem;
    border-bottom: 1px solid var(--border);
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-decoration: none;
}

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

.btn-primary:hover {
  background-color: #0d9488;
}

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

.btn-secondary:hover {
  background-color: var(--muted);
  border-color: var(--primary);
}

.btn-ghost {
  background: transparent;
  color: var(--foreground);
}

.btn-ghost:hover {
  background-color: var(--secondary);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.8125rem;
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1rem;
}

/* Hero Section */
.hero {
  padding: 6rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(20, 184, 166, 0.1) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--secondary);
  border: 1px solid var(--border);
  padding: 0.5rem 1rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  color: var(--muted-foreground);
  margin-bottom: 1.5rem;
}

.hero-badge svg {
  width: 1rem;
  height: 1rem;
  color: var(--primary);
}

.hero h1 {
  margin-bottom: 1.5rem;
}

.hero h1 span {
  color: var(--primary);
}

.hero p {
  color: var(--muted-foreground);
  font-size: 1.125rem;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Features Section */
.features {
  padding: 4rem 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background-color: var(--card);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
}

@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.feature-icon {
  width: 3rem;
  height: 3rem;
  background-color: var(--secondary);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.feature-icon svg {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--primary);
}

.feature-content h4 {
  margin-bottom: 0.25rem;
}

.feature-content p {
  color: var(--muted-foreground);
  font-size: 0.875rem;
}

/* Section Headers */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-header h2 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Books Grid */
.books-section {
  padding: 5rem 0;
}

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

/* Book Card */
.book-card {
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.3s;
}

.book-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
}

.book-image {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
  background-color: var(--secondary);
}

.book-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s;
}

.book-card:hover .book-image img {
  transform: scale(1.05);
}

.book-badge {
  position: absolute;
  top: 0.75rem;
  left: 0.75rem;
  background-color: var(--primary);
  color: var(--primary-foreground);
  padding: 0.25rem 0.5rem;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  font-weight: 500;
}

.book-content {
  padding: 1.25rem;
}

.book-category {
  display: inline-block;
  background-color: var(--secondary);
  color: var(--muted-foreground);
  padding: 0.25rem 0.5rem;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  margin-bottom: 0.75rem;
}

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

.book-description {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  margin-bottom: 1rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.book-price {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.add-to-cart-btn {
  background-color: var(--primary);
  color: var(--primary-foreground);
  border: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.add-to-cart-btn:hover {
  background-color: #0d9488;
}

.add-to-cart-btn svg {
  width: 1rem;
  height: 1rem;
}

/* Categories Section */
.categories-section {
  padding: 5rem 0;
  background-color: var(--card);
  border-top: 1px solid var(--border);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

@media (max-width: 768px) {
  .categories-grid {
    grid-template-columns: 1fr;
  }
}

.category-card {
  background-color: var(--secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  transition: all 0.3s;
}

.category-card:hover {
  border-color: var(--primary);
}

.category-icon {
  width: 4rem;
  height: 4rem;
  background-color: var(--card);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.category-icon svg {
  width: 2rem;
  height: 2rem;
  color: var(--primary);
}

.category-content h3 {
  margin-bottom: 0.5rem;
}

.category-content p {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  margin-bottom: 1rem;
}

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

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

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-brand p {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  margin: 1rem 0;
}

.footer-column h4 {
  margin-bottom: 1rem;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  transition: color 0.2s;
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-bottom p {
  color: var(--muted-foreground);
  font-size: 0.875rem;
}

.footer-legal {
  display: flex;
  gap: 1.5rem;
}

.footer-legal a {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  transition: color 0.2s;
}

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

/* Products Page */
.products-page {
  padding: 3rem 0 5rem;
}

.products-header {
  text-align: center;
  margin-bottom: 3rem;
}

.products-header h1 {
  margin-bottom: 1rem;
}

.products-header p {
  color: var(--muted-foreground);
  max-width: 600px;
  margin: 0 auto;
}

.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.filter-tab {
  background-color: var(--secondary);
  border: 1px solid var(--border);
  color: var(--muted-foreground);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-tab:hover {
  border-color: var(--primary);
  color: var(--foreground);
}

.filter-tab.active {
  background-color: var(--primary);
  border-color: var(--primary);
  color: var(--primary-foreground);
}

/* Cart Page */
.cart-page {
  padding: 3rem 0 5rem;
}

.cart-header {
  margin-bottom: 2rem;
}

.cart-header h1 {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.cart-header h1 svg {
  width: 2rem;
  height: 2rem;
  color: var(--primary);
}

.cart-layout {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: 2rem;
  align-items: start;
}

@media (max-width: 1024px) {
  .cart-layout {
    grid-template-columns: 1fr;
  }
}

.cart-items {
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.cart-item {
  display: flex;
  gap: 1.5rem;
  padding: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.cart-item:last-child {
  border-bottom: none;
}

.cart-item-image {
  width: 120px;
  height: 90px;
  border-radius: 0.5rem;
  overflow: hidden;
  flex-shrink: 0;
  background-color: var(--secondary);
}

.cart-item-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.cart-item-details {
  flex: 1;
}

.cart-item-title {
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.cart-item-category {
  color: var(--muted-foreground);
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
}

.cart-item-price {
  color: var(--primary);
  font-weight: 600;
}

.cart-item-actions {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  justify-content: space-between;
}

.quantity-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--secondary);
  border-radius: var(--radius);
  padding: 0.25rem;
}

.quantity-btn {
  width: 2rem;
  height: 2rem;
  background: transparent;
  border: none;
  color: var(--foreground);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.375rem;
  transition: background-color 0.2s;
}

.quantity-btn:hover {
  background-color: var(--muted);
}

.quantity-value {
  width: 2rem;
  text-align: center;
  font-weight: 500;
}

.remove-btn {
  background: transparent;
  border: none;
  color: var(--muted-foreground);
  cursor: pointer;
  font-size: 0.875rem;
  transition: color 0.2s;
}

.remove-btn:hover {
  color: #ef4444;
}

.cart-empty {
  padding: 4rem 2rem;
  text-align: center;
}

.cart-empty svg {
  width: 4rem;
  height: 4rem;
  color: var(--muted-foreground);
  margin-bottom: 1rem;
}

.cart-empty h3 {
  margin-bottom: 0.5rem;
}

.cart-empty p {
  color: var(--muted-foreground);
  margin-bottom: 1.5rem;
}

/* Cart Summary */
.cart-summary {
  background-color: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  position: sticky;
  top: 5rem;
}

.cart-summary h3 {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.summary-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  font-size: 0.875rem;
}

.summary-row.text-muted {
  color: var(--muted-foreground);
}

.summary-row.total {
  font-size: 1.125rem;
  font-weight: 700;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.summary-row.total .price {
  color: var(--primary);
}

.checkout-btn {
  width: 100%;
  margin-top: 1.5rem;
}

.summary-note {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  color: var(--muted-foreground);
  font-size: 0.75rem;
}

.summary-note svg {
  width: 1rem;
  height: 1rem;
  flex-shrink: 0;
  margin-top: 0.125rem;
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: var(--card);
  border: 1px solid var(--primary);
  border-radius: var(--radius);
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  transform: translateY(100px);
  opacity: 0;
  transition: all 0.3s;
  z-index: 100;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast svg {
  width: 1.25rem;
  height: 1.25rem;
  color: var(--primary);
}

/* Utilities */
.text-primary {
  color: var(--primary);
}

.text-muted {
  color: var(--muted-foreground);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}