/* BookHub - Professional Business Design */
:root {
  --primary: #1e3a5f;
  --primary-light: #2d5a8a;
  --accent: #c9a227;
  --accent-hover: #d4af37;
  --dark: #0f172a;
  --gray-100: #f8fafc;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-500: #64748b;
  --gray-700: #334155;
  --gray-900: #0f172a;
  --success: #059669;
  --danger: #dc2626;
  --warning: #d97706;
  --radius: 8px;
  --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Segoe UI', system-ui, -apple-system, sans-serif; color: var(--gray-900); line-height: 1.6; background: var(--gray-100); }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-light); }
img { max-width: 100%; height: auto; }

/* Header */
.site-header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: #fff;
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fff;
}
.logo span { color: var(--accent); }
.search-box {
  flex: 1;
  min-width: 200px;
  max-width: 400px;
}
.search-box form { display: flex; }
.search-box input {
  flex: 1;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: var(--radius) 0 0 var(--radius);
  font-size: 0.95rem;
}
.search-box button {
  padding: 0.5rem 1rem;
  background: var(--accent);
  border: none;
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--dark);
  font-weight: 600;
  cursor: pointer;
}
.search-box button:hover { background: var(--accent-hover); }
.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.nav-links a {
  color: #fff;
  font-weight: 500;
  transition: opacity 0.2s;
}
.nav-links a:hover { opacity: 0.9; }
.cart-count {
  background: var(--accent);
  color: var(--dark);
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 700;
}

/* Hero */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, #0f2744 100%);
  color: #fff;
  padding: 4rem 1.5rem;
  text-align: center;
}
.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  font-weight: 700;
}
.hero p { font-size: 1.2rem; opacity: 0.9; margin-bottom: 2rem; }
.hero .btn { margin: 0 0.25rem; }

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.6rem 1.25rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: all 0.2s;
  cursor: pointer;
  border: none;
  font-size: 0.95rem;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-light); }
.btn-accent {
  background: var(--accent);
  color: var(--dark);
}
.btn-accent:hover { background: var(--accent-hover); }
.btn-outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
}
.btn-outline:hover { background: var(--primary); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.85rem; }

/* Container */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
}
.section-title {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--dark);
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.section-title::before {
  content: '';
  width: 4px;
  height: 1.5rem;
  background: var(--accent);
  border-radius: 2px;
}

/* Books Grid */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.5rem;
}
.book-card {
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}
.book-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.book-card .cover {
  aspect-ratio: 2/3;
  background: var(--gray-200);
  overflow: hidden;
}
.book-card .cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.book-card .info {
  padding: 1rem;
}
.book-card .title { font-weight: 700; margin-bottom: 0.25rem; font-size: 1rem; }
.book-card .author { color: var(--gray-500); font-size: 0.9rem; margin-bottom: 0.5rem; }
.book-card .price-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}
.book-card .price { font-weight: 700; color: var(--primary); font-size: 1.1rem; }
.book-card .old-price { text-decoration: line-through; color: var(--gray-500); font-size: 0.9rem; }
.book-card .discount-badge {
  background: var(--success);
  color: #fff;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.75rem;
}
.out-of-stock { opacity: 0.7; }
.out-of-stock .cover::after {
  content: 'Out of Stock';
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.6);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}
.book-card .cover { position: relative; }

/* Forms */
.form-group { margin-bottom: 1rem; }
.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: var(--gray-700);
}
.form-control {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-size: 0.95rem;
}
.form-control:focus {
  outline: none;
  border-color: var(--primary);
}
.form-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
@media (max-width: 640px) { .form-row { grid-template-columns: 1fr; } }

/* Cards */
.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}
.card-title { font-size: 1.25rem; margin-bottom: 1rem; font-weight: 700; }

/* Alerts */
.alert {
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
}
.alert-success { background: #d1fae5; color: #065f46; }
.alert-error { background: #fee2e2; color: #991b1b; }
.alert-info { background: #dbeafe; color: #1e40af; }
.alert-warning { background: #fef3c7; color: #92400e; }

/* Footer */
.site-footer {
  background: var(--dark);
  color: #fff;
  margin-top: 3rem;
  padding: 2rem 1.5rem;
}
.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}
.footer h4 { margin-bottom: 0.75rem; font-size: 1rem; }
.footer a { color: rgba(255,255,255,0.8); }
.footer a:hover { color: #fff; }
.footer-bottom {
  text-align: center;
  padding-top: 1.5rem;
  margin-top: 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.9rem;
  opacity: 0.8;
}

/* Pagination */
.pagination {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  margin-top: 2rem;
  flex-wrap: wrap;
}
.pagination a, .pagination span {
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  background: #fff;
  border: 1px solid var(--gray-200);
  color: var(--gray-700);
}
.pagination a:hover { background: var(--primary); color: #fff; border-color: var(--primary); }
.pagination .current { background: var(--primary); color: #fff; border-color: var(--primary); }

/* Tables */
.table-wrap { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}
th, td { padding: 0.75rem 1rem; text-align: left; border-bottom: 1px solid var(--gray-200); }
th { background: var(--primary); color: #fff; font-weight: 600; }
tr:hover { background: var(--gray-100); }
.badge { padding: 0.25rem 0.6rem; border-radius: 999px; font-size: 0.8rem; font-weight: 600; }
.badge-success { background: #d1fae5; color: #065f46; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-warning { background: #fef3c7; color: #92400e; }
.badge-info { background: #dbeafe; color: #1e40af; }

/* Book Detail */
.book-detail { display: grid; grid-template-columns: 1fr 1.5fr; gap: 2rem; }
@media (max-width: 768px) { .book-detail { grid-template-columns: 1fr; } }
.book-detail .cover { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-lg); }
.book-detail .meta { margin: 1rem 0; }
.book-detail .meta span { margin-right: 1rem; color: var(--gray-500); }
.book-detail .qty-select { width: 80px; padding: 0.5rem; }

/* Cart */
.cart-table td { vertical-align: middle; }
.cart-table img { max-width: 80px; border-radius: var(--radius); }

/* Utils */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-2 { margin-bottom: 1rem; }
.text-muted { color: var(--gray-500); }
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }