:root {
  /* Permanently Dark Theme */
  --bg-primary: #0f172a;
  --bg-secondary: #0b1121;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent: #3b8fd9;
  --accent-hover: #1e70b8;
  --success: #7cc142;
  --success-hover: #639b34;
  --border: #1e293b;
  --card-bg: rgba(15, 23, 42, 0.8);
  --glass-border: rgba(30, 112, 184, 0.25);
  --header-bg: rgba(15, 23, 42, 0.92);
  --shadow: 0 10px 25px -5px rgb(0 0 0 / 0.4), 0 8px 10px -6px rgb(0 0 0 / 0.3);
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
}

/* Glassmorphism Classes */
.glass {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow);
}

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 3rem;
  text-align: center;
  background: linear-gradient(to right, var(--accent), var(--success));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.5rem;
  border-radius: 0.5rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

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

.btn-primary:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(30, 112, 184, 0.3);
}

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

.btn-outline:hover {
  background: var(--accent);
  color: white;
}

/* Header */
header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  padding: 1rem 0;
  transition: var(--transition);
}

header.scrolled {
  padding: 0.5rem 0;
  background: var(--header-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent);
}

.logo img {
  height: 40px;
}

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

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

/* Theme Toggle */
.theme-toggle {
  background: transparent;
  border: none;
  color: var(--text-primary);
  cursor: pointer;
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem;
  border-radius: 50%;
  transition: var(--transition);
}

.theme-toggle:hover {
  background: var(--bg-secondary);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: radial-gradient(circle at top right, rgba(14, 165, 233, 0.1), transparent),
              radial-gradient(circle at bottom left, rgba(16, 185, 129, 0.1), transparent);
  padding-top: 140px;
}

.hero-content {
  max-width: 700px;
}

.hero-badge {
  display: inline-block;
  padding: 0.5rem 1rem;
  background: rgba(124, 193, 66, 0.12);
  color: var(--success);
  border: 1px solid rgba(124, 193, 66, 0.2);
  border-radius: 2rem;
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

/* Products Grid */
.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
}

.category-card {
  padding: 1.5rem;
  border-radius: 1.5rem;
  text-align: center;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.category-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
  box-shadow: 0 20px 25px -5px rgb(30 112 184 / 0.15), 0 8px 10px -6px rgb(124 193 66 / 0.1);
}

/* Specialist Series Styles */
.specialist-tag {
  position: absolute;
  top: 1rem;
  right: 1rem;
  padding: 0.25rem 0.75rem;
  background: linear-gradient(135deg, var(--success), #a3e635);
  color: #fff;
  border-radius: 2rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  z-index: 10;
  box-shadow: 0 4px 10px rgba(124, 193, 66, 0.3);
}

.sub-category-title {
  font-size: 1.5rem;
  color: var(--accent);
  margin: 3rem 0 1.5rem;
  padding-left: 1rem;
  border-left: 4px solid var(--success);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

[data-theme="dark"] .specialist-tag {
  background: linear-gradient(135deg, #4d7c0f, var(--success));
}

.specialist-card.category-card {
  border-color: rgba(124, 193, 66, 0.2);
}

.specialist-card.category-card:hover {
  border-color: var(--success);
  box-shadow: 0 20px 25px -5px rgb(124 193 66 / 0.15);
}

/* Filter System Styles */
.filter-container {
  position: sticky;
  top: 70px;
  z-index: 90;
  background: var(--bg);
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2rem;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.filter-bar {
  display: flex;
  gap: 0.75rem;
  overflow-x: auto;
  padding: 0.5rem 0;
  scrollbar-width: none; /* Firefox */
}

.filter-bar::-webkit-scrollbar {
  display: none; /* Chrome, Safari, Opera */
}

.filter-btn {
  padding: 0.6rem 1.2rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 2rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  white-space: nowrap;
  transition: all 0.3s ease;
  cursor: pointer;
}

.filter-btn:hover {
  background: rgba(30, 112, 184, 0.05);
  border-color: var(--accent);
}

.filter-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(30, 112, 184, 0.3);
}

.product-image-container {
  width: 100%;
  aspect-ratio: 1/1;
  border-radius: 1rem;
  overflow: hidden;
  margin-bottom: 1.5rem;
  background: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
}

.product-image {
  width: 100%;
  height: 100%;
  object-fit: contain;
  transition: var(--transition);
}

.category-card:hover .product-image {
  transform: scale(1.1);
}

.category-icon {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  display: block;
  color: var(--accent);
}

/* Alphabetical Index */
.az-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 3rem;
  position: sticky;
  top: 80px;
  z-index: 100;
  padding: 1rem;
  border-radius: 1rem;
}

.az-link {
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  background: var(--bg-secondary);
  font-weight: 700;
  font-size: 0.875rem;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.az-link:hover {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

/* Search Bar */
.search-container {
  max-width: 600px;
  margin: 0 auto 4rem;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 1.25rem 1.5rem 1.25rem 3.5rem;
  border-radius: 1rem;
  border: 2px solid var(--border);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 1.1rem;
  transition: var(--transition);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(14, 165, 233, 0.1);
}

.search-icon {
  position: absolute;
  left: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  font-size: 1.25rem;
}

/* Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 2000;
}

.modal {
  width: 100%;
  max-width: 500px;
  padding: 2.5rem;
  border-radius: 1.5rem;
  position: relative;
}

.modal-close {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  cursor: pointer;
  font-size: 1.5rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid var(--border);
  background: var(--bg-primary);
  color: var(--text-primary);
}

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

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-logo {
  margin-bottom: 1.5rem;
}

.footer-links h4 {
  margin-bottom: 1.5rem;
}

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

.footer-links li {
  margin-bottom: 0.75rem;
}

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

/* Mobile Menu */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero h1 {
    font-size: 2.5rem;
  }
}