/* ==========================================
   GIFT FINDER 2025 - MODERN DESIGN SYSTEM
   ========================================== */

/* CSS Custom Properties - Design Tokens */
:root {
  /* ===== COLOR PALETTE ===== */
  /* Primary Brand Colors */
  --color-primary-50: #faf5ff;
  --color-primary-100: #f3e8ff;
  --color-primary-200: #e9d5ff;
  --color-primary-300: #d8b4fe;
  --color-primary-400: #c084fc;
  --color-primary-500: #a855f7;
  --color-primary-600: #9333ea;
  --color-primary-700: #7c3aed;
  --color-primary-800: #6b21a8;
  --color-primary-900: #581c87;

  /* Neutral Colors */
  --color-neutral-0: #ffffff;
  --color-neutral-50: #fafafa;
  --color-neutral-100: #f5f5f5;
  --color-neutral-200: #e5e5e5;
  --color-neutral-300: #d4d4d4;
  --color-neutral-400: #a3a3a3;
  --color-neutral-500: #737373;
  --color-neutral-600: #525252;
  --color-neutral-700: #404040;
  --color-neutral-800: #262626;
  --color-neutral-900: #171717;

  /* Semantic Colors */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;

  /* ===== GLASSMORPHISM VARIABLES ===== */
  --glass-bg: rgba(255, 255, 255, 0.1);
  --glass-bg-strong: rgba(255, 255, 255, 0.15);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --glass-shadow-hover: 0 16px 64px rgba(0, 0, 0, 0.15);

  /* ===== SPACING SYSTEM ===== */
  --space-xs: 0.25rem;    /* 4px */
  --space-sm: 0.5rem;     /* 8px */
  --space-md: 1rem;       /* 16px */
  --space-lg: 1.5rem;     /* 24px */
  --space-xl: 2rem;       /* 32px */
  --space-2xl: 3rem;      /* 48px */
  --space-3xl: 4rem;      /* 64px */

  /* ===== TYPOGRAPHY ===== */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Inter', sans-serif;

  /* Font Sizes */
  --text-xs: 0.75rem;     /* 12px */
  --text-sm: 0.875rem;    /* 14px */
  --text-base: 1rem;      /* 16px */
  --text-lg: 1.125rem;    /* 18px */
  --text-xl: 1.25rem;     /* 20px */
  --text-2xl: 1.5rem;     /* 24px */
  --text-3xl: 1.875rem;   /* 30px */
  --text-4xl: 2.25rem;    /* 36px */
  --text-5xl: 3rem;       /* 48px */

  /* ===== BORDER RADIUS ===== */
  --radius-sm: 0.375rem;   /* 6px */
  --radius-md: 0.5rem;     /* 8px */
  --radius-lg: 0.75rem;    /* 12px */
  --radius-xl: 1rem;       /* 16px */
  --radius-2xl: 1.5rem;    /* 24px */
  --radius-full: 9999px;

  /* ===== TRANSITIONS ===== */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 350ms ease;

  /* ===== BREAKPOINTS (for reference) ===== */
  --bp-sm: 640px;
  --bp-md: 768px;
  --bp-lg: 1024px;
  --bp-xl: 1280px;
  --bp-2xl: 1536px;
}

/* ===== GLOBAL RESET & BASE STYLES ===== */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-neutral-800);
  background: linear-gradient(135deg, 
    var(--color-primary-50) 0%, 
    var(--color-neutral-50) 50%, 
    var(--color-primary-100) 100%);
    min-height: 100vh;
  overflow-x: hidden;
}

/* ===== MODERN BACKGROUND PATTERN ===== */
body::before {
  content: '';
    position: fixed;
    top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    radial-gradient(circle at 25% 25%, rgba(168, 85, 247, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 75% 75%, rgba(59, 130, 246, 0.05) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* ===== TYPOGRAPHY UTILITIES ===== */
.text-display {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.025em;
}

.text-gradient {
  background: linear-gradient(135deg, var(--color-primary-600), var(--color-primary-400));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== GLASSMORPHISM COMPONENTS ===== */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--glass-shadow);
  transition: all var(--transition-normal);
}

.glass-card:hover {
  background: var(--glass-bg-strong);
  box-shadow: var(--glass-shadow-hover);
  transform: translateY(-2px);
}

.glass-header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

/* ===== PRODUCT CARD COMPONENT ===== */
.product-card {
  background: var(--color-neutral-0);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: all var(--transition-normal);
  border: 1px solid var(--color-neutral-100);
  position: relative;
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
  border-color: var(--color-primary-200);
}

.product-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--color-primary-500), var(--color-primary-400));
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.product-card:hover::before {
  opacity: 1;
}

.product-image {
  width: 100%;
  height: 240px;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

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

.product-content {
  padding: var(--space-lg);
}

.product-title {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-neutral-800);
  margin-bottom: var(--space-sm);
  line-height: 1.4;
}

.product-description {
  font-size: var(--text-sm);
  color: var(--color-neutral-600);
  margin-bottom: var(--space-md);
  line-height: 1.5;
}

.product-price {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-primary-600);
  margin-bottom: var(--space-md);
}

.product-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.product-tag {
  background: var(--color-primary-50);
  color: var(--color-primary-700);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 500;
  border: 1px solid var(--color-primary-100);
}

/* ===== BUTTON SYSTEM ===== */
.btn {
    display: inline-flex;
    align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-lg);
  font-weight: 600;
  font-size: var(--text-sm);
  text-decoration: none;
  transition: all var(--transition-normal);
  cursor: pointer;
  border: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary-600), var(--color-primary-500));
  color: var(--color-neutral-0);
  box-shadow: 0 4px 15px rgba(168, 85, 247, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--color-primary-700), var(--color-primary-600));
  box-shadow: 0 8px 25px rgba(168, 85, 247, 0.4);
  transform: translateY(-2px);
}

.btn-secondary {
  background: var(--color-neutral-0);
  color: var(--color-neutral-700);
  border: 2px solid var(--color-neutral-200);
}

.btn-secondary:hover {
  background: var(--color-neutral-50);
  border-color: var(--color-primary-300);
  color: var(--color-primary-700);
}

.btn-ghost {
  background: transparent;
  color: var(--color-neutral-600);
  border: 1px solid var(--color-neutral-200);
}

.btn-ghost:hover {
  background: var(--color-neutral-50);
  color: var(--color-neutral-800);
}

/* ===== LAYOUT SYSTEM ===== */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.app-layout {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
}

.app-main {
  flex: 1;
  padding: var(--space-xl) 0;
}

.app-footer {
  margin-top: auto;
  padding: var(--space-xl) 0;
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border-top: 1px solid var(--glass-border);
}

/* ===== GRID SYSTEM ===== */
.grid {
  display: grid;
  gap: var(--space-lg);
}

.grid-auto {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

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

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

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

/* ===== RESPONSIVE BREAKPOINTS ===== */
@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 var(--space-sm);
  }
  
  .product-image {
    height: 200px;
  }
  
  .product-content {
    padding: var(--space-md);
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1025px) {
  .grid-4 {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1280px) {
  .grid-4 {
    grid-template-columns: repeat(4, 1fr);
  }
}

/* ===== NAVIGATION COMPONENT ===== */
.nav-primary {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  padding: var(--space-md) 0;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.nav-link {
  color: var(--color-neutral-700);
  text-decoration: none;
  font-weight: 500;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary-600);
  background: var(--color-primary-50);
}

.nav-link::after {
    content: '';
    position: absolute;
  bottom: -2px;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--color-primary-500);
  transition: all var(--transition-normal);
  transform: translateX(-50%);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 80%;
}

/* ===== SEARCH COMPONENT ===== */
.search-container {
  position: relative;
  max-width: 500px;
  margin: 0 auto;
}

.search-input {
  width: 100%;
  padding: var(--space-md) var(--space-md) var(--space-md) var(--space-3xl);
  border: 2px solid var(--color-neutral-200);
  border-radius: var(--radius-full);
  font-size: var(--text-base);
  background: var(--color-neutral-0);
  transition: all var(--transition-normal);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary-400);
  box-shadow: 0 0 0 3px rgba(168, 85, 247, 0.1);
}

.search-icon {
  position: absolute;
  left: var(--space-md);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-neutral-400);
  pointer-events: none;
}

/* ===== FILTER COMPONENT ===== */
.filter-group {
  background: var(--color-neutral-0);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
  border: 1px solid var(--color-neutral-100);
}

.filter-title {
  font-size: var(--text-lg);
    font-weight: 600;
  color: var(--color-neutral-800);
  margin-bottom: var(--space-md);
}

.filter-options {
    display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.filter-option {
  padding: var(--space-sm) var(--space-md);
  border: 2px solid var(--color-neutral-200);
  border-radius: var(--radius-full);
  background: var(--color-neutral-0);
  color: var(--color-neutral-700);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: var(--text-sm);
  font-weight: 500;
}

.filter-option:hover {
  border-color: var(--color-primary-300);
  background: var(--color-primary-50);
  color: var(--color-primary-700);
}

.filter-option.active {
  background: var(--color-primary-500);
  border-color: var(--color-primary-500);
  color: var(--color-neutral-0);
}

/* ===== MODAL COMPONENT ===== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: var(--color-neutral-0);
  border-radius: var(--radius-2xl);
  padding: var(--space-2xl);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--glass-shadow-hover);
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

/* ===== UTILITY CLASSES ===== */
.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;
}

.hidden {
  display: none !important;
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.slide-up {
  animation: slideUp 0.4s ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== LOADING STATES ===== */
.skeleton {
  background: linear-gradient(90deg, var(--color-neutral-200) 25%, var(--color-neutral-100) 50%, var(--color-neutral-200) 75%);
  background-size: 200% 100%;
  animation: skeleton-loading 1.5s infinite;
}

@keyframes skeleton-loading {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

.loading-spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--color-neutral-200);
  border-top: 2px solid var(--color-primary-500);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Focus styles for keyboard navigation */
.btn:focus,
.nav-link:focus,
.search-input:focus,
.filter-option:focus {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --glass-bg: rgba(255, 255, 255, 0.95);
    --glass-border: rgba(0, 0, 0, 0.2);
  }
  
  .glass-card {
    border-width: 2px;
  }
}