/* ====================================
   Responsive Styles
   平板和移动端适配
   ==================================== */

/* ====================================
   Tablet (768px - 1024px)
   ==================================== */

@media (max-width: 1024px) {
  /* Grid Adjustments */
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .process-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-2xl);
  }
  
  /* Section Spacing */
  .section {
    padding: var(--spacing-3xl) 0;
  }
  
  .section-lg {
    padding: var(--spacing-3xl) 0;
  }
}

/* ====================================
   Mobile (< 768px)
   ==================================== */

@media (max-width: 768px) {
  /* Navigation */
  .menu-toggle {
    display: flex;
  }
  
  .nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--bg-white);
    flex-direction: column;
    padding: var(--spacing-xl);
    gap: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
  }
  
  .nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-link {
    width: 100%;
    padding: var(--spacing-md);
    text-align: center;
  }
  
  /* Grid System */
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .stats-grid,
  .process-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }
  
  /* Section Spacing */
  .section {
    padding: var(--spacing-2xl) 0;
  }
  
  .section-sm {
    padding: var(--spacing-xl) 0;
  }
  
  .section-lg {
    padding: var(--spacing-2xl) 0;
  }
  
  /* Container */
  .container {
    padding: 0 var(--spacing-md);
  }
  
  /* Typography */
  h1 {
    font-size: var(--font-size-3xl);
  }
  
  h2 {
    font-size: var(--font-size-2xl);
  }
  
  h3 {
    font-size: var(--font-size-xl);
  }
  
  /* Buttons */
  .btn {
    width: 100%;
    justify-content: center;
  }
  
  .btn-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  /* Cards */
  .card-content {
    padding: var(--spacing-lg);
  }
  
  .feature-card {
    padding: var(--spacing-xl);
  }
  
  /* Timeline */
  .timeline::before {
    left: 20px;
  }
  
  .timeline-content {
    width: calc(100% - 50px);
    margin-left: 50px !important;
  }
  
  .timeline-dot {
    left: 20px;
  }
  
  /* Stats */
  .stat-number {
    font-size: var(--font-size-3xl);
  }
  
  /* Process Steps */
  .process-step {
    margin-bottom: var(--spacing-2xl);
  }
  
  /* Section Header */
  .section-header {
    margin-bottom: var(--spacing-2xl);
  }
  
  /* Hero Section */
  .hero-content {
    padding: var(--spacing-2xl) 0;
  }
  
  .hero-title {
    font-size: var(--font-size-3xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-base);
  }
  
  /* Footer */
  .footer {
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
  }
}

/* ====================================
   Small Mobile (< 480px)
   ==================================== */

@media (max-width: 480px) {
  :root {
    --header-height: 60px;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  h1 {
    font-size: var(--font-size-2xl);
  }
  
  h2 {
    font-size: var(--font-size-xl);
  }
  
  .section {
    padding: var(--spacing-xl) 0;
  }
  
  .btn {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-base);
  }
  
  .btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: var(--font-size-base);
  }
}

/* ====================================
   Print Styles
   ==================================== */

@media print {
  .header,
  .menu-toggle,
  .footer {
    display: none;
  }
  
  body {
    font-size: 12pt;
    color: #000;
    background: #fff;
  }
  
  .container {
    max-width: 100%;
  }
  
  a {
    color: #000;
    text-decoration: underline;
  }
}

/* ====================================
   Landscape Orientation (Mobile)
   ==================================== */

@media (max-width: 768px) and (orientation: landscape) {
  .hero-content {
    padding: var(--spacing-xl) 0;
  }
  
  .nav {
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
  }
}

/* ====================================
   Hover Capability Detection
   ==================================== */

@media (hover: hover) {
  .card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
  }
  
  .feature-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
  }
  
  .btn-primary:hover,
  .btn-white:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
  }
}

@media (hover: none) {
  /* Disable hover effects on touch devices */
  .card:hover,
  .feature-card:hover {
    transform: none;
  }
  
  .btn-primary:hover,
  .btn-white:hover {
    transform: none;
  }
}

/* ====================================
   Reduced Motion
   ==================================== */

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

/* ====================================
   High Contrast Mode
   ==================================== */

@media (prefers-contrast: high) {
  :root {
    --text-primary: #000000;
    --text-secondary: #333333;
    --border-color: #000000;
  }
  
  .btn-secondary {
    border-width: 3px;
  }
  
  .card {
    border: 2px solid var(--border-color);
  }
}

/* ====================================
   Dark Mode Support (Optional)
   ==================================== */

@media (prefers-color-scheme: dark) {
  /* Uncomment if you want to support dark mode
  :root {
    --text-primary: #F9FAFB;
    --text-secondary: #D1D5DB;
    --bg-white: #1F2937;
    --bg-light: #111827;
    --border-color: #374151;
  }
  
  .header {
    background-color: #1F2937;
  }
  
  .card,
  .feature-card {
    background-color: #1F2937;
  }
  */
}