/* ============================================
   MOBILE OPTIMIZATIONS - High Impact
   ============================================
   Implements touch-friendly UI and responsive design
   Expected impact: +30% mobile engagement
   Based on WHATS_NEXT_PRIORITIES #1
*/

/* ============================================
   1. BASE MOBILE STYLES
   ============================================ */

/* Prevent text size adjustment on iOS */
html {
  -webkit-text-size-adjust: 100%;
  -moz-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
}

/* Touch-friendly tap targets (minimum 44x44px) */
button, .btn, a.btn, input[type="submit"], input[type="button"] {
  min-width: 44px;
  min-height: 44px;
  padding: 12px 20px;
  font-size: 16px; /* Prevents zoom on iOS */
  cursor: pointer;
}

/* Touch-friendly links */
a {
  min-height: 32px;
  display: inline-flex;
  align-items: center;
}

/* Prevent double-tap zoom */
a, button {
  touch-action: manipulation;
}

/* ============================================
   2. SHARE BUTTONS (VIRAL FEATURE)
   ============================================ */

.share-bar {
  display: flex;
  gap: 8px;
  margin: 16px 0;
  flex-wrap: wrap;
  justify-content: center;
}

.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border: 2px solid #ddd;
  border-radius: 8px;
  background: white;
  color: #333;
  font-size: 14px;
  font-weight: 600;
  transition: all 0.2s ease;
  cursor: pointer;
  min-width: 44px;
  min-height: 44px;
}

.share-btn:hover, .share-btn:active {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.share-btn.whatsapp {
  border-color: #25D366;
  color: #25D366;
}

.share-btn.whatsapp:hover {
  background: #25D366;
  color: white;
}

.share-btn.twitter {
  border-color: #1DA1F2;
  color: #1DA1F2;
}

.share-btn.twitter:hover {
  background: #1DA1F2;
  color: white;
}

.share-btn.copy {
  border-color: #6c757d;
  color: #6c757d;
}

.share-btn.copy:hover {
  background: #6c757d;
  color: white;
}

/* Copy success toast */
.copy-toast {
  position: fixed;
  bottom: -100px;
  left: 50%;
  transform: translateX(-50%);
  background: #28a745;
  color: white;
  padding: 16px 24px;
  border-radius: 8px;
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
  transition: bottom 0.3s ease;
  z-index: 10000;
}

.copy-toast.show {
  bottom: 24px;
}

/* ============================================
   3. RESPONSIVE IMAGES
   ============================================ */

.meme-image, .meme-card img, img {
  width: 100%;
  height: auto;
  max-width: 100%;
  display: block;
}

/* Progressive image loading */
img[data-src] {
  filter: blur(10px);
  transition: filter 0.3s ease;
}

img[data-src].loaded {
  filter: blur(0);
}

/* Lazy loading placeholder */
img[loading="lazy"] {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: loading 1.5s infinite;
}

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

/* ============================================
   4. MOBILE BREAKPOINTS
   ============================================ */

@media (max-width: 768px) {
  /* Typography adjustments */
  body {
    font-size: 16px;
    line-height: 1.6;
  }
  
  h1 {
    font-size: 24px;
  }
  
  h2 {
    font-size: 20px;
  }
  
  h3 {
    font-size: 18px;
  }
  
  /* Container spacing */
  .container {
    padding: 16px;
  }
  
  /* Navigation */
  nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
  }
  
  nav a {
    padding: 10px 16px;
    font-size: 14px;
  }
  
  /* Meme grid responsive */
  .meme-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  /* Meme cards */
  .meme-card {
    margin-bottom: 20px;
  }
  
  /* Form inputs */
  input[type="text"], 
  input[type="email"], 
  input[type="password"],
  textarea {
    font-size: 16px; /* Prevents zoom on iOS */
    padding: 12px;
    width: 100%;
    box-sizing: border-box;
  }
  
  /* Share bar mobile layout */
  .share-bar {
    flex-direction: column;
  }
  
  .share-btn {
    width: 100%;
    justify-content: center;
  }
  
  /* Stats and meta info */
  .meme-meta {
    flex-direction: column;
    gap: 8px;
  }
  
  /* Actions bar */
  .meme-actions {
    flex-direction: column;
    gap: 12px;
  }
  
  .meme-actions .btn {
    width: 100%;
    text-align: center;
  }
}

/* Small phones */
@media (max-width: 375px) {
  .container {
    padding: 12px;
  }
  
  .share-btn {
    font-size: 13px;
    padding: 10px 14px;
  }
  
  h1 {
    font-size: 20px;
  }
}

/* Tablet landscape */
@media (min-width: 769px) and (max-width: 1024px) {
  .meme-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
}

/* Desktop */
@media (min-width: 1025px) {
  .meme-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
  }
  
  .share-bar {
    justify-content: flex-start;
  }
}

/* ============================================
   5. PERFORMANCE OPTIMIZATIONS
   ============================================ */

/* Reduce animations on low-end devices */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  .share-btn {
    background: #2d2d2d;
    border-color: #444;
    color: #fff;
  }
  
  .share-btn:hover {
    background: #3d3d3d;
  }
}

/* High DPI displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  img {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
  }
}

/* ============================================
   6. SWIPE GESTURES (FUTURE ENHANCEMENT)
   ============================================ */

.swipe-container {
  touch-action: pan-y;
  user-select: none;
}

.swipe-indicator {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.7);
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 12px;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
}

.swipe-indicator.show {
  opacity: 1;
}

/* ============================================
   7. ACCESSIBILITY
   ============================================ */

/* Focus states for keyboard navigation */
button:focus, a:focus, input:focus {
  outline: 2px solid #4A90E2;
  outline-offset: 2px;
}

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

/* Skip to content link */
.skip-to-content {
  position: absolute;
  top: -40px;
  left: 0;
  background: #000;
  color: #fff;
  padding: 8px;
  z-index: 100;
}

.skip-to-content:focus {
  top: 0;
}