/* CSS Variables for theming */
:root {
  /* Light theme (default) */
  --bg-color: #fff;
  --text-color: #000;
  --link-color: #c0c0c0;
  --link-hover-color: #000;
  --card-bg: #f5f5f5;
  --card-shadow: rgba(0, 0, 0, 0.1);
  --header-bg: #f8f9fa;
  
  /* Emoji size */
  --current-emoji-size: 150px;
  
  /* Dark theme */
  --dark-bg: #1a1a1a;
  --dark-text: #fff;
  --dark-link: #aaa;
  --dark-link-hover: #fff;
  --dark-card-bg: #2d2d2d;
  --dark-card-shadow: rgba(0, 0, 0, 0.3);
  --dark-header-bg: #2d2d2d;
  
  /* Common */
  --transition-speed: 0.3s;
  --border-radius: 8px;
  --touch-target-gap: 16px;
}

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

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

/* Header */
.header {
  background-color: var(--header-bg);
  padding: 2rem 1rem;
  text-align: center;
  margin-bottom: 2rem;
  box-shadow: 0 2px 4px var(--card-shadow);
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--text-color);
}

.subtitle {
  font-size: 1.2rem;
  color: var(--link-color);
}

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--bg-color);
  color: var(--text-color);
  padding: 8px;
  z-index: 100;
  transition: top var(--transition-speed);
}

.skip-link:focus {
  top: 0;
}

/* Controls */
.controls {
  background-color: var(--header-bg);
  padding: 1rem;
  margin-bottom: 1rem;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px var(--card-shadow);
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.control-group label {
  font-size: 0.9rem;
  color: var(--text-color);
}

.control-select {
  padding: 0.5rem;
  border-radius: var(--border-radius);
  border: 1px solid var(--link-color);
  background-color: var(--bg-color);
  color: var(--text-color);
  cursor: pointer;
  transition: border-color var(--transition-speed);
}

.control-select:hover {
  border-color: var(--link-hover-color);
}

.control-select:focus {
  outline: none;
  border-color: var(--link-hover-color);
  box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.1);
}

/* Container and grid layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px;
  width: 100%;
}

.emoji-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(var(--current-emoji-size), 1fr));
  gap: var(--touch-target-gap);
  padding: 16px 0;
  justify-items: center;
  width: 100%;
}

/* Emoji styles */
img {
  width: var(--current-emoji-size);
  height: var(--current-emoji-size);
  border-radius: var(--border-radius);
  object-fit: contain;
  cursor: pointer;
  transition: transform var(--transition-speed) ease, opacity var(--transition-speed);
  background-color: var(--card-bg);
  box-shadow: 0 2px 4px var(--card-shadow);
  position: relative;
  padding: 8px;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

img:hover, img:active {
  transform: scale(1.2);
}

img:focus {
  outline: 2px solid var(--link-color);
  outline-offset: 2px;
}

img.loading {
  opacity: 0.7;
  pointer-events: none;
}

/* Loading indicator */
.loading-indicator {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 24px;
  height: 24px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 1s ease-in-out infinite;
  display: none;
}

img.loading .loading-indicator {
  display: block;
}

@keyframes spin {
  to { transform: translate(-50%, -50%) rotate(360deg); }
}

/* Copy feedback */
.copy-feedback {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background-color: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 10px 20px;
  border-radius: var(--border-radius);
  display: none;
  z-index: 1000;
  transition: opacity var(--transition-speed);
  backdrop-filter: blur(5px);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.copy-feedback.error {
  background-color: rgba(255, 0, 0, 0.8);
}

.copy-feedback.success {
  background-color: rgba(0, 128, 0, 0.8);
}

/* Footer */
.footer {
  text-align: center;
  padding: 20px;
  font-size: 0.9em;
  color: var(--text-color);
  margin-top: 2rem;
}

.footer p {
  margin: 0.5rem 0;
}

.footer-note {
  color: var(--link-color);
  font-size: 0.8em;
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: var(--dark-bg);
    --text-color: var(--dark-text);
    --link-color: var(--dark-link);
    --link-hover-color: var(--dark-link-hover);
    --card-bg: var(--dark-card-bg);
    --card-shadow: var(--dark-card-shadow);
    --header-bg: var(--dark-header-bg);
  }
}

/* Responsive design */
@media (max-width: 1024px) {
  .emoji-grid {
    grid-template-columns: repeat(auto-fill, minmax(var(--current-emoji-size), 1fr));
    gap: var(--touch-target-gap);
  }
  
  .container {
    padding: 16px;
  }
}

@media (max-width: 768px) {
  .emoji-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  img {
    width: calc((100vw - 48px) / 2);
    height: calc((100vw - 48px) / 2);
  }
  
  .header {
    padding: 16px;
  }
  
  .header h1 {
    font-size: 1.75rem;
  }
  
  .subtitle {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .emoji-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  img {
    width: calc((100vw - 32px) / 2);
    height: calc((100vw - 32px) / 2);
  }
  
  .container {
    padding: 12px;
  }
  
  .header {
    padding: 12px;
    margin-bottom: 16px;
  }
  
  .header h1 {
    font-size: 1.5rem;
    margin-bottom: 8px;
  }
  
  .subtitle {
    font-size: 0.9rem;
  }
  
  .copy-feedback {
    font-size: 0.9rem;
    padding: 12px 20px;
    bottom: 16px;
    left: 16px;
    right: 16px;
    transform: none;
    text-align: center;
  }
}

/* Touch device optimizations */
@media (hover: none) {
  img:hover {
    transform: none;
  }
  
  img:active {
    transform: scale(1.1);
  }
  
  .emoji-grid {
    gap: var(--touch-target-gap);
  }
}