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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 2rem 1rem;
  color: #333;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 2.5rem;
  color: white;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.subtitle {
  font-size: 1.1rem;
  opacity: 0.9;
}

.controls {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

button {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.btn-primary {
  background: white;
  color: #667eea;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.3);
}

.palette-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.color-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  cursor: pointer;
}

.color-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.color-card.locked {
  border: 3px solid #ffd700;
  box-shadow: 0 0 0 2px rgba(255, 215, 0, 0.3);
}

.color-preview {
  width: 100%;
  height: 150px;
  position: relative;
}

.color-info {
  padding: 1rem;
  background: white;
}

.color-hex {
  font-family: 'Courier New', monospace;
  font-size: 1.1rem;
  font-weight: 600;
  color: #333;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lock-icon {
  font-size: 1.2rem;
  cursor: pointer;
  user-select: none;
  transition: transform 0.2s ease;
}

.lock-icon:hover {
  transform: scale(1.2);
}

.lock-icon.locked {
  color: #ffd700;
}

.copy-hint {
  font-size: 0.85rem;
  color: #666;
  margin-top: 0.25rem;
}

.info {
  text-align: center;
  background: rgba(255, 255, 255, 0.9);
  padding: 1rem;
  border-radius: 8px;
  margin-top: 2rem;
}

.info p {
  color: #555;
  font-size: 0.95rem;
}

.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0, 0, 0, 0.8);
  color: white;
  padding: 1rem 2rem;
  border-radius: 8px;
  font-weight: 600;
  z-index: 1000;
  animation: slideUp 0.3s ease;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

@media (max-width: 768px) {
  header h1 {
    font-size: 2rem;
  }

  .palette-container {
    grid-template-columns: 1fr;
  }

  .color-preview {
    height: 120px;
  }
}