.upload-zone {
  position: relative;
  background: var(--color-bg-primary);
  border: 2px dashed var(--color-border);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-8);
  margin-bottom: var(--spacing-6);
  transition: all var(--transition-normal);
  overflow: hidden;
  cursor: pointer;
}
.upload-zone:hover {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
}
/* Gradient Overlay */
.upload-zone::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg,
      var(--color-primary-light) 0%,
      transparent 100%);
  opacity: 0;
  transition: opacity var(--transition-normal);
}
/* Drag States */
.upload-zone--dragover {
  border-color: var(--color-primary);
  transform: scale(1.01);
  box-shadow: var(--shadow-lg);
}
.upload-zone--dragover::before {
  opacity: 0.1;
}
/* Content */
.upload-zone__content {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-4);
  text-align: center;
  z-index: 1;
}
.upload-zone__icon {
  font-size: var(--font-size-4xl);
  color: var(--color-primary);
  transition: transform var(--transition-normal);
}
.upload-zone:hover .upload-zone__icon,
.upload-zone--dragover .upload-zone__icon {
  transform: translateY(-5px);
}
.upload-zone__title {
  font-size: var(--font-size-xl);
  font-weight: 500;
  color: var(--color-text-primary);
  margin: 0;
}
.upload-zone__subtitle {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  max-width: 400px;
  margin: 0 auto;
}
.upload-zone__input {
  display: none;
}
/* States */
.upload-zone--loading {
  pointer-events: none;
  opacity: 0.7;
}
.upload-zone--loading .upload-zone__icon {
  animation: bounce 1s infinite;
}
.upload-zone--error {
  border-color: var(--color-danger);
}
.upload-zone--error .upload-zone__icon {
  color: var(--color-danger);
}
/* Success Indicator */
.upload-success {
  position: absolute;
  top: var(--spacing-4);
  right: var(--spacing-4);
  background: var(--color-success);
  color: var(--color-text-inverse);
  padding: var(--spacing-2) var(--spacing-4);
  border-radius: var(--border-radius-full);
  font-size: var(--font-size-sm);
  opacity: 0;
  transform: translateX(20px);
  transition: all var(--transition-normal);
}
.upload-zone--success .upload-success {
  opacity: 1;
  transform: translateX(0);
}
/* Dark Mode */
[data-theme="dark"] {
  .upload-zone {
    background: var(--color-bg-primary);
  }
  .upload-zone:hover {
    background: var(--color-bg-tertiary);
  }
  .upload-zone::before {
    background: linear-gradient(135deg,
        var(--color-primary-dark) 0%,
        transparent 100%);
  }
  .upload-success {
    background: var(--color-success);
  }
}
/* Animations */
@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}
/* Mobile Responsive */
@media (max-width: 640px) {
  .upload-zone {
    padding: var(--spacing-4);
  }
  .upload-zone__icon {
    font-size: var(--font-size-3xl);
  }
  .upload-zone__title {
    font-size: var(--font-size-lg);
  }
}