.upload-section {
    border: 2px dashed #ccc;
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    margin-bottom: 2rem;
    transition: border-color 0.3s;
    cursor: pointer;
}

.upload-section.drag-over {
    border-color: #4CAF50;
    background: rgba(76, 175, 80, 0.1);
}

.upload-section i {
    font-size: 48px;
    color: #666;
    margin-bottom: 1rem;
}

.upload-section p {
    color: #666;
    margin: 0;
}

.size-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.size-option {
    background: #f5f5f5;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
}

.size-option:hover {
    background: #e9e9e9;
}

.size-option.selected {
    background: #4CAF50;
    color: white;
    border-color: #4CAF50;
}

.preview-section {
    background: #f9f9f9;
    border-radius: 8px;
    padding: 2rem;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.preview-item {
    background: white;
    border: 1px solid #eee;
    border-radius: 6px;
    padding: 1rem;
    text-align: center;
}

.preview-item img {
    max-width: 100%;
    height: auto;
    margin-bottom: 0.5rem;
}

.preview-item p {
    font-size: 0.875rem;
    color: #666;
    margin: 0;
}

.generate-btn {
    background: #4CAF50;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 1rem 2rem;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s;
    width: 100%;
    margin-top: 1.5rem;
}

.generate-btn:hover {
    background: #45a049;
}

.loading {
    position: relative;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.error-message {
    color: #f44336;
    margin-top: 1rem;
    text-align: center;
}

.success-message {
    color: #4CAF50;
    margin-top: 1rem;
    text-align: center;
}