style.css

.bg-checkerboard {
    background-image: 
        linear-gradient(45deg, #555 25%, transparent 25%),
        linear-gradient(-45deg, #555 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #555 75%),
        linear-gradient(-45deg, transparent 75%, #555 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

#drop-area.highlight {
    background-color: rgba(249, 115, 22, 0.1);
    border-color: rgba(249, 115, 22, 0.8);
}

#original-image, #result-image {
    object-fit: contain;
}