output-frame {
    width: 100%;
    height: 100%;
    display: block;
    background-color: #f0f0f0;
}

output-frame > iframe {
    position: relative;
    width: 100%;
    height: 100%;
    border: none;
}



@media (prefers-color-scheme: dark) {
    output-frame {
        background-color: #272727;
    }
}