Changing transparency of the infobox

CesiumJS
1

Is there any way to adjust the transparency of the infobox background? For example, if I wanted to make it 50% transparent so you could see the map through it.

2

You can do that by adding a CSS style to your Cesium app (the outer part, not the iframe).

.cesium-infoBox {
    background: rgba(38, 38, 38, 0.5);
}