Hintergrundfarbe keine
element {
background-color: transparent;
}
Long Finned Pilot Whale
element {
background-color: transparent;
}
div {
background: transparent
}
div {
opacity:25% ;
}
//javascript type css:
document.body.style.backgroundColor = "blue";
// or inline css:
<div style="background-color: blue;"></div>