Here is a special snippet to change your Audio feature.

Just like this:

To do that, just add the following css in the “advanced customization” section of your editor:

.audio-list .list {
margin: 0;
}
.audio-list .item.item-custom.text-center.ng-binding {
box-shadow: 0 1px 4px rgba(119,119,119,1);
}
.audio-list .list.col-34.col-offset-10 {
max-width: 140px;
margin: 3%;
box-shadow: 0 1px 4px rgba(119,119,119,1);
}
.audio-list .item.item-custom {
border: none;
}
.audio-list .list .item.item-image img {
border-bottom: 2px solid #DDD;
}

Information:

box-shadow – it’s the gradient

max-width – it’s the width of yours boxes

Don’t forget, the readability is very important.