libcosmic/examples/dock/style.css

row:hover {
    transition: 100ms;
    background: #888888;
    border-radius: 12px;
}
row {
    background: #333333;
    border-radius: 12px;
}
listview {
    border-radius: 12px;
    background: #333333;
}
window {
    background: rgba(50,50,50,0.0);
}
box#dock-container {
    border-radius: 12px;
    background: #333333;
}