whalesong/examples/drag-and-drop/style.css

html {
    width: 100%;
    height: 100%;
}

body {
    width: 100%;
    height: 100%;
}

#playground {
    background-color: lightgray;
    border: 1px solid black;
    width: 70%;
    height: 70%;
    display: block;
}