body {
    overflow: hidden;
}
#panel {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    padding: 4px;
    background: rgb(240, 240, 240);
    overflow: auto;
}
.margin {
    float: left;
    margin: 4px;
}
