#content {
    position: relative;
    max-width: 728px;
    padding: 20px 0px 50px 0px;
    left: 50%;
    transform: translateX(-50%);
}

.demo {
    border: 1px solid;
    margin-top: 10px;
    padding: 10px;
    min-height: 200px;
    box-sizing: border-box;
}

.demoGroup {
    display: inline-block;
    width: calc(50% - 2px);
    min-height: 120px;
}

ul.list {
    columns: 3;
    -webkit-columns: 3;
    -moz-columns: 3;
}