body {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: stretch;
    align-content: flex-start;
}

#menu {
    flex: 1 0 auto;
    text-align: left;
    text-indent: 1px;
    vertical-align: top;
    display: block;
    width: 20%;
    min-width: 200px;
    max-width: 350px;
    border-right-width: 3px;
    border-right-style: double;
    /*position: absolute;*/
    /*top: 2px;*/
    /*left: 0px;*/
    height: 99%;
    height: 100vh;
}
#container {
    flex: 1 1 80%;
    text-align: left;
    text-indent: 2px;
    vertical-align: top;
    display: block;
    /*position: absolute;*/
    /*top: 0px;*/
    /*left: 20%;*/
    padding: 5px;
    width: 80%;
}