.header {
    position: absolute;
    top: 0;
    height: 60px;
    left: 0;
    right: 0;
    text-align: center;
    background: ghostwhite;
    border-bottom: 5px solid lightsteelblue;
    box-sizing: border-box;
    padding: 0 20px;
}

.map {
    position: absolute;
    top: 60px;
    bottom: 0;
    left: 0;
    right: 20%;
}

.sidebar {
    position: absolute;
    top: 60px;
    bottom: 0;
    right: 0;
    width: 20%;
    background: ghostwhite;
    border-left: 5px solid lightsteelblue;
    box-sizing: border-box;
    padding: 0 20px;
}