body {
    display: grid;
    grid-template-areas:
    "header nav"
    "main main"
    "footer footer";
    margin: 0;
    padding: 0;
    grid-template-columns: 100px auto;
    grid-template-rows: 42px auto;
}

header {
    grid-area: header;
    line-height: 42px;
}

nav {
    grid-area: nav;
    line-height: 42px;
    text-align: right;
}

#main {
    grid-area: main;
}

footer {
    grid-area: footer;
    height: 100px;
    line-height: 100px;
}

.header-toolbar {
    height: 42px;
    padding: 6px;
    box-sizing: border-box;
    display: flex;
}

.header-toolbar > * {
    margin-left: 4px;
}

.header-toolbar > *:first-child {
    margin-left: 0;
}