body {
    height: 100vh;
    margin: 0;
    padding: 20px;

    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: 60px 1fr;
    grid-template-areas:
        "header"
        "main";
}

.header {
    grid-area: header;
}
.main {
    grid-area: main;

    display: grid;
    grid-template-columns: 1fr;
    grid-template-rows: 1fr 50px;
    grid-template-areas: 
        "graph"
        "buttons";
}

.buttons {
    grid-area: buttons;
}
.graph {
    grid-area: graph;
}