html, body {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
}

header, footer {
    background-color: aqua;
    padding: 14px 10px;
}

main {
    background-color: red;
    width: 80%;
    margin: 0 auto;
}


#map {
    height: 60vh;
}

.flex {
    display: flex;
}

.flex > *[main] {
    flex: 1;
}