* {
  box-sizing: border-box;
}

body {
    margin: 0 auto;
    max-width: 1000px;
}

header, main, footer {
    border: solid 2px coral;
    padding: 10px;
}

header {
    height: 20vh;
}

main {
    min-height: 70vh;
}

footer {
    height: 10vh;
}

@media screen and (max-width: 800px) {
    header {
        /* display: none; */
        background-color: #444444;
        color: white;
    }

    main {
        /* height: 90vh; */
        background-color: #eeeeee;
    }

    footer {
        background-color: coral;
        color: white;
    }
}