html,
body {
    width: 100%;
    height: 100%;
}

*,
*:before,
*:after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    margin: 0;
}

main {
    display: flex;
    justify-content: center;
    height: 100%;
    width: 100%;
}