body {
    margin: 0;
    max-height: 100vh;
    max-width: 100vw;
    overflow: auto;
}
main {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    min-height: 100vh;
    padding: 16px;
}

* {
    position: relative;
    box-sizing: border-box;
}