* {
    box-sizing: border-box;
}

body {
    background-color: aliceblue;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

div.stone {
    color: gray;
}

div.tree {
    color: forestgreen;
}

div.flower {
    color: orchid;
}
main {
    display: flex;
    justify-content: center;
}
section {
   
    display: flex;
    justify-content: center;
    flex-direction: column;
    margin: 1em;
}

/*
@media screen and (max-width: 480px) {
    body {
        height: auto;
        flex-direction: row;
    }
    main {
        flex-direction: column;
    }
}/*