body {
    margin: 0;
    display: flex;
    flex-direction: row;
    justify-content: center;
    background: url('background.jpg');
    background-size: cover;
    background-position: center;
}

#phone {
    width: max(50vh, 400px);
    height: calc(100vh);

    display: flex;
    flex-direction: column;
}

#content {
    display: inline-block;
    width: 100%;
    height: 100%;
    border: none;
}

@media only screen and (max-width: 600px) {
    #phone {
        width: 100vw;
        margin: 0;
    }
    #content {
        border: none;
    }
    .phone-item {
        display: none !important;
    }
    .phone-side {
        width: 0;
    }
}