@media only screen and (max-width: 450px) {

    button {
        display: block;
        width: 100px;
    }
    .btn_abrir{
        display: flex;
        background-color: #ffffff;
        width: 50px;
       position: absolute;
       left: 350px;
       border-color: #ffffff;
    }
    .btn_cerrar{
        width: 40px;
        height: 40px;
        display: block;
        position: relative;
        left: 350px;
        background-color: rgb(26, 204, 224);
       border-color: transparent;
    }
    .nav {
        display: none;
    }
    #hm_element1,
#hm_element2,
#hm_element3,
#hm_element4
{
font-size: 16px;
}
}