.overlay {
    height: 0%;
    width: 100%;
    position: fixed;
    z-index: 10000000;
    left: 0;
    top: 0;
    background-color: rgb(38,38,38);
    background-color: rgba(38,38,38, 0.80);
    overflow-x: hidden;
    transition: 0.5s;
}


.overlay-content {

    position: absolute;
    top: 50%;
    left: 50%;
    font-size: 50px;
    color: white;
    transform: translate(-50%,-50%);
    -ms-transform: translate(-50%,-50%);

}


.overlay a {
    padding: 8px;
    text-decoration: none;
    font-size: 36px;
    color: #D9D9D9;
    display: block;
    transition: 0.3s;
}

.overlay a:hover, .overlay a:focus {
    color: #f1f1f1;
}

.overlay .closebtn {
    position: absolute;
    top: 0;
    right: 45px;
    font-size: 100px;
}


@media screen and (max-height: 450px) {
    .overlay a {font-size: 20px}
    .overlay .closebtn {
        font-size: 40px;
        top: 15px;
        right: 35px;
    }
    .overlay-content {

        position: relative;
        padding: 20px;

        top: unset;
        left: unset;

        transform: unset;
        -ms-transform: unset;
    }
}


@media screen and (max-width: 600px) {
    .overlay a {font-size: 20px}
    .overlay .closebtn {
        font-size: 100px;
        top: -60px;
        right: 25px;
    }

    .overlay-content {

        position: relative;
        padding: 20px;

    }
}