.map-responsive{
    overflow:hidden;
    padding-bottom:56.25%;
    position:relative;
    height:0;
}
.map-responsive iframe{
    left:0;
    top:0;
    height:100%;
    width:100%;
    position:absolute;
}
.gallery{
    margin: 10px 50px;
}
.gallery img{
    width: 100px;
    padding: 5px;
    filter: grayscale(40%);
    transition: 1s;
}
.gallery img:hover{
    filter: grayscale(0);
}