a:link{
    transition: color 1s;
}

img{
    opacity: 0.25;
    transition: opacity 500ms;
    border-radius: 15px;
    width: 350px;
    margin-left: 5px;
    margin-right: 20px;
}

img:hover{
    opacity: 1;

}

figure img{
    position: absolute;
    top: 0px;
    left: 0px;
     
}

figure{
    position: relative;
}

figure .visible{
    opacity: 1;
}

figure .hidden{
    opacity: 0;
}

figure:hover .hidden{
    opacity: 1;
}

figure:hover .visible{
    opacity: 0;
}