a:link{
    transition: color 0.5s;
}

img{
    opacity: 0.25;
    transition: opacity 500ms;
    border-radius: 10%;
    align-items: center;
}

img:hover{
    opacity: 1;
}

/* challenge */

figure{
    position: relative;
}

figure img{
    position: absolute;
    top: 0;
    left: 0;
    opacity: 1;
}

figure .vidible{
    opacity: 1;
}

figure .hidden{
    opacity: 0;
}

figure:hover .hidden{
    opacity: 1;
}

p{
    color: #7fb069;
}