.gallery {
    height: 100%;
    margin-top: 110px;
    padding-top: 50px;
    padding-bottom: 50px;
    color: #000033;
}

.gallery_heading1 {
    font-weight: 700;
    line-height: 119%;
}
.photo{
    margin: 10px 50px;
}

.photo img{
    transition: 1s;
    padding: 15px;
    display: block;
    width: 100%;
}

.photo img:hover{
    filter: brightness(40%);
}