.main__container h3 {
    margin: 10px 0 20px;
}

.gallery-holder {
    -webkit-column-count: 3;    
    -webkit-column-gap: 5px;    
    -moz-column-count: 3;
    -moz-column-gap: 5px;
    column-count: 3;    
    column-gap: 5px; 
}

.gallery-holder-item {
    width:100%;
    box-sizing:border-box;
    padding: 10px;
}

.gallery-holder-item img {
    width: 100%;
    height: auto;
}