.isotope-grid {
    background: transparent;
}

/* clear fix */
.isotope-grid:after {
    content: '';
    display: block;
    clear: both;
}

/* ---- .grid-item ---- */
.isotope-grid-sizer--2,
.isotope-grid-item--2 {
    width: 50%;
}
.isotope-grid-sizer--3,
.isotope-grid-item--3 {
    width: 33.333%;
}
.isotope-grid-sizer--4,
.isotope-grid-item--4 {
    width: 25%;
}

.isotope-grid-item, 
.isotope-grid-item--2, 
.isotope-grid-item--3, 
.isotope-grid-item--4 {
    float: left;
    transform:translate3d(0,0,0);
    -webkit-transform:translate3d(0,0,0);
    -moz-transform:translate3d(0,0,0);
}

.isotope-grid-item img,
.isotope-grid-item--2 img,
.isotope-grid-item--3 img,
.isotope-grid-item--4 img {
    display: block;
    max-width: 100%;
}

.isotope-image-text {
    position: absolute;
    left: 10px;
    bottom: 10px;
    text-transform: none;
    letter-spacing: 0;
    font-size: 30px;
    width: 100%;
    background-color: rgba(95, 95, 95, 0.4);
    font-weight: 900;
    text-align: right;
    padding-right: 20px;
}
.not_visible_item{
    display: none;
}
.isotope-grid[show-not-valid='false'] .is-invalid {
    display: none;
}
.isotope-grid[show-not-valid='true'] .is-invalid {
    opacity: 0.4;
}
.isotope-grid .is-selected {
    border: 2px solid green;
    background-color: lightgreen;
}
.isotope-grid .is-selected.is-invalid {
    border: 2px solid red;
    background-color: salmon;
}