@keyframes opacityAni {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}

.portfolio-container {
    padding-top: 130px;
    padding-bottom: 130px;
}

section.portfolio-container .title {
    margin-bottom: 30px;
}

.portfolio-container .portfolio-list {
    margin-top: 50px;
    display: flex;
    flex-wrap: wrap;
}

.portfolio-container .portfolio-list .item{
    position: relative;
    overflow: hidden;
    width: calc(100% / 3 - 10px);
    padding-bottom: calc(100% / 3 - 10px);
    background-position: center !important;
    background-size: cover !important;
}

.portfolio-container .portfolio-list .item:nth-child(n+2){
    margin-left: 10px;
}

.portfolio-container .portfolio-list .item:nth-child(n+4){
    margin-top: 10px;
}

.portfolio-container .portfolio-list .item:nth-child(3n+1){
    margin-left: unset;
}

.portfolio-container .portfolio-list .item .thumbnail {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    transform: translate(50%,50%);
    z-index: -1;
}

.portfolio-container .portfolio-list .item .thumbnail img{
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform: translate(-50%, -50%);
    object-fit: cover;
}

.portfolio-container .portfolio-list .item .desc:before{
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background-color: #000;
    opacity: 0.6;
    z-index: -1;
}

.portfolio-container .portfolio-list .item .desc{
    position: absolute;
    width: 100%;
    height: 100%;
    display: none;
}

.portfolio-container .portfolio-list .item:hover .desc{
    display: block;
    transform-origin: top center;
    animation: opacityAni 0.5s;
}

.portfolio-container .portfolio-list .item .desc h2{
    position: absolute;
    bottom: 30%;
    left: 10%;
    color: #fff;
    margin-bottom: unset;
}

.portfolio-container .portfolio-list .item .desc h4{
    position: absolute;
    bottom: 25%;
    left: 10%;
    color: #fff;
    opacity: 0.7;
    margin-bottom: unset;
}

.portfolio-container .portfolio-list .item .desc .btn-more{
    position: absolute;
    bottom: 10%;
    left: 10%;
    color: #fff;
}

.portfolio-container .portfolio-list .item .desc .btn-more img{
    margin-right: 5px;
}

@media screen and (max-width: 767px) {
    .portfolio-container .portfolio-list .item{
        width: 100%;
        padding-bottom: 100%;
    }
    .portfolio-container .portfolio-list .item:nth-child(n+2){
        margin-left: unset;
        margin-top: 10px;
    }
}