.img-popup-grid {
     align-items: flex-start;
     padding: 0px;
 }

 .img-box-big-img:hover .overlayimg {
     opacity: 1;
     pointer-events: none;
 }

 .img-box-big-img .overlayimg i {
     color: #fff;
     font-size: 20px;
 }



 .close-image-big {
     position: absolute;
     top: 20px;
     right: 30px;
     color: #fff;
     font-size: 45px;
     font-weight: bold;
     cursor: pointer;
     z-index: 100000;
     /* Important */
     line-height: 1;
 }

 .close-image-big:hover {
     color: #ccc;
 }

 .image-big-popup {
     display: none;
     position: fixed;
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     background: rgba(0, 0, 0, 0.9);
     z-index: 99999;

     justify-content: center;
     align-items: center;
     flex-direction: column;
 }

 .image-big-popup img {
     max-width: 90%;
     max-height: 80%;
 }

 #imgpopupCaption {
     color: #fff;
     margin-top: 15px;
     font-size: 18px;
 }

 .close-image-big {
     position: fixed;
     /* Use fixed instead of absolute */
     top: 15px;
     right: 25px;
     color: #fff;
     font-size: 55px;
     font-weight: bold;
     cursor: pointer;
     z-index: 100000;
     line-height: 1;
 }

 .img-box-big-img {
     position: relative;
     display: inline-block;
     /* Makes the div only as big as the image */
     line-height: 0;
     /* Removes extra space below image */
 }

 .img-box-big-img img {
     display: block;
     width: 600px;
     max-width: 100%;
     height: auto;
 }

 .overlayimg {
     position: absolute;
     top: 0;
     left: 0;
     right: 0;
     bottom: 0;
     background: rgba(0, 0, 0, .45);
     display: flex;
     justify-content: center;
     align-items: center;
     opacity: 0;
     transition: .3s;
 }

 .img-box-big-img:hover .overlayimg {
     opacity: 1;
 }