/* CSS Document Portfolio Style */
.img-box {
  position: relative;
  overflow: hidden;
}

.img-box img {
  width: 100%;
  display: block;
}

.caption {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-size: 18px;
  opacity: 0;
  transition: opacity 0.3s ease;
  padding: 15px;
}

.img-box:hover .caption {
  opacity: 1;
}