.row {
  display: flex;
  flex-wrap: wrap;
  padding: 0 4px;
}

/* Create four equal columns that sits next to each other */
.column {
  flex: 25%;
  max-width: 25%;
  padding: 0 4px;
}

.column img {
  margin-top: 8px;
  vertical-align: middle;
  width: 100%;
}

/* Responsive layout - makes a two column-layout instead of four columns */
@media screen and (max-width: 800px) {
  .column {
    flex: 50%;
    max-width: 50%;
  }
}

/* Responsive layout - makes the two columns stack on top of each other instead of next to each other */
@media screen and (max-width: 600px) {
  .column {
    flex: 100%;
    max-width: 100%;
  }
}

* {box-sizing: border-box}

/* Container needed to position the overlay. Adjust the width as needed */
.container-grid {
  position: relative;
  width: 100%;
  
}

/* Make the image to responsive */
.image {
  display: block;
  width: 100%;
  height: auto;
}

/* The overlay effect - lays on top of the container and over the image */
.overlay {
  position: absolute;
  bottom: 0;
  background: rgb(0, 0, 0);
  background: rgba(0, 0, 0, 0.5); /* Black see-through */
  color: #f1f1f1;
  width: 100%;
  transition: .5s ease;
  opacity:0;
  font-size: 20px;
  padding: 20px;
  text-align: center;
}
.overlay a {
	color: white;
}

/* When you mouse over the container, fade in the overlay title */
.container-grid:hover .overlay {
  opacity: 1;
}