.overlay-container {
  display: flex; /* Enable flexbox for easy centering */
  justify-content: center; /* Horizontally center the square */
  align-items: center; /* Vertically align the square (optional) */
  width: 100%;
}

.centered-pictures {
  position: relative; /* Create a positioning context for the images */
}

.overlay-pics {
  position: absolute; /* Absolute positioning within the square */
  top: 0px;
  left: 0px;
}

.overlay-pics:nth-child(2) {
  opacity: 0;
}

.overlay-pics:nth-child(2):hover {
  opacity: 1;
}