* {box-sizing: border-box;}

.containerhover {
  position: relative;

}

.imagehover {
  display: block;
 
}

.overlayhover {
  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;
  color: white;
  font-size: 20px;
  padding: 20px;
  text-align: center;
}

.containerhover:hover .overlayhover {
  opacity: 1;
}