*:before,
*:after {
  box-sizing: border-box;
}
.col_3 {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  /* padding: 5px; */
}
.col_3 > div {
    position:relative;
  width: 33%;
  margin: auto;
  background-color: beige;
}
.col_3 > div > img {
    max-width: 100%;
    height: auto;
    width: auto;
}
.col_3 > div > a {
    position: absolute;
    top: 0;
    left: 0;
    height:100%;
    width: 100%;
}

@media screen and (max-width: 960px) {
  .col_3 > div {
    width: 50%;
  }
}
@media screen and (max-width: 480px) {
  .col_3 > div {
    width: 100%;
  }
}