.grid_holder {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  width: 100%;
}

.grid_cell {
  width: 12.5%;
  padding-bottom: 12.5%; /* Same as width, sets height */
  position: relative;

  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;

  transition: opacity .5s ease-in-out;
  -moz-transition: opacity .5s ease-in-out;
  -webkit-transition: opacity .5s ease-in-out;
}

.grid_cell:hover, .sq1:hover, .sq2:hover, .sq3:hover{
  opacity: .50;
}
.sq1{background-image: url('images/steps/img_001.jpg');}
.sq2{background-image: url('images/steps/img_002.jpg');}
.sq3{background-image: url('images/steps/img_003.jpg');}
.sq4{background-image: url('images/steps/img_004.jpg');}
.sq5{background-image: url('images/steps/img_005.jpg');}
.sq6{background-image: url('images/steps/img_006.jpg');}
.sq7{background-image: url('images/steps/img_007.jpg');}
.sq8{background-image: url('images/steps/img_008.jpg');}

.sq9{background-image: url('images/steps/img_009.jpg');}
.sq10{background-image: url('images/steps/img_010.jpg');}
.sq11{background-image: url('images/steps/img_011.jpg');}
.sq12{background-image: url('images/steps/img_012.jpg');}
.sq13{background-image: url('images/steps/img_013.jpg');}
.sq14{background-image: url('images/steps/img_014.jpg');}
.sq15{background-image: url('images/steps/img_015.jpg');}
.sq16{background-image: url('images/steps/img_016.jpg');}

.sq17{background-image: url('images/steps/img_017.jpg');}
.sq18{background-image: url('images/steps/img_018.jpg');}
.sq19{background-image: url('images/steps/img_019.jpg');}
.sq20{background-image: url('images/steps/img_020.jpg');}
.sq21{background-image: url('images/steps/img_021.jpg');}
.sq22{background-image: url('images/steps/img_022.jpg');}
.sq23{background-image: url('images/steps/img_023.jpg');}
.sq24{background-image: url('images/steps/img_024.jpg');}

.sq25{background-image: url('images/steps/img_025.jpg');}
.sq26{background-image: url('images/steps/img_026.jpg');}
.sq27{background-image: url('images/steps/img_027.jpg');}
.sq28{background-image: url('images/steps/img_028.jpg');}
.sq29{background-image: url('images/steps/img_029.jpg');}
.sq30{background-image: url('images/steps/img_030.jpg');}
.sq31{background-image: url('images/steps/img_031.jpg');}
.sq32{background-image: url('images/steps/img_032.jpg');}
.sq0{background-image: url('images/grid_two/500x500_00.png');}
.sq1{background-image: url('images/grid_two/500x500_01.png');}
.sq2{background-image: url('images/grid_two/500x500_02.png');}
.sq3{background-image: url('images/grid_two/500x500_03.png');}
.sq4{background-image: url('images/grid_two/500x500_04.png');}
.sq5{background-image: url('images/grid_two/500x500_05.png');}
.sq6{background-image: url('images/grid_two/500x500_06.png');}
.sq7{background-image: url('images/grid_two/500x500_07.png');}
.sq8{background-image: url('images/grid_two/500x500_08.png');}
.sq9{background-image: url('images/grid_two/500x500_09.png');}
.sq10{background-image: url('images/grid_two/500x500_10.png');}
.sq11{background-image: url('images/grid_two/500x500_11.png');}
.sq12{background-image: url('images/grid_two/500x500_12.png');}
.sq13{background-image: url('images/grid_two/500x500_13.png');}
.sq14{background-image: url('images/grid_two/500x500_14.png');}
.sq15{background-image: url('images/grid_two/500x500_15.png');}
.sq16{background-image: url('images/grid_two/500x500_16.png');}
.sq17{background-image: url('images/grid_two/500x500_17.png');}
.sq18{background-image: url('images/grid_two/500x500_18.png');}
.sq19{background-image: url('images/grid_two/500x500_19.png');}
.sq20{background-image: url('images/grid_two/500x500_20.png');}