ol.thumb-grid {
  padding: 20px;
  text-align: center;
}

ol.thumb-grid li {
  display: inline-block;
  background: #fff;
  margin: 20px 20px;
  width: 170px;
  height: 170px;
  overflow: hidden;
  border-radius: 5px;
  box-shadow: 0px 0px 5px #999;
}

img.thumb {
  height: 170px;
  width: 170px;
}

ol.thumb-grid li:hover {
  box-shadow: 0px 0px 10px #2C3E50;
}

ol.thumb-grid {
  padding: 20px;
  text-align: center;
}

ol.thumb-grid li {
  display: inline-block;
  background: #fff;
  margin: 20px 20px;
  width: 170px;
  height: 170px;
  overflow: hidden;
  border-radius: 5px;
  border: 1px solid #999;
  box-shadow: 0px 0px 5px #999;
}

img.thumb {
  height: 170px;
  width: 170px;
}

ol.thumb-grid li:hover {
  box-shadow: 2px 2px 5px #2C3E50;
}

Update thumb grid image shadow
Update thumb grid image shadow
