.item_wrapper:after {
  content: "";
  display: block;
  clear: both;
  height: 0;
}

.item {
  width: 100px;
  height: 100px;
  /*padding: 20px;*/
  float: left;
}

.popupbg {
  position: fixed;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 10;
  top: 0;
  left: 0;
  display: none;
}

.popup_wrapper {
  width: auto;
  height: auto;
  position: fixed;
  top: 50%;
  left: 50%;
  margin: -300px 0 0 -250px;
  z-index: 11;
  text-align: center;
  display: none;
}
.popup_wrapper .popup {
  position: relative;
}
.popup_wrapper .img {
  display: inline-block;
  width: auto;
  height: auto;
}

.popup_wrapper .caption {
    padding: 10px;
    font-size: 18px;
    color: #fff;
    background: rgba(0,0,0,0.5);
    width: 120px;
    position: relative;
    bottom: 50px;

}
.popup_wrapper .close_btn {
  line-height: 30px;
  position: absolute;
  left: 0;
  top: 0;
  width: 30px;
  height: 30px;
  border-radius: 15px;
    color: #000;
  background: #fff;
  margin: -15px -15px 0 0;
  font-size: 24px;
  vertical-align: middle;
  text-align: center;
  cursor: pointer;
}

@media screen and (max-width:520px) {

.popup_wrapper {
    left: 65%;
    margin: -300px 0 0 -250px;
  }

.popup_wrapper .close_btn {
  right: 15px;
  }

}