html, body, #grandfather, #bt_ap_div {
  padding: 0;
  margin: 0;
  top: 0px;
  left: 0px;
}

html {
  height: 100%;
}

body#grandfather {
  background-color: #F4F4F4;
  overflow: hidden;
  
  width: 100% !important;
  height: 100% !important;
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: justify;
  -webkit-justify-content: center;
  -ms-flex-pack: center;
  -moz-box-pack: justify;
  justify-content: center;
  -webkit-box-align: center;
  -webkit-align-items: center;
  -moz-box-align: center;
  -ms-flex-align: center;
  align-items: center;
}

.bt-ap-wrap {
  position: relative;
}

#bt_ap_div {
  overflow: hidden;
}