.loading {
  background: rgba(86,101,125,0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  opacity: 1;
  z-index: 9999;
  color: #fff;
  text-align: center;
}
.loading span {
  line-height: 2em;
  margin: 0 auto -50px;
  display: block;
}
.loading>div {
  width: 100%;
  height: 100%;
  -webkit-box-flex: 0;
  -ms-flex: 0 0 25%;
  flex: 0 0 25%;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  margin: 0;
  position: relative;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  overflow: hidden;
}

.bt-spinner {
  width: 75px;
  height: 75px;
  border-radius: 50%;
  background-color: transparent;
  border: 4px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  -webkit-animation: 1s spin linear infinite;
  animation: 1s spin linear infinite;
}

-webkit-@keyframes spin {
  -webkit-from {
    -webkit-transform: rotate(0deg);
    -ms-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  -webkit-to {
    -webkit-transform: rotate(360deg);
    -ms-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}

@-webkit-keyframes spin {
  from {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}

@keyframes spin {
  from {
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(360deg);
    transform: rotate(360deg);
  }
}