@mixin spinner($width, $height) {
  width: 0.9 * $width;
  height: 0.9 * $height;
  border-radius: 50%;
  box-sizing: border-box;
  border: solid 0.1*$height rgba(0, 0, 0, 0.2);
  border-top-color: #000;
  animation: spin 1s infinite linear;
}


@-webkit-keyframes spin {
  100% {
    -webkit-transform: rotate(360deg);
  }
}