@mixin animation($properties) {
  -webkit-animation: $properties;
  -moz-animation: $properties;
  -o-animation: $properties;
  animation: $properties;
}
@mixin box-sizing($property){
  -webkit-box-sizing: $property;
  -moz-box-sizing: $property;
  box-sizing: $property;
}

@-moz-keyframes spin {
  0% { -moz-transform: rotate(0deg); }
  100% { -moz-transform: rotate(359deg); }
}
@-webkit-keyframes spin {
  0% { -webkit-transform: rotate(0deg); }
  100% { -webkit-transform: rotate(359deg); }
}
@-o-keyframes spin {
  0% { -o-transform: rotate(0deg); }
  100% { -o-transform: rotate(359deg); }
}
@-ms-keyframes spin {
  0% { -ms-transform: rotate(0deg); }
  100% { -ms-transform: rotate(359deg); }
}
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(359deg); }
}