Browser Animation Bug

@keyframes _brlbs-flipInX {
 from {
 transform: perspective(400px) rotate3d(1, 0, 0, 90deg);
 animation-timing-function: ease-in;
 opacity: 0;
 }

 40% {
 transform: perspective(400px) rotate3d(1, 0, 0, -20deg);
 animation-timing-function: ease-in;
 }

 60% {
 transform: perspective(400px) rotate3d(1, 0, 0, 10deg);
 opacity: 1;
 }

 80% {
 transform: perspective(400px) rotate3d(1, 0, 0, -5deg);
 }

 99% {
  transform: perspective(400px);
 }

 to {
 transform: none;
 }
}