.loader {
  height: 40px;
  width: 40px;
  border-radius: 50%;
  box-shadow: inset 0 0 0 #0a7cbe;
  animation: load 2s linear infinite alternate;
}

@keyframes load {
  0% {
    box-shadow: inset -20px 40px 0 #0a7cbe;
  }

  100% {
    box-shadow: inset 20px -40px 0 #0a7cbe;
  }
}