webview/public/pdf/style/loader.css

.loader-container {
  position: fixed;
  top: 50%;
  left: 50%;
  display: flex;
  flex-direction: row;
  transform: translate(-50%, -50%);
}

.loader-container div {
  height: 20px;
  width: 5px;
  background: #FE4A49;
  margin: 3px;
  border-radius: 25px;
}

.loader-container div:nth-child(1) {
  animation: loader 1s ease-in-out infinite 0s;
}

.loader-container div:nth-child(2) {
  animation: loader 1s ease-in-out infinite 0.1s;
}

.loader-container div:nth-child(3) {
  animation: loader 1s ease-in-out infinite 0.2s;
}

.loader-container div:nth-child(4) {
  animation: loader 1s ease-in-out infinite 0.3s;
}

.loader-container div:nth-child(5) {
  animation: loader 1s ease-in-out infinite 0.4s;
}

.loader-container div:nth-child(6) {
  animation: loader 1s ease-in-out infinite 0.5s;
}

.loader-container div:nth-child(7) {
  animation: loader 1s ease-in-out infinite 0.6s;
}

@keyframes loader {
  0% {
    transform: scaleY(1);
    background: #FED766;
  }
  25% {
    background: #009FB7;
  }
  50% {
    transform: scaleY(2);
    background: #59CD90;
  }
  75% {
    background: #FE4A49;
  }
  100% {
    transform: scaleY(1);
    background: #D91E36;
  }
}