body {
  background: #eaecfa;
}

.loader {
  width: 250px;
  height: 50px;
  line-height: 50px;
  text-align: center;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  font-family: helvetica, arial, sans-serif;
  text-transform: uppercase;
  font-weight: 900;
  color: #1890ff;
  letter-spacing: 0.2em;
}
.loader::before, .loader::after {
  content: "";
  display: block;
  width: 15px;
  height: 15px;
  background: #1890ff;
  position: absolute;
  animation: load .7s infinite alternate ease-in-out;
}

.loader::before {
  top: 0;
}

.loader::after {
  bottom: 0;
}

@keyframes load {
  0% { left: 0; height: 30px; width: 15px }
  50% { height: 8px; width: 40px }
  100% { left: 235px; height: 30px; width: 15px}
}