React

by luka kupunia

HTML

<div class="box"></div>
<div class="line"></div>

CSS

body {
  margin: 0;
  box-sizing: border-box;
  
}
.box {
  width : 100%;
  height: 100vh;
  background: black;
}
.line {
  width: 10px;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  background : white;
  animation: a .1Ts infinite;
}
@keyframes a {
  50% {
    transform: translate(700px,0);
  }
  100% {
    transform: translate(0,0);
  }
}