* {

  margin: 0;

  padding: 0;

  box-sizing: border-box;

}

.line{

  position: relative;

  width: 400px;

  height: 2px;

  margin: 200px;

  overflow: hidden;

  transform: rotate(-30deg);

}

.line::after{

  content: '';

  width: 200%;

  position: absolute;

  left: 0;

  top:0;

  bottom:0;

  border-bottom:2px dashed #000;

  animation: 5s line linear infinite;

}

@keyframes line {

  0%{

    transform: translateX(0);

  }

  100%{

    transform: translateX(-50%);

  }

}