SOURCE

<div class="letter">
  百瓶无线前端
</div>

.letter{
  box-sizing:border-box;
  display:flex;
  justify-content:center;
  align-items:center;
  width:300px;
  height:150px;
  background-color:#fff;
  border: 16px solid transparent;
  border-image: 16 repeating-linear-gradient(-45deg,
  red 0, red 1em,
  transparent 0, transparent 2em, #58a 0, #58a 3em,
  transparent 0, transparent 4em);
  
}