<p>縦ボーダー</p>
<div class="box bg_border"></div>

<p>横ボーダー</p>
<div class="box bg_border is-side"></div>

.box{
  width:100%;
  height:200px;
}

/* 縦 */
.bg_border {
	background-color: #8be4f0;
	background-image:
	 linear-gradient(-90deg, #fff 50%, transparent 50%);
	background-size: 14px 14px;
}

/* 横 */
.is-side{
  	background-image:
	 linear-gradient(#fff 50%, transparent 50%,transparent 100%);
}