三角形
.get-list{ position: relative; width:100px; height: 50px; border-radius: 10px; background: olivedrab; } .get-list::before{ position: absolute; top:-16px; left:40%; display: block; content:''; border-width: 10px; border-style: solid; border-color: transparent transparent #ff4d4d transparent; }
<div class="get-list"></div>