效果
代码如下
<style>
div {
position: relative;
199px;
height: 20px;
border: 1px solid gray;
}
div::after {
content: '';
position: absolute;
top: 5px;
right: 5px;
6px;
height: 6px;
border-bottom: 1px solid black;
border-right: 1px solid black;
transform: rotate(45deg);
}
</style>
<body>
<div></div>
</body>