新学到了一个做箭头图标的方法，用起来
<style>
.arrow {
display: flex;
justify-content: space-between;
align-items: center;
}
.arrow::after {
content: '';
width: 20px;
height: 20px;
border-top: 3px solid #333;
border-right: 3px solid #333;
transform: rotate(45deg);
}
</style>
</head>
<body>
<div class="arrow"></div>
