自定义border

实现：

<view class="test">测试</view>
.test {
    width: 100px;
    height: 100px;
    line-height: 100px;
    text-align: center;
    position: relative;
    
    &::before {
        content: '';
        width: 60px;
        height: 1%;
        background-color: #ccc;
        position: absolute;
        left: 20px;
        bottom: 20%;
    }
}

效果如下：