vertical-align

img的位置与div的位置有偏差

可用 vertical-align 进行调整
eg:

<div className="shadow">
    <img src={require('../../../assets/images/rectangular.png')} alt=""/>
</div>

<style>
    .shadow {
        position: absolute;
        width: 359px;
        height: 16px;
        top: -9px;
        left: -12px;
        vertical-align: top;
        >img {
             vertical-align: top;
             width: 100%;
             height: 100%;
        }
    }
</style>