elementUi-table 斑马纹 -鼠标移入某行后样式怎么设置

加了这个后隔一行有悬浮色，不是每行都有，为什么呢？

.el-table--enable-row-hover .el-table__body tr:hover > td {
            @include background-color("background_color-el-table-hover");
        }

.el-table--enable-row-hover .el-table__body tr:hover>td.el-table__cell{
@include background-color("background_color-el-table-hover")
}

tbody tr:hover>td {
background-color:#90c0f1；
}