sass中使用穿透属性(deep)修改第三方组件样似

 <el-form-item>
          <el-button class="save-btn" type="primary" @click="submitForm('ruleForm')">保存</el-button>
 </el-form-item>

//按钮的字体色是白色
.save-btn /deep/ span{
 color: #fff;
}

.save-btn:hover{
 background:  #409EFF;
}

.save-btn:focus{
 background:  #409EFF;
}