element的tabs标签页卡片化后如何让头自动撑满并居中？具体解释如图

让这仨个哥们充满红色方框的区域，在线等！

<el-tabs type="border-card" style="margin-right:10px">
                <el-tab-pane>
                    <span slot="label"><i class="el-icon-document"></i> 常用制度</span>
                    <MyTable :rowHeader="rulesHeader" :data="rulesData" :height="240" :lastShow="true"></MyTable>
                    </el-tab-pane>
                <el-tab-pane>
                    <span slot="label"><i class="el-icon-collection"></i> 员工办事指南</span>
                    <MyTable :rowHeader="rulesHeader" :data="guideData" :height="240" :lastShow="true"></MyTable>
                    </el-tab-pane>
                <el-tab-pane>
                    <span slot="label"><i class="el-icon-suitcase"></i> 公司制度文件</span>
                    <MyTable :rowHeader="rulesHeader" :data="fileData" :height="240" :lastShow="true"></MyTable>
                    </el-tab-pane>
            </el-tabs>

stretch