Implementation code for adding slash to Vue element header

<template>
    <div class="app-container">
        <el-table :data="tableData3" style="width: 100%">
            <el-table-column width="120" prop="date"></el-table-column>
            <el-table-column prop="name" label="姓名" width="120"></el-table-column>
            <el-table-column label="Address">
                <el-table-column prop="province" label="省" width="120"></el-table-column>
                <el-table-column prop="city" label="都市" width="120"></el-table-column>
                <el-table-column prop="address" label="Address" width="300"></el-table-column>
                <el-table-column prop="zip" label="Postal Code" width="120"></el-table-column>
            </el-table-column>
        </el-table>
    </div>
</template>

<script>
    export default {
        filters: {},
        data() {
            return {
                tableData3: [{
                    date: '2016-05-03',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-02',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-04',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-01',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-08',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-06',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }, {
                    date: '2016-05-07',
                    name: 'Wang Xiaohu',
                    province: 'Shanghai',
                    city: 'Putuo District',
                    address: 'No. 1518, Jinshajiang Road, Putuo District, Shanghai',
                    zip: 200333
                }]
            }
        },
        created() {},
        methods: {}
    }
</script>
<style lang="scss">
    .el-table thead.is-group th {
        background: #fff;
    }
    
    .el-table thead.is-group tr:first-of-type th:first-of-type:before {
        content: 'Date';
        text-align: center;
        position: absolute;
        width: 152px;
        height: 1px;
        bottom: 30px;
        right: 0;
    }
    
    .el-table thead.is-group tr:first-of-type th:first-of-type:after {
        content: 'New delivery';
        text-align: center;
        position: absolute;
        width: 152px;
        top: 10px;
        left: 0;
    }
    
    .el-table thead.is-group tr:first-of-type th:first-of-type .cell {
        position: absolute;
        top: 0;
        left: 0;
        width: 152px;
        height: 1px;
        background-color: #EBEEF5;
        display: block;
        text-align: center;
        transform: rotate(38deg);
        transform-origin: top left;
        -ms-transform:rotate(38deg);
        -ms-transform-origin: top left;
        -webkit-transform: rotate(38deg);
        -webkit-transform-origin: top left;
    }
</style>