问如何使用javascript在PivotTable中插入:nth-child(x)和:之前？

EN

const DATA = {
        "Informacoes": {
            "qtRows": 3,
            "qtCols": 6,
            "Cabecalho": ["Id", "Encontro", "Nome", "Preco", "Quantidade", "Total"]
        },
        "Produtos":[
            {
            "Id":   200396,
            "Encontro": '2017-09-26 01:22',
            "Nome": 'Controlador do console de jogos',
            "Preco": 22.00,
            "Quantidade": 2,
            "Total": 44.00
        },
        {
            "Id": 200397,
            "Encontro": '2017-09-28 05:57',
            "Nome": 'iPhone X',
            "Preco":999.00,
            "Quantidade": 1,
            "Total": 999.00
        },
        {
            "Id": 200398,
            "Encontro": '2017-09-29 05:57',
            "Nome": 'Samsung S8 Black',
            "Preco": 756.00,
            "Quantidade": 1,
            "Total": 756.00
        }],
    };

    class TableDesktop{
        constructor(_id, _arrData){
            this.id        = _id;
            this.arrData   = _arrData;
        }

        set tableObject(_object){ this.table = _object; }
        get tableObject(       ){ return this.table;    }

        set theadObject(_object){ this.thead = _object; }
        get theadObject(       ){ return this.thead;    }

        set bodyObject(_object){ this.body = _object; }
        get bodyObject(       ){ return this.body;    }

    createTable(){
        this.generateThead();
        this.generateBody();
        this.generateTable();

        const TABLE_CONTAINER = document.getElementById('table-container');
        if(TABLE_CONTAINER.childNodes.length === 1){
            TABLE_CONTAINER.removeChild(TABLE_CONTAINER.childNodes[0]);
            TABLE_CONTAINER.appendChild(this.tableObject);
        } else{
            TABLE_CONTAINER.appendChild(this.tableObject);
        }
    }

    generateTable(){
        const TABLE = document.createElement('table');
        TABLE.setAttribute('class', 'table table100-head');
        TABLE.appendChild(this.theadObject);
        TABLE.appendChild(this.bodyObject);

        this.tableObject = TABLE;

        console.log(TABLE)
    }

    generateThead(){
        const TR    = document.createElement('tr'),
              THEAD = document.createElement('thead');

        for(let coluna = 0; coluna < this.arrData.Informacoes.qtCols; coluna++){
            const THEAD_VALUES = this.arrData.Informacoes.Cabecalho[coluna];

            const TH = document.createElement('th');
            TH.setAttribute('scope', 'col');
            TH.appendChild(document.createTextNode(THEAD_VALUES));

            TR.appendChild(TH);
        }

        THEAD.setAttribute('class', 'thead-dark');
        THEAD.appendChild(TR);

        this.theadObject = THEAD;
    }

    generateBody(){
        const BODY = document.createElement('tbody');

        let tr;

        for(let linha = 0; linha < this.arrData.Informacoes.qtRows; linha++){
            const BODY_VALUES = this.arrData.Produtos[linha];

            tr = document.createElement('tr');

            for(let coluna = 0; coluna < this.arrData.Informacoes.qtCols; coluna++){
                const THEAD_VALUES = this.arrData.Informacoes.Cabecalho[coluna];
                const TH = document.createElement('th');
                const TD = document.createElement('td');

                if(THEAD_VALUES === "Id"){
                    TH.setAttribute('scope', 'row');
                    TH.appendChild(document.createTextNode(BODY_VALUES.Id));
                    tr.appendChild(TH);
                } else {
                    TD.appendChild(document.createTextNode(BODY_VALUES[this.arrData.Informacoes.Cabecalho[coluna]]));
                    tr.appendChild(TD);
                }
            }

            BODY.appendChild(tr);
        }

        this.bodyObject = BODY;
    }
}


const TABLE_DESKTOP = new TableDesktop('container-table-desktop', DATA);
        TABLE_DESKTOP.createTable();

table tbody tr td:nth-child(1):before {
  content: "";
}
table tbody tr td:nth-child(2):before {
  content: "";
}
table tbody tr td:nth-child(3):before {
  content: "Name";
}
table tbody tr td:nth-child(4):before {
  content: "Price";
}
table tbody tr td:nth-child(5):before {
  content: "Quantity";
}
table tbody tr td:nth-child(6):before {
  content: "Total";
}

<div id="table-container"></div>