PyQt5 QPrintPreview not displaying proper table width

Question

I'm using an html invoice template that contains a table element. The table element has an attribute style with width: 100%. After rendering the template with context I want to preview the invoice in print preview dialog. Everything works fine, except for the table. It wraps the content in the cells but I want the table to span across the page. Another thing worth mentioning is that, style atributes like: border, margin, text-align are working and others like: width, height, background-color are not.

Here is the template:

<h1 style="text-align: center;">Račun br. {{ id_racun }}</h1>
<hr />
<h3>Datum izdavanja: {{ datum }}</h3>
<h3>Izdao operater: {{ zaposlenik }}</h3>
<hr />
<table style="width: 100%; border-collapse: collapse; border: 2px solid black;" border="1">
        <tr>
            <td><strong>&Scaron;ifra</strong></td>
            <td><strong>Naziv</strong></td>
            <td><strong>Cijena</strong></td>
            <td><strong>Popust</strong></td>
            <td><strong>Količina</strong></td>
            <td><strong>JM</strong></td>
            <td><strong>Ukupna cijena</strong></td>
        </tr>
        {% for stavka in stavke %}
        <tr>
            <td>{{ stavka[0] }}</td>
            <td>{{ stavka[1] }}</td>
            <td>{{ stavka[2] }}</td>
            <td>{{ stavka[3] }}</td>
            <td>{{ stavka[4] }}</td>
            <td>{{ stavka[5] }}</td>
            <td>{{ stavka[6] }}</td>
        </tr>
        {% endfor %}
</table>
<hr />
<h3 style="text-align: right;">Popust: {{ popust }} %</h3>
<h3 style="text-align: right;">Ukupno: {{ ukupno }} &euro;</h3>

Here is the code that loads html and the print preview:

    def previewDialog(self):
        previewDialog = QPrintPreviewDialog()
        previewDialog.paintRequested.connect(self.printPreview)
        previewDialog.exec_()

    def printPreview(self, printer):
        htmlDokument = self.HTMLracun
        dokument = QTextDocument()

        dokument.setHtml(htmlDokument)

        dokument.print_(printer)

Here is the output I'm getting: Print preview dialog

I've tried using QTextDocument.setDefaultStylesheet("table {width: 100%;}") and QTextDocument.setDefaultStylesheet("@media print {table {width: 100%;}}"), and it did nothing. I figured it has something to do with @media but I can't find a way to use it and test it.