dompdf: white margin on A4 page
<p>I am using dompdf (a PHP library) to create a PDF page and I have a problem to set proper dimensions. When I use CSS property:</p>

<pre class="lang-css prettyprint-override"><code>@page {
    size: 21cm 29.7cm; 
}
</code></pre>

<p>… and for example I want to have the upper part of the page in red color, the PDF file is OK, but after print I got white margin. How can I fix it?</p>