title: dompdf: white margin on A4 page
body: <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>