DOMXPath查询不返回任何结果

Question

我很难理解RegEx，而XPath似乎让我感到困惑。

属于$htmlsrc的Html：

<div class="text" style="font-family:monospace;">
<ol>
<li style="font-weight: normal; vertical-align:top;">
<div style="font: normal normal 1em/1.2em monospace; margin:0; padding:0; background:none; vertical-align:top;">
sQrNWk8+aiRtcn/gFM9ptAf8m3NcRf4av4m76rUZeAA=
</div>
</li>
</ol>
</div>

查询字符串的PHP：

        $dom = new DOMDocument();
        $dom->loadHTML($htmlsrc);
        $xpath = new DOMXPath($dom);
        $tags = $xpath->query('//div/ol/li/div');
        var_dump($tags);

我真的想返回sQrNWk8+aiRtcn/gFM9ptAf8m3NcRf4av4m76rUZeAA=，但var_dump($tags)只是显示一个空对象：

object(DOMNodeList)#24 (1) {
  ["length"]=>
  int(1)
}