W3C Validator: #call_to_action h4{padding:0px 5px;}

I was checking this site with W3C Validator, and got the error:

<strong>Element style not allowed as child of element div in this context. (Suppressing further errors from this subtree.)</strong>

<style type="text/css">#call_to_action h4{padding:0px 5px;}</style>

<div><dl><dt>Contexts in which element <a href="http://dev.w3.org/html5/spec-author-view/#the-style-element">style</a> may be used:</dt><dd>If the <a href="http://dev.w3.org/html5/spec-author-view/#attr-style-scoped">scoped</a> attribute is absent: where <a href="http://dev.w3.org/html5/spec-author-view/#metadata-content">metadata content</a> is expected.</dd><dd>If the <a href="http://dev.w3.org/html5/spec-author-view/#attr-style-scoped">scoped</a> attribute is absent: in a <a href="http://dev.w3.org/html5/spec-author-view/#the-noscript-element">noscript</a> element that is a child of a <a href="http://dev.w3.org/html5/spec-author-view/#the-head-element">head</a> element.</dd><dd>If the <a href="http://dev.w3.org/html5/spec-author-view/#attr-style-scoped">scoped</a> attribute is present: where <a href="http://dev.w3.org/html5/spec-author-view/#flow-content">flow content</a> is expected, but before any other <a href="http://dev.w3.org/html5/spec-author-view/#flow-content">flow content</a> other than <a href="http://dev.w3.org/html5/spec-author-view/#inter-element-whitespace">inter-element whitespace</a>, and not as the child of an element whose content model is <a href="http://dev.w3.org/html5/spec-author-view/#transparent">transparent</a>.</dd><dt>Content model for element <a href="http://dev.w3.org/html5/spec-author-view/#the-div-element">div</a>:</dt><dd><a href="http://dev.w3.org/html5/spec-author-view/#flow-content">Flow content</a>.</dd></dl></div>

After some digging around, I found out it was the plugin Social Essentials which was causing these errors. A WordPress pluging for sharing your posts to social networks.

For now I’ll be using Simple Social Sharing, till I might find a better alternative.