Inline CSS for headers in 'readthedocs' template

[Mopster]

The headers of the 'readthedocs' theme have their colors overriden by css inside in the html pages making it unable to override the default css using a custom CSS file.

  <style>
    body {font-size: 90%;}
    pre, code {font-size: 100%;}
    h3, h4, h5, h6 {color: #2980b9; font-weight: 300}
  </style> 

[d0ugal]

Thanks!