headings font-size scaling fixed

BUG: while entire page texts scale proportionally, headings gets smaller to the same size as normal text. This was fixed by modifying default Moodle's:

h1{font-size:32px}h2{font-size:28px}h3{font-size:24px}h4{font-size:20px}h5{font-size:16px}h6{font-size:12px}

to dynamically calculated values like:

#page #page-header h1, #page #region-main h1{font-size:'. (0.32 * $fontsize) .'px !important}
#page #page-header h2, #page #region-main h2{font-size:'. (0.28 * $fontsize) .'px !important}
#page #page-header h3, #page #region-main h3{font-size:'. (0.24 * $fontsize) .'px !important}
#page #page-header h4, #page #region-main h4{font-size:'. (0.20 * $fontsize) .'px !important}
#page #page-header h5, #page #region-main h5{font-size:'. (0.16 * $fontsize) .'px !important}
#page #page-header h6, #page #region-main h6{font-size:'. (0.12 * $fontsize) .'px !important}

Selectors are restricted to #page-header and #region-main as it's intended to avoid block's headings to enlarge as content's headings.

Initial idea was to use percentage table but this doesn't work
http://www.metahead.com/converting-font-sizes-from-pixel-point-em-percent
http://stackoverflow.com/questions/3055469/html-what-are-the-percentages-of-the-heading-tags

Also, initial default font-size was so far passed to php script via JS but it appear it is not correct so it's temporarly disabled in changesize.php; Default is set to 13px / 100%