edit rules in your css
it is as simple as
`<script src="dynamicallyAccessCSS.js"></script>`
...
onclick="getCSSRule('selectorYouWantToChange').style.colorOrSizeOrWhatever = '3px'"
or
onclick="getCSSRule('selectorYouWantToChange').style.setProperty ("width", "10px", "important")""
if you want to get an array of all of the rules that reference your selector, you use:
getCSSRule('selectorYouWantToChange', true)
to change the last rule
var myRules = getCSSRule('selectorYouWantToChange', true);
var lastRule = myRules[myRules.length-1]
lastRule.style.colorOrSizeOrWhatever = 'something'
this was inspired here: http://stackoverflow.com/questions/730048/how-to-change-remove-css-classes-definitions-at-runtime