A simple JavaScript library for getting/setting CSS stylesheet rules.

• Tiny - ~250 lines of code.
• No dependencies.
• MIT Licensed.

Download and include jss.js in your HTML:

<script type="text/javascript" src="jss.js"></script>

Add new rule (or extend existing rule):

jss.set('.special', {
    color: 'red',
    fontSize: '2em',
    padding: '10px'
});

Retrieve existing rule:

jss.get('.special');

// Returns:
{
    'color': 'red',
    'font-size': '2em',
    'padding-bottom': '10px',
    'padding-left': '10px',
    'padding-right': '10px',
    'padding-top': '10px'
}

Remove existing rule:

jss.remove('.special');

• To set styles that must be calculated or retrieved - for example, setting the user's preferred font-size or color from a cookie.
• To set behavioural, rather than aesthetic, styles (especially for UI widget/plugin developers). Tabs, carousels, tooltips, etc. often require some basic CSS simply to function. Users of the code should not be forced to include a stylesheet for core functionality. Eye-candy CSS, of course, should still be added through regular stylesheets.
• It's better than inline styles since CSS rules apply to all current and future elements, and don't clutter the HTML when viewing in Firebug / Developer Tools.