Horizontal Accordion using MooTools

I'm trying to create a horizontal accordion menu in mootools, instead of the standard vertical one. In the manual for Fx.Accordion it says "CSS mastery is required to make width transitions work" and I guess I haven't got enough of it. Could anyone help me out on making an horizontal accordion work?

http:/开发者_如何学Go/jsfiddle.net/Reanimation/L7Rej/2/

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Check our kwicks from David Walsh

http://davidwalsh.name/mootools-kwicks

Hope this helps