Datepicker Resizing Problem

I have a jQuery CMS app that has dynamic width depending on window size. I want to use the datepicker widget but I cannot get it to resize whenever the window size changes (parent div is set to 98% width). I can only apply a static width to it, which doesn't work on smaller resolutions (or if someone isn't running the app in a maximized window).

Any ideas? Thank you for your time.