How to customize drop down widget popup using javascript ?

Hi All , I want to customize drop down popup css using javascript . But the popup is dynamically generated . How to access document object of the popup  ? .So that I can set the css of the popup.   Thanks, Ashutos Lenka    
1 answers

In order to assign custom styling to a Mendix widget, you may want to assign a class to it and then use this class in your custom sass file. Here the documentation of how to style your app using sass and Calypso:

And here the learning path: