Q: can I add style (via css) to the <aside> tag?

<aside> is a great feature on iBooks... it's really cool to see the text of the footnote appearing on a pop-up window instead of going to another page...

Can I control the position of the pop-up, or the size, or the backgroud color, or the font-size ??   in other words,  can I style the aside window??

if it is not the case:  can that function be done with JS?  Can someone help me with that?

thank you so much!!

pablo