[O] applying html classes to the "figure div on HTML export

[Matt Price]

Hi,

Is there a way to apply an HTML class to the the <div class="figure">
element which is generated around an image link on HTML export?  I am
making a presentation using org--> deck.js (ox-deck.el), and I want
most of my images to be centred, but in cases where I have more than
one image, I want them to display in rows using the float:left
property.  If I just float the images using

 #+ATTR_HTML: :style float:left

then their captions do not display consistently above or below them.
I can use CSS to addres every div.figure, but that forces ALL images
to be aligned to the left-hand side of the slide, which is not what I
want.  I think I could also write some javascript to add the class
dynamically when there's more than one div.figure in a div.slide,  but
I odn't understand deck well enough to be sure how to do that.  Any
suggestions?

Thanks!

Matt