XF 2.2 How to change this padding width under certain condition?

[securedme]

I added options for users to display or hide their message avatars. But there's a padding of 10px that I would like to eliminate if the user chooses to hide the avatar.

How do I eliminate it?



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<xf:if is="hide avatar"> // I know how to set the condition
padding-left: 10px; // how do I change this?
</xf:if>

And which template should I modify?