WHMCS was build using Bootstrap.
So : i suggest you to add bootstrap clasess and id's on every elements of the virtualizor WHMCS module
Going this way, it will be easier for all of us to get the module to match our existing design.
The module is using tables, witout any classes and id's and each upgrades require lot's of work to get something nice for this reason.
Thank you for taking this into consideration.
Cheers!