to Vaadin? Apart from the plain question, if it is possible at all, I would be interested in a rough idea as to what extend the Metro UI CSS can be applied to Vaadin.
Just glanced at the Metro UI quickly. As it looks like it expects you to create a totally different looking HTML hierarchy than what Vaadin produces, you’re left with little options to try and use it.
In my opinion the best approach is to use the generated Metro UI CSS (not .less) and use the Vaadin Sass compiler and the @extend directive to add the styles to correct places in the Vaadin HTML structure.
I prototyped this approach with Bootstrap CSS, see the
source code and
demo app to understand better.