Change code for top menu (the part when you hover)

[joan-coquelin]

Hi everyone and thanks a lot in advance for your job and expertise ! 

I would like to change the top menu (prestashop 1.6), what I want to do is to add a bottom-border on my categories (vacuum cleaner, tablet machine, etc...)

The code for this part is for example for the catagory vacuum cleaner: <a href="https://equimatfrance.com/en/88-vacuum-cleaner" title="Vacuum cleaner" >Vacuum cleaner</a>

and I am looking for the file where I could add a class to these links something like <a class="mytopmenuhoveredlinkclass" href="https://equimatfrance.com/en/88-vacuum-cleaner" title="Vacuum cleaner" >Vacuum cleaner</a> so that I can add my css rule and do what I want for all the links of this menu.

 

I hope I am clear enough, thank you very much again for helping me out.

To show you what I want I leave a screen shot of my other site which has is done under prestashop 1.7 instead and it looks like this (you can see the blue bottom-border under each category).