[TYPO3-dev] dropdown login box in menu

[mardz iop]

I would like to create a dropdown login box in the menu. When users hover over "login" in the menu, it shows the login or register form. I found an example here: planet-sports.com/en/

I am quite new to TYPO3 so I don't know where I should start. Is there a way to do this with Typoscript only or should I modify the navbar with html and javascript? What is the best way to do this ?

I am using a custom theme (not done by myself)

The Menu is called in a "header.html" file like this:

<nav class="collapse navbar-collapse navbar-main-collapse" role="navigation">
        <f:cObject typoscriptObjectPath="menu.navbar" />
    </nav>