Hello @ZachSaucier and thank you for your quick response.
I've changed translateX to x and the ease property as you explained very clearly.
If someone unhover, I want the animation to reverse, if I'm not wrong this is the default behaviour
If someone hovers then unhovers then hovers again before the in animation is complete the animation should resume back to where it stopped
As for the out animation, it should always play the rest if someone unhover and play the in animation afterwards
I still didn't manage to reset the x position after the animation out is done
To better visualize what I'm trying to achieve, you can check the navbar items of this website : https://strapi.io/