laurentplenet

Thanks for your help, I finally found out the solution for the « In » transition :  See the Pen zYzzzMo by laurent-pnt (@laurent-pnt) on CodePen
 same for the « Out » transition :  See the Pen XWggowE by laurent-pnt (@laurent-pnt) on CodePen
 
I merged the both in one through my js and it works perfectly.