This is an accepted solution.
Hi Medy06! Hope you are doing well!
1. To fix the display of the title on the desktop, just set the float: none property to this element - https://prnt.sc/12be05t
2. If you don't have more than two Upsell products, then the following code will be enough - https://prnt.sc/12bedf2 https://prnt.sc/12bee2h.
I also noticed that your container is not quite centered - https://prnt.sc/12bef8q and to fix this you will need to add a left margin equal to the right margin for this container, but keep in mind that there are different indents on the desktop and mobile phones, so you have to use media query.
I do not recommend that you add custom code yourself unless you are a developer, as you might break something.