Thanks, Armin. I found that the best approach to make it work was:
Set the vertical alignment of the text slides to "Top."
Select "Fixed Height" for the carousel.
Set the height to 60vh.
Align the carousel to the bottom of the row in the grid layout.
Then you can save a css file named additionalstyles.css in the themes-folder /mylay/…, and this file you can open with for example Transmit (FTP-Client) & Sublime text (Editor), save, and in 2 seconds its done. then clean the browser cache and reload your website.
ahh yeah sorry I just tried myself and it didn't work, I thought that would work for a whole row. If you add the code to the grid id (#grid) it rounds the bottom of the website but not the top, hmm you might want to ask @arminunruh for help.