Assign a row class like "row-1" for row 1, "row-2" for row 2
There are plenty of ways to go about this question, my suggestion is overriding twig templates.
You would need to override the Twig template for that view. If you enable debug, clear cache, inspect element, you will see the template for that view. Then for that twig file, just use the loop index
loop.index  The current iteration of the loop. (1 indexed)

to track which row you are in.