How can I get each line of balls moving a bit slower than the left line, meaning that line 1 goes faster than line 2, and line 2 goes bit faster than line 3 and so on. Moreover, how can I get the reflection of the five line next to the current one. So line 1 till 5 are now working in attached codepen url, but i also want line 6 till 10 , but then moving the opposite direction of the current first five lines, instead of waving to the left, line 5-10 should be now waving to the right. Please keep the code DRY.