Why does it display lines of different heights, although there is one specific one in the code?

Question

css

Good time.
The essence of the problem - in the code, the height of the lines is 1 px. On a laptop monitor, certain lines are thicker. Now the lines on the screen are made using pseudo-elements. If I make a frame - there are no changes.

Answer 1

I believe that there is something like invalid or valid
https://webref.ru/css/invalid
in css, and since your mail with a phone number did not pass validation (filled in incorrectly), they are assigned a slightly different style.