[kjnnksgr] Shade alternate lines of wide text

Render text on a wide display with shading to guide the eye to stay on the line.  Perhaps a user stylesheet or browser extension.  The simplest way is to shade the background color alternate lines of text gray - white - gray - white.  Another way is to shade each line with a vertical gradient: white at the top of the character, grayer near the baseline.  (Recalling a study that a lot of the entropy in text is in the top half of a character.)

This is a one dimensional version of the checkerboard versus gradient.