At rest each word is a hollow outline. On hover the ink pours in solid — flooding from the side your cursor came in on, then draining out the side you leave.
Hover the nav links above, or the big words below — enter from the left, then from the right, and watch the pour direction flip.
Everything on this page scrolls and clicks normally — the fill layer sits on top of each word without touching its structure, its link, or the native cursor. The word you read is the word Google crawls.