need help with changing Interest Table Titles D:

i used this tutorial 4 changing the Interest Table Titles and it works on my end, but when i look at it on mobile or a private browser, it reverts back 2 the original text! the only things i changed were the text-shadow color and placement (changing "2px 2px" to "0px 0px"). turning off the transparency of the actual text (not the text-shadow) leaves a lot of random letters on the screen, so i'm not sure what 2 do.

i know nothing about coding, so forgive me if the solution is obvious :P thanks in advance !!