Change Mobile Text Sizes

Hi, I had a previous ticket that I thought was resolved but the solution provided doesn’t seem to have worked. I asked for custom CSS to change the font sizes of h1-h6 and p in the mobile view, and this is the code I was given:

@media handheld,only screen and (max-width:400px){
h1 { font-size: 24px; }
h2 { font-size: 22px; }
h3 { font-size: 20px; }
h4 { font-size: 18px; }
h5 { font-size: 16px; }
h6 { font-size: 14px; }
p { font-size: 14px; }
}

nothing seems to have changed when I place this code into the custom CSS area of the theme options panel and save.

Let me know if there’s another solution or another piece of code I need to add. I want the text sizes to change in all of the elements, not just in general text boxes. Thanks.