Github Pages font-face not working

I uploaded my project to Github pages and the font doesn't work! I've read other questions about the issue that lead me to think I need to change how I'm pointing the file, but I can't sort it out.

Here's my @font-face:

@font-face {
    font-family: headerFont;
    src: url(fonts/FreePixel.ttf);
}

Here's my file structure:

Portfolio/
    index.html
    css/
        styles.css
        fonts/
            FreePixel.ttf