Why isn't my customized checkout appearing on my website?

[Adam_1231]

I recently wanted to customize the checkout because I felt like it looked a little bland, so when I added the background image and font, they did not appear on the website, i tried with the dawn theme also but it still did not work. Pls help

[Adam_1231]

Here i added some pictures and they do not appear. is this  a problem with the settings or the theme?