Thanks for writing in!
You are experiencing this issue because you have added a broken css in your custom header.
text-shadow: rgb(0, 0, 0) 0px 0px 6px;
I went ahead and have corrected the issue already. The button and other elements should be have the set element stylings. Meanwhile, your font "Selfie Black" will not work because the font file is not loaded in the site. Please use the font manager if you want to use a custom font for your site. To know more about the font manager, please check this out: