mobile customization on mobile devices

Hello I'm having an issue on how my (one page) header (DIVI elegant theme website) is showing up on MOBILE devices. my optin link (Bloom form) is NOT showing on my mobile but it is showing on some peoples mobile devices The optin link works properly but the page doesn't show properly The header itself doesn't fit properly regarding the text on the mobile device although when using the divi customizing mobile feature it looks right but when I go to make adjustments (sliding the font size of the header) nothing happens. Though On the actual mobile devices there is a lot of white space at the bottom of the page. that's not there on the desktop page I currently am only using one page for my site (and a thank page which is on my site when you optin) Backend 1. Wordpress 2. Divi Elegant Theme 3. Bloom (for optin form) 4. Convertkit (email catcher ) Are you able to solve this problem. I see on youtube that sometype of CSS can be applied for mobile devices. Thank you . Site: [login to view URL]