Responsive Advice Generator using Flexbox

First of all, I struggled to make the card type of background and there is something that I have no idea how to fix when I uploaded the project it worked fine on all of my devices PC and Redmi Note 8 pro but then I Sent it to my brother and my friend both using an iPhone and the button would be at the bottom of the page on both devices so if anyone has any idea on how to fix this I would appreciate it. Thanks! (I also tested it using googles responsive tool and it worked there but not on the actual device.)