iOS CSS background image too big

Hello!

Can anyone please help me with this problem? When viewing my landing page on iPad/iPhone, the background image does not seem to scale to fit the screen. It seems the problem could be related to using background-attachment: fixed with background-size: cover. I tried adding a media query to change background-attachment to scroll on mobile devices but it did not seem to make a difference.

Here is the webpage: https://codepen.io/myronhuang/pen/VdWYVB?editors=0100

Thank You!