I’m assuming by “but I can see cropped image on mobile browser.”, you mean that it gets cut off to the right, yes?
This is because the image you are using is absolutely massive and the CSS is set to background-size: cover;.
This forces the browser to stretch the background image to fill the container, but since the image is already much bigger than most containers, it just cuts it off to the right (because it can’t shrink it any further).
Here’s my solution:
Reduce the file size for the background image to at most 1200px wide.