HTML CSS troubles

Hiya, all

I’ve been scratching my head on why my html form and card style crumble when it is larger than the 600 pixels. Been going back and forth between reference materials all day yesterday and this morning, and figured it may be time to ask for help.

Should the card also be centered to the form? Also when dragging size of the browser it doesn’t go smaller than the last screenshot, which could be part of my problem…

thanks in advance Y’all,