I'm afraid this looks very broken on my phone (I'll add a screenshot to discord for you) and has some foundational html errors. I'll go through each improvement in turn and hope it helps :
- All content should be contained within landmarks. This needs a main to wrap the component and a footer for the attribution. The component can be a section but a section cannot wrap the main and footer. You can place the centering styling on the body.
- the attribution should not be inside the component.
- link the fonts from Google fonts and apply in css.
- the image needs a proper description. I recommend you read the post in the resources channel on discord about how to write good alt text. This particular image needs to say what the image is (QR code) and where it goes (to FrontendMentor.io).
- the heading should not be a h1. This component would never be used for a page title when placed on a.real.web page. With that context in mind, make this a h2.
- get into the habit of including a full modern css reset at the start of the styles in every project. Andy Bell or Josh Comeau both have good ones you can look up and use.
- the component must not have a width. Instead give it a max width in rem. This will allow it to shrink narrower when it needs to, and using rem means the layout will work for all users including those who have a different text size.
- the component must not have a height at all. Never limit the height of elements that contain text. Let the browser do it's job and decide what height is needed based on the content inside the card.
- the image only needs a width or max width 100%. It does not need a height. It can optionally include an aspect ratio property abd/or object-fit.
- keep css selectors as simple and low specificity as possible. Don't chain or nest selectors or you will end up with a maintenance nightmare on larger projects later.
- Font size must never ever be in px. Extremely important.
- the content div is completely unnecessary in your solution. Keep html as simple as possible. The text align can go on the component.
- the component will need a little margin on all sides (or a wrapping element will need a little padding) so it can't hit screen edges.