the responsive page is written in pure CSS and HTML

• Does the solution include semantic HTML? Yes it does Includes some HTML semantic.

• Is it accessible, and what improvements could be made? Yes I hosted it, for A start I don't have any improvement that could be added.

• Does the layout look good on a range of screen sizes? yes it does it is responsive on every screen size.

• Is the code well-structured, readable, and reusable? Yes it is well structured and is reusable.

• Does the solution differ considerably from the design? Yes by a tiny bit.

HTML:

• Every webpage needs a <main> that wraps all of the content, except for <header> and footer>. This is vital for accessibility, as it helps screen readers identify a page's "main" section. Change .container to a <main>, and remove role="main"> - a main element has that role by default.

• Remove .canvas, you don't need that <div>.

• The alt text should be written naturally, without using - between the words. Write something short and descriptive, without including words like "image" or "photo". Screen readers start announcing images with "image", so an alt text of "image of qr code" would be read like this: "image, image of qr code". The alt text must also say where it leads(the frontendmentor website). A good alt text would be "QR code leading to the Frontend Mentor website."

• Change "improve" to "Improve".

• I would change the heading to a <h2> - a page should only have one <h1>, reserved for the main heading. As this is a card heading, it would likely not be the main heading on a page with several components.

CSS:

• I would recommend adding 1rem of padding on the body, to ensure the card doesn't touch the edges on small screens.

• You can remove font-optical-sizing: auto and font-style: normal from body, as these are default values.

• To center the card horizontally and vertically, I would use Flexbox on the body:

display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
min-height: 100svh;

• Remove all the properties on .container, it doesn't need any styles.

• On .canvas, remove max-width and padding. Move background-color to the body, and box-shadow to .card.

• Remove display: inline-block on the card, it is not needed.

• max-width on the card must be in rem - around 20rem works fine.

• Instead of setting margins on the card elements individually, I would use Flexbox to control the spacing, and also to center the content. Put this on .card:

display: flex;
flex-direction: column;
align-items: center;
gap: 20px;

• font-size must never be in px. This is a big accessibility issue, as it prevents the font size from scaling with the user's default setting in the browser. Use rem instead.

• Paragraphs have a default value of font-weight: 400, so there is no need to declare it.

Use figma file to get proper description para text-color. Don't limit height of whole page as component should be in centric position. Looks Cool.