margin

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. Wrap the card in a <main>. I would also give the div a class:<div class="card">.

• The alt text must also say where it leads(frontendmentor website). You should remove "image", as screen readers announce that by default. A good alt text would be "QR code leading to the Frontend Mentor website."

• Remove the width attribute.

CSS:

• Including a CSS Reset at the top is good practice.

• Use the style guide to find the correct font-family.

• Remove the margin on the card.

• 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 widths in px. In web design, we rarely want to set fixed sizes, as we want our components to grow and shrink according to different screens.

• Remove height: auto, as that is the default value for images.

• Add a max-width of around 20rem on the card, to prevent it from getting too wide on larger screens.

• On the image, add display: block and max-width: 100% - the max-width prevents it from overflowing its container.

• I would increase the padding to around 16px.