Adjustable QR code

HTML:

• Change .div1 to a <main>.

• Alt text should also tell where it leads.

• "Improve your frontend skills" is a heading, not a paragraph.

CSS:

• Add a CSS Reset at the top - I recommend the one by Andy Bell.

• Don't use positioning to center the card. Instead, use Flexbox on the body:

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

• Don't set fixed width on the card. You can set a max-width, to prevent the card from getting too big at larger screens.

• Remove margin-bottom: 0px. If you did want something to have 0 margin, you would just write "0".

• Font-size must never be in px. Use rem instead.