QR code component using flexbox

I think your solution is great! I completely understand your statement regarding overcomplicating the markup (I do it a lot too), it's fairly easy to do but good on you for reviewing and refactoring upon that.

I also like the simplicity of how your CSS file is laid out with the variables, reset, and base styles. I especially enjoy the comments of your variables containing the sizes of your intrinsic units in pixels. It shows you paid close attention to detail regarding the design spec.

Great work!

You should reduce the line of comments in css file because its not a good practise to have comments for block of code or line code that is auto explanatory.

Auto-close tags that isn't mandatory to have a close tag to improve the acessibility e.g: <Link rel="icon" href="" />

Headings should follow a logical order without skipping levels (e.g., don’t jump from <h1> to <h4>). Proper nesting helps screen readers and search engines understand the structure of the content.

You don't have any h1 and you skipped to h2.