QR Code Component using HTML and CSS

Hi Rafael, good work on this! :)

Your code looks clean and organized, just one thing, don't use px units for margins, padding and font-size.

For padding and margins are better ems unit, since the adapt better if the text shrinks or grow.

For font-size, use rems, since they adapt better if the user takes the time to change font size from browser settings. If you keep using pxs for font size, they won't adapt to the user preferences.