QR Code with HTML & CSS

Great job on the project! I think using the "margin: auto; property" was a good solution and its something I did myself. I think the code is pretty well structured but could use a few improvements. I like that you added a class to the qr code image and the container, but I think it would be better if you selected the css classes in the stylesheet. Selecting ".container" instead of "div.container" would make it more semantic. I would also use a class for the h1 element and p instead of selecting the element itself in the css. I personally use the BEM naming convention because using a convention makes the css more readable and less prone to errors. You can take a look at https://github.com/awesome-css-group/awesome-css#naming-conventions--methodologies-bulb for some naming conventions. I recommend taking a look at BEM or Kickoff CSS for a naming convention. Making code semantic is important in bigger projects, where it can be harder to debug or change things around. Also you can use "margin: 0 auto;" instead of doing "margin-right: auto; margin-left: auto;" on the image and it would do the same thing. Some smaller changes I would make is to add a margin to the top of the container to keep it centered vertically. Also a border-radius on the qr code image would look good. Great work!