qr-code-component-main

Replace<div class="container"> with the main tag and <h2> with <h1> to fix the accessibility issues. click here for more on web-accessibility and semantic html

For a responsive content replace the width of .container with max-width value. and give the image a max- width of 100%. There is no need to give . container an extra padding bottom value.

To center .container on the page, add min-height:100vh; display: flex; align-items: center: justify-content: center; or min-height:100vh; display: grid place-items: center to the body.

To center .container on the page using flexbox:
body{
min-height: 100vh;
display: flex;
align-items: center;
justify-content: center;
}

To center .container on the page using grid:
body{
min-height: 100vh;
display: grid;
place-items: center;
}

Hope am helpful.

Well done for completing this challenge. HAPPY CODING