All solutions

Odd, but this Junior level challenge was easier than previous newbie ones, but nevertheless I had some parts where I stuck for a while.

1. Background image (bg-pattern-quotation.svg) positioning was a little bit tricky and I am still not sure that I have done it right. Its centre is positioned at 75% from the left of container and I havent found easy way to repeat it. How to position background image exactly as it is done in the challenge designs?
2. I used <article> and <header> tags for HTML markup. Is it valid use of this tags ?

Will be glad to receive any feedback.

This one was a little harder than previous ones. Is there any way to vertically align text inside element, without adding nested element for text only and aligning using flexbox or grid?

Cards are not centred vertically at the desktop design mockup. I used margin at the top of wrapping container to shift cards down. Is there any best practice for such layouts? Why are there always HTML issues when I submit solution with *-inline or *-block declarations?

I have spent most of the time dealing with responsive design. I used breakpoints to switch from mobile to desktop design, but it complicated style sheet in that challenge. What is the best practices to deal with responsive font sizes, paddings, and margins? What is the best practice to provide spacing between text lines and other elements: margins or paddings? What is the best practice to provide margins around images: fixed or relative units?

I used used Flexbox to align main content in the center of viewport, and attribution element was messing with alignment. I used absolute positioning to exclude it from the flow and position it at the bottom of the page. Is there any best practice solution to position element at the bottom of the page and do not influence flexbox alignment?