Colour contrast between text and background is important on web pages. It affects some people’s ability to perceive the information (in other words to be able to receive the information visually).
Accessibility
Colour Contrast - Why Does It Matter? — GOV.UK
Knowledge
What's the Best Font Size For the web? Well, It Depends… — Imarc
Picking a font size for the web used to be really easy. 16 points and you’re done. You could feel confident that your content would be decently readable on PC or Mac, Netscape or IE. Man, have times changed.
Typography
What's the Best Font Size For the web? Well, It Depends… — Imarc
Knowledge
User Interviews: How, When, and Why to Conduct Them — NN/g
User interviews have become a popular technique for getting user feedback, mainly because they are fast and easy. Use them to learn about users’ perceptions of your design, not about its usability.
Interviews
User Interviews: How, When, and Why to Conduct Them — NN/g
A Lottie is a JSON-based animation file format that enables designers to ship animations on any platform as easily as shipping static assets. They are small files that work on any device and can scale up or down without pixelation.