CSS (Cascading Style Sheets)

Cascading Style Sheets (CSS) is a simple mechanism for adding style (eg: fonts, colors, spacing) to Web documents

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Learn CSS

An evergreen CSS course and reference to level up your web styling expertise
https://web.dev/learn/css

Fluid-responsive font-size calculator

Fluidly scale typography smoothly across viewport widths. Generate a fluid-responsive property (font-size) value for embedding directly into your stylesheet
https://websemantics.uk/tools/responsive-font-calculator

The difference between the alignment values of start, flex-start, and self-start:

https://csslayout.news/whats-the-difference-between-the-alignment-values-of-start-flex-start-and-self-start

Defensive CSS

A collection of snippets that can help you in writing CSS that is protected.
In other words, you will have fewer issues in the future.
https://ishadeed.com/article/defensive-css

CSS cheat sheet for Flexbox

https://twitter.com/simonpaix/status/1402303521047842821

CSS chear sheet for Units

https://twitter.com/codingyuri/status/1418207183838187533