HTML/CSS/JS Basics

https://developer.mozilla.org/en-US/docs/Web/JavaScript - great reference resource for anything relating to HTML, CSS, or JS

React and Next.js

https://nextjs.org/learn/foundations/about-nextjs - good intro to Next.js and React, assumes knowledge of basic HTML/CSS/JS

https://react.dev/learn

https://egghead.io/courses/the-beginner-s-guide-to-react - free course on React to get a deeper understanding of what React does

Advanced Styling + Tailwind CSS

https://css-tricks.com/the-thought-process-behind-a-flexbox-layout/ - basic overview of flexbox

https://css-tricks.com/snippets/css/a-guide-to-flexbox/ - flexbox reference with detailed explanations and examples of each property

https://css-tricks.com/snippets/css/complete-guide-grid/ - same as above but for CSS Grid, comes in handy for more advanced layouts that can’t be easily achieved with flexbox

https://knightsoftheflexboxtable.com/ - Good exercise for learning how flexbox works and remembering the corresponding Tailwind classes