What should you learn after HTML & CSS?

If you want to become a great front-end / full-stack web developer, here’s what you can learn next. (In no particular order)

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Learn about layouts - static, fluid, adaptive, responsive. And learn by developing complete websites - lots of them!

Create clones of your favourite websites and get to the details! 80% of the look can be achieved without much effort. It’s the little DETAILS that take time and teach you the most. (Like using the exact icons, placement, shadows, fonts)

Learn to get your website working on all major browsers and for all screen sizes.

Learn basic typography - serif, sans-serif, display fonts - what to use for headings, paragraphs. What combination of fonts go well and so on.

Learn about spacing - you can observe great websites and take notes of how the elements are spaced out

Get a basic idea of Sass and BEM. If you become a part of a developing a huge project, you can quickly apply them when needed

Learn basic SEO and website performance optimisation

And THEN learn JavaScript to take your website to a whole new level - for user interaction and to interact with APIs, backend and so on.

I know I have missed out a lot more things to learn. Please add in comments what you think the #CodeNewbies should learn after HTML & CSS

I missed out accessibility - very important. Do learn how to make the web more accessible - at least the basics.

Thanks to @jLampStack and @thisiskrishna91 for reminding.