postcss-plugins VS less.js

the author of the most popular PostCSS plugin himself recommended the postcss-preset-env over his own creation which is cssnex, and

The example in A) won't work as the plugin can't convert the functions with variables in it. https://github.com/csstools/postcss-plugins/tree/main/plugin...

You can use this today if you're using PostCSS in your build process (which is the case if you use autoprefixer)! https://preset-env.cssdb.org/

Switching from a ready-made tool like Sass or a recommendation package like cssnext (deprecated since 2019) or PostCSS Preset Env (archived in 2022), to the modular PostCSS Preset Env plugin set we can choose a helpful and convenient set of future CSS features beyond the current stable client CSS.

To implement :has support, the css-has-pseudo polyfill can be used. This polyfill includes both a PostCSS plugin and a JS function to be used in the HTML page.

Yes, it's behind a flag and only in future versions, but it is a huge step forward. Those versions will soon be available, and we can try it locally (unfortunately, not on production without a polyfill or a plugin).

w/ postcss-preset-env(v7.8.3): convert modern CSS into something most browsers can understand, determining the polyfills you need based on your targeted browsers or runtime environments. It takes the support data that comes from MDN and Can I Use and determine from a browserlist whether those transformations are needed. It also packs Autoprefixer within and shares the list with it, so prefixes are only applied when you're going to need them given your browser support list.

There's a @ custom-media proposal (and PostCSS plugin) that can make it a lot easier to use media queries across components. Define your MQs in your global CSS, use everywhere. If you're worried about repeating MQs in your CSS from a bloat perspective, there are PostCSS plugins for that as well.

The term you are looking for is "nesting". CSS currently does not support it. But there is a draft being worked on. No browser currently supports it, though. Most CSS Pre- or Postprocessors like Sass, Less, Stylus, PostCSS support nesting.

LESS [ https://lesscss.org ]

Traditionally CSS lacked features such as variables, nesting, mixins, and functions. This was frustrating for Developers as it often led to CSS quickly becoming complex and cumbersome. In an attempt to make code easier and less repetitive CSS pre-processors were born. You would write CSS in the format the pre-processor understood and, at build time, you'd have some nice CSS. The most common pre-processors these days are Sass, Less, and Stylus. Any examples I give going forward will be about Sass as that's what I'm most familiar with.

In the past, you’d need to rely on pre-processors such as SaSS or Less, but not anymore… Native CSS nesting has landed on all major modern browsers.

Consider using CSS preprocessors like Sass or Less not only for better code organization but also for potential performance improvements.

Extensions of CSS: for example, Sass, Less, Tailwind, CSS Modules, to make stuff look a certain way on your own.

LiveCodes provides many of the commonly used developer tools. These include Monaco editor (that powers VS Code), Prettier, Emmet, Vim/Emacs modes, Babel, TypeScript, SCSS, Less, PostCSS, Jest and Testing Library, among others. All these tools run seamlessly in the browser without any installations or configurations. It feels like a very light-weight version of your own local development environment including the keyboard shortcuts, IntelliSense and code navigation features.

LESS

The CSS Working Group had been aware of the need for CSS variables since its inception in 1997. By the late 2000s, developers had created various workarounds like custom PHP scripts and preprocessors like Less and Sass to compensate for this deficiency.

He could do with LESS

While we may disagree whether Sass is still relevant today, Mayank's case for using Sass in 2022 sums up the many use cases for Sass/SCSS including a timeline from 2006 (Sass) to "2022+" (nesting). Nesting CSS used to one of the few good reasons left to choose Sass, SCSS (or less) in a new web project.