Chrome extensions for quick site redesigns

There’s this thing I hate about the modern web which is that sites are rarely one giant html file filled with goodies. You can’t just “run a site” locally. You need an npm or a gulp step or a docker if you’re lucky. And probably a local server, but not the one you have installed. Which, I mean, makes sense, because modern web sites are big and powerful and have complicated front-ends and do more things than a giant html file would. But it also kind of sucks because the build ceremonial sacrifices can be a bit overwhelming. Maybe you just want to see what the links would look like if they didn’t have underlines. Maybe you want to change the fonts. Maybe you’re never even going to ship these changes, you just want to get a feel for them.

Boy, have I got an idea for you: Chrome extensions. Hear me out. A Chrome extension is a bit of code that runs on a specific page (or set of pages). It can be anything you want. In particular, it can be a CSS stylesheet.

Then, re-theming a site is just a matter of installing this Chrome extension. If you want to share it with people, you can just zip it up and send it around. It’s obviously not production ready, but it’s amaaaaazing for prototyping.

I made a glitch project that gets you started with writing a Chrome extension that injects a CSS stylesheet. There’s only one thing you need to know: this stylesheet is a User Agent stylesheet, which means it has the lowest specificity. So some of its styles won’t get applied unless you slap some !importants on it (or have extra specific selectors). Or, if you have an ID, you can do my favourite CSS hack ever that I learnt from Surma and will take to the grave:

#foo#foo {
  /* this is a really winner #foo selector */
  color: red;

That’s it! If you want to see an example of such an extension in the wild, I made picasso, which is just a pretty Google Calendar theme. Originally it was just a local extension I kept on my machine, but eventually I published it because I realized other people may want to give their calendar a bubble bath. Anyway, happy retheming!