documentation/How-to-edit-css.md

+The Lektor-based sites predominently use Sass as a powerful CSS preprocessor. Because Sass is compiled, editing the styles of one of the Lektor sites requires a bit more work than editing a CSS file directly.
+
+### Installing the Sass compiler
+
+The javascript implementation of sass from npm doesn't compile our SCSS anymore, so you'll have to install the [dart sass compiler](https://github.com/sass/dart-sass). Here's a script to automate that process (don't forget to add the install directory to your path!):
+
+```bash
+#!/usr/bin/env bash
+
+set -e
+set -u
+
+# replace with macos or windows (through something like cygwin) as appropriate
+package_name='linux'
+
+download_url=$(curl \
+               https://api.github.com/repos/sass/dart-sass/releases/latest \
+               | grep -E "browser_download_url.*$package_name-x64" \
+               | awk '{print $2}' \
+               | cut -d "\"" -f 2)
+
+mkdir -p "$HOME/bin"
+extension=$(echo $download_url | rev | cut -d '.' -f -2 | rev)
+case "$extension" in
+    tar.gz)
+      curl -L "$download_url" | tar xvz --strip-components=1 -C "$HOME/bin" -- dart-sass/sass;;
+    zip)
+      tmpfile=$(mktemp /tmp/temporary_sass_download.XXXXXX.zip)
+      trap "rm -f $tmpfile" 0 2 3 15  # remove on exit
+      curl -L "$download_url" -o "$tmpfile"
+      unzip -p "$tmpfile" >&3 "$HOME/bin/sass"
+      ;;
+    *)
+      echo "Unknown file extension" && exit 1;;
+esac
+
+chmod +x "$HOME/bin"
+
+echo "sass installed to $HOME/bin, please make sure that directory is in your path"
+```
+
+### Editing and rebuilding Sass files
+
+If you're editing a CSS file directly from the [lego repo][1], the following command will rebuild all the scss:
+
+```bash
+sass assets/scss:assets/static/css
+```
+
+More likely, you'll be making multiple changes from another repository that uses lego as a submodule.
+In that case, the following command will automatically recompile any changed SCSS files:
+
+```bash
+sass --watch lego/assets/scss:lego/assets/static/css
+```
+
+Don't forget to commit your changes to the lego repo and make an MR when you're done!
+
+```bash
+cd lego
+git add assets/scss
+git commit
+```
+
+[1]: https://gitlab.torproject.org/tpo/web/lego/
+
+### More Sass resources
+
+- Install Sass: <https://sass-lang.com/install
+- Learn Sass: <https://sass-lang.com/guide>
+- Sass documentation: <https://sass-lang.com/documentation>
+