Advanced LESS Usage & Bootstrap
We've only scratched the surface of what's possible here. Concrete5 ships with a full and complete LESS parser, meaning anything that LESS can do, Concrete5's style customizer can do. You don't even have to use Concrete5's Style Customizer to make use of the LESS parser.
Here are some things you can try:
You can use built-in Bootstrap mixins in your Concrete5 theme LESS files.
Use Concrete5 Style Customizer variables as part of these mixins (e.g. make a gradient mixin configurable through the Concrete5 style customizer)
Use Concrete5 customizable styles as part of built-in LESS mixins like lighten().
Use LESS Expressions and Variables
Use Bootstrap variables as the basis for Concrete5 variables.
Important note: You can't use Bootstrap variables as Concrete5 customizer variables out of the box, since Concrete5 customizer have specific naming suffixes.
The 5.7 style customizer is one of the most useful and powerful things to come to Concrete5 theming ever, and we can't wait to see what you do with it.