pip install --upgrade sphinx sphinx-autobuild

Sphinx is the main documentation package; sphinx-autobuild is used for hot-load development.

After cloning the repo, run

sphinx-autobuild docs/source docs/build/_html

sphinx-build -b html sourcedir builddir

See the official docs, as well as this Stack Overflow thread to assign a custom CSS to the Sphinx template.

1. Place the following line into source/_templates/layout.html:

{% set css_files = css_files + ['_static/css/alabaster-custom.css'] %}

2. If hot-loading doesn't reload the custom CSS, simply copy your custom CSS into the folder _html/_static/css.