# Add your own CSS rules To customize the look of your site further, you can customize your CSS stylesheets, as described in the [ReadTheDocs Docs](https://docs.readthedocs.io/en/stable/guides/adding-custom-css.html#adding-custom-css-or-javascript-to-sphinx-documentation). First, create a CSS file and place it in `_static/custom.css`. An example CSS file to change the color of the top-level headers might look like this. ```css h1 { color: #003B71 !important; } ``` You also need these two lines in your `conf.py` file ```python html_static_path = ["_static"] html_css_files = ["custom.css"] ```