Modifying content width of the Sphinx theme 'Read the Docs'

Question

I am using \'Read the Docs\' Sphinx theme for my documentation. In the original theme, given below

http://read-the-docs.readthedocs.org/en/latest/theme.html

Answer 1

The HTML option added in Sphinx 1.8.0b1 (released Sep 2018) simplifies the process. The recommendation in Read The Docs Documentation is adding custom css to the theme via the html_css_files option in conf.py.

html_css_files = [
    'custom.css',
]

Put the custom.css in the html static path folder (Default is _static folder).

Content of custom.css:

.wy-nav-content {
    max-width: 75% !important;
}