First, get a copy of the style sheet:
Then, run the makeinfo --html command specifying the
--css-ref option. For example:
$ makeinfo --html --css-ref=texinfo-7.css --output=/tmp/mydocs/ main.texi
Every HTML page in the resulting documentation will have an HTML link element like this:
<link rel="stylesheet" type="text/css" href="texinfo-7.css">
You can pass --css-ref any location accepted by link’s
href attribute. For example:
static/css/texinfo-7.css /static/css/texinfo-7.css https://luis-felipe.gitlab.io/texinfo-css/static/css/texinfo-7.css
Finally, make sure to place the style sheet file in the indicated location.