Change size of body text in Jupyter notebook

Question

I'd like to increase the size of all body text (I don't know the right term, but text that is not in a special markdown category) in a dozen Jupyter notebooks. The notebooks are all stored in one repo, so they can share a css file. But I've no expertise in css.

The directory containing these notebooks has this custom.css file

h4 {
    font-weight: normal;
    text-align: justify;
}

#TOC, #book-cover {
    width: 50%;
    float: left;
}

#TOC {
    font-size: 130%;
}

#main_content_wrap p, #main_content_wrap ol {
    text-align: justify;
}

#main_content_wrap ul li {
    list-style-type: none;
    margin-bottom: 5px;
}

#main_content_wrap ul li a {
    font-weight: bold;
}

#image-cc {
    width: auto !important;
}

but I do not know if it is being used. The system (a Docker container) contains a .jupyter directory, but it contains no css files.

Ideally, I'd like a reference to a clear, fairly simple manual on using css for Jupyter notebooks. I'm aware of this good CSS reference , but it does not consider Jupyter notebooks. ("Give a man a fish ..., teach a man to fish ...")

Thanks, Arthur

Answer 1

If you set the body tag font size, it will change the text everywhere. This includes relative sized css like your #TOC id which is based in % and also will impact any relative size values like em .

body { font-size: 20px; }