How do I increase highlight for selected text of input cells in Jupyter notebook on Ubuntu in Chromium?

Question

When I select text of input cells in Jupyter Notebook on Ubuntu in Chromium, I can barely see the highlight. Like this (everything after "100" is highlighted):

On output cells I can easily see the highlighted text (blue background):

How can I fix this? It's hard to do copy-paste edits on input cells when I can barely see what I've selected.

Answer 1

Follow these steps:

1. Find your configuration folder (I will assume it is ~/.jupyter) with

   import jupyter_core
   jupyter_core.paths.jupyter_config_dir()
   

   You can easily find what would be the corresponding directory for Windows, if needed.

2. Create a folder ~/.jupyter/custom, if it does not exist. Other folders might also work (How do I set custom CSS for my IPython/IHaskell/Jupyter Notebook?).

3. Create an empty file ~/.jupyter/custom/custom.css, if it does not exist.

4. Add

   .cm-s-ipython div.CodeMirror-selected {
       background: #859900 !important;
   }
   

   to your custom.css. Use a suitable color.

5. Reload your notebook in the browser, for immediate results.

Answer 2

I solved by loading jupyter notebook from Terminal (not anaconda), once loaded, I looked for the .css in the execution files that load in the terminal window, and found the styling file.

The file name is style.min.css

/home/<user>/anaconda3/lib/python3.6/site-packages/notebook/static/style/style.min.css

ctrl + f to browse inside the file and your set!

FYI my version of jn:

$ jupyter notebook --version
6.0.0