Custom Style Script customizes the way a webpage looks or behaves, by adding a small JavaScript or CSS code. You can also specify a URL to add the code or add it to all pages.

Key features:
1. Add custom JavaScript codes or styles (CSS) to a specific page or all pages.
2. Each code item has several options to adjust (see options page for details).
3. You can add several code items and active or inactive them separately.
4. An example of how to add a code is available on the addon's options page.
5. Before adding the code (JS or CSS) please make sure you have validated the code.
6. Online JS or CSS links (i.e. jQuery or bootstrap) can also be added to any page. See the addon's options page for details.

Note: to report bugs, or request a feature, please visit the addon's homepage (https://mybrowseraddon.com/custom-style-script.html) and fill out the bug report form.