userContent.css

/*
 * In this file you can enable styles which apply to web pages' content.
 * To enable a specific feature, uncomment its @import line by removing "/*" at
 * the beginning of the line. To disable it, put the "/*" back.
 */

/* Firefox' internal pages
 * Applies to all about: pages (settings, addons, new tab, etc). */
/*@import "pages/about-light.css"; /**/
/*@import "pages/about-dark.css"; /**/

/* Firefox' source viewer
 * Applies to all view-source: pages. */
/*@import "pages/view-source-dark.css"; /**/

/* Import a custom stylesheet
 * Everything you add in your customContent.css file (it doesn't exist by
 * default) will be included here and preserved between updates, so you can move
 * your configuration to that file if you don't like setting it up after every
 * update. You can also apply your own custom styles in that file. */
@import "customContent.css"; /**/