tabs and webNavigation: to listen the tab create and update events, and insert css or replace css for the pages.
webRequest and webRequestBlocking: for "modify CSP headers".
contextMenus: Add right-click menus into browser's menu.
storage: storage all styles and settings.
downloads: export styles.
*://*/*: get permission to insert css to all websites.
clipboardWrite: auto copy md5 value when export one style.

If you think my explanations is reasonable, please revise your comments. If you have any other opinions, please submit a issue on GitHub