so, someone know how to reduce that big circle?

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

i don't think it is a conflict or bug problem. the big circle seems to be the defaut design (at least from some screenshot i have seen, the circle is that big). i just want to know if there is a parameter in about:config that can reduce the size, if not, a code to use in chrome.css.

I don't have a touch pad to check this out, so you would have to check this arrow in the Browser Toolbox.

• https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox

To enable the Browser Toolbox, see:

• select "Enable remote debugging" in the Web Developer Tools settings
• https://developer.mozilla.org/en-US/docs/Tools/Settings