This is loading for me on Chrome and my phone, but not across some other browsers / devices.
I’ve included examples from Safari as well as from an iPhone, which both show a font that I think is Times New Roman (or similar!) Is there a way to make sure the same font is used for every device and browser?
a System Font requires the font to be installed on the device. So unless you force all your users to download the font then no you cannot guarantee any System Font to be the same across all devices.
If Century Gothic is a font you really want then you would need to own a license copy of the font and install it locally.