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I am trying to make the primary navigation list items a larger font size.

I have tried changing it in Appearance > Theme Options > Menu Settings
But when I save and refresh the page the setting go back to the default

I have tried putting
#nav-main ul.sf-menu a {
font-size: 15px;
}
into the style.css file of the child theme which didn’t work. I then put it in the Appearance > Theme Options > Advanced Setting > Custom CSS which didn’t work and so then I put it in the Customize > Additional CSS which also did not work.

I’m not sure what to do now. My theme is up to date.

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