Hi,

1) This is if you want to change the header logo size.

@media (max-width: 991px) {
    .header-wrapper header .logo a {
        font-size: 20px !Important;
    }
}

That works if you're using font as a logo, if you're using image, please use width and height.

{
    height: 100px !important;
    width: 100px !important;
}

2) Yes, we use the REM unit which means it's root element size.

So, you can manipulate with the following font sizes.

@media (min-width: 1201px) {
    html {
        font-size: 11px !important;
    }
}
@media (min-width: 769px) {
    html {
        font-size: 10px !important;
    }
}
html {
    font-size: 8px !important;
}

I've send you the default font sizes, you can change them to any number. By changing these means you'll change each font in the theme that uses rem as unit(most of them use). For example the page heading.

- https://prnt.sc/qmnzw3

It uses 6.5rem, so in 600 pixel, it will be 8 * 6.5, in 800 it will be 10 * 6.5 and so on.

Feel free to ask for anything you need.

Kind Regards

You are welcome anytime, feel free to ask for anything you need

If you like our theme, please leave us a rate with 5 stars at ThemeForest, that would help us a lot.

Kind Regards,
NeuronThemes