Manipulate unicode-range while importing from Google Fonts - css

Question

My question can be seen as a follow-up of this answer.
I use Google Fonts for my project and now want to change the unicode-range, so only numbers are affected (see linked answer above). My problem is that I don't get it to work with an include:
#import url("http://fonts.googleapis.com/css?family=Lato:300,400,700");
When I import the font like this, the font-face is already generated by Google (Google provides also the correct font-face setup to avoid cross browser problems, very convenient). I tried overwriting the imported font-face like this:
#font-face {
font-family: 'Lato';
font-style: normal;
font-weight: 400;
unicode-range: U+30-39;
}
But that didn't work. To achieve the desired affect of having only numbers attached, I need to take the CSS from the Google import URL and copy it into my own CSS/SASS document. But then I lose the cross browser service that was done by Google Fonts API and also the speed of their CDN.
Is there a way to change the unicode-range while maintaining the Google font import or do I really need to host the fonts myself when I want to use unicode-range?

Answer 1

If you want set the range while you are importing, just add to the link the variable 'subset'.
For example:
#import url("http://fonts.googleapis.com/css?family=Lato:300,400,700&subset=latin");
Or, if the text is very small you can change the subset variable for text, and add the content inside.
For example:
#import url("http://fonts.googleapis.com/css?family=Inconsolata&text=Hello");
Documentation

Answer 2

What is unicode-range?
It's a prop used to tell the browser when to download a font file. As soon as any character that belongs to the given range is rendered: the font file is downloaded.
The unicode-range is not intended to assign the style to the characters from the given range .
Solution
The best option is to use the text parameter to get a font file per style that contains just the characters you need, in this case the range [0-9].
URL:
https://fonts.googleapis.com/css?family=Lato:300,400,700&text=0123456789
Google Fonts response:
#font-face {
font-family: 'Lato';
font-style: normal;
font-weight: 300;
src: url(https://fonts.gstatic.com/l/font?kit=S6u9w4BMUTPHh7USewqdFhfZ3-4B28Jv7vc&skey=91f32e07d083dd3a&v=v22) format('woff2');
}
#font-face {
font-family: 'Lato';
font-style: normal;
font-weight: 400;
src: url(https://fonts.gstatic.com/l/font?kit=S6uyw4BMUTPHvxwiUT-eLhTc2OsC1s0&skey=2d58b92a99e1c086&v=v22) format('woff2');
}
#font-face {
font-family: 'Lato';
font-style: normal;
font-weight: 700;
src: url(https://fonts.gstatic.com/l/font?kit=S6u9w4BMUTPHh6UVewqdFhfZ3-4B28Jv7vc&skey=3480a19627739c0d&v=v22) format('woff2');
}