Helvetica and similar fonts containing cyrilyc letters

I need to setup Helvetica font on website, downgrading to other similar fonts when helvetica not available. Fonts mast contain cyrilyc. Must be system font, and work on all systems.
I dont known is SF Pro contain cyrilyc. It even prefered then helvetica.
Please help to find all similar system fonts on all OS/device.

body { font-family: "SF Pro", "Helvetica CY", "Arial", sans-serif; } 

Which text fonts survive images compression the best? [on hold]

I’m creating diagrams in Office Excel for people in my community and the platform it is uploaded on has a tendency to compress the images. Sometimes this results in near unreadable text. It is uploaded as an image because that is the desired format of the community.

Can you give me some advice on which fonts would likely survive compression the best?

Best regards, Kenneth

SVG and Google Fonts

I would like to use SVG files for some tables on a website, the code weighs in at a lightweight 35Kb and, of course, it’s scalable.

I am using <object> as the embedding method (basically after trying and failing with <img>.

Unfortunately the only way I can get the use of site fonts is by putting in a call to google fonts within the SVG file itself.

<style>   @import url('https://fonts.googleapis.com/css?family=Work+Sans'); </style> 

which, instinctively seems like bad practice.

Is it bad practice? Is there a better way to access the site fonts?

Selection, storing, caching of custom fonts

I would like you something about font paths and font caching in Drupal 8 (8.7.2).

My aim is to use a custom font, without using the @font-your-face-module.

Just for trying out, on my local installation, I added the font-family in line 17 of core/themes/bartik/css/components/site-branding.css

At this moment, my font file resides on my desktop folder, Drupal chaching is disabled.

Actually, the font is displayed correctly – no need to put the font file in a drupal directory, no need to define any path to the font file.

How can this work? How does Drupal know from where to pull the font?

Even stranger, the fonts remains displayed correctly even after deleting the font file from desktop and performing cache deletion in Drupal.

Can someone figure out how Drupal pulls and stores fonts?

Thank you very much in advance