Works correctly in the latest versions of Firefox & Blink-based browsers (Chrome, Opera). I have no intention to add support for IE, Edge or Safari as none of them have support for the fetch API used in the code.
I'm not planning to provide separation of Russian & Ukrainian teams, either, as it requires adding a dozen of lines which may become unnecessary in future.
Still, anyone may submit a pull request with polyfills to add support for IE, Edge, Safari and various kinds of mobile & fossil browsers and/or the fix for the Rus-Ukr teams which will be temporarily merged into the gh-pages branch.