That's punycode. Your browser is configured to display everything as ascii, using the punycode "transcoding". It's a good practice, see the binance hack that us

That's punycode. Your browser is configured to display everything as ascii, using the punycode "transcoding". It's a good practice, see the binance hack that used binance.com with a tiny diacritic on one of the letters, that lead to a huge phishing attack.