Many pages (including coding-related) have broken layout when using Yandex Browser (just a Chrome-based browser). The strange thing that this depends only on user-agent (the string that is used by browser to identify itself). When user-agent is set to Chrome's, everything is fine.
Yandex Browser's user-agent:
Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 YaBrowser/126.96.36.19924 Yowser/2.5 Safari/537.36
This is just Chrome's user-agent with "YaBrowser/188.8.131.5224 Yowser/2.5" inserted. And this little change breaks the page!