Select form control (size="1") in vertical-lr writing-mode (Mongolian)

Actual (live) result in your browser:

Expected result (approx. rendering):

1 ᠳ᠋ᠤᠭᠡᠷ ᠮᠦᠷ

2 ᠳ᠋ᠤᠭᠡᠷ ᠮᠦᠷ

3 ᠳ᠋ᠤᠭᠡᠷ ᠮᠦᠷ

4 ᠳ᠋ᠤᠭᠡᠷ ᠮᠦᠷ

5 ᠳ᠋ᠤᠭᠡᠷ ᠮᠦᠷ