Hello, @Kazi Sabit,
1- Alright, I have removed the line and now the text of buttons appears in 1 line see image: https://postimg.cc/tsv50dR3 I have done this with the help of CSS code you can see it here: https://postimg.cc/5XzwrhGV
2- Regarding the button issue on mobile it is also fixed with the help of CSS code as you can see in this image: https://postimg.cc/KR8bJF11 here is the resulting image: https://postimg.cc/QF6H00N3
Regards 8Themes Team.