Recently, I created a blog. The problem is that its menus are showing up twice in mobile version. On desktop, it's working fine. I can't attach picture because of reputation so please visit this blog http://99hax.com on mobile and you can see menu in header. Below those menus, you'll see a menus button. Clicking on it will show same menus. This blog is hosted by awardspace and I have installed wordpress in it. That's why I am not able to understand what's the problem.
The following custom CSS was added to the site:
.main-menu {
display: inline-block;
}
That CSS overrides the display: none; CSS that is used to hide the main menu on smaller screens.
You can remove that CSS from the Additional CSS panel of the Customizer (in the dashboard navigate to Appearance > Customize)