Vietnamese font on Theme Rose

I want to display Vietnamese character on my website but it has font issue. How can I change the font setting?

Hi!
TO change font of post title, for instanse, you need to edit the code:

a.post_ttl, .post-caption h1 {
	color:#636363;
	font-family: 'oleo_script_swash_capsregular';
	font-size:30px;
}

inside style.css file located in the directory of the theme on your server.
There are several css files: style.css located in the directory of the theme and the others inside /css folder. Inspecting the page you will be able to find the line and the file you have to edit. We don't provide such kind of services.