Diffrenet width for desktop and mobile

[gamestoenjoy]

Hi,

In use WordPress with the theme twenty thirteen.

I have empty spaces when I check my site in desktop, so I want to use width of 50%
In style.css I changed for .site the width to 50% instead of 100% and it worked great in the desktop, but when I checked my site in mobile it also changed the width to 50%
I want the desktop version of my site to be 50% width, but the mobile version to still be 100%

I also added:
.site {
width: 50%;
}
to all @media besides @media (max-width: 359px) which is used for mobile, but noting happened...
The site is still shown with 100% width in my desktop.

What am I doing wrong?

My site: Online Conversion

Thanks for your help,
Oren

 

[RH-Calvin]

Not an expert with WordPress, but I can suggest you for a responsive web design for your website. This will help enable your desktop as well as mobile format for your website with equally spaced characters and design.

 

[creativehead]

problem might be with CSS class-

Code (CSS):
@media screen and (min-width: 1280px) {
.site {
width: 50%;
}
}
This should display your site in 50% width on resolutions of 1280px and higher. Try not to edit theme core files.Not to lost changes when you update the theme and to keep track of your changes add it in your site using the following plugin if your theme doesn't have custom CSS tab:
http://wordpress.org/plugins/simple-custom-css

 

[gamestoenjoy]

@creativehead it worked, thank you!