Where to set viewport size in wordpress theme genesis

[admin]

I have the following meta tag in functions.php file under wordpress.

<meta name="viewport" content="width=device-width">

and custom CSS as:

.x-navbar .desktop .x-nav>li>a>span {
padding-left:15px;
padding-right:15px;
}

.x-comments-area{
display:none;
}

@media (max-width: 1024px) and (min-width:801px){
.x-navbar {
  font-size: 12px;
}

.x-navbar .desktop .x-nav>li>a>span {
padding-left:5px;
padding-right:5px;
}
}

I need to change viewport size as google insight says:

<blockquote>
The page content is 389 CSS pixels wide, but the viewport is only 375
CSS pixels wide.
</blockquote>

I would like to know where I put the changes in genesis theme as I have got the wordpress website for optimization.