Пример CSS медиа запросов под разные размеры экрана

 
@media only screen and (max-width: 1200px)
{
	#page-wrapper
	{
		width: 1024px;
		border: 10px green solid;
	}
}
@media only screen and (min-width:1200px)
{
	#page-wrapper
	{
		width: 1200px;
		border: 10px blue solid;
	}
}

 
    /* default styles here for older browsers. 
       I tend to go for a 600px - 960px width max but using percentages
    */
    @media only screen and (min-width:960px){
        /* styles for browsers larger than 960px; */
    }
    @media only screen and (min-width:1440px){
        /* styles for browsers larger than 1440px; */
    }
    @media only screen and (min-width:2000px){
        /* for sumo sized (mac) screens */
    }
    @media only screen and (max-device-width:480px){
       /* styles for mobile browsers smaller than 480px; (iPhone) */
    }
    @media only screen and (device-width:768px){
       /* default iPad screens */
    }
    /* different techniques for iPad screening */
    @media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:portrait) {
      /* For portrait layouts only */
    }

    @media only screen and (min-device-width: 481px) and (max-device-width: 1024px) and (orientation:landscape) {
      /* For landscape layouts only */
    }