viewport units

1vw = 1% of viewport width
1vh = 1% of viewport width
1vmin = 1vw or 1vh, whichever is smaller
1vmax = 1vw or 1vh, whichever is larger

 

ie8

<!--[if lte IE 8]>
<link rel="stylesheet" type="text/css" href="ie8-and-down.css" />
<![end]-->

.size{
    width: 1130px; //wartość na sztywno w px
}