Background-blur
:before
{
content: "";
position: fixed;
left: 0;
right: 0;
z-index: -1;
display: block;
width: 100%;
height: 100%;
background: url('/imgs/background-2.jpg');
background-size: cover;
background-position: top center;
-webkit-filter: blur(5px);
-moz-filter: blur(5px);
-o-filter: blur(5px);
-ms-filter: blur(5px);
filter: blur(5px);
}