Mixin de desfoque simples, funcionará no Chrome 28+, Safari 6+, IE6-9, Firefox 10+
@mixin blur($px: 0) {
-webkit-filter: blur(#{$px}px) !important;
-ms-filter: blur(#{$px}px) !important;
-moz-filter: blur(#{$px}px) !important;
filter: url("data:image/svg+xml;utf8,<svg >);
filter:progid:DXImageTransform.Microsoft.Blur(PixelRadius='#{$px}');
}