SASS gradient mixin
@mixin linearGradient($top, $bottom){
background: $top; /* Old browsers */
background: -moz-linear-gradient(top, $top 0%, $bottom 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,$top), color-stop(100%,$bottom)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, $top 0%,$bottom 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, $top 0%,$bottom 100%); /* Opera 11.10+ */
background: -ms-linear-gradient(top, $top 0%,$bottom 100%); /* IE10+ */
background: linear-gradient(to bottom, $top 0%,$bottom 100%); /* W3C */
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorStr='#{ie-hex-str($top)}', EndColorStr='#{ie-hex-str($bottom)}')";
}