SASS:@mixin:doubleborder

doubleborder.scss

@mixin doubleborder($side, $innerColor, $outerColor) {
    $shadow: "0 0 0";
    border-#{$side}: 1px solid $innerColor;
    @if ($side == "top") { $shadow: 0 -1px 0; }
    @if ($side == "right") { $shadow: 1px 0 0; }
    @if ($side == "bottom") { $shadow: 0 1px 0; }
    @if ($side == "left") { $shadow: -1px 0 0; }
    -webkit-box-shadow: $shadow $outerColor;
    -moz-box-shadow: $shadow $outerColor;
    -o-box-shadow: $shadow $outerColor;
    box-shadow: $shadow $outerColor;
}

#blog {
    @include doubleborder(top, #fff, #cdd4b4);
}