SASS 3.3 Animation mixin

@mixin animation($animate...) {
    $max: length($animate);
    $animations: '';

    @for $i from 1 through $max {
        $animations: #{$animations + nth($animate, $i)};

        @if $i < $max {
            $animations: #{$animations + ", "};
        }
    }
    -webkit-animation: $animations;
    -moz-animation:    $animations;
    -ms-animation:    $animations;
    -o-animation:      $animations;
    animation:         $animations;
}

@mixin keyframes($animationName) {
    @at-root{
        @-webkit-keyframes #{$animationName} {
             @content;
         }
        @-moz-keyframes #{$animationName} {
            @content;
        }
        @-o-keyframes #{$animationName} {
            @content;
        }
        @keyframes #{$animationName} {
            @content;
        }
    }
}