Use Sass to compensate for deficiencies detected by Modernizr.js

sass-modernizr.scss

// For example, use "no-cssanimations" for a browser that lacks CSS3 animation support

@mixin modernizr($test) {
    html.#{$test} & {
        @content;
    }
}

Usage:

.selector {
    left: 0;

    @include modernizr(no-cssanimations) { left: 400px; }
}

Compiles to:

.selector {
    left: 0;
}

html.no-cssanimations .selector {
    left: 400px;
}