hackernews.js

register_user_stylesheet(
    "data:text/css," +
        escape (
          "@-moz-document url-prefix(http://news.ycombinator.com/) {" +
            ".current {" +
            "   -moz-animation: 2s flash;" +
            "   background-color: #FCEDCC;" +
            "}" +
            "@-moz-keyframes flash { " +
            "   0%  { background-color: inherit; }" + 
            "   20% { background-color: #FFCD7D; }" +
            "  100% { background-color: #FCEDCC; }" + 
            "}" +
            ".current-comment > td.default {" +
            "   -moz-animation: 2s flash;" +
            "   background-color: #FCEDCC;" +
            "}" +
            "}"
));