change flowert to sushi (original : http://pastebin.com/x4U2bLu2) for stylish

heartToSushiOnTwitter.user.css

@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document url("https://twitter.com/") {
    .HeartAnimationContainer {
       visibility: hidden;
    }
    .HeartAnimationContainer:after {
       content: '🍣';
       visibility: visible;
       display: block;
       position: absolute;
    }
}
 
.Icon--heartBadge {
    visibility: hidden;
}
 
.Icon--heartBadge:after {
    content: '🍣';
    visibility: visible;
    font-style: normal;
    vertical-align: baseline;
    display: inline-block;
    position: relative;
}