CSS3 红包雨动画应用

效果：
完整代码：
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <style>
            *{
                padding: 0;
                margin: 0;
            }
            body,html{
                height:100%;
            }
            .rightmenu{
                width:18%;
                height: 95%;
                float:left;
            }
            .rightmenu textarea{
                width:100%;
                height: 100%;
                line-height: 25px;
                font-size: 16px;
                padding-top:20px;
                padding-left:20px;
            }
            .content{
                width:80%;
                position:relative;
                height:100%;
                background:#f2f2f2;
                float:left;
            }
            .content .yudi{
                position:absolute;
                opacity: 0;
                animation: drops 1.5s linear;
                
                /*红包样式*/
                width:60px;
                height:72px;
               background: url("img/redpacket.png");

                /*落雨样式*/
                /*4px;
                height: 6px;
                background: #666;
                clip-path: ellipse(10% 30% at 50% 50%);
                animation: drops 2s cubic-bezier(0.54, 0, 0.26, 0.69) infinite;*/
                
            }
            @keyframes drops{
                0%{
                    opacity: 0;
                }
                20%{
                    opacity: 1;
                }
                90%{
                    opacity: 1;
                }
                100%{
                    opacity: 0;
                    transform: translate3d(10px,80vh,-10px);  /*vh:相对于视口的高度。视口被均分为100单位的vh*/
                }
            }
        </style>
        <title></title>
    </head>
    <body>
        <div class="content">
        </div>
        <div class="rightmenu">
            <textarea></textarea>
        </div>
    </body>
    <script src="js/jquery-3.1.1.min.js"></script>
    <script>
        var moneysum=0;//抢到的红包总额
        var redcount=0;//红包计数
        var redpacketall=40;//红包总数
        var infohtml="";//抢红包的记录
        var $content=$('.content');
        for(var i=0;i<redpacketall;i++){
            var lefts=Math.floor(Math.random()*95);
            var tops=Math.floor(Math.random()*5+2);
            var delay=Math.floor(Math.random()*100);//10秒内的随机时间
            var $div=$('<div/>').addClass('yudi').css({
                "left":lefts+"%",
                "top":tops+"%",
                "animation-delay":delay/10+"s"
            });
            $content.append($div);
        }
        $('.content .yudi').on('click',function(){
            var money=Math.floor(Math.random()*10);//创建随机红包
            $(this).hide();
            redcount+=1;
            moneysum+=money;
            infohtml+="恭喜您获得了"+money+"元红包
";
            $('.rightmenu textarea').val(infohtml);
            activitieend();
        })

        $('.content .yudi').on("animationend",function(){ //监听动画结束
            redcount+=1;
            activitieend();
        })
        
        function activitieend()//当计数器达到红包总数时，活动结束
        {
            if(redcount==redpacketall)
            {
                infohtml+="红包合计："+moneysum+"元";
                $('.rightmenu textarea').val(infohtml);
                alert("活动结束，恭喜您获得了"+moneysum+"元红包");
            }
        }
    </script>
</html>