1 <!-- 为页面添加爱心特效 -->
 2 (function (window, document, undefined) {
 3     var hearts = [];
 4     window.requestAnimationFrame = (function () {
 5         return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
 6             function (callback) {
 7                 setTimeout(callback, 1000 / 60);
 8             }
 9     })();
10     init();
11 
12     function init() {
13         css(".heart{width: 10px;height: 10px;position: fixed;background: #f00;transform: rotate(45deg);-webkit-transform: rotate(45deg);-moz-transform: rotate(45deg);}.heart:after,.heart:before{content: '';width: inherit;height: inherit;background: inherit;border-radius: 50%;-webkit-border-radius: 50%;-moz-border-radius: 50%;position: absolute;}.heart:after{top: -5px;}.heart:before{left: -5px;}");
14         attachEvent();
15         gameloop();
16     }
17 
18     function gameloop() {
19         for (var i = 0; i < hearts.length; i++) {
20             if (hearts[i].alpha <= 0) {
21                 document.body.removeChild(hearts[i].el);
22                 hearts.splice(i, 1);
23                 continue;
24             }
25             hearts[i].y--;
26             hearts[i].scale += 0.004;
27             hearts[i].alpha -= 0.013;
28             hearts[i].el.style.cssText = "left:" + hearts[i].x + "px;top:" + hearts[i].y + "px;opacity:" + hearts[i].alpha + ";transform:scale(" + hearts[i].scale + "," + hearts[i].scale + ") rotate(45deg);background:" + hearts[i].color;
29         }
30         requestAnimationFrame(gameloop);
31     }
32 
33     function attachEvent() {
34         var old = typeof window.onclick === "function" && window.onclick;
35         window.onclick = function (event) {
36             old && old();
37             createHeart(event);
38         }
39     }
40 
41     function createHeart(event) {
42         var d = document.createElement("div");
43         d.className = "heart";
44         hearts.push({
45             el: d,
46             x: event.clientX - 5,
47             y: event.clientY - 5,
48             scale: 1,
49             alpha: 1,
50             color: randomColor()
51         });
52         document.body.appendChild(d);
53     }
54 
55     function css(css) {
56         var style = document.createElement("style");
57         style.type = "text/css";
58         try {
59             style.appendChild(document.createTextNode(css));
60         } catch (ex) {
61             style.styleSheet.cssText = css;
62         }
63         document.getElementsByTagName('head')[0].appendChild(style);
64     }
65 
66     function randomColor() {
67         return "rgb(" + (~~(Math.random() * 255)) + "," + (~~(Math.random() * 255)) + "," + (~~(Math.random() * 255)) + ")";
68     }
69 })(window, document);