完整代码：
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title>
</head>
<body>
<script>
! function() {function n(n, e, t) {return n.getAttribute(e) || t}function e(n) {return document.getElementsByTagName(n)}function t() {var t = e("script"),o = t.length,i = t[o - 1];return {l: o,z: n(i, "zIndex", -1),o: n(i, "opacity", .5),c: n(i, "color", "0,0,0"),n: n(i, "count", 99)}}function o() {a = m.width = window.innerWidth || document.documentElement.clientWidth || document.body.clientWidth, c = m.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight}function i() {r.clearRect(0, 0, a, c);var n, e, t, o, m, l;s.forEach(function(i, x) {for(i.x += i.xa, i.y += i.ya, i.xa *= i.x > a || i.x < 0 ? -1 : 1, i.ya *= i.y > c || i.y < 0 ? -1 : 1, r.fillRect(i.x - .5, i.y - .5, 1, 1), e = x + 1; e < u.length; e += 1) {n = u[e], null !== n.x && null !== n.y && (o = i.x - n.x, m = i.y - n.y, l = o * o + m * m, l < n.max && (n === y && l >= n.max / 2 && (i.x -= .03 * o, i.y -= .03 * m), t = (n.max - l) / n.max, r.beginPath(), r.lineWidth = t / 2, r.strokeStyle = "rgba(" + d.c + "," + (t + .2) + ")", r.moveTo(i.x, i.y), r.lineTo(n.x, n.y), r.stroke()))}}), x(i)}var a, c, u, m = document.createElement("canvas"),d = t(),l = "c_n" + d.l,r = m.getContext("2d"),x = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(n) {window.setTimeout(n, 1e3 / 45)},w = Math.random,y = {x: null,y: null,max: 2e4};m.id = l, m.style.cssText = "position:fixed;top:0;left:0;z-index:" + d.z + ";opacity:" + d.o, e("body")[0].appendChild(m), o(), window.onresize = o, window.onmousemove = function(n) {n = n || window.event, y.x = n.clientX, y.y = n.clientY}, window.onmouseout = function() {y.x = null, y.y = null};for(var s = [], f = 0; d.n > f; f += 1) {var h = w() * a,g = w() * c,v = 2 * w() - 1,p = 2 * w() - 1;s.push({x: h,y: g,xa: v,ya: p,max: 6e3})}u = s.concat([y]), setTimeout(function() {i()}, 100)
}();
</script>
</body>
</html>
效果图：
