SOURCE

// 音量大小,0.01-1
document.getElementById('oAu').volume = 0.7;

//宇宙特效
"use strict";
var canvas = document.getElementById('canvas'),
ctx = canvas.getContext('2d'),
w = canvas.width = window.innerWidth,
h = canvas.height = window.innerHeight,

hue = 217,
stars = [],
count = 0,
maxStars = 1100; //星星数量,默认1300
var canvas2 = document.createElement('canvas'),
ctx2 = canvas2.getContext('2d');
canvas2.width = 100;
canvas2.height = 100;
var half = canvas2.width / 2,
gradient2 = ctx2.createRadialGradient(half, half, 0, half, half, half);
gradient2.addColorStop(0.025, '#CCC');
gradient2.addColorStop(0.1, 'hsl(' + hue + ', 61%, 33%)');
gradient2.addColorStop(0.25, 'hsl(' + hue + ', 64%, 6%)');
gradient2.addColorStop(1, 'transparent');

ctx2.fillStyle = gradient2;
ctx2.beginPath();
ctx2.arc(half, half, half, 0, Math.PI * 2);
ctx2.fill();

// End cache
function random(min, max) {
  if (arguments.length < 2) {
    max = min;
    min = 0;
  }

  if (min > max) {
    var hold = max;
    max = min;
    min = hold;
  }

  return Math.floor(Math.random() * (max - min + 1)) + min;
}

function maxOrbit(x, y) {
  var max = Math.max(x, y),
  diameter = Math.round(Math.sqrt(max * max + max * max));
  return diameter / 2;
  //星星移动范围，值越大范围越小，
}

var Star = function() {

  this.orbitRadius = random(maxOrbit(w, h));
  this.radius = random(60, this.orbitRadius) / 10; //星星大小,值越大星星越小,默认8
  this.orbitX = w / 2;
  this.orbitY = h / 2;
  this.timePassed = random(0, maxStars);
  this.speed = random(this.orbitRadius) / 80000; //星星移动速度,值越大越慢,默认5W
  this.alpha = random(2, 10) / 10;

  count++;
  stars[count] = this;
}

Star.prototype.draw = function() {
  var x = Math.sin(this.timePassed) * this.orbitRadius + this.orbitX,
  y = Math.cos(this.timePassed) * this.orbitRadius + this.orbitY,
  twinkle = random(10);

  if (twinkle === 1 && this.alpha > 0) {
    this.alpha -= 0.05;
  } else if (twinkle === 2 && this.alpha < 1) {
    this.alpha += 0.05;
  }

  ctx.globalAlpha = this.alpha;
  ctx.drawImage(canvas2, x - this.radius / 2, y - this.radius / 2, this.radius, this.radius);
  this.timePassed += this.speed;
}

for (var i = 0; i < maxStars; i++) {
  new Star();
}

function animation() {
  ctx.globalCompositeOperation = 'source-over';
  ctx.globalAlpha = 0.5; //尾巴
  ctx.fillStyle = 'hsla(' + hue + ', 64%, 6%, 2)';
  ctx.fillRect(0, 0, w, h)

  ctx.globalCompositeOperation = 'lighter';
  for (var i = 1,
  l = stars.length; i < l; i++) {
    stars[i].draw();
  };

  window.requestAnimationFrame(animation);
}

animation();

<canvas id="canvas">
</canvas>
<audio class="audio" id="oAu" src="http://m2.music.126.net/_lEPRuhlSTnuPesqWU-W2A==/5792227255321905.mp3"
autoplay loop>
</audio>
<!-- autoplay:自动播放, loop:循环, controls:显示音频控件 -->
<div class="wrapper" oncontextmenu="return false;">
  <div class="btn_w">
    <a class="btn" href="javascript:;">
      登 录
    </a>
    <a class="btn" href="javascript:;">
      注 册
    </a>
  </div>
</div>

/*css reset */

body,
p,
div,
ol,
ul,
li,
dl,
dt,
dd,
h1,
h2,
h3,
h4,
h5,
h6,
form,
input,
iframe,
nav {
  margin: 0;
  padding: 0;
}

html,
body {
  width: 100%;
  height: 100%;
}

body {
  font: 14px Microsoft YaHei;
  -webkit-text-size-adjust: 100%;
  -moz-user-select: none;
  -webkit-user-select: none;
  user-select: none;
  position: relative;
  background: #000;
}

a {
  text-decoration: none;
}

ol,
ul {
  list-style: none;
}

img {
  border: 0;
}

.wrapper .btn_w {
  position: absolute;
  margin: auto;
  top: 50%;
  left: 50%;
  margin-top: -22px;
  margin-left: -155px;
  z-index: 10;
}

.wrapper .btn_w .btn {
  background: transparent url(http://ww3.sinaimg.cn/large/bea70753gw1f2g4snrc2cj203m02e3yb.jpg) no-repeat 0 0;
  display: inline-block;
  width: 130px;
  height: 43px;
  margin: 0 10px;
  font: 18px/43px Microsoft YaHei;
  color: #069;
  text-align: center;
  transition: .5s;
}

.wrapper .btn_w .btn:hover {
  background-position: 0 -43px;
  color: #27b;
  box-shadow: 0 0 6px #27b;
}

#canvas {
  width: 100%;
  height: 100%;
  display: block;
  opacity: .8;
}