今天早上心血来潮，看到自己的电脑桌面是太空的界面，便有心继上次星星海特效后的再一次制作。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>太空</title>
<style>
body{
width: 100%;
height: 1000px;
background: linear-gradient(to bottom right, #000, #2073c2 60%, #dff6ff);
overflow: hidden;
}
span{
display: block;
position: absolute;
border-radius: 50%;
box-shadow: 0.4px 0.4px 0.4px 0px #fff;
}
</style>
</head>
<body>
<script>
window.onload = function(){
var screenW = document.documentElement.clientWidth;
var screenH = document.documentElement.clientHeight;
var colorArr = ['#fff','skyblue','orange'];
console.log(screenW);
for( var i=0; i<800; i++ ){
var span = document.createElement('span');
var width = Math.random() * 3;
var colorIndex = parseInt(Math.random() * 3);
var x = parseInt(Math.random() * screenW);
var y = parseInt(Math.random() * screenH);
span.style.width = parseInt(width) + 'px';
span.style.height = parseInt(width) + 'px';
span.style.background = colorArr[colorIndex];
span.style.left = x + 'px';
span.style.top = y + 'px';
document.body.appendChild(span);
}
}
</script>
</body>
</html>
代码复制即可看到效果（火狐浏览器测试）
