CSS空格属性
使用空白属性可在元素内部使用空白：
示例
<!DOCTYPE html>
<html>
<head>
<style>
p.demo1 {
white-space: normal;
}
p.demo2 {
white-space: pre;
}
</style>
</head>
<body>
<h2>Control white-space</h2>
<p class = "demo1">
This is demo text.
This is demo text.
</p>
<p class = "demo2">
This is demo text.
This is demo text.
</p>
</body>
</html>