您必须使用等宽字体（也称为打字机字体）。这是一种所有字符占用相同空格的字体。

You must use a monospace font (also known as typewriter font). That is a font in which all the characters take the same space.

在CSS中，字体名称 monospace 到用户系统上的默认monospace字体。将 monospace 包含在< pre> 元素的font-familly列表的结尾是个好习惯，

In CSS the font name monospace is translated to the default monospace font on the user system. It's good practice to include monospace at the end of a font-familly list for the <pre> element so that it can be used as a fallback.

例如：

pre {font-family: Consolas,monospace}

将使用Consolas等宽字体到默认值。

will use the Consolas monospace font if it's available or fallback to the default.