Express中存在绝对路径和相对路径的困难

我在Express应用程序中有一条API路由，如下所示:

I have a route for an API in an Express app that looks like this:

app.get('/:username/:bookmark/', function(req, res) {

  // do stuff

})

如预期的那样，此路由解析为:

As expected, this route resolves to:

GET /username/bookmark/

但是，我想使用相对URL作为静态资源.例如，我希望到我的main.css的路线解析为:

However, I would like to use relative URLs for my static resources. For example, I would like the route to my main.css to resolve to:

GET /css/main.css

相反，它当前解析为:

GET /username/bookmark/css/main.css

如何让我的应用将静态内容解析为/css/main.css并从URL中删除API的主要组件?

How can I get my app to resolve static content to /css/main.css and remove the leading components of the API from the URL?