node.js - can't load css when param express.js too long

I'm writting a application by Node.js,express.js,ejs....

I'm using this code to use ejs and load css:

app.engine('.html', require('ejs').__express);
app.set('views', __dirname + '/views');
app.set('view engine', 'html');
app.use(express.static(__dirname + '/views'));

This is my dir struct

myapp
--Controller
----admin.js
--db
----db.js
--views
----admin
------user.html
------addUser.html
----css
------style.css
--app.js

Html load css like this

<link href="../css/style.css" rel="stylesheet">

And i had used css for my web. when i use params :

app.get('/admin/users', admin.users);
app.get('/admin/add', admin.add);

url are:

loocalhost:1080/admin/users

loocalhost:1080/admin/add

then my css active. but when i use param:

app.get('/admin/users/add', admin.add);

url is:

loocalhost:1080/admin/users/add

then my css not active.

so how to fix it?? Please help.