css and images not recognized by nginx: Resource interpreted as Stylesheet but transferred with MIME type text/html

I'm trying to run Rainloop in a subdirectory. http://babylon/webmail. I get the css and js are not recognized. For example:

Resource interpreted as Stylesheet but transferred with MIME type text/html: "http://babylon/webmail/rainloop/v/1.10.5.192/static/css/rainloop/v/1.10.5.192/static/css/app.min.css?standard".

Some possible (but didnt work) solutions I tried:

1. "include /etc/nginx/mime.types;" is found in nginx.conf.

2. Some say, location for php is screwing up that part, so I should add this line:

   fastcgi_split_path_info ^(.+.php)(/.+)$; #this line

But still it doesn't work.

3. I add new locations for css and javascript with root but also nothing.

My config is this one: (it is an included file)

location ^~ /webmail {
    root /srv/rainloop/public_html;
    try_files $uri $uri/ /webmail/index.php?$query_string;
    access_log /srv/rainloop/logs/access.log;
    error_log /srv/rainloop/logs/error.log;
    index index.php;
    access_log /var/log/nginx/scripts.log scripts;

    location ~ \.php$ {
        #if (!-f $request_filename) { return 404; }
        include fastcgi_params;
        #fastcgi_split_path_info ^(.+\.php)(/.+)$; #this line
        fastcgi_pass unix:/var/run/php5-fpm.sock;
        fastcgi_index index.php;
        #fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param SCRIPT_FILENAME /srv/rainloop/public_html/index.php;
    }

    location ~ /\.ht {
        deny all;
    }

    location ^~ /webmail/data {
        deny all;
    }
}