Problems with image path - css

Question

I have a project built in CodeIgniter. In my localhost, the website work fine, but in the remote server, fail the image inclusion from CSS & JS.
The site, is guest in a subdomain. The server file system hierarchy is:
--/
---apps (subdomain folder for my app)
----application
----[other CI forlders]
----css
----js
----img
--[other web folders (no CI)]
--index.html
In CSS files i define the images paths this way: "../img/"
For example:
#maincontainer {background-image: url('../img/main_bg.gif');}
But, in Chrome and FF, show error to load resources:
Failed to load resource: the server responded with a status of 404
(Not Found) http://apps.manantiales.edu.ar/img/main_bg.gif
Any ideas?

Answer 1

You are on a subdomain, therefore, the correct path would be:
http://manantiales.edu.ar/apps/img/main_bg.gif
You can use rules in your htaccess file to make the subdomain path work
or
Just use absolute paths like diEcho suggested. You can embed php code in css files like this:
maincontainer {background-image: url('< ?php echo site_url('img/main_bg.gif');?>');}
(I have put an extraspace at < ?php as not sure how to format it to show correctly here)

Answer 2

You can simply do it like this
--/
---apps (subdomain folder for my app)
----application
----[other CI forlders]
--[other web folders (no CI)]
--index.html
--css
--js
--img
#maincontainer {background-image: url('../img/main_bg.gif');}
and in html files;
<?= base_url();?>css/css.css