CSS renders differently on web server than on development environment

Question

I have this problem where the web application that I have created in my development environment, displays differently after I upload it to the web server.

I am using the same browser and the same machine to view the pages. The only thing different, is the "server". I am using .net 3.5 and on my development environment the pages are served using the ASP.net Development Server. On the web server, the pages are served using IIS 6.0.

I have only a single CSS file that is contained within the "App_Themes/Default" folder that is used to control all the CSS in my application.

Here are some of the things that don't display the same:

1) I have a collapsible panel control that when expanded is supposed to show on top of all the other page elements. On the dev environment, it behaves correctly. On the web server, the panel slides underneath the other elements.

2) I have my element defined with a background and a certain font size. When displayed on my development environment, the text displays on one line. However, on the web server, the text is wrapped even though the text is the same size. It's as if the containing div is somehow rendered "smaller".

3) The width of buttons that do not have a fixed width (so the width is determined by the button text) is different between the development environment and the web server. The bottons on the server are always wider.

I checked to make sure there are no references to other CSS elements in the machine.config and global web.config on the server and on my development environment.

I know the server is reading from the CSS because in general, it looks similar (same colors, backgrounds, font style, etc). It's just that the sizes seems to be off and the layering of the divs.

Has anyone run in to this problem before? Any ideas of what I could look for?

Answer 1

Looks like you are comparing them in Internet Explorer 8. Microsoft introduced different rendering modes for local and Internet servers so that web developers would break down in tears.

If there’s no X-UA-Compatible value and site is in Local Intranet security zone, it will be rendered in EmulateIE7 mode by default.

Add X-UA-Compatible header or META to force full IE8 standards mode.

See also http://sharovatov.wordpress.com/2009/05/18/ie8-rendering-modes-theory-and-practice/

Answer 2

We were having an issue with compatibility modes too, so I ended up just adding:

<meta http-equiv="X-UA-Compatible" content="IE=Edge">

Since I knew it worked fine in IE7, 8, and 9.

Answer 3

I had the same problem in Google Chrome. Apparently media queries get messed up if the page is zoomed in or out. Make sure your zoom level is 100% for both sites.

Answer 4

This at least sounds like that the production server added a xml declaration to the HTML or changed the doctype which caused the page being rendered in non-standards-compliant mode. This is also known as quirks mode, you see this very good back in MSIE. The symptoms which you described are recognizeable as box model bug in MSIE.

Rightclick the pages and check the HTML source. Are they both exactly the same? (including meta tags, xml declaration, whitespace, etc)

If you're FTP'ing from Windows to Linux, please ensure that you're transferring in binary mode to ensure that the whitespace (spaces, linebreaks) remain unchanged. Also ensure that you're saving documents as UTF-8 (or at least ISO-8859-1) and NOT as MS-proprietary encoding such as CP1252.

Answer 5

For those of you that are having this problem in an Intranet site setting the meta tag won't fix the problem if "Display intranet sites in Compatibility View" is checked on (which it is in a lot of cases)

You have to send the HTTP response header at the server level, see here

Answer 6

The CSS that is coming from the server may be a older cached version - try refreshing the page using Ctrl+F5 so it get re-requested.