I also had faced the same problem but I got a solution. The solution is:

<link href="./css/stylesheet.css" rel="stylesheet" type="text/css" />

Note that the "." before "/css" is indicating the current working directory on Ubuntu. I hope this will help you.

Answer from user276769 on askubuntu.com
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Stack Overflow
stackoverflow.com › questions › 32038511 › css-is-not-working
linux - CSS is not working? - Stack Overflow
May 24, 2017 - Use Browser's dev tools(F12) and check there is any error while loading the CSS files. ... One issue could be the serving up of resources over HTTPS. For example, you main site contains very many absolute paths.
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Arch Linux Forums
bbs.archlinux.org › viewtopic.php
[SOLVED] external css files don't work with html5 doctype. / Programming & Scripting / Arch Linux Forums
But honestly I'm not up-to-date what the modern browser consider valid html5 and what not. But my guess is: you need to enclose your sample text in <p> or <div> or something. Otherwise, the text breaks ou tof the body-structure and the body in considered empty. ... Yes, it works when CSS code in inside html.
Discussions

linux - CSS doesn't work for some reason - Stack Overflow
So I have stumbled upon this problem, ... is more interesting, it doesn't work only for files that I create and it doesn't work only for me. So when I go to any webpage, CSS will work perfectly, however when I go to websites created by me, it wont work only for me, but it will work for other people. Things I've done so far: Tested other browsers (didn't work on chromium and firefox) ... Some people said that it might be because of adblock, disabled it everywhere, still no results. I have Linux Mint 15, and ... More on stackoverflow.com
🌐 stackoverflow.com
May 23, 2017
External css file and Ubuntu conflict!
Christopher Bernat is having issues with: So... Hell-o! As I've written, I'm using the newest Ubuntu and my problem is quite... Stupid probably (I'm new to Linux, but I know that... More on teamtreehouse.com
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4
December 10, 2014
userChrome.css not working on Linux

Removing the @namespace url line worked, thank you!

More on reddit.com
🌐 r/firefox
6
1
May 26, 2021
HTML not loading CSS file - Stack Overflow
It is best to always add ./ for files in current directory, so it will work on Windows and Linux. 2019-12-14T19:14:19.297Z+00:00 ... Working on a Mac and the dot helped me too. Tried everything for hours and turns out the problem was a simple ./ 2023-02-12T13:48:24.893Z+00:00 ... Thank you all for the dot comments! I'm on a Mac and the dot ./ helped me too. 2024-02-22T20:50:00.71Z+00:00 ... I want to use a .css ... More on stackoverflow.com
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Ubuntu Forums
ubuntuforums.org › showthread.php
Apache2: Css Doesn't work!
August 28, 2015 - A help and support forum for Ubuntu Linux.
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Ask Ubuntu
askubuntu.com › questions › 757305 › apache-2-4-7-doesnt-load-all-css-files
apache2 - Apache 2.4.7 doesn't load all .css files - Ask Ubuntu
The .css files are stored in /var/www/html/css/ on the ubuntu server and the /var/www/html/index.html file include both .css files via this two instructions located in the head of the html file: <link rel="stylesheet" href="css/style.css" type="text/css"/> <link rel="stylesheet" href="css/modalCustomization.css" type="text/css"/> The file /var/www/html/css/style.css will be loaded correctly. The file /var/www/html/css/modalCustomization.css will not be loaded. Any suggestions why the Apache on the ubuntu server is doing/not doing that? ... I just found a solution from another question. Everything works if I add a ./ before the path in index.html.
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Team Treehouse
teamtreehouse.com › community › external-css-file-and-ubuntu-conflict
External css file and Ubuntu conflict! (Example) | Treehouse Community
December 10, 2014 - Can you post your index.php file so we see what the issue maybe. ... I don't think your problem is related to unbuntu sine I've uses it many times without issue. My guess is a syntax problem. I think "/css/style.css" should work. ... It doesn't work for some reason. I tried to add it even via php itself, but... Still nothing.
Find elsewhere
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Reddit
reddit.com › r/firefox › userchrome.css not working on linux
r/firefox on Reddit: userChrome.css not working on Linux
May 26, 2021 -

My tab bar is way, way too small on Linux. I followed Arch's own documentation on how to fix this by increasing layout.css.devPixelsPerPx (mine is at 1.4), and then adjusting font size by editing userChrome.css to select the desired size. Problem is that Firefox won't actually change anything based on what I put in that file. I have set toolkit.legacyUserProfileCustomizations.stylesheets to True, and my userChrome.css file looks like this (yes, I'm using nano because Vim is too advanced for my smooth brain). I changed it to a ton of different values and I can confirm that the font size is not actually changing.

Any insight is appreciated.

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Server Fault
serverfault.com › questions › 188376 › site-not-showing-css
linux - Site not showing CSS - Server Fault
October 7, 2010 - My site http://www.gamer-source.com/ is not showing any CSS on the page. I see that CSS is indeed loading properly if I visit the URLs. I've cleared minify's cache so I know that's not the issue...
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Stack Overflow
stackoverflow.com › questions › 10830595 › html-external-css-link-fails-on-linux
Html, external CSS link fails on Linux - Stack Overflow
June 2, 2012 - The problem can probably be permission on the css file. The user apache ir running on must be able to read the file, otherwhise it will fail to load it ... You can also check which user apache is running on in this question Finding out what ...
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codestudy
codestudy.net › blog › complete-list-of-reasons-why-a-css-file-might-not-be-working
Complete List of Reasons Why a CSS File Isn’t Working: Troubleshooting Guide for Local Development
File Permissions: The server can’t ... live-server or VS Code’s “Live Server” extension avoid permission/CORS issues. Check File Permissions: On Linux/macOS, run chmod 644 css/styles.css to ensure read access. ... CSS not working ...
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Reddit
reddit.com › r/linux_gaming › i need help with css
r/linux_gaming on Reddit: I need help with CSS
April 21, 2025 -

I installed Ubuntu 24.04 LTS a few days ago and when I run the CSS, it appears that it is running and after a few seconds it closes and never opens the game. As I understand it, Valve games are native to Linux, so they do not require Proton. I have already tried other games (CS1.6, HL1 and HL2) and they work as if nothing had happened.

Someone knows why this happens and how I can solve it? Maybe it's a very beginner's problem haha, idk

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Super User
superuser.com › questions › 1453326 › can-t-access-css-files-via-xampp-localhost-setup
apache http server - Can’t access CSS files via XAMPP localhost setup - Super User
A problem that I've run into is ... put into the chrome browser. It seems that this happens if the path to the CSS file is wrong or the permissions to the file are not readable....
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sebhastian
sebhastian.com › css-not-linking-html
How to fix CSS not linking to your HTML document | sebhastian
August 17, 2021 - Open the Chrome DevTools by pressing Shift + CTRL + J on Windows/ Linux or Option + CMD + J on Mac. Right-click on the reload (refresh) icon and select the third option · The image below shows the Chrome Empty Cache and Hard Reload option you need to select: ... With that, you should see the latest CSS changes reflected on your web page. Alternatively, you can also invalidate the browser cache by using CSS versioning as explained here:
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Stack Overflow
stackoverflow.com › questions › 67044886 › strange-css-behaviour-on-linux-server-only
html - Strange css behaviour on Linux server only - Stack Overflow
April 11, 2021 - It's unnerving that it's fixed without knowing how ... I dont see how the Server OS should influence the CSS. The Server doesnt read or compile CSS. CSS is read client sided by the browser not by the server.