Instead of using the basic HTML tag :
<link rel="stylesheet" type="text/css" href="css/myvendor.css">
You need to make sure that the path included in the tag is correct for either the server or client.
If all your HTML files and folders are located within the vendor folder, then the path I specified in the tag above should work.
If you're still encountering issues with including the css file, it could be due to the file not existing, being incorrectly named, or having a faulty CSS structure (it's always best to double check your CSS files). In such cases, try using tools like Inspect Element or Firebug (an add-on for Firefox and potentially Chrome) to identify the problem.
UPDATE: If you're using Jade, remember to include 'type='text/css' within your tag to specify the file type.
link(rel='stylesheet', href='css/myvendor.css', type='text/css' )
Referencing the documentation on JADE, you can simplify the process by using template inheritance in multiple views with similar structures.
In Jade, you can include the CSS file like this:
!!! 5
html
head
title Learning Inheritance
link(rel='stylesheet', href='/css/myvendor.css')
body
!!!
Alternatively, there is another solution discussed in a different Stack Overflow question:
head
title test include
| <style type='text/css'>
include css/myvendor.css
| </style>