Browsers don't see css files on the web server named with "_" symbol, for example "cuk_style.css"

Question

Browsers (opera, IE, Chrome, Mozilla) don't see a css named "cuk_style.css" on the web server. They see CSS named with "_" symbol only when open web page for the first time, but next time - don't. Nevertheless on mobile phone browser (Chrome) site is opened correctly every time. Renaming file into "style.css" without first word & "_" symbol, the issue was solved. Why did this happen?

Answer 1

Underscore is an allowable character for a CSS file name, but I can't say that I have ever used it myself. Generally I try to make my CSS files have single word names. I would recommend that instead of using an underscore that you try using a hyphen/dash '-'. (cuk-style.css) Then retest your web pages. The hyphen/dash '-' is more commonly accepted way to represent a space in front end web development.