.CSS File Extension
Full form: Cascading Style Sheets
What is a .css file?
A style language that controls colours, fonts, layout and animations of HTML pages. Files that end with .css belong to the web family of file types, so your computer links them with a suitable program automatically.
Where is .css used?
Designing beautiful, responsive websites. Because the format is so common, almost every modern device and software understands it.
Examples of .css file names
style.css
How to open a .css file
You can open it with: VS Code, Notepad, any code editor. If it does not open, check that the file is not damaged and that you have downloaded it fully; also confirm that the extension was not renamed by mistake.
Quick tips
Never rename a file just to change its extension, because that does not convert the data inside. Use a proper converter or the Save As / Export option. Keep a backup copy of important web files before editing them.