CSS File Joiner
Combine several CSS files into one, in the order you choose, with overridden duplicate declarations tidied away safely.
About this tool
Files are joined in the order shown — drag a file, or use its arrow buttons, to change where it lands. Each file is marked with a comment so you can find its rules in the result.
When the same selector appears more than once at the top level, the tool removes only what can never apply: a declaration in an earlier rule is dropped when a later rule with exactly the same selector sets the same property (unless the earlier one is !important and the later one isn't). Everything else is kept, so .btn { color: red; padding: 2px } followed by .btn { padding: 4px } keeps the red colour and loses only the overridden padding. A rule left with no declarations is removed. The summary tells you how many declarations were removed and from which selectors.
@charset, @import and @namespace statements are moved to the top of the output, because browsers ignore them anywhere else. Rules inside @media, @supports and other blocks are passed through unchanged, and comments and quoted strings (such as content: "}") are handled correctly.