diff --git a/README.md b/README.md
index 1c89ad1..be3987d 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,7 @@ Supported File Types:
  * PHP
  * LESS
  * Sass (SCSS)
+ * CSS
 
 ## Install
 
diff --git a/package.json b/package.json
index 51e2bc5..8092513 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,8 @@
     "onLanguage:typescript",
     "onLanguage:less",
     "onLanguage:sass",
-    "onLanguage:scss"
+    "onLanguage:scss",
+    "onLanguage:css"
   ],
   "main": "./src/extension",
   "scripts": {
@@ -56,4 +57,4 @@
     "margin",
     "css-in-js"
   ]
-}
+}
\ No newline at end of file
diff --git a/src/constants.js b/src/constants.js
index feb7aa0..c6dfa0f 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -1,6 +1,20 @@
 // eslint-disable-next-line max-len
 const colourRegex = /(#(?:[0-9a-fA-F]{2}){2,4}\b|#[0-9a-fA-F]{3}\b|(?:rgba?|hsla?)\(\s*(?:\d+%?(?:,|\s)+){2,3}[\s/]*[\d.]+%?\s*\))/;
-const supportedFileTypes = ['js', 'jsx', 'ts', 'tsx', 'json', 'coffee', 'html', 'jade', 'php', 'less', 'sass', 'scss'];
+const supportedFileTypes = [
+  'js',
+  'jsx',
+  'ts',
+  'tsx',
+  'json',
+  'coffee',
+  'html',
+  'jade',
+  'php',
+  'less',
+  'sass',
+  'scss',
+  'css'
+];
 
 module.exports = {
   colourRegex,