Added Masthead, CMDPalette and PostHeader Components

postcss.config.mjs

@@ -1,11 +1,15 @@
 import postcssGlobalData from '@csstools/postcss-global-data';
 import postcssImport from 'postcss-import';
 import postcssPresetEnv from 'postcss-preset-env';
+import postcssMixins from 'postcss-mixins';
 
 export default {
   plugins: [
     postcssGlobalData({
-      files: ['./src/styles/custom-media.css'],
+      files: ['./src/styles/base/custom-media.css'],
+    }),
+    postcssMixins({
+      mixinsDir: './src/styles/mixins/',
     }),
     postcssImport(),
     postcssPresetEnv({