Add cssnano for CSS minification in production builds and update documentation

Author: liberaldev

CLAUDE.md

@@ -175,6 +175,7 @@ lang: en
 - `postcss-cli` - PostCSS command-line interface
 - `postcss-import` - PostCSS plugin for @import resolution
 - `autoprefixer` - PostCSS plugin for vendor prefix automation
+- `cssnano` - CSS minification tool (activated only in production builds to optimize CSS file size)
 
 ## Important Conventions
 

package.json

@@ -5,6 +5,7 @@
   "devDependencies": {
     "@tailwindcss/typography": "^0.5.19",
     "autoprefixer": "^10.4.23",
+    "cssnano": "^7.1.2",
     "postcss": "^8.5.6",
     "postcss-cli": "^11.0.1",
     "postcss-import": "^16.1.1",

postcss.config.js

@@ -7,5 +7,10 @@ module.exports = {
     },
     tailwindcss: {},
     autoprefixer: {},
+    ...(process.env.JEKYLL_ENV === 'production' && {
+      cssnano: {
+        preset: 'default'
+      }
+    })
   }
 };