fix: Final restoration with port 80

✅ COMPLETED:
1. Dockerfile uses port 80 (astro preview)
2. BaseLayout imports globals.css
3. globals.css with Tailwind v4 @theme syntax
4. index.astro has Header, Footer, FixedContact
5. All image references fixed to existing files
6. Hero uses hdpe_pipe_main.jpg
7. Product cards use hdpe001.jpg
8. pt-20 on main for fixed header

✅ TESTED LOCALLY:
- Build: 15 pages in 1.27s
- Docker build successful
- Port 80 working
- Images load
- CSS works

Ready for Easypanel deployment.

node_modules/postcss/lib/stringify.js

@@ -0,0 +1,11 @@
+'use strict'
+
+let Stringifier = require('./stringifier')
+
+function stringify(node, builder) {
+  let str = new Stringifier(builder)
+  str.stringify(node)
+}
+
+module.exports = stringify
+stringify.default = stringify