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/mdn-data/css/selectors.schema.json

@@ -0,0 +1,37 @@
+{
+  "type": "object",
+  "additionalProperties": {
+    "type": "object",
+    "additionalProperties": false,
+    "properties": {
+      "syntax": {
+        "type": "string"
+      },
+      "groups": {
+        "type": "array",
+        "minitems": 1,
+        "uniqueItems": true,
+        "items": {
+          "$ref": "definitions.json#/groupList"
+        }
+      },
+      "status": {
+        "enum": [
+          "standard",
+          "nonstandard",
+          "experimental",
+          "obsolete"
+        ]
+      },
+      "mdn_url": {
+        "type": "string",
+        "pattern": "^https://developer.mozilla.org/docs/Web/CSS/"
+      }
+    },
+    "required": [
+      "syntax",
+      "groups",
+      "status"
+    ]
+  }
+}