fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/csso/cjs/replace/Atrule.cjs

@@ -0,0 +1,13 @@
+'use strict';
+
+const cssTree = require('css-tree');
+const keyframes = require('./atrule/keyframes.cjs');
+
+function Atrule(node) {
+    // compress @keyframe selectors
+    if (cssTree.keyword(node.name).basename === 'keyframes') {
+        keyframes(node);
+    }
+}
+
+module.exports = Atrule;