1 files changed, 28 insertions, 0 deletions
diff --git a/vanilla/node_modules/css-tree/lib/syntax/atrule/container.js b/vanilla/node_modules/css-tree/lib/syntax/atrule/container.js
new file mode 100644
index 0000000..aa550de
--- /dev/null
+++ b/vanilla/node_modules/css-tree/lib/syntax/atrule/container.js
@@ -0,0 +1,28 @@
+import { Ident } from '../../tokenizer/index.js';
+
+// https://drafts.csswg.org/css-contain-3/#container-rule
+// The keywords `none`, `and`, `not`, and `or` are excluded from the <custom-ident> above.
+const nonContainerNameKeywords = new Set(['none', 'and', 'not', 'or']);
+
+export default {
+    parse: {
+        prelude() {
+            const children = this.createList();
+
+            if (this.tokenType === Ident) {
+                const name = this.substring(this.tokenStart, this.tokenEnd);
+
+                if (!nonContainerNameKeywords.has(name.toLowerCase())) {
+                    children.push(this.Identifier());
+                }
+            }
+
+            children.push(this.Condition('container'));
+
+            return children;
+        },
+        block(nested = false) {
+            return this.Block(nested);
+        }
+    }
+};