diff --git a/src/config.rs b/src/config.rs
index 328facf..6a41b9e 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -179,6 +179,20 @@ impl TypeEngineConfig {
                     ..Default::default()
                 },
             });
+        patterns
+            .entry("css".into())
+            .or_insert_with(|| GlobEngineConfig {
+                extend_glob: Vec::new(),
+                engine: EngineConfig {
+                    dict: Some(DictConfig {
+                        extend_identifiers: maplit::hashmap! {
+                            "thead".into() => "thead".into(),
+                        },
+                        ..Default::default()
+                    }),
+                    ..Default::default()
+                },
+            });
         patterns
             .entry("html".into())
             .or_insert_with(|| GlobEngineConfig {