From 6fbd0b65c0112775bbe7aba23398ec982a5bb9f5 Mon Sep 17 00:00:00 2001
From: Naoki Ikeguchi <me@s6n.jp>
Date: Tue, 14 Apr 2026 00:15:24 +0900
Subject: [PATCH] fix(parser/css): parse conditional block correctly inside
 embedded snippets

Co-authored-by: Codex <noreply@openai.com>
---
 .changeset/fast-zebras-move.md                |   5 +
 .../src/syntax/block/conditional_block.rs     |   7 +-
 .../src/workspace/server.tests.rs             | 132 ++++++++++++++++++
 3 files changed, 142 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/fast-zebras-move.md

diff --git a/.changeset/fast-zebras-move.md b/.changeset/fast-zebras-move.md
new file mode 100644
index 000000000000..ad992404c116
--- /dev/null
+++ b/.changeset/fast-zebras-move.md
@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": patch
+---
+
+Fixed [#9113](https://github.com/biomejs/biome/issues/9113): Biome now parses and formats `@media` and other conditional blocks correctly inside embedded CSS snippets.
diff --git a/crates/biome_css_parser/src/syntax/block/conditional_block.rs b/crates/biome_css_parser/src/syntax/block/conditional_block.rs
index 45aec7dfd5c3..016a07cee08d 100644
--- a/crates/biome_css_parser/src/syntax/block/conditional_block.rs
+++ b/crates/biome_css_parser/src/syntax/block/conditional_block.rs
@@ -1,6 +1,7 @@
-use crate::parser::CssParser;
+use biome_css_syntax::EmbeddingKind;
 use biome_parser::CompletedMarker;
 
+use crate::parser::CssParser;
 use crate::syntax::block::{parse_declaration_or_rule_list_block, parse_rule_block};
 
 ///
@@ -18,7 +19,9 @@ use crate::syntax::block::{parse_declaration_or_rule_list_block, parse_rule_bloc
 ///
 #[inline]
 pub(crate) fn parse_conditional_block(p: &mut CssParser) -> CompletedMarker {
-    if p.state_mut().is_nesting_block {
+    if p.state().is_nesting_block
+        || matches!(p.source_type.as_embedding_kind(), EmbeddingKind::Styled)
+    {
         parse_declaration_or_rule_list_block(p)
     } else {
         parse_rule_block(p)
diff --git a/crates/biome_service/src/workspace/server.tests.rs b/crates/biome_service/src/workspace/server.tests.rs
index 57d584c8de69..da37e247a7aa 100644
--- a/crates/biome_service/src/workspace/server.tests.rs
+++ b/crates/biome_service/src/workspace/server.tests.rs
@@ -762,6 +762,138 @@ const PortfolioIcon = styled.div`
     ");
 }
 
+#[test]
+fn issue_9113() {
+    const FILE_PATH: &str = "/project/file.ts";
+    const FILE_CONTENT: &str = r#"import styled from 'styled-components';
+
+const Wrapper = styled.div`
+  height: 20px;
+
+  @media screen and (min-width: 768px) {
+    height: 40px;
+  }
+`;
+
+const Container = styled.div`
+	     	display: grid;
+	grid-template-rows: auto;
+	grid-gap: 2px;
+	margin: 4px 4px 0;
+
+    /* top level seems fine */
+	grid-template-columns: repeat(3, 1fr);
+
+    	  @media (min-width: 480px) {
+    		    grid-template-columns: repeat(4, 1fr);
+	}
+
+	   @media (min-width: 640px) {
+		  grid-template-columns: repeat(5, 1fr);
+	}
+
+    	@media (min-width: 780px) {
+    		grid-template-columns: repeat(6, 1fr);
+    	}
+`;"#;
+
+    let fs = MemoryFileSystem::default();
+    fs.insert(Utf8PathBuf::from(FILE_PATH), FILE_CONTENT);
+
+    let (workspace, project_key) = setup_workspace_and_open_project(fs, "/");
+
+    workspace
+        .update_settings(UpdateSettingsParams {
+            project_key,
+            workspace_directory: None,
+            configuration: Configuration {
+                javascript: Some(JsConfiguration {
+                    experimental_embedded_snippets_enabled: Some(true.into()),
+                    ..Default::default()
+                }),
+                ..Default::default()
+            },
+            extended_configurations: vec![],
+            module_graph_resolution_kind: ModuleGraphResolutionKind::None,
+        })
+        .unwrap();
+
+    workspace
+        .open_file(OpenFileParams {
+            project_key,
+            path: BiomePath::new(FILE_PATH),
+            content: FileContent::FromServer,
+            document_file_source: None,
+            persist_node_cache: false,
+            inline_config: None,
+        })
+        .unwrap();
+
+    let result = workspace
+        .pull_diagnostics(PullDiagnosticsParams {
+            project_key,
+            path: BiomePath::new(FILE_PATH),
+            only: vec![],
+            skip: vec![],
+            enabled_rules: vec![],
+            categories: Default::default(),
+            include_code_fix: false,
+            inline_config: None,
+            max_diagnostics: None,
+            diagnostic_level: Severity::Error,
+            enforce_assist: false,
+        })
+        .unwrap();
+
+    assert!(
+        result.diagnostics.is_empty(),
+        "Expected no diagnostics for embedded CSS, got: {:#?}",
+        result.diagnostics
+    );
+
+    let result = workspace
+        .format_file(FormatFileParams {
+            project_key,
+            path: Utf8PathBuf::from(FILE_PATH).into(),
+            inline_config: None,
+        })
+        .unwrap();
+
+    insta::assert_snapshot!(result.as_code(), @r#"
+    import styled from "styled-components";
+
+    const Wrapper = styled.div`
+    	height: 20px;
+
+    	@media screen and (min-width: 768px) {
+    		height: 40px;
+    	}
+    `;
+
+    const Container = styled.div`
+    	display: grid;
+    	grid-template-rows: auto;
+    	grid-gap: 2px;
+    	margin: 4px 4px 0;
+
+    	/* top level seems fine */
+    	grid-template-columns: repeat(3, 1fr);
+
+    	@media (min-width: 480px) {
+    		grid-template-columns: repeat(4, 1fr);
+    	}
+
+    	@media (min-width: 640px) {
+    		grid-template-columns: repeat(5, 1fr);
+    	}
+
+    	@media (min-width: 780px) {
+    		grid-template-columns: repeat(6, 1fr);
+    	}
+    `;
+    "#);
+}
+
 #[test]
 fn format_js_with_embedded_graphql() {
     const FILE_PATH: &str = "/project/file.js";