diff --git a/.changeset/eighty-trees-thank.md b/.changeset/eighty-trees-thank.md
new file mode 100644
index 000000000000..2711113692c7
--- /dev/null
+++ b/.changeset/eighty-trees-thank.md
@@ -0,0 +1,7 @@
+---
+'astro': minor
+---
+
+This PR introduces a new internal CSS parser for `@astrojs/compiler`. See [`withastro/compiler#329`](https://github.com/withastro/compiler/pull/329) for more details.
+
+This fixes Astro's support for modern CSS syntax like `@container`, `@layer`, and nesting. **Note** While Astro now correctly parses this modern syntax, it does not automatically compile features for browser compatability purposes.
diff --git a/packages/astro/package.json b/packages/astro/package.json
index e3e1e739136c..5df402378792 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -61,7 +61,7 @@
     "test:match": "mocha --timeout 20000 -g"
   },
   "dependencies": {
-    "@astrojs/compiler": "^0.12.1",
+    "@astrojs/compiler": "^0.13.0",
     "@astrojs/language-server": "^0.8.10",
     "@astrojs/markdown-remark": "^0.6.4",
     "@astrojs/prism": "0.4.0",
diff --git a/packages/astro/test/astro-partial-html.test.js b/packages/astro/test/astro-partial-html.test.js
index 1c6b43fb6a65..f2d1852dd83b 100644
--- a/packages/astro/test/astro-partial-html.test.js
+++ b/packages/astro/test/astro-partial-html.test.js
@@ -33,7 +33,7 @@ describe('Partial HTML', async () => {
 				},
 			})
 			.then((res) => res.text());
-		expect(css).to.match(/\.astro-[^{]+{color:red;}/);
+		expect(css).to.match(/\.astro-[^{]+{color:red}/);
 	});
 
 	it('injects framework styles', async () => {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 60767d54c778..c63cb359dd1e 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -354,7 +354,7 @@ importers:
 
   packages/astro:
     specifiers:
-      '@astrojs/compiler': ^0.12.1
+      '@astrojs/compiler': ^0.13.0
       '@astrojs/language-server': ^0.8.10
       '@astrojs/markdown-remark': ^0.6.4
       '@astrojs/parser': ^0.22.2
@@ -426,7 +426,7 @@ importers:
       yargs-parser: ^21.0.1
       zod: ^3.13.4
     dependencies:
-      '@astrojs/compiler': 0.12.1
+      '@astrojs/compiler': 0.13.0
       '@astrojs/language-server': 0.8.10
       '@astrojs/markdown-remark': link:../markdown/remark
       '@astrojs/prism': link:../astro-prism
@@ -1554,8 +1554,8 @@ packages:
       leven: 3.1.0
     dev: true
 
-  /@astrojs/compiler/0.12.1:
-    resolution: {integrity: sha512-XpKZyJlnDhszulwwse/1uV+ZiyTpg6xNH5TrriYDVdzB8dUbQLdE7tX4Cxhdw5QrJpV57AaPrPXvJKi1jnIkxw==}
+  /@astrojs/compiler/0.13.0:
+    resolution: {integrity: sha512-omPv8V2OG05Nx7cV1PiYKV2GewsVf91kZDRUajPsjAHVEorIDMNV8ekv1gjjgAt8UVKbQYev2hzGhmdyHdo06Q==}
     dependencies:
       tsm: 2.2.1
       uvu: 0.5.3
@@ -9126,6 +9126,7 @@ packages:
   /source-map/0.6.1:
     resolution: {integrity: sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==}
     engines: {node: '>=0.10.0'}
+    requiresBuild: true
 
   /source-map/0.7.3:
     resolution: {integrity: sha512-CkCj6giN3S+n9qrYiBTX5gystlENnRW5jZeNLHpe6aue+SrHcG5VYwujhW9s4dY31mEGsxBDrHR6oI69fTXsaQ==}