diff --git a/packages/tailwindcss-language-server/package.json b/packages/tailwindcss-language-server/package.json
index 40b3e05ac..9fded1e59 100644
--- a/packages/tailwindcss-language-server/package.json
+++ b/packages/tailwindcss-language-server/package.json
@@ -89,7 +89,7 @@
     "rimraf": "3.0.2",
     "stack-trace": "0.0.10",
     "tailwindcss": "3.4.18",
-    "tailwindcss-v4": "npm:tailwindcss@4.1.17",
+    "tailwindcss-v4": "npm:tailwindcss@4.1.18",
     "tinyglobby": "^0.2.12",
     "tsconfck": "^3.1.4",
     "tsconfig-paths": "^4.2.0",
diff --git a/packages/tailwindcss-language-server/src/project-locator.test.ts b/packages/tailwindcss-language-server/src/project-locator.test.ts
index 8e53c180e..529987953 100644
--- a/packages/tailwindcss-language-server/src/project-locator.test.ts
+++ b/packages/tailwindcss-language-server/src/project-locator.test.ts
@@ -455,7 +455,7 @@ testLocator({
   },
   expected: [
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/src/a/b/c/index.css',
       content: [],
     },
@@ -487,12 +487,12 @@ testLocator({
   },
   expected: [
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/index.css',
       content: [],
     },
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/src/vendor/c.css',
       content: [],
     },
@@ -519,12 +519,12 @@ testLocator({
   },
   expected: [
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/src/app.css',
       content: [],
     },
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/a/foo.css',
       content: [],
     },
@@ -554,12 +554,12 @@ testLocator({
   },
   expected: [
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/src/app.css',
       content: [],
     },
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/a/foo.css',
       content: [],
     },
@@ -581,7 +581,7 @@ testLocator({
   },
   expected: [
     {
-      version: '4.1.17 (bundled)',
+      version: '4.1.18 (bundled)',
       config: '/src/app.css',
       content: [],
     },
diff --git a/packages/tailwindcss-language-server/tests/colors/colors.test.js b/packages/tailwindcss-language-server/tests/colors/colors.test.js
index 92da0d588..f17e7ab23 100644
--- a/packages/tailwindcss-language-server/tests/colors/colors.test.js
+++ b/packages/tailwindcss-language-server/tests/colors/colors.test.js
@@ -349,7 +349,7 @@ defineTest({
 
     expect(c.project).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
@@ -388,7 +388,7 @@ defineTest({
 
     expect(c.project).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
diff --git a/packages/tailwindcss-language-server/tests/env/v4.test.js b/packages/tailwindcss-language-server/tests/env/v4.test.js
index f054287ac..df4ee18fb 100644
--- a/packages/tailwindcss-language-server/tests/env/v4.test.js
+++ b/packages/tailwindcss-language-server/tests/env/v4.test.js
@@ -21,7 +21,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
@@ -137,7 +137,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
@@ -188,7 +188,7 @@ defineTest({
     'package.json': json`
       {
         "dependencies": {
-          "tailwindcss": "4.1.17"
+          "tailwindcss": "4.1.18"
         }
       }
     `,
@@ -205,7 +205,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: false,
       },
     })
@@ -243,7 +243,7 @@ defineTest({
     'package.json': json`
       {
         "dependencies": {
-          "tailwindcss": "4.1.17"
+          "tailwindcss": "4.1.18"
         }
       }
     `,
@@ -270,7 +270,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: false,
       },
     })
@@ -322,7 +322,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
@@ -354,7 +354,7 @@ defineTest({
     'package.json': json`
       {
         "dependencies": {
-          "tailwindcss": "4.1.17"
+          "tailwindcss": "4.1.18"
         }
       }
     `,
@@ -831,7 +831,7 @@ defineTest({
 
     expect(await client.project()).toMatchObject({
       tailwind: {
-        version: '4.1.17',
+        version: '4.1.18',
         isDefaultVersion: true,
       },
     })
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package-lock.json
index db44ced8d..a4ae0b1ff 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/basic/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package-lock.json
index 74935ce06..e072fed92 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/css-loading-js/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package-lock.json
index 3a6f2cc8f..9ce001b72 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/dependencies/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package-lock.json
index ce9b94be5..7bae87ca0 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/invalid-import-order/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package-lock.json
index 6f89483bb..56ae23459 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/missing-files/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package-lock.json
index f46fb487b..73b3521d3 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/multi-config/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package-lock.json
index 0580cf520..b1fa0b8e8 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/path-mappings/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package-lock.json
index 6d75bfb8a..d679cffdb 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package-lock.json
@@ -5,13 +5,13 @@
   "packages": {
     "": {
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     }
   }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package.json
index f1752f593..b3c9f0cce 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/with-prefix/package.json
@@ -1,5 +1,5 @@
 {
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package-lock.json b/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package-lock.json
index 3dd6db074..8835c6b80 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package-lock.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package-lock.json
@@ -8,7 +8,7 @@
         "packages/*"
       ],
       "dependencies": {
-        "tailwindcss": "4.1.17"
+        "tailwindcss": "4.1.18"
       }
     },
     "node_modules/@private/admin": {
@@ -32,9 +32,9 @@
       "link": true
     },
     "node_modules/tailwindcss": {
-      "version": "4.1.17",
-      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.17.tgz",
-      "integrity": "sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==",
+      "version": "4.1.18",
+      "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.1.18.tgz",
+      "integrity": "sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==",
       "license": "MIT"
     },
     "packages/admin": {
diff --git a/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package.json b/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package.json
index 5a5b8df96..09a644428 100644
--- a/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package.json
+++ b/packages/tailwindcss-language-server/tests/fixtures/v4/workspaces/package.json
@@ -3,6 +3,6 @@
     "packages/*"
   ],
   "dependencies": {
-    "tailwindcss": "4.1.17"
+    "tailwindcss": "4.1.18"
   }
 }
diff --git a/packages/tailwindcss-language-service/src/completions/file-paths.test.ts b/packages/tailwindcss-language-service/src/completions/file-paths.test.ts
index ed5213923..1be97f223 100644
--- a/packages/tailwindcss-language-service/src/completions/file-paths.test.ts
+++ b/packages/tailwindcss-language-service/src/completions/file-paths.test.ts
@@ -3,7 +3,7 @@ import { findFileDirective } from './file-paths'
 
 test('Detecting v3 directives that point to files', async () => {
   function find(text: string) {
-    return findFileDirective({ enabled: true, v4: false }, text)
+    return findFileDirective({ enabled: true, v4: false, features: [] }, text)
   }
 
   await expect(find('@config "./')).resolves.toEqual({
@@ -22,7 +22,7 @@ test('Detecting v3 directives that point to files', async () => {
 
 test('Detecting v4 directives that point to files', async () => {
   function find(text: string) {
-    return findFileDirective({ enabled: true, v4: true }, text)
+    return findFileDirective({ enabled: true, v4: true, features: [] }, text)
   }
 
   await expect(find('@config "./')).resolves.toEqual({
@@ -64,7 +64,7 @@ test('Detecting v4 directives that point to files', async () => {
 
 test('@source inline is ignored', async () => {
   function find(text: string) {
-    return findFileDirective({ enabled: true, v4: true }, text)
+    return findFileDirective({ enabled: true, v4: true, features: [] }, text)
   }
 
   await expect(find('@source inline("')).resolves.toEqual(null)
diff --git a/packages/tailwindcss-language-service/src/css/ast.ts b/packages/tailwindcss-language-service/src/css/ast.ts
index ac95d204a..6d206c964 100644
--- a/packages/tailwindcss-language-service/src/css/ast.ts
+++ b/packages/tailwindcss-language-service/src/css/ast.ts
@@ -1,6 +1,5 @@
-import { parseAtRule } from './parse'
 import type { SourceLocation } from './source'
-import type { VisitContext } from '../util/walk'
+import { parseAtRule } from './parse'
 
 const AT_SIGN = 0x40
 
@@ -17,7 +16,7 @@ export type AtRule = {
   kind: 'at-rule'
   name: string
   params: string
-  nodes: AstNode[]
+  nodes: AstNode[] | null
 
   src?: SourceLocation
   dst?: SourceLocation
@@ -70,7 +69,7 @@ export function styleRule(selector: string, nodes: AstNode[] = []): StyleRule {
   }
 }
 
-export function atRule(name: string, params: string = '', nodes: AstNode[] = []): AtRule {
+export function atRule(name: string, params: string = '', nodes: AstNode[] | null = []): AtRule {
   return {
     kind: 'at-rule',
     name,
@@ -79,12 +78,12 @@ export function atRule(name: string, params: string = '', nodes: AstNode[] = [])
   }
 }
 
-export function rule(selector: string, nodes: AstNode[] = []): StyleRule | AtRule {
+export function rule(selector: string, nodes: AstNode[] | null = []): StyleRule | AtRule {
   if (selector.charCodeAt(0) === AT_SIGN) {
     return parseAtRule(selector, nodes)
   }
 
-  return styleRule(selector, nodes)
+  return styleRule(selector, nodes ?? [])
 }
 
 export function decl(property: string, value: string | undefined, important = false): Declaration {
@@ -117,95 +116,3 @@ export function atRoot(nodes: AstNode[]): AtRoot {
     nodes,
   }
 }
-
-export function cloneAstNode<T extends AstNode>(node: T): T {
-  switch (node.kind) {
-    case 'rule':
-      return {
-        kind: node.kind,
-        selector: node.selector,
-        nodes: node.nodes.map(cloneAstNode),
-        src: node.src,
-        dst: node.dst,
-      } satisfies StyleRule as T
-
-    case 'at-rule':
-      return {
-        kind: node.kind,
-        name: node.name,
-        params: node.params,
-        nodes: node.nodes.map(cloneAstNode),
-        src: node.src,
-        dst: node.dst,
-      } satisfies AtRule as T
-
-    case 'at-root':
-      return {
-        kind: node.kind,
-        nodes: node.nodes.map(cloneAstNode),
-        src: node.src,
-        dst: node.dst,
-      } satisfies AtRoot as T
-
-    case 'context':
-      return {
-        kind: node.kind,
-        context: { ...node.context },
-        nodes: node.nodes.map(cloneAstNode),
-        src: node.src,
-        dst: node.dst,
-      } satisfies Context as T
-
-    case 'declaration':
-      return {
-        kind: node.kind,
-        property: node.property,
-        value: node.value,
-        important: node.important,
-        src: node.src,
-        dst: node.dst,
-      } satisfies Declaration as T
-
-    case 'comment':
-      return {
-        kind: node.kind,
-        value: node.value,
-        src: node.src,
-        dst: node.dst,
-      } satisfies Comment as T
-
-    default:
-      node satisfies never
-      throw new Error(`Unknown node kind: ${(node as any).kind}`)
-  }
-}
-
-export function cssContext(
-  ctx: VisitContext<AstNode>,
-): VisitContext<AstNode> & { context: Record<string, string | boolean> } {
-  return {
-    depth: ctx.depth,
-    get context() {
-      let context: Record<string, string | boolean> = {}
-      for (let child of ctx.path()) {
-        if (child.kind === 'context') {
-          Object.assign(context, child.context)
-        }
-      }
-
-      // Once computed, we never need to compute this again
-      Object.defineProperty(this, 'context', { value: context })
-      return context
-    },
-    get parent() {
-      let parent = (this.path().pop() as Extract<AstNode, { nodes: AstNode[] }>) ?? null
-
-      // Once computed, we never need to compute this again
-      Object.defineProperty(this, 'parent', { value: parent })
-      return parent
-    },
-    path() {
-      return ctx.path().filter((n) => n.kind !== 'context')
-    },
-  }
-}
diff --git a/packages/tailwindcss-language-service/src/css/clone-ast-node.ts b/packages/tailwindcss-language-service/src/css/clone-ast-node.ts
index ec62e4825..7d0c4ea82 100644
--- a/packages/tailwindcss-language-service/src/css/clone-ast-node.ts
+++ b/packages/tailwindcss-language-service/src/css/clone-ast-node.ts
@@ -16,7 +16,7 @@ export function cloneAstNode<T extends AstNode>(node: T): T {
         kind: node.kind,
         name: node.name,
         params: node.params,
-        nodes: node.nodes.map(cloneAstNode),
+        nodes: node.nodes?.map(cloneAstNode) ?? null,
         src: node.src,
         dst: node.dst,
       } satisfies AtRule as T
diff --git a/packages/tailwindcss-language-service/src/css/css-context.ts b/packages/tailwindcss-language-service/src/css/css-context.ts
new file mode 100644
index 000000000..02ca10013
--- /dev/null
+++ b/packages/tailwindcss-language-service/src/css/css-context.ts
@@ -0,0 +1,32 @@
+import type { VisitContext } from '../util/walk'
+import type { AstNode } from './ast'
+
+export function cssContext(
+  ctx: VisitContext<AstNode>,
+): VisitContext<AstNode> & { context: Record<string, string | boolean> } {
+  return {
+    depth: ctx.depth,
+    get context() {
+      let context: Record<string, string | boolean> = {}
+      for (let child of ctx.path()) {
+        if (child.kind === 'context') {
+          Object.assign(context, child.context)
+        }
+      }
+
+      // Once computed, we never need to compute this again
+      Object.defineProperty(this, 'context', { value: context })
+      return context
+    },
+    get parent() {
+      let parent = (this.path().pop() as Extract<AstNode, { nodes: AstNode[] }>) ?? null
+
+      // Once computed, we never need to compute this again
+      Object.defineProperty(this, 'parent', { value: parent })
+      return parent
+    },
+    path() {
+      return ctx.path().filter((n) => n.kind !== 'context')
+    },
+  }
+}
diff --git a/packages/tailwindcss-language-service/src/css/from-postcss-ast.ts b/packages/tailwindcss-language-service/src/css/from-postcss-ast.ts
index 9fb26ff7c..04cc59ad8 100644
--- a/packages/tailwindcss-language-service/src/css/from-postcss-ast.ts
+++ b/packages/tailwindcss-language-service/src/css/from-postcss-ast.ts
@@ -44,9 +44,9 @@ export function fromPostCSSAst(root: postcss.Root): AstNode[] {
 
     // AtRule
     else if (node.type === 'atrule') {
-      let astNode = atRule(`@${node.name}`, node.params)
+      let astNode = atRule(`@${node.name}`, node.params, node.nodes ? [] : null)
       astNode.src = toSource(node)
-      node.each((child) => transform(child, astNode.nodes))
+      node.each((child) => transform(child, astNode.nodes!))
       parent.push(astNode)
     }
 
diff --git a/packages/tailwindcss-language-service/src/css/index.ts b/packages/tailwindcss-language-service/src/css/index.ts
index c053e61b6..3612b101d 100644
--- a/packages/tailwindcss-language-service/src/css/index.ts
+++ b/packages/tailwindcss-language-service/src/css/index.ts
@@ -1,6 +1,7 @@
 export * from './ast'
 export * from './source'
 export { parse } from './parse'
+export { cloneAstNode } from './clone-ast-node'
 export { fromPostCSSAst } from './from-postcss-ast'
 export { toPostCSSAst } from './to-postcss-ast'
 export { toCss } from './to-css'
diff --git a/packages/tailwindcss-language-service/src/css/parse.ts b/packages/tailwindcss-language-service/src/css/parse.ts
index d0f8ff223..4386f6d63 100644
--- a/packages/tailwindcss-language-service/src/css/parse.ts
+++ b/packages/tailwindcss-language-service/src/css/parse.ts
@@ -277,6 +277,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
       }
 
       if (parent) {
+        parent.nodes ??= []
         parent.nodes.push(declaration)
       } else {
         ast.push(declaration)
@@ -303,6 +304,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
 
       // At-rule is nested inside of a rule, attach it to the parent.
       if (parent) {
+        parent.nodes ??= []
         parent.nodes.push(node)
       }
 
@@ -343,6 +345,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
       }
 
       if (parent) {
+        parent.nodes ??= []
         parent.nodes.push(declaration)
       } else {
         ast.push(declaration)
@@ -369,6 +372,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
 
       // Attach the rule to the parent in case it's nested.
       if (parent) {
+        parent.nodes ??= []
         parent.nodes.push(node)
       }
 
@@ -421,6 +425,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
 
           // At-rule is nested inside of a rule, attach it to the parent.
           if (parent) {
+            parent.nodes ??= []
             parent.nodes.push(node)
           }
 
@@ -460,6 +465,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
               node.dst = [source, bufferStart, i]
             }
 
+            parent.nodes ??= []
             parent.nodes.push(node)
           }
         }
@@ -548,7 +554,7 @@ export function parse(input: string, opts?: ParseOptions): AstNode[] {
   return ast
 }
 
-export function parseAtRule(buffer: string, nodes: AstNode[] = []): AtRule {
+export function parseAtRule(buffer: string, nodes: AstNode[] | null = []): AtRule {
   let name = buffer
   let params = ''
 
diff --git a/packages/tailwindcss-language-service/src/css/to-css.ts b/packages/tailwindcss-language-service/src/css/to-css.ts
index 83e94742e..b2e6c869a 100644
--- a/packages/tailwindcss-language-service/src/css/to-css.ts
+++ b/packages/tailwindcss-language-service/src/css/to-css.ts
@@ -3,6 +3,7 @@ import { Source } from './source'
 
 export function toCss(ast: AstNode[], track?: boolean): string {
   let pos = 0
+  let supportsBodylessAtRules = false
 
   let source: Source = {
     file: null,
@@ -84,6 +85,10 @@ export function toCss(ast: AstNode[], track?: boolean): string {
 
     // AtRule
     else if (node.kind === 'at-rule') {
+      let isBodyless = supportsBodylessAtRules
+        ? !node.nodes
+        : !node.nodes || node.nodes.length === 0
+
       // Print at-rules without nodes with a `;` instead of an empty block.
       //
       // E.g.:
@@ -91,7 +96,7 @@ export function toCss(ast: AstNode[], track?: boolean): string {
       // ```css
       // @layer base, components, utilities;
       // ```
-      if (node.nodes.length === 0) {
+      if (isBodyless) {
         let css = `${indent}${node.name} ${node.params};\n`
 
         if (track) {
diff --git a/packages/tailwindcss-language-service/src/css/to-postcss-ast.ts b/packages/tailwindcss-language-service/src/css/to-postcss-ast.ts
index 3495f323c..697aaaad8 100644
--- a/packages/tailwindcss-language-service/src/css/to-postcss-ast.ts
+++ b/packages/tailwindcss-language-service/src/css/to-postcss-ast.ts
@@ -85,11 +85,15 @@ export function toPostCSSAst(ast: AstNode[], source?: postcss.Source): postcss.R
 
     // AtRule
     else if (node.kind === 'at-rule') {
-      let astNode = postcss.atRule({ name: node.name.slice(1), params: node.params })
+      let astNode = postcss.atRule({
+        name: node.name.slice(1),
+        params: node.params,
+        nodes: node.nodes ? [] : undefined,
+      })
       updateSource(astNode, node.src)
       astNode.raws.semicolon = true
       parent.append(astNode)
-      for (let child of node.nodes) {
+      for (let child of node.nodes ?? []) {
         transform(child, astNode)
       }
     }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 216c758a7..dc75d0020 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -204,8 +204,8 @@ importers:
         specifier: 3.4.18
         version: 3.4.18
       tailwindcss-v4:
-        specifier: npm:tailwindcss@4.1.17
-        version: tailwindcss@4.1.17
+        specifier: npm:tailwindcss@4.1.18
+        version: tailwindcss@4.1.18
       tinyglobby:
         specifier: ^0.2.12
         version: 0.2.12
@@ -2434,8 +2434,8 @@ packages:
     engines: {node: '>=14.0.0'}
     hasBin: true
 
-  tailwindcss@4.1.17:
-    resolution: {integrity: sha512-j9Ee2YjuQqYT9bbRTfTZht9W/ytp5H+jJpZKiYdP/bpnXARAuELt9ofP0lPnmHjbga7SNQIxdTAXCmtKVYjN+Q==}
+  tailwindcss@4.1.18:
+    resolution: {integrity: sha512-4+Z+0yiYyEtUVCScyfHCxOYP06L5Ne+JiHhY2IjR2KWMIWhJOYZKLSGZaP5HkZ8+bY0cxfzwDE5uOmzFXyIwxw==}
 
   tapable@2.2.1:
     resolution: {integrity: sha512-GNzQvQTOIP6RyTfE2Qxb8ZVlNmw0n88vp1szwWRimP02mnTsx3Wtn5qRdqY9w2XduFNUgvOwhNnQsjwCp+kqaQ==}
@@ -4674,7 +4674,7 @@ snapshots:
     transitivePeerDependencies:
       - ts-node
 
-  tailwindcss@4.1.17: {}
+  tailwindcss@4.1.18: {}
 
   tapable@2.2.1: {}