diff --git a/package.json b/package.json
index eacb09b6f..8b070edb0 100644
--- a/package.json
+++ b/package.json
@@ -58,7 +58,7 @@
     "eslint-plugin-prefer-let": "^3.0.1",
     "eslint-plugin-promise": "^6.0.1",
     "nanospy": "^0.5.0",
-    "postcss": "^8.4.16",
+    "postcss": "^8.4.17",
     "size-limit": "^8.1.0",
     "uvu": "^0.5.6"
   },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index b46bcf456..a62527205 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -17,7 +17,7 @@ specifiers:
   nanospy: ^0.5.0
   normalize-range: ^0.1.2
   picocolors: ^1.0.0
-  postcss: ^8.4.16
+  postcss: ^8.4.17
   postcss-value-parser: ^4.2.0
   size-limit: ^8.1.0
   uvu: ^0.5.6
@@ -42,7 +42,7 @@ devDependencies:
   eslint-plugin-prefer-let: 3.0.1
   eslint-plugin-promise: 6.0.1_eslint@8.23.1
   nanospy: 0.5.0
-  postcss: 8.4.16
+  postcss: 8.4.17
   size-limit: 8.1.0
   uvu: 0.5.6
 
@@ -1682,8 +1682,8 @@ packages:
     resolution: {integrity: sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ==}
     dev: false
 
-  /postcss/8.4.16:
-    resolution: {integrity: sha512-ipHE1XBvKzm5xI7hiHCZJCSugxvsdq2mPnsq5+UF+VHCjiBvtDrlxJfMBToWaP9D5XlgNmcFGqoHmUn0EYEaRQ==}
+  /postcss/8.4.17:
+    resolution: {integrity: sha512-UNxNOLQydcOFi41yHNMcKRZ39NeXlr8AxGuZJsdub8vIb12fHzcq37DTU/QtbI6WLxNg2gF9Z+8qtRwTj1UI1Q==}
     engines: {node: ^10 || ^12 || >=14}
     dependencies:
       nanoid: 3.3.4
diff --git a/test/cases/example.out.css b/test/cases/example.out.css
index 4de4de5f8..57e12debb 100644
--- a/test/cases/example.out.css
+++ b/test/cases/example.out.css
@@ -1,8 +1,6 @@
 ::-moz-placeholder {
   color: gray;
-}
-
-::placeholder {
+}::placeholder {
   color: gray;
 }
 
diff --git a/test/cases/file-selector-button.out.css b/test/cases/file-selector-button.out.css
index 8dcb632bb..d7b4ab6bc 100644
--- a/test/cases/file-selector-button.out.css
+++ b/test/cases/file-selector-button.out.css
@@ -1,8 +1,6 @@
 ::-webkit-file-upload-button {
   background: black
-}
-
-::file-selector-button {
+}::file-selector-button {
   background: black
 }
 
diff --git a/test/cases/fullscreen.out.css b/test/cases/fullscreen.out.css
index 350311046..ac6a62c74 100644
--- a/test/cases/fullscreen.out.css
+++ b/test/cases/fullscreen.out.css
@@ -1,6 +1,5 @@
 :-webkit-full-screen {
   background: black
-}
-:fullscreen {
+}:fullscreen {
   background: black
 }
diff --git a/test/cases/keyframes.out.css b/test/cases/keyframes.out.css
index ad7a7a6fc..4fcf0cfae 100644
--- a/test/cases/keyframes.out.css
+++ b/test/cases/keyframes.out.css
@@ -17,8 +17,7 @@
     -webkit-transform: rotate(0);
             transform: rotate(0)
   }
-}
-@-o-keyframes anim {
+}@-o-keyframes anim {
   from {
     top: calc(10% + 10px);
     -o-transform: rotate(10deg);
@@ -33,8 +32,7 @@
     -o-transform: rotate(0);
        transform: rotate(0)
   }
-}
-@keyframes anim {
+}@keyframes anim {
   from {
     top: -webkit-calc(10% + 10px);
     top: calc(10% + 10px);
diff --git a/test/cases/placeholder-shown.out.css b/test/cases/placeholder-shown.out.css
index a22c988e4..550413935 100644
--- a/test/cases/placeholder-shown.out.css
+++ b/test/cases/placeholder-shown.out.css
@@ -1,6 +1,5 @@
 :-ms-input-placeholder {
   background: #eee
-}
-:placeholder-shown {
+}:placeholder-shown {
   background: #eee
 }
diff --git a/test/cases/placeholder.out.css b/test/cases/placeholder.out.css
index a3dc80cad..fccd81ee4 100644
--- a/test/cases/placeholder.out.css
+++ b/test/cases/placeholder.out.css
@@ -1,18 +1,13 @@
 ::-webkit-input-placeholder {
   color: #999
-}
-:-moz-placeholder {
+}:-moz-placeholder {
   color: #999
-}
-::-moz-placeholder {
+}::-moz-placeholder {
   color: #999
-}
-:-ms-input-placeholder {
+}:-ms-input-placeholder {
   color: #999
-}
-::-ms-input-placeholder {
+}::-ms-input-placeholder {
   color: #999
-}
-::placeholder {
+}::placeholder {
   color: #999
 }
diff --git a/test/cases/viewport.out.css b/test/cases/viewport.out.css
index 2f2030ad1..e18e7689c 100644
--- a/test/cases/viewport.out.css
+++ b/test/cases/viewport.out.css
@@ -1,6 +1,5 @@
 @-ms-viewport {
   width: device-width;
-}
-@viewport {
+}@viewport {
   width: device-width;
 }