diff --git a/package.json b/package.json
index a03518a..687fb8b 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
         "jsdom": "^16.6.0",
         "markdown-it": "^12.0.6",
         "markdown-it-anchor": "^7.1.0",
-        "postcss": "^8.3.2",
+        "postcss": "^8.4.20",
         "postcss-cli": "^8.3.1",
         "rollup": "^2.51.2",
         "rollup-plugin-postcss": "^4.0.0",
diff --git a/yarn.lock b/yarn.lock
index ce240aa..e2c3b8a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2016,7 +2016,7 @@ __metadata:
     markdown-it-anchor: ^7.1.0
     markdownlint: ^0.23.1
     markdownlint-cli2: ^0.1.3
-    postcss: ^8.3.2
+    postcss: ^8.4.20
     postcss-cli: ^8.3.1
     prettier: ^2.3.1
     rollup: ^2.51.2
@@ -5244,7 +5244,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss@npm:^8.1.6, postcss@npm:^8.3.2, postcss@npm:^8.3.5":
+"postcss@npm:^8.1.6, postcss@npm:^8.3.5":
   version: 8.4.14
   resolution: "postcss@npm:8.4.14"
   dependencies:
@@ -5255,6 +5255,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"postcss@npm:^8.4.20":
+  version: 8.4.20
+  resolution: "postcss@npm:8.4.20"
+  dependencies:
+    nanoid: ^3.3.4
+    picocolors: ^1.0.0
+    source-map-js: ^1.0.2
+  checksum: 1a5609ea1c1b204f9c2974a0019ae9eef2d99bf645c2c9aac675166c4cb1005be7b5e2ba196160bc771f5d9ac896ed883f236f888c891e835e59d28fff6651aa
+  languageName: node
+  linkType: hard
+
 "posthtml-parser@npm:^0.11.0":
   version: 0.11.0
   resolution: "posthtml-parser@npm:0.11.0"