diff --git a/lib/metalsmith.js b/lib/metalsmith.js
index 0ab967404b..70f6d74b01 100644
--- a/lib/metalsmith.js
+++ b/lib/metalsmith.js
@@ -13,7 +13,7 @@ const permalinks = require('metalsmith-permalinks') // apply a permalink pattern
 const canonical = require('metalsmith-canonical') // add a canonical url property to pages
 
 const sass = require('@metalsmith/sass') // convert Sass files to CSS using Dart Sass
-const postcss = require('metalsmith-postcss')
+const postcss = require('@metalsmith/postcss')
 
 const rollup = require('metalsmith-rollup') // used to build GOV.UK Frontend JavaScript
 const resolve = require('rollup-plugin-node-resolve') // rollup plugin to resolve node_modules
diff --git a/package-lock.json b/package-lock.json
index a26123f3d5..a7036c103b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -8,6 +8,7 @@
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
+        "@metalsmith/postcss": "^5.0.0",
         "acorn": "^6.4.1",
         "autoprefixer": "^9.5.1",
         "clipboard": "^2.0.4",
@@ -18,9 +19,8 @@
         "highlight.js": "^10.4.1",
         "html5shiv": "^3.7.3",
         "lunr": "^2.3.6",
-        "metalsmith-postcss": "^4.2.0",
         "modernizr": "^3.7.1",
-        "postcss": "^6.0.23",
+        "postcss": "^8.4.14",
         "sass-export": "^2.1.0",
         "serve-static": "^1.13.2",
         "slugger": "^1.0.1"
@@ -1869,6 +1869,18 @@
         "@jridgewell/sourcemap-codec": "^1.4.10"
       }
     },
+    "node_modules/@metalsmith/postcss": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/@metalsmith/postcss/-/postcss-5.0.0.tgz",
+      "integrity": "sha512-sMjGcerJMi76m9tFac/3I+20dvLHkmYfMnYFDnLrWyWNSerqNjS/vdI81sSQRvAhNRjr0QK+F+YBOKguBIcdUA==",
+      "engines": {
+        "node": ">=12"
+      },
+      "peerDependencies": {
+        "metalsmith": "^2.4.1",
+        "postcss": "^5.0.4 || ^6.0.0 || ^7.0.0 || ^8.0.0"
+      }
+    },
     "node_modules/@metalsmith/sass": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/@metalsmith/sass/-/sass-1.0.0.tgz",
@@ -3330,7 +3342,6 @@
     },
     "node_modules/cross-spawn": {
       "version": "7.0.3",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "path-key": "^3.1.0",
@@ -3343,7 +3354,6 @@
     },
     "node_modules/cross-spawn/node_modules/path-key": {
       "version": "3.1.1",
-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=8"
@@ -3351,7 +3361,6 @@
     },
     "node_modules/cross-spawn/node_modules/shebang-command": {
       "version": "2.0.0",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "shebang-regex": "^3.0.0"
@@ -3362,7 +3371,6 @@
     },
     "node_modules/cross-spawn/node_modules/shebang-regex": {
       "version": "3.0.0",
-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=8"
@@ -3370,7 +3378,6 @@
     },
     "node_modules/cross-spawn/node_modules/which": {
       "version": "2.0.2",
-      "dev": true,
       "license": "ISC",
       "dependencies": {
         "isexe": "^2.0.0"
@@ -6240,7 +6247,6 @@
     },
     "node_modules/is-utf8": {
       "version": "0.2.1",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/is-wsl": {
@@ -9389,7 +9395,6 @@
       "version": "2.5.0",
       "resolved": "https://registry.npmjs.org/metalsmith/-/metalsmith-2.5.0.tgz",
       "integrity": "sha512-tBFpCMq8t/ZeD8qbvyWSLjyW7aO8RJYeFSk8LyclgHYaeMWiSPrMxXc3NORVCJ3iG17aRxuL/+nla58Qq3DBcQ==",
-      "dev": true,
       "hasInstallScript": true,
       "dependencies": {
         "commander": "^6.2.1",
@@ -9655,16 +9660,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/metalsmith-postcss": {
-      "version": "4.2.0",
-      "license": "MIT",
-      "dependencies": {
-        "minimatch": "^3.0.4"
-      },
-      "peerDependencies": {
-        "postcss": "^5.0.4 || ^6.0.0"
-      }
-    },
     "node_modules/metalsmith-rollup": {
       "version": "2.0.0",
       "dev": true,
@@ -9716,7 +9711,6 @@
       "version": "6.2.1",
       "resolved": "https://registry.npmjs.org/commander/-/commander-6.2.1.tgz",
       "integrity": "sha512-U7VdrJFnJgo4xjrHpTzu0yrHPGImdsmD95ZlgYSEajAn2JKzDhDTPG9kBTefmObL2w/ngeZnilk+OV9CG3d7UA==",
-      "dev": true,
       "engines": {
         "node": ">= 6"
       }
@@ -9725,7 +9719,6 @@
       "version": "4.3.4",
       "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
       "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
-      "dev": true,
       "dependencies": {
         "ms": "2.1.2"
       },
@@ -9742,7 +9735,6 @@
       "version": "7.2.0",
       "resolved": "https://registry.npmjs.org/glob/-/glob-7.2.0.tgz",
       "integrity": "sha512-lmLf6gtyrPq8tTjSmrO94wBeQbFR3HbLHbuyD69wuyQkImp2hWqMGB47OX65FBkPffO641IP9jWa1z4ivqG26Q==",
-      "dev": true,
       "dependencies": {
         "fs.realpath": "^1.0.0",
         "inflight": "^1.0.4",
@@ -9761,14 +9753,12 @@
     "node_modules/metalsmith/node_modules/ms": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-      "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
-      "dev": true
+      "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
     },
     "node_modules/metalsmith/node_modules/rimraf": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-3.0.2.tgz",
       "integrity": "sha512-JZkJMZkAGFFPP2YqXZXPbMlMBgsxzE8ILs4lMIX/2o0L9UBw9O/Y3o6wFw/i9YLapcUJWwqbi3kdxIPdC62TIA==",
-      "dev": true,
       "dependencies": {
         "glob": "^7.1.3"
       },
@@ -9783,7 +9773,6 @@
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/stat-mode/-/stat-mode-1.0.0.tgz",
       "integrity": "sha512-jH9EhtKIjuXZ2cWxmXS8ZP80XyC3iasQxMDV8jzhNJpfDb7VbQLVW4Wvsxz9QZvzV+G4YoSfBUVKDOyxLzi/sg==",
-      "dev": true,
       "engines": {
         "node": ">= 6"
       }
@@ -9792,7 +9781,6 @@
       "version": "4.0.5",
       "resolved": "https://registry.npmjs.org/micromatch/-/micromatch-4.0.5.tgz",
       "integrity": "sha512-DMy+ERcEW2q8Z2Po+WNXuw3c5YaUSFjAO5GsJqfEl7UjvtIuFKO6ZrKvcItdy98dwFI2N1tg3zNIdKaQT+aNdA==",
-      "dev": true,
       "dependencies": {
         "braces": "^3.0.2",
         "picomatch": "^2.3.1"
@@ -10099,6 +10087,17 @@
       "version": "0.0.7",
       "license": "ISC"
     },
+    "node_modules/nanoid": {
+      "version": "3.3.4",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.4.tgz",
+      "integrity": "sha512-MqBkQh/OHTS2egovRtLk45wEyNXwF+cokD+1YPf9u5VfJiRdAiRwB2froX5Co9Rh20xs4siNPm8naNotSD6RBw==",
+      "bin": {
+        "nanoid": "bin/nanoid.cjs"
+      },
+      "engines": {
+        "node": "^10 || ^12 || ^13.7 || ^14 || >=15.0.1"
+      }
+    },
     "node_modules/natural-compare": {
       "version": "1.4.0",
       "license": "MIT"
@@ -10595,6 +10594,11 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/picocolors": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.0.0.tgz",
+      "integrity": "sha512-1fygroTLlHu66zi26VoTDv8yRgm0Fccecssto+MhsZ0D/DGW2sm8E8AjW7NU5VVTRt5GxbeZ5qBuJr+HyLYkjQ=="
+    },
     "node_modules/picomatch": {
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.1.tgz",
@@ -10847,60 +10851,32 @@
       }
     },
     "node_modules/postcss": {
-      "version": "6.0.23",
-      "license": "MIT",
+      "version": "8.4.14",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.14.tgz",
+      "integrity": "sha512-E398TUmfAYFPBSdzgeieK2Y1+1cpdxJx8yXbK/m57nRhKSmk1GB2tO4lbLBtlkfPQTDKfe4Xqv1ASWPpayPEig==",
+      "funding": [
+        {
+          "type": "opencollective",
+          "url": "https://opencollective.com/postcss/"
+        },
+        {
+          "type": "tidelift",
+          "url": "https://tidelift.com/funding/github/npm/postcss"
+        }
+      ],
       "dependencies": {
-        "chalk": "^2.4.1",
-        "source-map": "^0.6.1",
-        "supports-color": "^5.4.0"
+        "nanoid": "^3.3.4",
+        "picocolors": "^1.0.0",
+        "source-map-js": "^1.0.2"
       },
       "engines": {
-        "node": ">=4.0.0"
+        "node": "^10 || ^12 || >=14"
       }
     },
     "node_modules/postcss-value-parser": {
       "version": "3.3.1",
       "license": "MIT"
     },
-    "node_modules/postcss/node_modules/ansi-styles": {
-      "version": "3.2.1",
-      "license": "MIT",
-      "dependencies": {
-        "color-convert": "^1.9.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
-    "node_modules/postcss/node_modules/chalk": {
-      "version": "2.4.2",
-      "license": "MIT",
-      "dependencies": {
-        "ansi-styles": "^3.2.1",
-        "escape-string-regexp": "^1.0.5",
-        "supports-color": "^5.3.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
-    "node_modules/postcss/node_modules/source-map": {
-      "version": "0.6.1",
-      "license": "BSD-3-Clause",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
-    "node_modules/postcss/node_modules/supports-color": {
-      "version": "5.5.0",
-      "license": "MIT",
-      "dependencies": {
-        "has-flag": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=4"
-      }
-    },
     "node_modules/preact": {
       "version": "8.5.3",
       "dev": true,
@@ -12257,8 +12233,9 @@
       }
     },
     "node_modules/source-map-js": {
-      "version": "1.0.1",
-      "license": "BSD-3-Clause",
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/source-map-js/-/source-map-js-1.0.2.tgz",
+      "integrity": "sha512-R0XvVJ9WusLiqTCEiGCmICCMplcCkIwwR11mOSD9CR5u+IXYdiseeEuXCVAjS54zqwkLcPNnmU4OeJ6tUrWhDw==",
       "engines": {
         "node": ">=0.10.0"
       }
@@ -13561,7 +13538,6 @@
     },
     "node_modules/ware": {
       "version": "1.3.0",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "wrap-fn": "^0.1.0"
@@ -13629,7 +13605,6 @@
     },
     "node_modules/wrap-fn": {
       "version": "0.1.5",
-      "dev": true,
       "license": "MIT",
       "dependencies": {
         "co": "3.1.0"
@@ -13637,7 +13612,6 @@
     },
     "node_modules/wrap-fn/node_modules/co": {
       "version": "3.1.0",
-      "dev": true,
       "license": "MIT"
     },
     "node_modules/wrappy": {
@@ -15148,6 +15122,12 @@
         "@jridgewell/sourcemap-codec": "^1.4.10"
       }
     },
+    "@metalsmith/postcss": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/@metalsmith/postcss/-/postcss-5.0.0.tgz",
+      "integrity": "sha512-sMjGcerJMi76m9tFac/3I+20dvLHkmYfMnYFDnLrWyWNSerqNjS/vdI81sSQRvAhNRjr0QK+F+YBOKguBIcdUA==",
+      "requires": {}
+    },
     "@metalsmith/sass": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/@metalsmith/sass/-/sass-1.0.0.tgz",
@@ -16167,7 +16147,6 @@
     },
     "cross-spawn": {
       "version": "7.0.3",
-      "dev": true,
       "requires": {
         "path-key": "^3.1.0",
         "shebang-command": "^2.0.0",
@@ -16175,23 +16154,19 @@
       },
       "dependencies": {
         "path-key": {
-          "version": "3.1.1",
-          "dev": true
+          "version": "3.1.1"
         },
         "shebang-command": {
           "version": "2.0.0",
-          "dev": true,
           "requires": {
             "shebang-regex": "^3.0.0"
           }
         },
         "shebang-regex": {
-          "version": "3.0.0",
-          "dev": true
+          "version": "3.0.0"
         },
         "which": {
           "version": "2.0.2",
-          "dev": true,
           "requires": {
             "isexe": "^2.0.0"
           }
@@ -18158,8 +18133,7 @@
       "dev": true
     },
     "is-utf8": {
-      "version": "0.2.1",
-      "dev": true
+      "version": "0.2.1"
     },
     "is-wsl": {
       "version": "1.1.0",
@@ -20214,7 +20188,6 @@
       "version": "2.5.0",
       "resolved": "https://registry.npmjs.org/metalsmith/-/metalsmith-2.5.0.tgz",
       "integrity": "sha512-tBFpCMq8t/ZeD8qbvyWSLjyW7aO8RJYeFSk8LyclgHYaeMWiSPrMxXc3NORVCJ3iG17aRxuL/+nla58Qq3DBcQ==",
-      "dev": true,
       "requires": {
         "commander": "^6.2.1",
         "cross-spawn": "^7.0.3",
@@ -20230,14 +20203,12 @@
         "commander": {
           "version": "6.2.1",
           "resolved": "https://registry.npmjs.org/commander/-/commander-6.2.1.tgz",
-          "integrity": "sha512-U7VdrJFnJgo4xjrHpTzu0yrHPGImdsmD95ZlgYSEajAn2JKzDhDTPG9kBTefmObL2w/ngeZnilk+OV9CG3d7UA==",
-          "dev": true
+          "integrity": "sha512-U7VdrJFnJgo4xjrHpTzu0yrHPGImdsmD95ZlgYSEajAn2JKzDhDTPG9kBTefmObL2w/ngeZnilk+OV9CG3d7UA=="
         },
         "debug": {
           "version": "4.3.4",
           "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.4.tgz",
           "integrity": "sha512-PRWFHuSU3eDtQJPvnNY7Jcket1j0t5OuOsFzPPzsekD52Zl8qUfFIPEiswXqIvHWGVHOgX+7G/vCNNhehwxfkQ==",
-          "dev": true,
           "requires": {
             "ms": "2.1.2"
           }
@@ -20246,7 +20217,6 @@
           "version": "7.2.0",
           "resolved": "https://registry.npmjs.org/glob/-/glob-7.2.0.tgz",
           "integrity": "sha512-lmLf6gtyrPq8tTjSmrO94wBeQbFR3HbLHbuyD69wuyQkImp2hWqMGB47OX65FBkPffO641IP9jWa1z4ivqG26Q==",
-          "dev": true,
           "requires": {
             "fs.realpath": "^1.0.0",
             "inflight": "^1.0.4",
@@ -20259,14 +20229,12 @@
         "ms": {
           "version": "2.1.2",
           "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
-          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
-          "dev": true
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w=="
         },
         "rimraf": {
           "version": "3.0.2",
           "resolved": "https://registry.npmjs.org/rimraf/-/rimraf-3.0.2.tgz",
           "integrity": "sha512-JZkJMZkAGFFPP2YqXZXPbMlMBgsxzE8ILs4lMIX/2o0L9UBw9O/Y3o6wFw/i9YLapcUJWwqbi3kdxIPdC62TIA==",
-          "dev": true,
           "requires": {
             "glob": "^7.1.3"
           }
@@ -20274,8 +20242,7 @@
         "stat-mode": {
           "version": "1.0.0",
           "resolved": "https://registry.npmjs.org/stat-mode/-/stat-mode-1.0.0.tgz",
-          "integrity": "sha512-jH9EhtKIjuXZ2cWxmXS8ZP80XyC3iasQxMDV8jzhNJpfDb7VbQLVW4Wvsxz9QZvzV+G4YoSfBUVKDOyxLzi/sg==",
-          "dev": true
+          "integrity": "sha512-jH9EhtKIjuXZ2cWxmXS8ZP80XyC3iasQxMDV8jzhNJpfDb7VbQLVW4Wvsxz9QZvzV+G4YoSfBUVKDOyxLzi/sg=="
         }
       }
     },
@@ -20474,12 +20441,6 @@
         }
       }
     },
-    "metalsmith-postcss": {
-      "version": "4.2.0",
-      "requires": {
-        "minimatch": "^3.0.4"
-      }
-    },
     "metalsmith-rollup": {
       "version": "2.0.0",
       "dev": true,
@@ -20517,7 +20478,6 @@
       "version": "4.0.5",
       "resolved": "https://registry.npmjs.org/micromatch/-/micromatch-4.0.5.tgz",
       "integrity": "sha512-DMy+ERcEW2q8Z2Po+WNXuw3c5YaUSFjAO5GsJqfEl7UjvtIuFKO6ZrKvcItdy98dwFI2N1tg3zNIdKaQT+aNdA==",
-      "dev": true,
       "requires": {
         "braces": "^3.0.2",
         "picomatch": "^2.3.1"
@@ -20721,6 +20681,11 @@
     "mute-stream": {
       "version": "0.0.7"
     },
+    "nanoid": {
+      "version": "3.3.4",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.4.tgz",
+      "integrity": "sha512-MqBkQh/OHTS2egovRtLk45wEyNXwF+cokD+1YPf9u5VfJiRdAiRwB2froX5Co9Rh20xs4siNPm8naNotSD6RBw=="
+    },
     "natural-compare": {
       "version": "1.4.0"
     },
@@ -21025,6 +20990,11 @@
       "version": "2.1.0",
       "dev": true
     },
+    "picocolors": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.0.0.tgz",
+      "integrity": "sha512-1fygroTLlHu66zi26VoTDv8yRgm0Fccecssto+MhsZ0D/DGW2sm8E8AjW7NU5VVTRt5GxbeZ5qBuJr+HyLYkjQ=="
+    },
     "picomatch": {
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.1.tgz",
@@ -21182,36 +21152,13 @@
       }
     },
     "postcss": {
-      "version": "6.0.23",
+      "version": "8.4.14",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.14.tgz",
+      "integrity": "sha512-E398TUmfAYFPBSdzgeieK2Y1+1cpdxJx8yXbK/m57nRhKSmk1GB2tO4lbLBtlkfPQTDKfe4Xqv1ASWPpayPEig==",
       "requires": {
-        "chalk": "^2.4.1",
-        "source-map": "^0.6.1",
-        "supports-color": "^5.4.0"
-      },
-      "dependencies": {
-        "ansi-styles": {
-          "version": "3.2.1",
-          "requires": {
-            "color-convert": "^1.9.0"
-          }
-        },
-        "chalk": {
-          "version": "2.4.2",
-          "requires": {
-            "ansi-styles": "^3.2.1",
-            "escape-string-regexp": "^1.0.5",
-            "supports-color": "^5.3.0"
-          }
-        },
-        "source-map": {
-          "version": "0.6.1"
-        },
-        "supports-color": {
-          "version": "5.5.0",
-          "requires": {
-            "has-flag": "^3.0.0"
-          }
-        }
+        "nanoid": "^3.3.4",
+        "picocolors": "^1.0.0",
+        "source-map-js": "^1.0.2"
       }
     },
     "postcss-value-parser": {
@@ -22211,7 +22158,9 @@
       }
     },
     "source-map-js": {
-      "version": "1.0.1"
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/source-map-js/-/source-map-js-1.0.2.tgz",
+      "integrity": "sha512-R0XvVJ9WusLiqTCEiGCmICCMplcCkIwwR11mOSD9CR5u+IXYdiseeEuXCVAjS54zqwkLcPNnmU4OeJ6tUrWhDw=="
     },
     "source-map-support": {
       "version": "0.5.20",
@@ -23110,7 +23059,6 @@
     },
     "ware": {
       "version": "1.3.0",
-      "dev": true,
       "requires": {
         "wrap-fn": "^0.1.0"
       }
@@ -23158,14 +23106,12 @@
     },
     "wrap-fn": {
       "version": "0.1.5",
-      "dev": true,
       "requires": {
         "co": "3.1.0"
       },
       "dependencies": {
         "co": {
-          "version": "3.1.0",
-          "dev": true
+          "version": "3.1.0"
         }
       }
     },
diff --git a/package.json b/package.json
index 1918d880a6..fef0406bbb 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
     ]
   },
   "dependencies": {
+    "@metalsmith/postcss": "^5.0.0",
     "acorn": "^6.4.1",
     "autoprefixer": "^9.5.1",
     "clipboard": "^2.0.4",
@@ -38,9 +39,8 @@
     "highlight.js": "^10.4.1",
     "html5shiv": "^3.7.3",
     "lunr": "^2.3.6",
-    "metalsmith-postcss": "^4.2.0",
     "modernizr": "^3.7.1",
-    "postcss": "^6.0.23",
+    "postcss": "^8.4.14",
     "sass-export": "^2.1.0",
     "serve-static": "^1.13.2",
     "slugger": "^1.0.1"