diff --git a/package-lock.json b/package-lock.json
index 0c9dca4..41cdb39 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -58,6 +58,16 @@
         "color-convert": "^1.9.0"
       }
     },
+    "anymatch": {
+      "version": "3.1.3",
+      "resolved": "https://registry.npmjs.org/anymatch/-/anymatch-3.1.3.tgz",
+      "integrity": "sha512-KMReFUr0B4t+D+OBkjR3KYqvocp2XaSzO55UcB6mgQMd3KbcE+mWTyvVV7D/zsdEbNnV6acZUutkiHQXvTr1Rw==",
+      "dev": true,
+      "requires": {
+        "normalize-path": "^3.0.0",
+        "picomatch": "^2.0.4"
+      }
+    },
     "asn1": {
       "version": "0.2.4",
       "resolved": "https://registry.npmjs.org/asn1/-/asn1-0.2.4.tgz",
@@ -112,6 +122,12 @@
         "tweetnacl": "^0.14.3"
       }
     },
+    "binary-extensions": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/binary-extensions/-/binary-extensions-2.2.0.tgz",
+      "integrity": "sha512-jDctJ/IVQbZoJykoeHbhXpOlNBqGNcwXJKJog42E5HDPUwQTSdjCHdihjj0DlnheQ7blbT6dHOafNAiS8ooQKA==",
+      "dev": true
+    },
     "boxen": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/boxen/-/boxen-1.3.0.tgz",
@@ -145,6 +161,15 @@
         }
       }
     },
+    "braces": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/braces/-/braces-3.0.2.tgz",
+      "integrity": "sha512-b8um+L1RzM3WDSzvhm6gIz1yfTbBt6YTlcEKAvsmqCZZFw46z626lVj9j1yEPW33H5H+lBQpZMP1k8l+78Ha0A==",
+      "dev": true,
+      "requires": {
+        "fill-range": "^7.0.1"
+      }
+    },
     "camelcase": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/camelcase/-/camelcase-4.1.0.tgz",
@@ -186,6 +211,22 @@
       "integrity": "sha1-wKHS86cJLgN3S/qD8UwPxXkKhmc=",
       "dev": true
     },
+    "chokidar": {
+      "version": "3.5.3",
+      "resolved": "https://registry.npmjs.org/chokidar/-/chokidar-3.5.3.tgz",
+      "integrity": "sha512-Dr3sfKRP6oTcjf2JmUmFJfeVMvXBdegxB0iVQ5eb2V10uFJUCAS8OByZdVAyVb8xXNz3GjjTgj9kLWsZTqE6kw==",
+      "dev": true,
+      "requires": {
+        "anymatch": "~3.1.2",
+        "braces": "~3.0.2",
+        "fsevents": "~2.3.2",
+        "glob-parent": "~5.1.2",
+        "is-binary-path": "~2.1.0",
+        "is-glob": "~4.0.1",
+        "normalize-path": "~3.0.0",
+        "readdirp": "~3.6.0"
+      }
+    },
     "chrome-launcher": {
       "version": "0.11.1",
       "resolved": "https://registry.npmjs.org/chrome-launcher/-/chrome-launcher-0.11.1.tgz",
@@ -206,23 +247,49 @@
       "dev": true
     },
     "clean-css": {
-      "version": "4.2.1",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.2.1.tgz",
-      "integrity": "sha512-4ZxI6dy4lrY6FHzfiy1aEOXgu4LIsW2MhwG0VBKdcoGoH/XLFgaHSdLTGr4O8Be6A8r3MOphEiI8Gc1n0ecf3g==",
+      "version": "5.3.2",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.3.2.tgz",
+      "integrity": "sha512-JVJbM+f3d3Q704rF4bqQ5UUyTtuJ0JRKNbTKVEeujCCBoMdkEi+V+e8oktO9qGQNSvHrFTM6JZRXrUvGR1czww==",
       "dev": true,
       "requires": {
         "source-map": "~0.6.0"
       }
     },
     "clean-css-cli": {
-      "version": "4.3.0",
-      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-4.3.0.tgz",
-      "integrity": "sha512-8GHZfr+mG3zB/Lgqrr27qHBFsPSn0fyEI3f2rIZpxPxUbn2J6A8xyyeBRVTW8duDuXigN0s80vsXiXJOEFIO5Q==",
+      "version": "5.6.2",
+      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-5.6.2.tgz",
+      "integrity": "sha512-GDQkr6zVqHJhO3yWTy3sA22sMCT6iUqaJuBdqZMW6oI25MtiJ2iZXDmWzErpjoRotsB+TYPTpuZSNSgaC1n4lA==",
       "dev": true,
       "requires": {
-        "clean-css": "^4.2.1",
-        "commander": "2.x",
-        "glob": "7.x"
+        "chokidar": "^3.5.2",
+        "clean-css": "^5.3.2",
+        "commander": "7.x",
+        "glob": "^7.1.6"
+      },
+      "dependencies": {
+        "glob": {
+          "version": "7.2.3",
+          "resolved": "https://registry.npmjs.org/glob/-/glob-7.2.3.tgz",
+          "integrity": "sha512-nFR0zLpU2YCaRxwoCJvL6UvCH2JFyFVIvwTLsIf21AuHlMskA1hhTdk+LlYJtOlYt9v6dvszD2BGRqBL+iQK9Q==",
+          "dev": true,
+          "requires": {
+            "fs.realpath": "^1.0.0",
+            "inflight": "^1.0.4",
+            "inherits": "2",
+            "minimatch": "^3.1.1",
+            "once": "^1.3.0",
+            "path-is-absolute": "^1.0.0"
+          }
+        },
+        "minimatch": {
+          "version": "3.1.2",
+          "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-3.1.2.tgz",
+          "integrity": "sha512-J7p63hRiAjw1NDEww1W7i37+ByIrOWO5XQQAzZ3VOcL0PNybwpfmV/N05zFAzwQ9USyEcX6t3UO+K5aqBQOIHw==",
+          "dev": true,
+          "requires": {
+            "brace-expansion": "^1.1.7"
+          }
+        }
       }
     },
     "cli-boxes": {
@@ -327,9 +394,9 @@
       }
     },
     "commander": {
-      "version": "2.20.0",
-      "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.0.tgz",
-      "integrity": "sha512-7j2y+40w61zy6YC2iRNpUe/NwhNyoXrYpHMrSunaMG64nRnaf96zO/KMQR4OyN/UnE5KLyEBnKHd4aG3rskjpQ==",
+      "version": "7.2.0",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-7.2.0.tgz",
+      "integrity": "sha512-QrWXB+ZQSVPmIWIhtEO9H+gwHaMGYiF5ChvoJ+K9ZGHG/sVsa6yiesAD1GC/x46sET00Xlwo1u49RVVVzvcSkw==",
       "dev": true
     },
     "concat-map": {
@@ -564,6 +631,15 @@
         "escape-string-regexp": "^1.0.5"
       }
     },
+    "fill-range": {
+      "version": "7.0.1",
+      "resolved": "https://registry.npmjs.org/fill-range/-/fill-range-7.0.1.tgz",
+      "integrity": "sha512-qOo9F+dMUmC2Lcb4BbVvnKJxTPjCm+RRpe4gDuGrzkL7mEVl/djYSu2OdQ2Pa302N4oqkSg9ir6jaLWJ2USVpQ==",
+      "dev": true,
+      "requires": {
+        "to-regex-range": "^5.0.1"
+      }
+    },
     "find-up": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/find-up/-/find-up-3.0.0.tgz",
@@ -596,6 +672,13 @@
       "integrity": "sha1-FQStJSMVjKpA20onh8sBQRmU6k8=",
       "dev": true
     },
+    "fsevents": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "dev": true,
+      "optional": true
+    },
     "get-caller-file": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
@@ -631,6 +714,15 @@
         "path-is-absolute": "^1.0.0"
       }
     },
+    "glob-parent": {
+      "version": "5.1.2",
+      "resolved": "https://registry.npmjs.org/glob-parent/-/glob-parent-5.1.2.tgz",
+      "integrity": "sha512-AOIgSQCepiJYwP3ARnGx+5VnTu2HBYdzbGP45eLw1vr3zB3vZLeyed1sC9hnbcOc9/SrMyM5RPQrkGz4aS9Zow==",
+      "dev": true,
+      "requires": {
+        "is-glob": "^4.0.1"
+      }
+    },
     "global-dirs": {
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/global-dirs/-/global-dirs-0.1.1.tgz",
@@ -822,6 +914,15 @@
       "integrity": "sha1-EEqOSqym09jNFXqO+L+rLXo//bY=",
       "dev": true
     },
+    "is-binary-path": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/is-binary-path/-/is-binary-path-2.1.0.tgz",
+      "integrity": "sha512-ZMERYes6pDydyuGidse7OsHxtbI7WVeUEozgR/g7rd0xUimYNlvZRE/K2MgZTjWy725IfelLeVcEM97mmtRGXw==",
+      "dev": true,
+      "requires": {
+        "binary-extensions": "^2.0.0"
+      }
+    },
     "is-buffer": {
       "version": "1.1.6",
       "resolved": "https://registry.npmjs.org/is-buffer/-/is-buffer-1.1.6.tgz",
@@ -837,12 +938,27 @@
         "ci-info": "^1.5.0"
       }
     },
+    "is-extglob": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/is-extglob/-/is-extglob-2.1.1.tgz",
+      "integrity": "sha512-SbKbANkN603Vi4jEZv49LeVJMn4yGwsbzZworEoyEiutsN3nJYdbO36zfhGJ6QEDpOZIFkDtnq5JRxmvl3jsoQ==",
+      "dev": true
+    },
     "is-fullwidth-code-point": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/is-fullwidth-code-point/-/is-fullwidth-code-point-2.0.0.tgz",
       "integrity": "sha1-o7MKXE8ZkYMWeqq5O+764937ZU8=",
       "dev": true
     },
+    "is-glob": {
+      "version": "4.0.3",
+      "resolved": "https://registry.npmjs.org/is-glob/-/is-glob-4.0.3.tgz",
+      "integrity": "sha512-xelSayHH36ZgE7ZWhli7pW34hNbNl8Ojv5KVmkJD4hBdD3th8Tfk9vYasLM+mXWOZhFkgZfxhLSnrwRr4elSSg==",
+      "dev": true,
+      "requires": {
+        "is-extglob": "^2.1.1"
+      }
+    },
     "is-installed-globally": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/is-installed-globally/-/is-installed-globally-0.1.0.tgz",
@@ -859,6 +975,12 @@
       "integrity": "sha1-8vtjpl5JBbQGyGBydloaTceTufQ=",
       "dev": true
     },
+    "is-number": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/is-number/-/is-number-7.0.0.tgz",
+      "integrity": "sha512-41Cifkg6e8TylSpdtTpeLVMqvSBEVzTttHvERD741+pnZ8ANv0004MRL43QKPDlK9cGvNp6NZWZUBlbGXYxxng==",
+      "dev": true
+    },
     "is-obj": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/is-obj/-/is-obj-1.0.1.tgz",
@@ -1274,6 +1396,12 @@
         }
       }
     },
+    "normalize-path": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
+      "integrity": "sha512-6eZs5Ls3WtCisHWp9S2GUy8dqkpGi4BVSz3GaqiE6ezub0512ESztXUwUB6C6IKbQkY2Pnb/mD4WYojCRwcwLA==",
+      "dev": true
+    },
     "npm-run-path": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/npm-run-path/-/npm-run-path-2.0.2.tgz",
@@ -1435,6 +1563,12 @@
       "integrity": "sha1-Ywn04OX6kT7BxpMHrjZLSzd8nns=",
       "dev": true
     },
+    "picomatch": {
+      "version": "2.3.1",
+      "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-2.3.1.tgz",
+      "integrity": "sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==",
+      "dev": true
+    },
     "pify": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/pify/-/pify-3.0.0.tgz",
@@ -1726,6 +1860,15 @@
         "semver": "^5.6.0"
       }
     },
+    "readdirp": {
+      "version": "3.6.0",
+      "resolved": "https://registry.npmjs.org/readdirp/-/readdirp-3.6.0.tgz",
+      "integrity": "sha512-hOS089on8RduqdbhvQ5Z37A0ESjsqz6qnRcffsMU3495FuTdqSm+7bhJ29JvIOsBDEEnan5DPu9t3To9VRlMzA==",
+      "dev": true,
+      "requires": {
+        "picomatch": "^2.2.1"
+      }
+    },
     "registry-auth-token": {
       "version": "3.4.0",
       "resolved": "https://registry.npmjs.org/registry-auth-token/-/registry-auth-token-3.4.0.tgz",
@@ -2019,6 +2162,15 @@
         "os-tmpdir": "~1.0.2"
       }
     },
+    "to-regex-range": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/to-regex-range/-/to-regex-range-5.0.1.tgz",
+      "integrity": "sha512-65P7iz6X5yEr1cwcgvQxbbIw7Uk3gOy5dIdtZ4rDveLqhrdJP+Li/Hx6tyK0NEb+2GCyneCMJiGqrADCSNk8sQ==",
+      "dev": true,
+      "requires": {
+        "is-number": "^7.0.0"
+      }
+    },
     "tough-cookie": {
       "version": "2.4.3",
       "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-2.4.3.tgz",
diff --git a/package.json b/package.json
index cb6c61d..bb8762b 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "natives": "1.1.3"
   },
   "devDependencies": {
-    "clean-css-cli": "4.3.0",
+    "clean-css-cli": "5.6.2",
     "lighthouse": "5.2.0",
     "purgecss": "1.3.0",
     "tachyons-sass": "^4.9.5"