root: stylelint config updates

- Switches to stylelint-config-standard. This config adds
additional rules to enforce common stylistic conventions
found in many CSS style guides, including Google's.
- Adds alphabetical properties rule.

Change-Id: Ic2df16c38662777f729a6301c1e567faa330a92d
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/283712
Trust: Jamal Carvalho <jamal@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
TryBot-Result: kokoro <noreply+kokoro@google.com>
diff --git a/.stylelintrc.yaml b/.stylelintrc.yaml
index 2d0487e..433efa2 100644
--- a/.stylelintrc.yaml
+++ b/.stylelintrc.yaml
@@ -1,10 +1,13 @@
 extends:
-  - stylelint-config-recommended
+  - stylelint-config-standard
   - stylelint-prettier/recommended
+plugins:
+  - stylelint-order
 rules:
   unit-disallowed-list:
-    - "px"
+    - 'px'
   declaration-property-value-allowed-list:
-    "/color/":
-    - "/^var\\(--/"
-    - "transparent"
+    '/color/':
+      - "/^var\\(--/"
+      - 'transparent'
+  order/properties-alphabetical-order: true
diff --git a/package-lock.json b/package-lock.json
index 74a7f93..2750953 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -5179,6 +5179,60 @@
         "util-deprecate": "^1.0.2"
       }
     },
+    "postcss-sorting": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/postcss-sorting/-/postcss-sorting-5.0.1.tgz",
+      "integrity": "sha512-Y9fUFkIhfrm6i0Ta3n+89j56EFqaNRdUKqXyRp6kvTcSXnmgEjaVowCXH+JBe9+YKWqd4nc28r2sgwnzJalccA==",
+      "requires": {
+        "lodash": "^4.17.14",
+        "postcss": "^7.0.17"
+      },
+      "dependencies": {
+        "chalk": {
+          "version": "2.4.2",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.2.tgz",
+          "integrity": "sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==",
+          "requires": {
+            "ansi-styles": "^3.2.1",
+            "escape-string-regexp": "^1.0.5",
+            "supports-color": "^5.3.0"
+          },
+          "dependencies": {
+            "supports-color": {
+              "version": "5.5.0",
+              "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
+              "integrity": "sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==",
+              "requires": {
+                "has-flag": "^3.0.0"
+              }
+            }
+          }
+        },
+        "postcss": {
+          "version": "7.0.35",
+          "resolved": "https://registry.npmjs.org/postcss/-/postcss-7.0.35.tgz",
+          "integrity": "sha512-3QT8bBJeX/S5zKTTjTCIjRF3If4avAT6kqxcASlTWEtAFCb9NH0OUxNDfgZSWdP5fJnBYCMEWkIFfWeugjzYMg==",
+          "requires": {
+            "chalk": "^2.4.2",
+            "source-map": "^0.6.1",
+            "supports-color": "^6.1.0"
+          }
+        },
+        "source-map": {
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+        },
+        "supports-color": {
+          "version": "6.1.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-6.1.0.tgz",
+          "integrity": "sha512-qe1jfm1Mg7Nq/NSh6XE24gPXROEVsWHxC1LIx//XNlD9iw7YZQGjZNjYN7xGaEG6iKdA8EtNFW6R0gjnVXp+wQ==",
+          "requires": {
+            "has-flag": "^3.0.0"
+          }
+        }
+      }
+    },
     "postcss-syntax": {
       "version": "0.36.2",
       "resolved": "https://registry.npmjs.org/postcss-syntax/-/postcss-syntax-0.36.2.tgz",
@@ -6563,6 +6617,69 @@
       "resolved": "https://registry.npmjs.org/stylelint-config-recommended/-/stylelint-config-recommended-3.0.0.tgz",
       "integrity": "sha512-F6yTRuc06xr1h5Qw/ykb2LuFynJ2IxkKfCMf+1xqPffkxh0S09Zc902XCffcsw/XMFq/OzQ1w54fLIDtmRNHnQ=="
     },
+    "stylelint-config-standard": {
+      "version": "20.0.0",
+      "resolved": "https://registry.npmjs.org/stylelint-config-standard/-/stylelint-config-standard-20.0.0.tgz",
+      "integrity": "sha512-IB2iFdzOTA/zS4jSVav6z+wGtin08qfj+YyExHB3LF9lnouQht//YyB0KZq9gGz5HNPkddHOzcY8HsUey6ZUlA==",
+      "requires": {
+        "stylelint-config-recommended": "^3.0.0"
+      }
+    },
+    "stylelint-order": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/stylelint-order/-/stylelint-order-4.1.0.tgz",
+      "integrity": "sha512-sVTikaDvMqg2aJjh4r48jsdfmqLT+nqB1MOsaBnvM3OwLx4S+WXcsxsgk5w18h/OZoxZCxuyXMh61iBHcj9Qiw==",
+      "requires": {
+        "lodash": "^4.17.15",
+        "postcss": "^7.0.31",
+        "postcss-sorting": "^5.0.1"
+      },
+      "dependencies": {
+        "chalk": {
+          "version": "2.4.2",
+          "resolved": "https://registry.npmjs.org/chalk/-/chalk-2.4.2.tgz",
+          "integrity": "sha512-Mti+f9lpJNcwF4tWV8/OrTTtF1gZi+f8FqlyAdouralcFWFQWF2+NgCHShjkCb+IFBLq9buZwE1xckQU4peSuQ==",
+          "requires": {
+            "ansi-styles": "^3.2.1",
+            "escape-string-regexp": "^1.0.5",
+            "supports-color": "^5.3.0"
+          },
+          "dependencies": {
+            "supports-color": {
+              "version": "5.5.0",
+              "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-5.5.0.tgz",
+              "integrity": "sha512-QjVjwdXIt408MIiAqCX4oUKsgU2EqAGzs2Ppkm4aQYbjm+ZEWEcW4SfFNTr4uMNZma0ey4f5lgLrkB0aX0QMow==",
+              "requires": {
+                "has-flag": "^3.0.0"
+              }
+            }
+          }
+        },
+        "postcss": {
+          "version": "7.0.35",
+          "resolved": "https://registry.npmjs.org/postcss/-/postcss-7.0.35.tgz",
+          "integrity": "sha512-3QT8bBJeX/S5zKTTjTCIjRF3If4avAT6kqxcASlTWEtAFCb9NH0OUxNDfgZSWdP5fJnBYCMEWkIFfWeugjzYMg==",
+          "requires": {
+            "chalk": "^2.4.2",
+            "source-map": "^0.6.1",
+            "supports-color": "^6.1.0"
+          }
+        },
+        "source-map": {
+          "version": "0.6.1",
+          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+          "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="
+        },
+        "supports-color": {
+          "version": "6.1.0",
+          "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-6.1.0.tgz",
+          "integrity": "sha512-qe1jfm1Mg7Nq/NSh6XE24gPXROEVsWHxC1LIx//XNlD9iw7YZQGjZNjYN7xGaEG6iKdA8EtNFW6R0gjnVXp+wQ==",
+          "requires": {
+            "has-flag": "^3.0.0"
+          }
+        }
+      }
+    },
     "stylelint-prettier": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/stylelint-prettier/-/stylelint-prettier-1.1.2.tgz",
diff --git a/package.json b/package.json
index 5e1bd89..6d0cbcf 100644
--- a/package.json
+++ b/package.json
@@ -37,6 +37,8 @@
     "stylelint": "13.8.0",
     "stylelint-config-prettier": "8.0.2",
     "stylelint-config-recommended": "3.0.0",
+    "stylelint-config-standard": "^20.0.0",
+    "stylelint-order": "^4.1.0",
     "stylelint-prettier": "1.1.2",
     "ts-jest": "26.4.4",
     "typescript": "4.0.3"