Index: .stylelintrc
===================================================================
--- .stylelintrc	(revision 0)
+++ .stylelintrc	(working copy)
@@ -0,0 +1,62 @@
+{
+  "rules": {
+    "at-rule-empty-line-before": [ 2, "always", {
+      "except": ["blockless-group"],
+      "ignore": ["after-comment"]
+    } ],
+    "at-rule-no-vendor-prefix": 2,
+    "block-closing-brace-newline-after": [ 2, "always" ],
+    "block-closing-brace-newline-before": [ 2, "always" ],
+    "block-opening-brace-newline-after": [ 2, "always" ],
+    "block-opening-brace-space-before": [ 2, "always" ],
+    "color-hex-case": [ 2, "lower" ],
+    "color-hex-length": [ 2, "short" ],
+    "color-no-invalid-hex": 2,
+    "declaration-bang-space-after": [ 2, "never" ],
+    "declaration-bang-space-before": [ 2, "always" ],
+    "declaration-block-semicolon-newline-after": [ 2, "always" ],
+    "declaration-block-semicolon-space-before": [ 2, "never" ],
+    "declaration-colon-newline-after": [ 2, "always-multi-line" ],
+    "declaration-colon-space-after": [ 2, "always-single-line" ],
+    "declaration-colon-space-before": [ 2, "never" ],
+    "function-calc-no-unspaced-operator": 2,
+    "function-comma-space-after": [ 2, "always" ],
+    "function-comma-space-before": [ 2, "never" ],
+    "function-linear-gradient-no-nonstandard-direction": 2,
+    "function-parentheses-space-inside": [ 2, "never" ],
+    "function-space-after": [ 2, "always" ],
+    "function-url-quotes": [ 2, "none" ],
+    "indentation": [ 2, "tab" ],
+    "media-feature-colon-space-after": [ 2, "always" ],
+    "media-feature-colon-space-before": [ 2, "never" ],
+    "media-feature-name-no-vendor-prefix": 2,
+    "media-feature-range-operator-space-after": [ 2, "always" ],
+    "media-feature-range-operator-space-before": [ 2, "always" ],
+    "media-query-list-comma-newline-after": [ 2, "always-multi-line" ],
+    "media-query-list-comma-space-after": [ 2, "always-single-line" ],
+    "media-query-list-comma-space-before": [ 2, "never" ],
+    "media-query-parentheses-space-inside": [ 2, "never" ],
+    "no-eol-whitespace": 2,
+    "no-missing-eof-newline": 2,
+    "number-leading-zero": [ 2, "always" ],
+    "number-no-trailing-zeros": 2,
+    "number-zero-length-no-unit": 2,
+    "property-no-vendor-prefix": 2,
+    "rule-no-shorthand-property-overrides": 2,
+    "rule-nested-empty-line-before": [ 2, "always", {
+      "except": ["first-nested"]
+    } ],
+    "rule-non-nested-empty-line-before": [ 2, "always" ],
+    "rule-trailing-semicolon": [ 2, "always" ],
+    "selector-combinator-space-after": [ 2, "always" ],
+    "selector-combinator-space-before": [ 2, "always" ],
+    "selector-list-comma-newline-after": [ 2, "always" ],
+    "selector-list-comma-space-before": [ 2, "never" ],
+    "selector-no-vendor-prefix": 2,
+    "string-quotes": [ 2, "double" ],
+    "value-list-comma-newline-after": [ 2, "always-multi-line" ],
+    "value-list-comma-space-after": [ 2, "always-single-line" ],
+    "value-list-comma-space-before": [ 2, "never" ],
+    "value-no-vendor-prefix": 2
+  }
+}
Index: Gruntfile.js
===================================================================
--- Gruntfile.js	(revision 35285)
+++ Gruntfile.js	(working copy)
@@ -3,7 +3,7 @@
 	var path = require('path'),
 		SOURCE_DIR = 'src/',
 		BUILD_DIR = 'build/',
-		autoprefixer = require('autoprefixer-core'),
+		autoprefixer = require('autoprefixer'),
 		mediaConfig = {},
 		mediaBuilds = ['audiovideo', 'grid', 'models', 'views'];
 
@@ -45,6 +45,27 @@
 				src: [
 					'wp-admin/css/colors/*/colors.css'
 				]
+			},
+			lint: {
+				options: {
+					syntax: require('postcss-scss'),
+					processors: [
+						require('stylelint'),
+						require('postcss-reporter')({clearMessages: true})
+					]
+				},
+				expand: true,
+				cwd: SOURCE_DIR,
+				dest: SOURCE_DIR,
+				src: [
+					// CSS
+					'wp-admin/css/*.css',
+					'wp-includes/css/*.css',
+					// SCSS
+					'wp-admin/css/colors/**/*.scss',
+					// Exceptions
+					'!wp-includes/css/jquery-ui-dialog.css'
+				]
 			}
 		},
 		clean: {
@@ -614,6 +635,7 @@
 
 	grunt.registerTask( 'precommit', 'Runs front-end dev/test tasks in preparation for a commit.', [
 		'postcss:core',
+		'postcss:lint',
 		'imagemin:core',
 		'browserify',
 		'jshint:corejs',
Index: package.json
===================================================================
--- package.json	(revision 35285)
+++ package.json	(working copy)
@@ -9,7 +9,7 @@
   "author": "The WordPress Contributors",
   "license": "GPL-2.0+",
   "devDependencies": {
-    "autoprefixer-core": "~5.2.1",
+    "autoprefixer": "~6.0.3",
     "grunt": "~0.4.5",
     "grunt-browserify": "~4.0.0",
     "grunt-contrib-clean": "~0.6.0",
@@ -26,9 +26,12 @@
     "grunt-jsvalidate": "~0.2.2",
     "grunt-legacy-util": "^0.2.0",
     "grunt-patch-wordpress": "~0.3.0",
-    "grunt-postcss": "~0.5.4",
+    "grunt-postcss": "~0.6.0",
     "grunt-rtlcss": "~1.6.0",
     "grunt-sass": "~1.0.0",
+    "postcss-reporter": "~1.3.0",
+    "postcss-scss": "~0.1.2",
+    "stylelint": "~2.0.0",
     "matchdep": "~0.3.0"
   }
 }