diff --git a/examples/basics/siteConfig.js b/examples/basics/siteConfig.js
index eb415cb60c9f..7d95e66b6e62 100644
--- a/examples/basics/siteConfig.js
+++ b/examples/basics/siteConfig.js
@@ -32,22 +32,6 @@ const siteConfig = {
   headerIcon: 'img/docusaurus.svg',
   footerIcon: 'img/docusaurus.svg',
   favicon: 'img/favicon.png',
-  /* colors for website */
-  colors: {
-    primaryColor: '#2E8555',
-    secondaryColor: '#205C3B',
-  },
-  /* custom fonts for website */
-  /*fonts: {
-    myFont: [
-      "Times New Roman",
-      "Serif"
-    ],
-    myOtherFont: [
-      "-apple-system",
-      "system-ui"
-    ]
-  },*/
   // This copyright info is used in /core/Footer.js and blog rss/atom feeds.
   copyright:
     'Copyright © ' +
diff --git a/examples/basics/stylesConfig.pcss b/examples/basics/stylesConfig.pcss
new file mode 100644
index 000000000000..875f8223d65d
--- /dev/null
+++ b/examples/basics/stylesConfig.pcss
@@ -0,0 +1,6 @@
+// Check what you can do with precss!
+// https://github.com/jonathantneal/precss
+
+$primaryColor: #2E8555;
+$secondaryColor: #205C3B;
+$codeColor: color-mod($primaryColor alpha(70%));
diff --git a/lib/server/server.js b/lib/server/server.js
index 4b1a7275cac0..88e25571836c 100644
--- a/lib/server/server.js
+++ b/lib/server/server.js
@@ -8,7 +8,7 @@
 
 function execute(port) {
   const extractTranslations = require('../write-translations.js');
-
+  const asyncHandler = require('express-async-handler');
   const env = require('./env.js');
   const translation = require('./translation.js');
   const express = require('express');
@@ -432,16 +432,21 @@ function execute(port) {
   });
 
   // generate the main.css file by concatenating user provided css to the end
-  app.get(/main\.css$/, (req, res) => {
-    const mainCssPath =
-      __dirname +
-      '/../static/' +
-      req.path.toString().replace(siteConfig.baseUrl, '/');
+  app.get(
+    /main\.css$/,
+    asyncHandler(async (req, res, next) => {
+      const mainCssPath =
+        __dirname +
+        '/../static/' +
+        req.path.toString().replace(siteConfig.baseUrl, '/');
 
-    const styles = new Styles(siteConfig, mainCssPath);
+      const styles = new Styles(siteConfig, mainCssPath);
 
-    styles.getCssContent().then(cssContent => res.send(cssContent));
-  });
+      const cssContent = await styles.getCssContent();
+
+      res.send(cssContent.css);
+    })
+  );
 
   // serve static assets from these locations
   app.use(
diff --git a/lib/server/styles.js b/lib/server/styles.js
index e53e0a6c616a..52bab5126352 100644
--- a/lib/server/styles.js
+++ b/lib/server/styles.js
@@ -1,7 +1,10 @@
 const fs = require('fs');
 const glob = require('glob');
 const color = require('color');
+const postcss = require('postcss');
+const precss = require('precss');
 const chalk = require('chalk');
+const autoprefixer = require('autoprefixer');
 
 const CWD = process.cwd();
 
@@ -23,8 +26,25 @@ class Styles {
     return false;
   }
 
+  getStylesConfigContent() {
+    return __dirname + '/../static/css/styleConfig.pcss';
+  }
+
+  getFileContent(file) {
+    return fs.readFileSync(file, {encoding: 'utf8'});
+  }
+
   getCssContent() {
-    let cssContent = fs.readFileSync(this.mainCssPath, {encoding: 'utf8'});
+    const config = CWD + '/stylesConfig.pcss';
+    const stylesConfigFile = fs.existsSync(config)
+      ? config
+      : this.getStylesConfigContent();
+
+    const stylesConfigContent = this.getFileContent(stylesConfigFile);
+
+    const mainCssContent = this.getFileContent(this.mainCssPath);
+
+    let cssContent = stylesConfigContent + mainCssContent;
 
     let files = glob.sync(CWD + '/static/**/*.css');
 
@@ -32,45 +52,25 @@ class Styles {
       if (this.isSeparateCss(file)) {
         return;
       }
-      cssContent =
-        cssContent + '\n' + fs.readFileSync(file, {encoding: 'utf8'});
+      cssContent = cssContent + this.getFileContent(file);
     });
 
     if (
-      !this.siteConfig.colors ||
-      !this.siteConfig.colors.primaryColor ||
-      !this.siteConfig.colors.secondaryColor
+      this.siteConfig.colors ||
+      this.siteConfig.colors.primaryColor ||
+      this.siteConfig.colors.secondaryColor
     ) {
       console.error(
         `${chalk.yellow(
-          'Missing color configuration.'
-        )} Make sure siteConfig.colors includes primaryColor and secondaryColor fields.`
+          'Deprecated color configuration.'
+        )} Make sure to use stylesConfig.pcss in your website folder`
       );
     }
 
-    Object.keys(this.siteConfig.colors).forEach(key => {
-      const color = this.siteConfig.colors[key];
-      cssContent = cssContent.replace(new RegExp('\\$' + key, 'g'), color);
+    return postcss([precss, autoprefixer]).process(cssContent, {
+      from: undefined,
     });
-    const codeColor = color(this.siteConfig.colors.primaryColor)
-      .alpha(0.07)
-      .string();
-    cssContent = cssContent.replace(new RegExp('\\$codeColor', 'g'), codeColor);
-
-    if (this.siteConfig.fonts) {
-      Object.keys(this.siteConfig.fonts).forEach(key => {
-        const fontString = this.siteConfig.fonts[key]
-          .map(font => '"' + font + '"')
-          .join(', ');
-        cssContent = cssContent.replace(
-          new RegExp('\\$' + key, 'g'),
-          fontString
-        );
-      });
-    }
-
-    return Promise.resolve(cssContent);
   }
 }
 
-module.exports = Styles;
\ No newline at end of file
+module.exports = Styles;
diff --git a/lib/static/css/stylesConfig.pcss b/lib/static/css/stylesConfig.pcss
new file mode 100644
index 000000000000..875f8223d65d
--- /dev/null
+++ b/lib/static/css/stylesConfig.pcss
@@ -0,0 +1,6 @@
+// Check what you can do with precss!
+// https://github.com/jonathantneal/precss
+
+$primaryColor: #2E8555;
+$secondaryColor: #205C3B;
+$codeColor: color-mod($primaryColor alpha(70%));
diff --git a/package.json b/package.json
index 4799c40e3b18..d3564f269122 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "test": "jest"
   },
   "dependencies": {
+    "autoprefixer": "^7.2.5",
     "babel-plugin-transform-class-properties": "^6.24.1",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-preset-env": "^1.6.0",
@@ -38,10 +39,13 @@
     "crowdin-cli": "^0.3.0",
     "escape-string-regexp": "^1.0.5",
     "express": "^4.15.3",
+    "express-async-handler": "^1.0.3",
     "feed": "^1.1.0",
     "fs-extra": "^5.0.0",
     "glob": "^7.1.2",
     "highlight.js": "^9.12.0",
+    "postcss": "^6.0.16",
+    "precss": "^3.1.0",
     "react": "^15.5.4",
     "react-dom": "^15.5.4",
     "react-dom-factories": "^1.0.1",
diff --git a/yarn.lock b/yarn.lock
index 8ebd186a420c..8de94f00ae70 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,6 +2,14 @@
 # yarn lockfile v1
 
 
+"@csstools/convert-colors@^1.3":
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/@csstools/convert-colors/-/convert-colors-1.3.0.tgz#471eeea45a24c4778f53cd2c906fbc52d4c71065"
+
+"@csstools/sass-import-resolve@^1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@csstools/sass-import-resolve/-/sass-import-resolve-1.0.0.tgz#32c3cdb2f7af3cd8f0dca357b592e7271f3831b5"
+
 abab@^1.0.3:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/abab/-/abab-1.0.4.tgz#5faad9c2c07f60dd76770f71cf025b62a63cfd4e"
@@ -178,6 +186,17 @@ autolinker@~0.15.0:
   version "0.15.3"
   resolved "https://registry.yarnpkg.com/autolinker/-/autolinker-0.15.3.tgz#342417d8f2f3461b14cf09088d5edf8791dc9832"
 
+autoprefixer@^7.2.5:
+  version "7.2.5"
+  resolved "https://registry.yarnpkg.com/autoprefixer/-/autoprefixer-7.2.5.tgz#04ccbd0c6a61131b6d13f53d371926092952d192"
+  dependencies:
+    browserslist "^2.11.1"
+    caniuse-lite "^1.0.30000791"
+    normalize-range "^0.1.2"
+    num2fraction "^1.2.2"
+    postcss "^6.0.16"
+    postcss-value-parser "^3.2.3"
+
 aws-sign2@~0.6.0:
   version "0.6.0"
   resolved "https://registry.yarnpkg.com/aws-sign2/-/aws-sign2-0.6.0.tgz#14342dd38dbcc94d0e5b87d763cd63612c0e794f"
@@ -651,6 +670,14 @@ babel-plugin-transform-strict-mode@^6.24.1:
     babel-runtime "^6.22.0"
     babel-types "^6.24.1"
 
+babel-polyfill@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-polyfill/-/babel-polyfill-6.26.0.tgz#379937abc67d7895970adc621f284cd966cf2153"
+  dependencies:
+    babel-runtime "^6.26.0"
+    core-js "^2.5.0"
+    regenerator-runtime "^0.10.5"
+
 babel-preset-env@^1.6.0:
   version "1.6.1"
   resolved "https://registry.yarnpkg.com/babel-preset-env/-/babel-preset-env-1.6.1.tgz#a18b564cc9b9afdf4aae57ae3c1b0d99188e6f48"
@@ -722,7 +749,7 @@ babel-register@^6.24.1, babel-register@^6.26.0:
     mkdirp "^0.5.1"
     source-map-support "^0.4.15"
 
-babel-runtime@^6.18.0, babel-runtime@^6.22.0, babel-runtime@^6.26.0:
+babel-runtime@^6.18.0, babel-runtime@^6.22.0, babel-runtime@^6.23.0, babel-runtime@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.26.0.tgz#965c7058668e82b55d7bfe04ff2337bc8b5647fe"
   dependencies:
@@ -766,6 +793,10 @@ babylon@^6.17.4, babylon@^6.18.0:
   version "6.18.0"
   resolved "https://registry.yarnpkg.com/babylon/-/babylon-6.18.0.tgz#af2f3b88fa6f5c1e4c634d1a0f8eac4f55b395e3"
 
+balanced-match@^0.4.2:
+  version "0.4.2"
+  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-0.4.2.tgz#cb3f3e3c732dc0f01ee70b403f302e61d7709838"
+
 balanced-match@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
@@ -847,6 +878,13 @@ browserslist@^2.1.2:
     caniuse-lite "^1.0.30000744"
     electron-to-chromium "^1.3.24"
 
+browserslist@^2.11, browserslist@^2.11.1, browserslist@^2.4.0:
+  version "2.11.3"
+  resolved "https://registry.yarnpkg.com/browserslist/-/browserslist-2.11.3.tgz#fe36167aed1bbcde4827ebfe71347a2cc70b99b2"
+  dependencies:
+    caniuse-lite "^1.0.30000792"
+    electron-to-chromium "^1.3.30"
+
 bser@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/bser/-/bser-2.0.0.tgz#9ac78d3ed5d915804fd87acb158bc797147a1719"
@@ -873,6 +911,10 @@ camelcase@^4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-4.1.0.tgz#d545635be1e33c542649c69173e5de6acfae34dd"
 
+caniuse-lite@^1.0, caniuse-lite@^1.0.30000791, caniuse-lite@^1.0.30000792:
+  version "1.0.30000792"
+  resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000792.tgz#d0cea981f8118f3961471afbb43c9a1e5bbf0332"
+
 caniuse-lite@^1.0.30000744:
   version "1.0.30000749"
   resolved "https://registry.yarnpkg.com/caniuse-lite/-/caniuse-lite-1.0.30000749.tgz#2ff382865aead8cca35dacfbab04f58effa4c01c"
@@ -898,7 +940,7 @@ chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
-chalk@^2.0.1, chalk@^2.1.0:
+chalk@^2.0.1, chalk@^2.1.0, chalk@^2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.3.0.tgz#b5ea48efc9c1793dccc9b4767c93914d3f2d52ba"
   dependencies:
@@ -938,15 +980,15 @@ code-point-at@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
 
-color-convert@^1.9.0:
-  version "1.9.0"
-  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-1.9.0.tgz#1accf97dd739b983bf994d56fec8f95853641b7a"
+color-convert@^1.8.2, color-convert@^1.9.1:
+  version "1.9.1"
+  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-1.9.1.tgz#c1261107aeb2f294ebffec9ed9ecad529a6097ed"
   dependencies:
     color-name "^1.1.1"
 
-color-convert@^1.9.1:
-  version "1.9.1"
-  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-1.9.1.tgz#c1261107aeb2f294ebffec9ed9ecad529a6097ed"
+color-convert@^1.9.0:
+  version "1.9.0"
+  resolved "https://registry.yarnpkg.com/color-convert/-/color-convert-1.9.0.tgz#1accf97dd739b983bf994d56fec8f95853641b7a"
   dependencies:
     color-name "^1.1.1"
 
@@ -954,13 +996,20 @@ color-name@^1.0.0, color-name@^1.1.1:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/color-name/-/color-name-1.1.3.tgz#a7d0558bd89c42f795dd42328f740831ca53bc25"
 
-color-string@^1.5.2:
+color-string@^1.4.0, color-string@^1.5.2:
   version "1.5.2"
   resolved "https://registry.yarnpkg.com/color-string/-/color-string-1.5.2.tgz#26e45814bc3c9a7cbd6751648a41434514a773a9"
   dependencies:
     color-name "^1.0.0"
     simple-swizzle "^0.2.2"
 
+color@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/color/-/color-1.0.3.tgz#e48e832d85f14ef694fb468811c2d5cfe729b55d"
+  dependencies:
+    color-convert "^1.8.2"
+    color-string "^1.4.0"
+
 color@^2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/color/-/color-2.0.1.tgz#e4ed78a3c4603d0891eba5430b04b86314f4c839"
@@ -1062,6 +1111,10 @@ cryptiles@3.x.x:
   dependencies:
     boom "5.x.x"
 
+cssdb@^1.5:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/cssdb/-/cssdb-1.5.0.tgz#e6179657bf96eb063eb316b2f5a5f4c4a2633df7"
+
 cssom@0.3.x, "cssom@>= 0.3.2 < 0.4.0":
   version "0.3.2"
   resolved "https://registry.yarnpkg.com/cssom/-/cssom-0.3.2.tgz#b8036170c79f07a90ff2f16e22284027a243848b"
@@ -1146,6 +1199,12 @@ diff@^3.2.0:
   version "3.4.0"
   resolved "https://registry.yarnpkg.com/diff/-/diff-3.4.0.tgz#b1d85507daf3964828de54b37d0d73ba67dda56c"
 
+dot-prop@^4.1.1:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/dot-prop/-/dot-prop-4.2.0.tgz#1f19e0c2e1aa0e32797c49799f2837ac6af69c57"
+  dependencies:
+    is-obj "^1.0.0"
+
 ecc-jsbn@~0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/ecc-jsbn/-/ecc-jsbn-0.1.1.tgz#0fc73a9ed5f0d53c38193398523ef7e543777505"
@@ -1160,6 +1219,10 @@ electron-to-chromium@^1.3.24:
   version "1.3.27"
   resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.27.tgz#78ecb8a399066187bb374eede35d9c70565a803d"
 
+electron-to-chromium@^1.3.30:
+  version "1.3.31"
+  resolved "https://registry.yarnpkg.com/electron-to-chromium/-/electron-to-chromium-1.3.31.tgz#00d832cba9fe2358652b0c48a8816c8e3a037e9f"
+
 encodeurl@~1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/encodeurl/-/encodeurl-1.0.1.tgz#79e3d58655346909fe6f0f45a5de68103b294d20"
@@ -1262,6 +1325,10 @@ expect@^21.2.1:
     jest-message-util "^21.2.1"
     jest-regex-util "^21.2.0"
 
+express-async-handler@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/express-async-handler/-/express-async-handler-1.0.3.tgz#2175dedb340ce202f244c6e49ecc12ef459a17d2"
+
 express@^4.15.3:
   version "4.16.2"
   resolved "https://registry.yarnpkg.com/express/-/express-4.16.2.tgz#e35c6dfe2d64b7dca0a5cd4f21781be3299e076c"
@@ -1399,6 +1466,10 @@ find-up@^2.0.0, find-up@^2.1.0:
   dependencies:
     locate-path "^2.0.0"
 
+flatten@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/flatten/-/flatten-1.0.2.tgz#dae46a9d78fbe25292258cc1e780a41d95c03782"
+
 for-in@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/for-in/-/for-in-1.0.2.tgz#81068d295a8142ec0ac726c6e2200c30fb6d5e80"
@@ -1676,6 +1747,10 @@ imurmurhash@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/imurmurhash/-/imurmurhash-0.1.4.tgz#9218b9b2b928a238b13dc4fb6b6d576f231453ea"
 
+indexes-of@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/indexes-of/-/indexes-of-1.0.1.tgz#f30f716c8e2bd346c7b67d3df3915566a7c05607"
+
 inflight@^1.0.4:
   version "1.0.6"
   resolved "https://registry.yarnpkg.com/inflight/-/inflight-1.0.6.tgz#49bd6331d7d02d0c09bc910a1075ba8165b56df9"
@@ -1785,6 +1860,10 @@ is-number@^3.0.0:
   dependencies:
     kind-of "^3.0.2"
 
+is-obj@^1.0.0:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/is-obj/-/is-obj-1.0.1.tgz#3e4729ac1f5fde025cd7d83a896dab9f4f67db0f"
+
 is-posix-bracket@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/is-posix-bracket/-/is-posix-bracket-0.1.1.tgz#3334dc79774368e92f016e6fbc0a88f5cd6e6bc4"
@@ -2124,6 +2203,10 @@ jest@^21.2.1:
   dependencies:
     jest-cli "^21.2.1"
 
+js-base64@^2.1.9:
+  version "2.4.3"
+  resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.3.tgz#2e545ec2b0f2957f41356510205214e98fad6582"
+
 js-tokens@^3.0.0, js-tokens@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
@@ -2271,6 +2354,23 @@ locate-path@^2.0.0:
     p-locate "^2.0.0"
     path-exists "^3.0.0"
 
+lodash._reinterpolate@~3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/lodash._reinterpolate/-/lodash._reinterpolate-3.0.0.tgz#0ccf2d89166af03b3663c796538b75ac6e114d9d"
+
+lodash.template@^4.2.4:
+  version "4.4.0"
+  resolved "https://registry.yarnpkg.com/lodash.template/-/lodash.template-4.4.0.tgz#e73a0385c8355591746e020b99679c690e68fba0"
+  dependencies:
+    lodash._reinterpolate "~3.0.0"
+    lodash.templatesettings "^4.0.0"
+
+lodash.templatesettings@^4.0.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/lodash.templatesettings/-/lodash.templatesettings-4.1.0.tgz#2b4d4e95ba440d915ff08bc899e4553666713316"
+  dependencies:
+    lodash._reinterpolate "~3.0.0"
+
 lodash@^4.14.0, lodash@^4.17.4:
   version "4.17.4"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
@@ -2454,6 +2554,10 @@ normalize-path@^2.0.0, normalize-path@^2.0.1:
   dependencies:
     remove-trailing-separator "^1.0.1"
 
+normalize-range@^0.1.2:
+  version "0.1.2"
+  resolved "https://registry.yarnpkg.com/normalize-range/-/normalize-range-0.1.2.tgz#2d10c06bdfd312ea9777695a4d28439456b75942"
+
 npm-run-path@^2.0.0:
   version "2.0.2"
   resolved "https://registry.yarnpkg.com/npm-run-path/-/npm-run-path-2.0.2.tgz#35a9232dfa35d7067b4cb2ddf2357b1871536c5f"
@@ -2469,6 +2573,10 @@ npmlog@^4.0.2:
     gauge "~2.7.3"
     set-blocking "~2.0.0"
 
+num2fraction@^1.2.2:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/num2fraction/-/num2fraction-1.2.2.tgz#6f682b6a027a4e9ddfa4564cd2589d1d4e669ede"
+
 number-is-nan@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/number-is-nan/-/number-is-nan-1.0.1.tgz#097b602b53422a522c1afb8790318336941a011d"
@@ -2481,7 +2589,7 @@ oauth-sign@~0.8.1, oauth-sign@~0.8.2:
   version "0.8.2"
   resolved "https://registry.yarnpkg.com/oauth-sign/-/oauth-sign-0.8.2.tgz#46a6ab7f0aead8deae9ec0565780b7d4efeb9d43"
 
-object-assign@^4.1.0, object-assign@^4.1.1:
+object-assign@^4.0.1, object-assign@^4.1.0, object-assign@^4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
 
@@ -2652,6 +2760,290 @@ pinkie@^2.0.0:
   version "2.0.4"
   resolved "https://registry.yarnpkg.com/pinkie/-/pinkie-2.0.4.tgz#72556b80cfa0d48a974e80e77248e80ed4f7f870"
 
+postcss-advanced-variables@^2.3:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/postcss-advanced-variables/-/postcss-advanced-variables-2.3.0.tgz#357621c7a2bb3a5313f64384ac166addbc7e124a"
+  dependencies:
+    "@csstools/sass-import-resolve" "^1.0.0"
+    babel-polyfill "^6.26.0"
+    postcss "^6.0"
+
+postcss-apply@^0.8:
+  version "0.8.0"
+  resolved "https://registry.yarnpkg.com/postcss-apply/-/postcss-apply-0.8.0.tgz#14e544bbb5cb6f1c1e048857965d79ae066b1343"
+  dependencies:
+    babel-runtime "^6.23.0"
+    balanced-match "^0.4.2"
+    postcss "^6.0.0"
+
+postcss-atroot@^0.1:
+  version "0.1.3"
+  resolved "https://registry.yarnpkg.com/postcss-atroot/-/postcss-atroot-0.1.3.tgz#6752c0230c745140549345b2b0e30ebeda01a405"
+  dependencies:
+    postcss "^5.0.5"
+
+postcss-attribute-case-insensitive@^2.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-attribute-case-insensitive/-/postcss-attribute-case-insensitive-2.0.0.tgz#94dc422c8f90997f16bd33a3654bbbec084963b4"
+  dependencies:
+    postcss "^6.0.0"
+    postcss-selector-parser "^2.2.3"
+
+postcss-color-hex-alpha@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-color-hex-alpha/-/postcss-color-hex-alpha-3.0.0.tgz#1e53e6c8acb237955e8fd08b7ecdb1b8b8309f95"
+  dependencies:
+    color "^1.0.3"
+    postcss "^6.0.1"
+    postcss-message-helpers "^2.0.0"
+
+postcss-color-mod-function@^2.2:
+  version "2.3.0"
+  resolved "https://registry.yarnpkg.com/postcss-color-mod-function/-/postcss-color-mod-function-2.3.0.tgz#56ba67d7fadccf190795efbc529b015c8fa68fdc"
+  dependencies:
+    "@csstools/convert-colors" "^1.3"
+    postcss "^6.0"
+    postcss-values-parser "^1.3"
+
+postcss-color-rebeccapurple@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-color-rebeccapurple/-/postcss-color-rebeccapurple-3.0.0.tgz#eebaf03d363b4300b96792bd3081c19ed66513d3"
+  dependencies:
+    postcss "^6.0.1"
+    postcss-value-parser "^3.3.0"
+
+postcss-color-rgb@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-color-rgb/-/postcss-color-rgb-2.0.0.tgz#14539c8a7131494b482e0dd1cc265ff6514b5263"
+  dependencies:
+    postcss "^6.0.1"
+    postcss-value-parser "^3.3.0"
+
+postcss-custom-media@^6.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-custom-media/-/postcss-custom-media-6.0.0.tgz#be532784110ecb295044fb5395a18006eb21a737"
+  dependencies:
+    postcss "^6.0.1"
+
+postcss-custom-properties@^6.2:
+  version "6.2.0"
+  resolved "https://registry.yarnpkg.com/postcss-custom-properties/-/postcss-custom-properties-6.2.0.tgz#5d929a7f06e9b84e0f11334194c0ba9a30acfbe9"
+  dependencies:
+    balanced-match "^1.0.0"
+    postcss "^6.0.13"
+
+postcss-custom-selectors@^4.0:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/postcss-custom-selectors/-/postcss-custom-selectors-4.0.1.tgz#781382f94c52e727ef5ca4776ea2adf49a611382"
+  dependencies:
+    postcss "^6.0.1"
+    postcss-selector-matches "^3.0.0"
+
+postcss-dir-pseudo-class@^2.1:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/postcss-dir-pseudo-class/-/postcss-dir-pseudo-class-2.1.0.tgz#d441b000688d0ecdd88cc040da922e72b62cf830"
+  dependencies:
+    browserslist "^2.4.0"
+    postcss "^6.0.11"
+    postcss-selector-parser "^2.2.3"
+
+postcss-extend-rule@^1.1:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/postcss-extend-rule/-/postcss-extend-rule-1.1.0.tgz#11e4d590ffe4253b853ef1fc03be7167da607d38"
+  dependencies:
+    postcss "^6.0.11"
+    postcss-nesting "^4.2.1"
+
+postcss-font-family-system-ui@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-font-family-system-ui/-/postcss-font-family-system-ui-3.0.0.tgz#675fe7a9e029669f05f8dba2e44c2225ede80623"
+  dependencies:
+    postcss "^6.0"
+
+postcss-font-variant@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-font-variant/-/postcss-font-variant-3.0.0.tgz#08ccc88f6050ba82ed8ef2cc76c0c6a6b41f183e"
+  dependencies:
+    postcss "^6.0.1"
+
+postcss-image-set-polyfill@^0.4:
+  version "0.4.4"
+  resolved "https://registry.yarnpkg.com/postcss-image-set-polyfill/-/postcss-image-set-polyfill-0.4.4.tgz#5acdebd25aeb237dde0791c524b68947400995f8"
+  dependencies:
+    postcss "6.0.1"
+    postcss-media-query-parser "0.2.3"
+    postcss-value-parser "3.3.0"
+
+postcss-initial@^2.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-initial/-/postcss-initial-2.0.0.tgz#72715f7336e0bb79351d99ee65c4a253a8441ba4"
+  dependencies:
+    lodash.template "^4.2.4"
+    postcss "^6.0.1"
+
+postcss-logical@^1.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/postcss-logical/-/postcss-logical-1.0.2.tgz#b70199cc55676e48e2eca5421c58250b0c298c4a"
+  dependencies:
+    postcss "^6.0.9"
+
+postcss-media-minmax@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-media-minmax/-/postcss-media-minmax-3.0.0.tgz#675256037a43ef40bc4f0760bfd06d4dc69d48d2"
+  dependencies:
+    postcss "^6.0.1"
+
+postcss-media-query-parser@0.2.3:
+  version "0.2.3"
+  resolved "https://registry.yarnpkg.com/postcss-media-query-parser/-/postcss-media-query-parser-0.2.3.tgz#27b39c6f4d94f81b1a73b8f76351c609e5cef244"
+
+postcss-message-helpers@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-message-helpers/-/postcss-message-helpers-2.0.0.tgz#a4f2f4fab6e4fe002f0aed000478cdf52f9ba60e"
+
+postcss-nested@^3.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-nested/-/postcss-nested-3.0.0.tgz#cde40bd07a078565f3df72e2dc2665871c724852"
+  dependencies:
+    postcss "^6.0.14"
+    postcss-selector-parser "^3.1.1"
+
+postcss-nesting@^4.2, postcss-nesting@^4.2.1:
+  version "4.2.1"
+  resolved "https://registry.yarnpkg.com/postcss-nesting/-/postcss-nesting-4.2.1.tgz#0483bce338b3f0828ced90ff530b29b98b00300d"
+  dependencies:
+    postcss "^6.0.11"
+
+postcss-preset-env@^2.1:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/postcss-preset-env/-/postcss-preset-env-2.1.0.tgz#1c3de84e11c5e14c1424a0fb66ad506089adfe7c"
+  dependencies:
+    browserslist "^2.11"
+    caniuse-lite "^1.0"
+    cssdb "^1.5"
+    postcss "^6.0"
+    postcss-apply "^0.8"
+    postcss-attribute-case-insensitive "^2.0"
+    postcss-color-hex-alpha "^3.0"
+    postcss-color-mod-function "^2.2"
+    postcss-color-rebeccapurple "^3.0"
+    postcss-color-rgb "^2.0.0"
+    postcss-custom-media "^6.0"
+    postcss-custom-properties "^6.2"
+    postcss-custom-selectors "^4.0"
+    postcss-dir-pseudo-class "^2.1"
+    postcss-font-family-system-ui "^3.0"
+    postcss-font-variant "^3.0"
+    postcss-image-set-polyfill "^0.4"
+    postcss-initial "^2.0"
+    postcss-logical "^1.0"
+    postcss-media-minmax "^3.0"
+    postcss-nesting "^4.2"
+    postcss-pseudo-class-any-link "^4.0"
+    postcss-replace-overflow-wrap "^2.0"
+    postcss-selector-matches "^3.0"
+    postcss-selector-not "^3.0"
+
+postcss-property-lookup@^2.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-property-lookup/-/postcss-property-lookup-2.0.0.tgz#c995d1df42a75420f2aea834c2cbe296b2c15922"
+  dependencies:
+    object-assign "^4.0.1"
+    postcss "^6.0.6"
+    tcomb "^3.2.21"
+
+postcss-pseudo-class-any-link@^4.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-pseudo-class-any-link/-/postcss-pseudo-class-any-link-4.0.0.tgz#9152a0613d3450720513e8892854bae42d0ee68e"
+  dependencies:
+    postcss "^6.0.1"
+    postcss-selector-parser "^2.2.3"
+
+postcss-replace-overflow-wrap@^2.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/postcss-replace-overflow-wrap/-/postcss-replace-overflow-wrap-2.0.0.tgz#794db6faa54f8db100854392a93af45768b4e25b"
+  dependencies:
+    postcss "^6.0.1"
+
+postcss-selector-matches@^3.0, postcss-selector-matches@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/postcss-selector-matches/-/postcss-selector-matches-3.0.1.tgz#e5634011e13950881861bbdd58c2d0111ffc96ab"
+  dependencies:
+    balanced-match "^0.4.2"
+    postcss "^6.0.1"
+
+postcss-selector-not@^3.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/postcss-selector-not/-/postcss-selector-not-3.0.1.tgz#2e4db2f0965336c01e7cec7db6c60dff767335d9"
+  dependencies:
+    balanced-match "^0.4.2"
+    postcss "^6.0.1"
+
+postcss-selector-parser@^2.2.3:
+  version "2.2.3"
+  resolved "https://registry.yarnpkg.com/postcss-selector-parser/-/postcss-selector-parser-2.2.3.tgz#f9437788606c3c9acee16ffe8d8b16297f27bb90"
+  dependencies:
+    flatten "^1.0.2"
+    indexes-of "^1.0.1"
+    uniq "^1.0.1"
+
+postcss-selector-parser@^3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/postcss-selector-parser/-/postcss-selector-parser-3.1.1.tgz#4f875f4afb0c96573d5cf4d74011aee250a7e865"
+  dependencies:
+    dot-prop "^4.1.1"
+    indexes-of "^1.0.1"
+    uniq "^1.0.1"
+
+postcss-value-parser@3.3.0, postcss-value-parser@^3.2.3, postcss-value-parser@^3.3.0:
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/postcss-value-parser/-/postcss-value-parser-3.3.0.tgz#87f38f9f18f774a4ab4c8a232f5c5ce8872a9d15"
+
+postcss-values-parser@^1.3:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/postcss-values-parser/-/postcss-values-parser-1.3.1.tgz#2a6ceb39cecbbacd1d060f3b16f4c52dd6720c96"
+  dependencies:
+    flatten "^1.0.2"
+    indexes-of "^1.0.1"
+    uniq "^1.0.1"
+
+postcss@6.0.1:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.1.tgz#000dbd1f8eef217aa368b9a212c5fc40b2a8f3f2"
+  dependencies:
+    chalk "^1.1.3"
+    source-map "^0.5.6"
+    supports-color "^3.2.3"
+
+postcss@^5.0.5:
+  version "5.2.18"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-5.2.18.tgz#badfa1497d46244f6390f58b319830d9107853c5"
+  dependencies:
+    chalk "^1.1.3"
+    js-base64 "^2.1.9"
+    source-map "^0.5.6"
+    supports-color "^3.2.3"
+
+postcss@^6.0, postcss@^6.0.0, postcss@^6.0.1, postcss@^6.0.11, postcss@^6.0.13, postcss@^6.0.14, postcss@^6.0.16, postcss@^6.0.6, postcss@^6.0.9:
+  version "6.0.16"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-6.0.16.tgz#112e2fe2a6d2109be0957687243170ea5589e146"
+  dependencies:
+    chalk "^2.3.0"
+    source-map "^0.6.1"
+    supports-color "^5.1.0"
+
+precss@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/precss/-/precss-3.1.0.tgz#d9698550d2f763c52b800bfa1c6ba54fb023313c"
+  dependencies:
+    postcss "^6.0"
+    postcss-advanced-variables "^2.3"
+    postcss-atroot "^0.1"
+    postcss-extend-rule "^1.1"
+    postcss-nested "^3.0"
+    postcss-preset-env "^2.1"
+    postcss-property-lookup "^2.0"
+
 prelude-ls@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
@@ -2828,6 +3220,10 @@ regenerate@^1.2.1:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/regenerate/-/regenerate-1.3.3.tgz#0c336d3980553d755c39b586ae3b20aa49c82b7f"
 
+regenerator-runtime@^0.10.5:
+  version "0.10.5"
+  resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.10.5.tgz#336c3efc1220adcedda2c9fab67b5a7955a33658"
+
 regenerator-runtime@^0.11.0:
   version "0.11.0"
   resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.11.0.tgz#7e54fe5b5ccd5d6624ea6255c3473be090b802e1"
@@ -3113,6 +3509,10 @@ source-map@^0.5.3, source-map@^0.5.6, source-map@~0.5.1, source-map@~0.5.6:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
 
+source-map@^0.6.1:
+  version "0.6.1"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
+
 spdx-correct@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/spdx-correct/-/spdx-correct-1.0.2.tgz#4b3073d933ff51f3912f03ac5519498a4150db40"
@@ -3219,7 +3619,7 @@ supports-color@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-2.0.0.tgz#535d045ce6b6363fa40117084629995e9df324c7"
 
-supports-color@^3.1.2:
+supports-color@^3.1.2, supports-color@^3.2.3:
   version "3.2.3"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-3.2.3.tgz#65ac0504b3954171d8a64946b2ae3cbb8a5f54f6"
   dependencies:
@@ -3231,6 +3631,12 @@ supports-color@^4.0.0:
   dependencies:
     has-flag "^2.0.0"
 
+supports-color@^5.1.0:
+  version "5.1.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-5.1.0.tgz#058a021d1b619f7ddf3980d712ea3590ce7de3d5"
+  dependencies:
+    has-flag "^2.0.0"
+
 symbol-tree@^3.2.1:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/symbol-tree/-/symbol-tree-3.2.2.tgz#ae27db38f660a7ae2e1c3b7d1bc290819b8519e6"
@@ -3256,6 +3662,10 @@ tar@^2.2.1:
     fstream "^1.0.2"
     inherits "2"
 
+tcomb@^3.2.21:
+  version "3.2.24"
+  resolved "https://registry.yarnpkg.com/tcomb/-/tcomb-3.2.24.tgz#7f427053cc393b5997c4c3d859ca20411180887b"
+
 tcp-port-used@^0.1.2:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/tcp-port-used/-/tcp-port-used-0.1.2.tgz#9450e8768c83b416fd4d1a6a9449eeccbf496c29"
@@ -3356,6 +3766,10 @@ underscore@~1.7.0:
   version "1.7.0"
   resolved "https://registry.yarnpkg.com/underscore/-/underscore-1.7.0.tgz#6bbaf0877500d36be34ecaa584e0db9fef035209"
 
+uniq@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/uniq/-/uniq-1.0.1.tgz#b31c5ae8254844a3a8281541ce2b04b865a734ff"
+
 universalify@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/universalify/-/universalify-0.1.1.tgz#fa71badd4437af4c148841e3b3b165f9e9e590b7"