diff --git a/build/mincss.js b/build/mincss.js
new file mode 100644
index 00000000..f6c5ec21
--- /dev/null
+++ b/build/mincss.js
@@ -0,0 +1,12 @@
+const cssnano = require('cssnano').process
+const path = require('path')
+const fs = require('fs')
+
+files = fs.readdirSync(path.resolve('lib/themes'))
+
+files.forEach(file => {
+  file = path.resolve('lib/themes', file)
+  cssnano(fs.readFileSync(file)).then(result => {
+    fs.writeFileSync(file, result.css)
+  })
+})
diff --git a/package-lock.json b/package-lock.json
index 1e3064e4..3067dc3d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -555,7 +555,7 @@
       "dev": true,
       "requires": {
         "browserslist": "1.7.7",
-        "caniuse-db": "1.0.30000810",
+        "caniuse-db": "1.0.30000811",
         "normalize-range": "0.1.2",
         "num2fraction": "1.2.2",
         "postcss": "5.2.18",
@@ -765,7 +765,7 @@
       "integrity": "sha1-C9dnBCWL6CmyOYu1Dkti0aFmsLk=",
       "dev": true,
       "requires": {
-        "caniuse-db": "1.0.30000810",
+        "caniuse-db": "1.0.30000811",
         "electron-to-chromium": "1.3.34"
       }
     },
@@ -903,15 +903,15 @@
       "dev": true,
       "requires": {
         "browserslist": "1.7.7",
-        "caniuse-db": "1.0.30000810",
+        "caniuse-db": "1.0.30000811",
         "lodash.memoize": "4.1.2",
         "lodash.uniq": "4.5.0"
       }
     },
     "caniuse-db": {
-      "version": "1.0.30000810",
-      "resolved": "https://registry.npmjs.org/caniuse-db/-/caniuse-db-1.0.30000810.tgz",
-      "integrity": "sha1-vSWDDEHvq2Qzmi44H0lnc0PIRQk=",
+      "version": "1.0.30000811",
+      "resolved": "https://registry.npmjs.org/caniuse-db/-/caniuse-db-1.0.30000811.tgz",
+      "integrity": "sha1-Ge+5I4OT1AB4Myw0SFyBjWQcQwU=",
       "dev": true
     },
     "caniuse-lite": {
@@ -1723,26 +1723,6 @@
         "postcss-zindex": "2.2.0"
       }
     },
-    "cssnano-cli": {
-      "version": "1.0.5",
-      "resolved": "https://registry.npmjs.org/cssnano-cli/-/cssnano-cli-1.0.5.tgz",
-      "integrity": "sha1-mMYZsyfZCsrLQjArwMhPWS4oAfU=",
-      "dev": true,
-      "requires": {
-        "cssnano": "3.10.0",
-        "minimist": "1.2.0",
-        "read-file-stdin": "0.2.1",
-        "write-file-stdout": "0.0.2"
-      },
-      "dependencies": {
-        "minimist": {
-          "version": "1.2.0",
-          "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz",
-          "integrity": "sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=",
-          "dev": true
-        }
-      }
-    },
     "csso": {
       "version": "2.3.2",
       "resolved": "https://registry.npmjs.org/csso/-/csso-2.3.2.tgz",
@@ -3409,12 +3389,6 @@
       "integrity": "sha1-GwqzvVU7Kg1jmdKcDj6gslIHgyc=",
       "dev": true
     },
-    "gather-stream": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/gather-stream/-/gather-stream-1.0.0.tgz",
-      "integrity": "sha1-szmUr0V6gRVwDUEPMXczy+egkEs=",
-      "dev": true
-    },
     "gauge": {
       "version": "2.7.4",
       "resolved": "https://registry.npmjs.org/gauge/-/gauge-2.7.4.tgz",
@@ -6480,15 +6454,6 @@
         "graceful-fs": "4.1.11"
       }
     },
-    "read-file-stdin": {
-      "version": "0.2.1",
-      "resolved": "https://registry.npmjs.org/read-file-stdin/-/read-file-stdin-0.2.1.tgz",
-      "integrity": "sha1-JezP86FTtoCa+ssj7hU4fbng7mE=",
-      "dev": true,
-      "requires": {
-        "gather-stream": "1.0.0"
-      }
-    },
     "read-pkg": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/read-pkg/-/read-pkg-1.1.0.tgz",
@@ -8245,12 +8210,6 @@
         "signal-exit": "3.0.2"
       }
     },
-    "write-file-stdout": {
-      "version": "0.0.2",
-      "resolved": "https://registry.npmjs.org/write-file-stdout/-/write-file-stdout-0.0.2.tgz",
-      "integrity": "sha1-wlLXx8WxtAKJdjDjRTx7/mkNnKE=",
-      "dev": true
-    },
     "write-json-file": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/write-json-file/-/write-json-file-2.3.0.tgz",
diff --git a/package.json b/package.json
index 8e6d2d41..3844bdf6 100644
--- a/package.json
+++ b/package.json
@@ -14,11 +14,7 @@
     "url": "git+https://github.com/QingWei-Li/docsify.git"
   },
   "main": "lib/docsify.js",
-  "files": [
-    "lib",
-    "src",
-    "themes"
-  ],
+  "files": ["lib", "src", "themes"],
   "scripts": {
     "bootstrap": "npm i && lerna bootstrap && npm run build:ssr",
     "serve": "node server",
@@ -30,12 +26,14 @@
     "css": "stylus src/themes/*.styl -u autoprefixer-stylus",
     "watch:css": "run-p 'css -- -o themes -w'",
     "watch:js": "node build/build.js",
-    "build:css:min": "mkdir lib/themes && run-p 'css -- -o lib/themes' && cssnano lib/themes/*",
+    "build:css:min":
+      "mkdir lib/themes && run-p 'css -- -o lib/themes' && node build/mincss.js",
     "build:css": "mkdir themes && run-p 'css --  -o themes'",
     "build:js": "cross-env NODE_ENV=production node build/build.js",
     "build:ssr": "node build/ssr.js",
     "build:cover": "node build/cover.js",
-    "build": "rimraf lib themes && run-s build:js build:css build:css:min build:ssr build:cover",
+    "build":
+      "rimraf lib themes && run-s build:js build:css build:css:min build:ssr build:cover",
     "pub:next": "cross-env RELEASE_TAG=next sh build/release.sh",
     "pub": "sh build/release.sh",
     "postinstall": "opencollective postinstall"
@@ -53,7 +51,7 @@
     "chokidar": "^2.0.2",
     "conventional-changelog-cli": "^1.3.5",
     "cross-env": "^5.1.3",
-    "cssnano-cli": "^1.0.5",
+    "cssnano": "^3.10.0",
     "eslint": "^4.14.0",
     "eslint-config-xo-space": "^0.18.0",
     "lerna": "^2.5.1",
@@ -69,13 +67,7 @@
     "rollup-plugin-uglify": "^2.0.1",
     "stylus": "^0.54.5"
   },
-  "keywords": [
-    "doc",
-    "docs",
-    "documentation",
-    "creator",
-    "generator"
-  ],
+  "keywords": ["doc", "docs", "documentation", "creator", "generator"],
   "collective": {
     "type": "opencollective",
     "url": "https://opencollective.com/docsify",