diff --git a/locales/en.json b/locales/en.json
index 6b2a206..49e93a8 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -102,5 +102,6 @@
 	"Select From Available Snippets": "Select From Available Snippets",
 	"OR": "OR",
 	"Export to Snippet": "Export to Snippet",
-	"Select Visibility Level": "Select Visibility Level"
+	"Select Visibility Level": "Select Visibility Level",
+	"Night Theme": "Night Theme"
 }
diff --git a/public/css/extra.css b/public/css/extra.css
index 169a1a5..1b13290 100644
--- a/public/css/extra.css
+++ b/public/css/extra.css
@@ -179,6 +179,11 @@
     border-left: 1px solid black;
 }
 
+.night .ui-toc-dropdown .nav>li>a:focus, .night .ui-toc-dropdown .nav>li>a:hover{
+    color: white;
+    border-left-color: white;
+}
+
 .ui-toc-dropdown[dir='rtl'] .nav>li>a:focus,.ui-toc-dropdown[dir='rtl'] .nav>li>a:hover {
     padding-right: 19px;
     border-left: none;
@@ -192,6 +197,10 @@
     background-color: transparent;
     border-left: 2px solid black;
 }
+.night .ui-toc-dropdown .nav>.active:focus>a,.night .ui-toc-dropdown .nav>.active:hover>a,.night .ui-toc-dropdown .nav>.active>a {
+    color: white;
+    border-left: 2px solid white;
+}
 
 .ui-toc-dropdown[dir='rtl'] .nav>.active:focus>a,.ui-toc-dropdown[dir='rtl'] .nav>.active:hover>a,.ui-toc-dropdown[dir='rtl'] .nav>.active>a {
     padding-right: 18px;
@@ -216,6 +225,10 @@
     font-weight: 400;
 }
 
+.night .ui-toc-dropdown .nav > li > a{
+    color: #aaa;
+}
+
 .ui-toc-dropdown[dir='rtl'] .nav .nav>li>a {
     padding-right: 30px;
 }
@@ -350,13 +363,23 @@ small .dropdown a:focus, small .dropdown a:hover {
 }
 
 .unselectable {
-    -moz-user-select: none; 
-    -khtml-user-select: none; 
-    -webkit-user-select: none; 
+    -moz-user-select: none;
+    -khtml-user-select: none;
+    -webkit-user-select: none;
     -o-user-select: none;
     user-select: none;
 }
 
+.night .navbar{
+    background: #333;
+    border-bottom-color: #333;
+    color: #eee;
+}
+
+.night .navbar a{
+    color: #eee;
+}
+
 @media print {
     div, table, img, pre, blockquote {
         page-break-inside: avoid !important;
@@ -364,4 +387,4 @@ small .dropdown a:focus, small .dropdown a:hover {
     a[href]:after {
         font-size: 12px !important;
     }
-}
\ No newline at end of file
+}
diff --git a/public/css/github-extract.css b/public/css/github-extract.css
index 4d2650d..7f7058a 100644
--- a/public/css/github-extract.css
+++ b/public/css/github-extract.css
@@ -68,6 +68,9 @@
     color: #777;
     border-left: 0.25em solid #ddd;
 }
+.night .markdown-body blockquote{
+    color: #bcbcbc;
+}
 
 .markdown-body blockquote>:first-child {
     margin-top: 0;
@@ -107,6 +110,15 @@
     line-height: 1.25;
 }
 
+.night .markdown-body h1,
+.night .markdown-body h2,
+.night .markdown-body h3,
+.night .markdown-body h4,
+.night .markdown-body h5,
+.night .markdown-body h6 {
+    color: #ddd;
+}
+
 .markdown-body h1 .octicon-link,
 .markdown-body h2 .octicon-link,
 .markdown-body h3 .octicon-link,
@@ -118,6 +130,15 @@
     visibility: hidden;
 }
 
+.night .markdown-body h1 .octicon-link,
+.night .markdown-body h2 .octicon-link,
+.night .markdown-body h3 .octicon-link,
+.night .markdown-body h4 .octicon-link,
+.night .markdown-body h5 .octicon-link,
+.night .markdown-body h6 .octicon-link {
+    color: #fff;
+}
+
 .markdown-body h1:hover .anchor,
 .markdown-body h2:hover .anchor,
 .markdown-body h3:hover .anchor,
@@ -180,6 +201,8 @@
     color: #777
 }
 
+
+
 .markdown-body ul,
 .markdown-body ol {
     padding-left: 2em
@@ -246,11 +269,19 @@
     background-color: #fff;
     border-top: 1px solid #ccc;
 }
+.night .markdown-body table tr {
+    background-color: #5f5f5f;
+}
 
 .markdown-body table tr:nth-child(2n) {
     background-color: #f8f8f8;
 }
 
+.night .markdown-body table tr:nth-child(2n){
+
+    background-color: #4f4f4f;
+}
+
 .markdown-body img {
     max-width: 100%;
     box-sizing: content-box;
@@ -370,6 +401,14 @@
     border-radius: 3px;
 }
 
+.night .markdown-body code,
+.night .markdown-body tt {
+
+    color: #eee;
+    background-color: rgba(230, 230, 230, 0.36);
+
+}
+
 .markdown-body code::before,
 .markdown-body code::after,
 .markdown-body tt::before,
@@ -512,4 +551,4 @@
     margin: 0.31em 0 0.2em -1.3em !important;
     vertical-align: middle;
     cursor: default !important;
-}
\ No newline at end of file
+}
diff --git a/public/css/index.css b/public/css/index.css
index 8f483aa..b00eba4 100644
--- a/public/css/index.css
+++ b/public/css/index.css
@@ -10,6 +10,16 @@ body {
     padding-top: 51px;
     /*overflow: hidden;*/
 }
+
+.night a,
+.night .open-files-container li.selected a {
+    color: #5EB7E0;
+}
+
+body.night{
+    background: #333 !important;
+}
+
 .CodeMirror {
     font-family: "Source Code Pro", Consolas, monaco, monospace;
     letter-spacing: 0.025em;
@@ -117,6 +127,11 @@ body {
     margin-left: 0;
     margin-right: 0;
 }
+
+.night .ui-content{
+    background-color: #333;
+}
+
 .ui-edit-area {
     height: 100%;
     /*padding-left: 15px;*/
@@ -144,6 +159,12 @@ body {
 .ui-edit-area .ui-sync-toggle:active {
     box-shadow: inset 0 3px 5px rgba(0,0,0,.125), 2px 0px 2px #e7e7e7;
 }
+
+.night .ui-edit-area .ui-resizable-handle.ui-resizable-e{
+   background: #3c3c3c;
+   box-shadow: 3px 0px 6px #353535;
+}
+
 .ui-view-area {
     /*overflow-y: scroll;*/
     -webkit-overflow-scrolling: touch;
@@ -154,6 +175,13 @@ body {
         padding-right: 15px;
     }
 }
+
+.night .ui-view-area{
+    background: #333;
+    color: #ededed;
+}
+
+
 .ui-scrollable {
     height: 100%;
     overflow-x: hidden;
@@ -238,12 +266,32 @@ body {
 .navbar-nav > li > a {
     cursor: pointer;
 }
+
+.night .navbar-default .navbar-nav > li > a:focus,
+.night .navbar-default .navbar-nav > li > a:hover,
+.night .navbar-default .navbar-brand:focus,
+.night .navbar-default .navbar-brand:hover{
+    color: #fff;
+}
+
+.night .navbar-default .navbar-nav > .open > a,
+.night .navbar-default .navbar-nav > .open > a:focus,
+.night .navbar-default .navbar-nav > .open > a:hover {
+    color: white;
+    background: #000;
+
+}
 .dropdown-menu > li > a {
     cursor: pointer;
     text-overflow: ellipsis;
     max-width: calc(100vw - 30px);
     overflow: hidden;
 }
+
+.night .dropdown-menu{
+    background: #222;
+}
+
 .dropdown-menu.CodeMirror-other-cursor {
     transition: none;
 }
@@ -276,8 +324,8 @@ div[contenteditable]:empty:not(:focus):before{
     max-height: 40vh;
     overflow: auto;
 }
-.dropdown-menu.list::-webkit-scrollbar { 
-    display: none; 
+.dropdown-menu.list::-webkit-scrollbar {
+    display: none;
 }
 .dropdown-menu .emoji {
     margin-bottom: 0 !important;
@@ -292,6 +340,16 @@ div[contenteditable]:empty:not(:focus):before{
     background: inherit;
 }
 
+.night .navbar .btn-default{
+    background-color: #333;
+    border-color: #565656;
+    color: #eee;
+}
+
+.night .btn.btn-default.ui-view.active{
+    background: #202020;
+}
+
 .btn-file {
     position: relative;
     overflow: hidden;
@@ -312,6 +370,12 @@ div[contenteditable]:empty:not(:focus):before{
     display: block;
 }
 
+.night .btn.focus,
+.night .btn:focus,
+.night .btn:hover{
+    color: #fff;
+}
+
 .info-label {
 	width: 36%;
 	text-align: right;
@@ -481,8 +545,8 @@ div[contenteditable]:empty:not(:focus):before{
     border: 1px solid #2893ef;
 }
 
-.status-bar .indent-width-input::-webkit-inner-spin-button, 
-.status-bar .indent-width-input::-webkit-outer-spin-button { 
+.status-bar .indent-width-input::-webkit-inner-spin-button,
+.status-bar .indent-width-input::-webkit-outer-spin-button {
     -webkit-appearance: none;
     margin: 0;
 }
@@ -524,4 +588,4 @@ div[contenteditable]:empty:not(:focus):before{
     .CodeMirror {
         height: auto !important;
     }
-}
\ No newline at end of file
+}
diff --git a/public/css/markdown.css b/public/css/markdown.css
index ad3a655..6741729 100644
--- a/public/css/markdown.css
+++ b/public/css/markdown.css
@@ -69,6 +69,12 @@
     border-collapse: inherit !important;
 }
 
+.night .markdown-body .gist table tr:nth-child(2n){
+
+    background-color: #ddd;
+
+}
+
 .markdown-body code[data-gist-id] {
     background: none;
     padding: 0;
@@ -93,6 +99,7 @@
 
 .markdown-body code[data-gist-id] table tr {
     background: unset;
+
 }
 
 /*fixed style for rtl in pre and code*/
@@ -121,6 +128,16 @@
     white-space: inherit;
 }
 
+.night .markdown-body pre.graphviz .graph > polygon{
+    fill: #333;
+}
+
+.night .markdown-body pre.mermaid .titleText,
+.night .markdown-body pre.mermaid text,
+.night .markdown-body pre.mermaid .sectionTitle{
+    fill: white;
+}
+
 .markdown-body pre.flow-chart > code,
 .markdown-body pre.sequence-diagram > code,
 .markdown-body pre.graphviz > code,
@@ -138,6 +155,27 @@
     height: 100%;
 }
 
+.night .markdown-body .abc path{
+    fill: #eee;
+}
+
+.night .markdown-body .abc path.note_selected{
+    fill: ##4DD0E1;
+}
+
+.night tspan{
+    fill: #fefefe;
+}
+
+.night pre rect{
+    fill: transparent;
+}
+
+.night pre.flow-chart rect,
+.night pre.flow-chart path{
+    stroke: white;
+}
+
 .markdown-body pre > code.wrap {
     white-space: pre-wrap;       /* Since CSS 2.1 */
     white-space: -moz-pre-wrap;  /* Mozilla, since 1999 */
diff --git a/public/js/index.js b/public/js/index.js
index b336af9..5ff716f 100644
--- a/public/js/index.js
+++ b/public/js/index.js
@@ -1633,6 +1633,10 @@ ui.toolbar.view.click(function () {
 ui.toolbar.both.click(function () {
   changeMode(modeType.both)
 })
+
+ui.toolbar.night.click(function () {
+  toggleNightMode()
+})
 // permission
 // freely
 ui.infobar.permission.freely.click(function () {
@@ -1666,6 +1670,17 @@ $('.ui-delete-modal-confirm').click(function () {
   socket.emit('delete')
 })
 
+function toggleNightMode () {
+  var $body = $('body')
+  var isActive = ui.toolbar.night.hasClass('active')
+  if (isActive) {
+    $body.removeClass('night')
+    appState.nightMode = false
+  } else {
+    $body.addClass('night')
+    appState.nightMode = true
+  }
+}
 function emitPermission (_permission) {
   if (_permission !== permission) {
     socket.emit('permission', _permission)
diff --git a/public/js/lib/appState.js b/public/js/lib/appState.js
index fb8030e..87aaf73 100644
--- a/public/js/lib/appState.js
+++ b/public/js/lib/appState.js
@@ -2,7 +2,8 @@ import modeType from './modeType'
 
 let state = {
   syncscroll: true,
-  currentMode: modeType.view
+  currentMode: modeType.view,
+  nightMode: false
 }
 
 export default state
diff --git a/public/js/lib/editor/ui-elements.js b/public/js/lib/editor/ui-elements.js
index 0d330d7..88a1e3c 100644
--- a/public/js/lib/editor/ui-elements.js
+++ b/public/js/lib/editor/ui-elements.js
@@ -37,6 +37,7 @@ export const getUIElements = () => ({
     edit: $('.ui-edit'),
     view: $('.ui-view'),
     both: $('.ui-both'),
+    night: $('.ui-night'),
     uploadImage: $('.ui-upload-image')
   },
   infobar: {
diff --git a/public/views/hackmd/header.ejs b/public/views/hackmd/header.ejs
index 80df2c7..b87f21f 100644
--- a/public/views/hackmd/header.ejs
+++ b/public/views/hackmd/header.ejs
@@ -96,6 +96,11 @@
                     <input type="radio" name="mode" autocomplete="off"><i class="fa fa-pencil"></i>
                 </label>
             </div>
+            <div class="btn-group" data-toggle="buttons">
+                <label class="btn ui-night" title="<%= __('Night Theme') %>">
+                    <input type="checkbox" name="night"><i class="fa fa-moon-o"></i>
+                </label>
+            </div>
             <span class="btn btn-link btn-file ui-help" title="<%= __('Help') %>" data-toggle="modal" data-target=".help-modal">
                 <i class="fa fa-question-circle"></i>
             </span>