HackMD - Personal Dark Stylesheet.

dark-override.css

/* Used colors 
Dark: #16161d
S0: #2b2b2b
S1: #66666E
S2: #4c4c4c || #9999A1
S3: #E6E6E9
S4: #F4F4F6 (For active or static text)

This stylesheet has many improvements over the basic hackmd one (i adapted some parts of stackedit.io i liked over to hackmd.)
*/
@import url('https://fonts.googleapis.com/css?family=Source+Sans+Pro|PT+Sans');

.navbar-default {
    background-color: #16161d;
    border-color: #2b2b2b;
}

.navbar-default .btn-link {
    color: #9999A1;
}

.navbar-default .btn-link:focus, .navbar-default .btn-link:hover {
    color: #f4f4f6;
}

.navbar-default .navbar-brand {
    color: #9999A1;
}

.navbar-default .navbar-brand:focus, .navbar-default .navbar-brand:hover {
    color: #f4f4f6;
    background-color: transparent;
}

.navbar-default .navbar-nav>li>a {
    color: #9999A1;
}

.navbar-default .navbar-nav>li>a:focus, .navbar-default .navbar-nav>li>a:hover {
    color: #f4f4f6;
    background-color: transparent;
}

.navbar-default .navbar-nav>.open>a, .navbar-default .navbar-nav>.open>a:focus, .navbar-default .navbar-nav>.open>a:hover {
    color: #f4f4f6;
    background-color: #2b2b2b;
}

.navbar-nav .btn-default {
    color: #9999A1;
    background-color: #2b2b2b;
    border-color: #9999a1;
}

.navbar-nav .btn-default:hover {
    color: #f4f4f6;
    background-color: #16161d;
    border-color: #9999a1;
}

.navbar-nav .btn-default.active, .btn-default:active, .open>.dropdown-toggle.btn-default {
    color: #f4f4f6;
    background-color: #16161d;
    border-color: #9999a1;
}

.dropdown-menu,
.dropdown-menu.list {
    background-color: #2b2b2b !important;
}

.dropdown-header {
    color: #f4f4f6;
}

.dropdown-menu>li>a {
    color: #9999A1 !important;
}

.dropdown-menu>li>a:focus, .dropdown-menu>li>a:hover {
    color: #f4f4f6 !important;
    background-color: #16161d !important;
}

.dropdown-menu .divider {
    background-color: #16161d !important;
}

.cm-s-one-dark .cm-header {
    color: #337ab7;
}

.cm-s-one-dark .cm-variable-2 {
    color: #b7dbff;
}

.cm-s-one-dark .cm-string {
    color: #8ebdbd;
}

.modal-title {
    color: #F4F4F6;
}

.modal-header, .modal-footer {
    background-color: #16161d;
}

.modal-header {
    border-bottom: 1px solid #66666E !important;
}

.modal-footer {
    border-top: 1px solid #66666E !important;
}

.modal-body {
    color: #f4f4f6 !important;
    background-color: #2b2b2b;
}

.modal-header .close {
    color: #9999A1 !important;
    text-shadow: 0 1px 0 #16161d !important;
    opacity: 1 !important;
}

.modal-header .close:focus, .modal-header .close:hover {
    color: #F4F4F6 !important;
    opacity: .8 !important;
}

.panel {
    background-color: #2b2b2b !important;
    color: #F4F4F6;
}

.panel-default>.panel-heading {
    color: #F4F4F6;
    background-color: #16161d;
    border-color: #66666E;
}

.panel-default {
    border-color: #66666E !important;
}

.panel-body .table>thead>tr>th {
    border-bottom: 2px solid #66666E !important;
}

.panel-body .table>tbody>tr>td, .panel-body .table>tbody>tr>th, .panel-body .table>tfoot>tr>td,
.panel-body .table>tfoot>tr>th, .panel-body.table>thead>tr>td, .panel-body .table>thead>tr>th {
    border-top: 1px solid #66666E !important;
}

#ui-toc .expand-toggle:hover, #ui-toc .expand-toggle:focus, #ui-toc .back-to-top:hover,
#ui-toc .back-to-top:focus, #ui-toc .go-to-bottom:hover, #ui-toc .go-to-bottom:focus {
    color: #bea2e8 !important;
}

#ui-toc .nav>li>a {
    color: #9999A1 !important;
}

#ui-toc .nav>li>a:focus, #ui-toc .nav>li>a:hover {
    color: #f4f4f6 !important;
    border-left: 2px solid #a29f9f !important;
}

#ui-toc .nav>.active:focus>a, #ui-toc .nav>.active:hover>a, #ui-toc .nav>.active>a {
    color: #f4f4f6 !important;
    border-left: 2px solid #a29f9f !important;
}

html {
    font-family: sans-serif;
    -ms-text-size-adjust: 100%;
    -webkit-text-size-adjust: 100%
}

body {
    font-family: "Source Sans Pro",sans-serif !important;
    background-color: #f6f6f6 !important;
}

pre, code {
    font-family: "Source Code Pro", monospace !important;
}

.markdown-body .highlight pre, .markdown-body pre {
    background-color: #f0f0f0 !important;
    border-radius: 0 !important;
}

.markdown-body blockquote {
    font-size: 1em;
    padding: 10px 20px;
    border-left: 10px solid rgba(128,128,128,0.075);
    background-color: rgba(128,128,128,0.05);
    border-top-right-radius: 5px;
    border-bottom-right-radius: 5px;
}

blockquote p {
   font-weight: 300;
}

.cm-comment,
.CodeMirror-code {
    font: normal .9em "Source Code Pro",monospace !important; 
}

.markdown-body {
    font-family: "Source Sans Pro",sans-serif !important;
}

.CodeMirror,
.CodeMirror-line {
   font-family: "PT Sans",sans-serif !important;
   font-size: 18px !important;
   letter-spacing: normal;
}

.cm-header {
    font-weight: 600;
}

.cm-header-1 {
    font-size: 1.5em
}

.cm-header-2  {
    font-size: 1.3em
}

.cm-header-3  {
    font-size: 1.1em
}

.cm-header-4 { 
    font-size: 1.05em
}

.cm-header-5  {
    font-size: 1.025em
}

.cm-header-6  {
    font-size: 1em
}