style.css

/**
 * Theme Name: Fake Editor
 * Description: Simulates the wp-admin post editor for unauthenticated users
 * Author Name: Andrew Duthie
 * Author URI: http://andrewduthie.com
 */

body {
	margin: 0;
}

.toolbar,
.sidebar {
	background-color: #23282d;
}

.toolbar {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	height: 32px;
	z-index: 99999;
}

.sidebar,
.metadata {
	position: fixed;
	top: 32px;
	bottom: 0;
}

.sidebar {
	left: 0;
	width: 160px;
}

.metadata {
	right: 0;
	width: 280px;
	border-left: 1px solid #e1e5e9;
}

.sidebar__selected {
	position: relative;
	height: 34px;
	margin-top: 45px;
	background-color: #0073aa;
}

.sidebar__selected::after {
	content: '';
	position: absolute;
	top: 50%;
	right: 0;
	margin-top: -8px;
	height: 0;
	width: 0;
	border: 8px solid transparent;
	pointer-events: none;
	border-right-color: #fff;
}

.sidebar__selected-submenu {
	background-color: #32373c;
	height: 122px;
}

.content {
	margin: 32px 280px 0 160px;
	padding: 20px;
}

body.admin-bar .content {
	margin-top: 0;
}