diff --git a/public/src/forum/admin/themes.js b/public/src/forum/admin/themes.js
index 636edd2680..699796e36b 100644
--- a/public/src/forum/admin/themes.js
+++ b/public/src/forum/admin/themes.js
@@ -97,6 +97,11 @@ define(['forum/admin/settings'], function(Settings) {
 			instListEl.appendChild(themeFrag);
 		});
 
+		// Proper tabbing for "Custom CSS" field
+		var	customCSSEl = $('textarea[data-field]')[0];
+		tabIndent.config.tab = '    ';
+		tabIndent.render(customCSSEl);
+
 		Settings.prepare();
 	}
 
diff --git a/public/templates/admin/header.tpl b/public/templates/admin/header.tpl
index 5ea25324ed..211c27046d 100644
--- a/public/templates/admin/header.tpl
+++ b/public/templates/admin/header.tpl
@@ -24,6 +24,7 @@
 	<script src="{relative_path}/vendor/colorpicker/colorpicker.js"></script>
 	<script src="{relative_path}/vendor/xregexp/xregexp.js"></script>
 	<script src="{relative_path}/vendor/xregexp/unicode/unicode-base.js"></script>
+	<script src="{relative_path}/vendor/tabIndent/tabIndent.js"></script>
 
 	<script>
 		require.config({
diff --git a/public/vendor/tabIndent/tabIndent.js b/public/vendor/tabIndent/tabIndent.js
new file mode 100644
index 0000000000..284d96f358
--- /dev/null
+++ b/public/vendor/tabIndent/tabIndent.js
@@ -0,0 +1,252 @@
+tabIndent = {
+	version: '0.1.8',
+	config: {
+		tab: '\t'
+	},
+	events: {
+		keydown: function(e) {
+			var tab = tabIndent.config.tab;
+			var tabWidth = tab.length;
+			if (e.keyCode === 9) {
+				e.preventDefault();
+				var	currentStart = this.selectionStart,
+					currentEnd = this.selectionEnd;
+				if (e.shiftKey === false) {
+					// Normal Tab Behaviour
+					if (!tabIndent.isMultiLine(this)) {
+						// Add tab before selection, maintain highlighted text selection
+						this.value = this.value.slice(0, currentStart) + tab + this.value.slice(currentStart);
+						this.selectionStart = currentStart + tabWidth;
+						this.selectionEnd = currentEnd + tabWidth;
+					} else {
+						// Iterating through the startIndices, if the index falls within selectionStart and selectionEnd, indent it there.
+						var	startIndices = tabIndent.findStartIndices(this),
+							l = startIndices.length,
+							newStart = undefined,
+							newEnd = undefined,
+							affectedRows = 0;
+
+						while(l--) {
+							var lowerBound = startIndices[l];
+							if (startIndices[l+1] && currentStart != startIndices[l+1]) lowerBound = startIndices[l+1];
+
+							if (lowerBound >= currentStart && startIndices[l] < currentEnd) {
+								this.value = this.value.slice(0, startIndices[l]) + tab + this.value.slice(startIndices[l]);
+
+								newStart = startIndices[l];
+								if (!newEnd) newEnd = (startIndices[l+1] ? startIndices[l+1] - 1 : 'end');
+								affectedRows++;
+							}
+						}
+
+						this.selectionStart = newStart;
+						this.selectionEnd = (newEnd !== 'end' ? newEnd + (tabWidth * affectedRows) : this.value.length);
+					}
+				} else {
+					// Shift-Tab Behaviour
+					if (!tabIndent.isMultiLine(this)) {
+						if (this.value.substr(currentStart - tabWidth, tabWidth) == tab) {
+							// If there's a tab before the selectionStart, remove it
+							this.value = this.value.substr(0, currentStart - tabWidth) + this.value.substr(currentStart);
+							this.selectionStart = currentStart - tabWidth;
+							this.selectionEnd = currentEnd - tabWidth;
+						} else if (this.value.substr(currentStart - 1, 1) == "\n" && this.value.substr(currentStart, tabWidth) == tab) {
+							// However, if the selection is at the start of the line, and the first character is a tab, remove it
+							this.value = this.value.substring(0, currentStart) + this.value.substr(currentStart + tabWidth);
+							this.selectionStart = currentStart;
+							this.selectionEnd = currentEnd - tabWidth;
+						}
+					} else {
+						// Iterating through the startIndices, if the index falls within selectionStart and selectionEnd, remove an indent from that row
+						var	startIndices = tabIndent.findStartIndices(this),
+							l = startIndices.length,
+							newStart = undefined,
+							newEnd = undefined,
+							affectedRows = 0;
+
+						while(l--) {
+							var lowerBound = startIndices[l];
+							if (startIndices[l+1] && currentStart != startIndices[l+1]) lowerBound = startIndices[l+1];
+
+							if (lowerBound >= currentStart && startIndices[l] < currentEnd) {
+								if (this.value.substr(startIndices[l], tabWidth) == tab) {
+									// Remove a tab
+									this.value = this.value.slice(0, startIndices[l]) + this.value.slice(startIndices[l] + tabWidth);
+									affectedRows++;
+								} else {}	// Do nothing
+
+								newStart = startIndices[l];
+								if (!newEnd) newEnd = (startIndices[l+1] ? startIndices[l+1] - 1 : 'end');
+							}
+						}
+
+						this.selectionStart = newStart;
+						this.selectionEnd = (newEnd !== 'end' ? newEnd - (affectedRows * tabWidth) : this.value.length);
+					}
+				}
+			} else if (e.keyCode === 27) {	// Esc
+				tabIndent.events.disable(e);
+			} else if (e.keyCode === 13 && e.shiftKey === false) {	// Enter
+				var	self = tabIndent,
+					cursorPos = this.selectionStart,
+					startIndices = self.findStartIndices(this),
+					numStartIndices = startIndices.length,
+					startIndex = 0,
+					endIndex = 0,
+					tabMatch = new RegExp("^" + tab.replace('\t', '\\t').replace(/ /g, '\\s') + "+", 'g'),
+					lineText = '';
+					tabs = null;
+
+				for(var x=0;x<numStartIndices;x++) {
+					if (startIndices[x+1] && (cursorPos >= startIndices[x]) && (cursorPos < startIndices[x+1])) {
+						startIndex = startIndices[x];
+						endIndex = startIndices[x+1] - 1;
+						break;
+					} else {
+						startIndex = startIndices[numStartIndices-1];
+						endIndex = this.value.length;
+					}
+				}
+
+				lineText = this.value.slice(startIndex, endIndex);
+				tabs = lineText.match(tabMatch);
+				if (tabs !== null) {
+					e.preventDefault();
+					var indentText = tabs[0];
+					var indentWidth = indentText.length;
+					var inLinePos = cursorPos - startIndex;
+					if (indentWidth > inLinePos) {
+						indentWidth = inLinePos;
+						indentText = indentText.slice(0, inLinePos);
+					}
+					
+					this.value = this.value.slice(0, cursorPos) + "\n" + indentText + this.value.slice(cursorPos);
+					this.selectionStart = cursorPos + indentWidth + 1;
+					this.selectionEnd = this.selectionStart;
+				}
+			}
+		},
+		disable: function(e) {
+			var events = this;
+
+			// Temporarily suspend the main tabIndent event
+			tabIndent.remove(e.target);
+		},
+		focus: function() {
+			var	self = tabIndent,
+				el = this,
+				delayedRefocus = setTimeout(function() {
+					var classes = (el.getAttribute('class') || '').split(' '),
+					contains = classes.indexOf('tabIndent');
+
+					el.addEventListener('keydown', self.events.keydown);
+					el.style.backgroundImage = "url(data:image/png;base64,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)";
+					el.style.backgroundPosition = 'top right';
+					el.style.backgroundRepeat = 'no-repeat';
+
+					if (contains !== -1) classes.splice(contains, 1);
+					classes.push('tabIndent-rendered');
+					el.setAttribute('class', classes.join(' '));
+
+					el.removeEventListener('focus', self.events.keydown);
+				}, 500);
+
+			// If they were just tabbing through the input, let them continue unimpeded
+			el.addEventListener('blur', function b() {
+				clearTimeout(delayedRefocus);
+				el.removeEventListener('blur', b);
+			});
+		}
+	},
+	render: function(el) {
+		var self = this;
+
+		if (el.nodeName === 'TEXTAREA') {
+			el.addEventListener('focus', self.events.focus);
+
+			el.addEventListener('blur', function b(e) {
+				self.events.disable(e);
+			});
+		}
+	},
+	renderAll: function() {
+		// Find all elements with the tabIndent class
+		var textareas = document.getElementsByTagName('textarea'),
+			t = textareas.length,
+			contains = -1,
+			classes = [],
+			el = undefined;
+
+		while(t--) {
+			classes = (textareas[t].getAttribute('class') || '').split(' ');
+			contains = classes.indexOf('tabIndent');
+
+			if (contains !== -1) {
+				el = textareas[t];
+				this.render(el);
+			}
+			contains = -1;
+			classes = [];
+			el = undefined;
+		}
+	},
+	remove: function(el) {
+		if (el.nodeName === 'TEXTAREA') {
+			var classes = (el.getAttribute('class') || '').split(' '),
+				contains = classes.indexOf('tabIndent-rendered');
+
+			if (contains !== -1) {
+				el.removeEventListener('keydown', this.events.keydown);
+				el.style.backgroundImage = '';
+
+				classes.splice(contains, 1);
+				classes.push('tabIndent');
+				el.setAttribute('class', (classes.length > 1 ? classes.join(' ') : classes[0]));
+			}
+		}
+	},
+	removeAll: function() {
+		// Find all elements with the tabIndent class
+		var textareas = document.getElementsByTagName('textarea'),
+			t = textareas.length,
+			contains = -1,
+			classes = [],
+			el = undefined;
+
+		while(t--) {
+			classes = (textareas[t].getAttribute('class') || '').split(' ');
+			contains = classes.indexOf('tabIndent-rendered');
+
+			if (contains !== -1) {
+				el = textareas[t];
+				this.remove(el);
+			}
+			contains = -1;
+			classes = [];
+			el = undefined;
+		}
+	},
+	isMultiLine: function(el) {
+		// Extract the selection
+		var	snippet = el.value.slice(el.selectionStart, el.selectionEnd),
+			nlRegex = new RegExp(/\n/);
+
+		if (nlRegex.test(snippet)) return true;
+		else return false;
+	},
+	findStartIndices: function(el) {
+		var	text = el.value,
+			startIndices = [],
+			offset = 0;
+
+		while(text.match(/\n/) && text.match(/\n/).length > 0) {
+			offset = (startIndices.length > 0 ? startIndices[startIndices.length - 1] : 0);
+			var lineEnd = text.search("\n");
+			startIndices.push(lineEnd + offset + 1);
+			text = text.substring(lineEnd + 1);
+		}
+		startIndices.unshift(0);
+
+		return startIndices;
+	}
+}
\ No newline at end of file