diff --git a/anki/utils.py b/anki/utils.py
index 7e534c994..b01fc1b90 100644
--- a/anki/utils.py
+++ b/anki/utils.py
@@ -188,6 +188,12 @@ def entsToTxt(html):
         return text # leave as is
     return reEnts.sub(fixup, html)
 
+def bodyClass(col, card):
+    bodyclass = "card card%d" % (card.ord+1)
+    if col.conf.get("nightMode"):
+        bodyclass += " nightMode"
+    return bodyclass
+
 # IDs
 ##############################################################################
 
diff --git a/aqt/browser.py b/aqt/browser.py
index 9778abdf5..369b929b8 100644
--- a/aqt/browser.py
+++ b/aqt/browser.py
@@ -13,8 +13,9 @@ import json
 from aqt.qt import *
 import anki
 import aqt.forms
-from anki.utils import fmtTimeSpan, ids2str, stripHTMLMedia, htmlToTextLine, isWin, intTime,\
-    isMac, isLin
+from anki.utils import fmtTimeSpan, ids2str, stripHTMLMedia, htmlToTextLine, \
+    isWin, intTime, \
+    isMac, isLin, bodyClass
 from aqt.utils import saveGeom, restoreGeom, saveSplitter, restoreSplitter, \
     saveHeader, restoreHeader, saveState, restoreState, applyStyles, getTag, \
     showInfo, askUser, tooltip, openHelp, showWarning, shortcut, mungeQA, \
@@ -1347,7 +1348,7 @@ where id in %s""" % ids2str(sf))
                 txt = c.a()
             txt = re.sub("\[\[type:[^]]+\]\]", "", txt)
 
-            bodyclass="card card%d" % (c.ord+1)
+            bodyclass = bodyClass(self.mw.col, c)
 
             clearAudioQueue()
             if self.mw.reviewer.autoplay(c):
diff --git a/aqt/clayout.py b/aqt/clayout.py
index 7be98f7b5..da6e24375 100644
--- a/aqt/clayout.py
+++ b/aqt/clayout.py
@@ -12,7 +12,7 @@ from anki.sound import playFromText, clearAudioQueue
 from aqt.utils import saveGeom, restoreGeom, mungeQA,\
     showInfo, askUser, getOnlyText, \
      showWarning, openHelp, downArrow
-from anki.utils import isMac, isWin, joinFields
+from anki.utils import isMac, isWin, joinFields, bodyClass
 from aqt.webview import AnkiWebView
 import json
 from anki.hooks import runFilter
@@ -297,7 +297,8 @@ Please create a new card type first."""))
 
         c = self.card
         ti = self.maybeTextInput
-        bodyclass="card card%d" % (c.ord+1)
+
+        bodyclass = bodyClass(self.mw.col, c)
 
         q = ti(mungeQA(self.mw.col, c.q(reload=True)))
         q = runFilter("prepareQA", q, c, "clayoutQuestion")
diff --git a/aqt/preferences.py b/aqt/preferences.py
index b08f37058..1fbf5f3f2 100644
--- a/aqt/preferences.py
+++ b/aqt/preferences.py
@@ -80,6 +80,7 @@ class Preferences(QDialog):
         f.timeLimit.setValue(qc['timeLim']/60.0)
         f.showEstimates.setChecked(qc['estTimes'])
         f.showProgress.setChecked(qc['dueCounts'])
+        f.nightMode.setChecked(qc.get("nightMode", False))
         f.newSpread.addItems(list(c.newCardSchedulingLabels().values()))
         f.newSpread.setCurrentIndex(qc['newSpread'])
         f.useCurrent.setCurrentIndex(int(not qc.get("addToCur", True)))
@@ -91,6 +92,7 @@ class Preferences(QDialog):
         qc['dueCounts'] = f.showProgress.isChecked()
         qc['estTimes'] = f.showEstimates.isChecked()
         qc['newSpread'] = f.newSpread.currentIndex()
+        qc['nightMode'] = f.nightMode.isChecked()
         qc['timeLim'] = f.timeLimit.value()*60
         qc['collapseTime'] = f.lrnCutoff.value()*60
         qc['addToCur'] = not f.useCurrent.currentIndex()
diff --git a/aqt/reviewer.py b/aqt/reviewer.py
index f87b1be57..300300f42 100644
--- a/aqt/reviewer.py
+++ b/aqt/reviewer.py
@@ -10,7 +10,7 @@ import html.parser
 
 from anki.lang import _, ngettext
 from aqt.qt import *
-from anki.utils import stripHTML, json
+from anki.utils import stripHTML, json, bodyClass
 from anki.hooks import addHook, runHook, runFilter
 from anki.sound import playFromText, clearAudioQueue, play
 from aqt.utils import mungeQA, tooltip, askUserDialog, \
@@ -167,7 +167,7 @@ The front of this card is empty. Please run Tools>Empty Cards.""")
         q = self._mungeQA(q)
         q = runFilter("prepareQA", q, c, "reviewQuestion")
 
-        bodyclass = "card card%d" % (c.ord+1)
+        bodyclass = bodyClass(self.mw.col, c)
 
         self.web.eval("_showQuestion(%s,'%s');" % (json.dumps(q), bodyclass))
         self._drawFlag()
diff --git a/designer/preferences.ui b/designer/preferences.ui
index 5a9f8f5b0..7efd5e8bd 100644
--- a/designer/preferences.ui
+++ b/designer/preferences.ui
@@ -78,6 +78,13 @@
          </property>
         </widget>
        </item>
+       <item>
+        <widget class="QCheckBox" name="nightMode">
+         <property name="text">
+          <string>Show cards as white on black (night mode)</string>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="QComboBox" name="useCurrent">
          <item>
@@ -429,6 +436,7 @@
   <tabstop>showEstimates</tabstop>
   <tabstop>showProgress</tabstop>
   <tabstop>pastePNG</tabstop>
+  <tabstop>nightMode</tabstop>
   <tabstop>useCurrent</tabstop>
   <tabstop>newSpread</tabstop>
   <tabstop>dayOffset</tabstop>
diff --git a/web/reviewer.css b/web/reviewer.css
index 738de242d..6ddf431fc 100644
--- a/web/reviewer.css
+++ b/web/reviewer.css
@@ -8,6 +8,11 @@ body {
     overflow-wrap: break-word;
 }
 
+body.nightMode {
+    background-color: black;
+    color: white;
+}
+
 img {
     max-width: 95%;
     max-height: 95%;