diff --git a/web/templates/base.html b/web/templates/base.html
index 241b3c9..896cb21 100644
--- a/web/templates/base.html
+++ b/web/templates/base.html
@@ -1,6 +1,6 @@
 {% load static %}
 <!DOCTYPE html>
-<html lang="en">
+<html lang="en" data-theme="{{ request.session.theme|default:'classic' }}">
 <head>
   <meta charset="utf-8">
   <title>{% block title %}Illustrations{% endblock %}</title>
@@ -10,13 +10,14 @@
   {# === THEME SYSTEM (BEGIN) === #}
   <link rel="stylesheet" href="{% static 'css/theme-base.css' %}">
   <link id="theme-css" rel="stylesheet"
-        href="{% static 'themes/' %}{{ request.session.theme|default:'midnight' }}.css">
+        href="{% static 'themes/' %}{{ request.session.theme|default:'classic' }}.css">
   <script>
     // Early apply from localStorage to prevent flash if a user-selected theme exists
     (function () {
       try {
         var stored = localStorage.getItem('theme');
         if (stored) {
+          document.documentElement.setAttribute('data-theme', stored);
           document.getElementById('theme-css').href = '{% static "themes/" %}' + stored + '.css';
         }
       } catch (e) {}
