diff --git a/doc/en/_themes/flask/slim_searchbox.html b/doc/en/_themes/flask/slim_searchbox.html
new file mode 100644
index 000000000..e98ad4ed9
--- /dev/null
+++ b/doc/en/_themes/flask/slim_searchbox.html
@@ -0,0 +1,15 @@
+{#
+    basic/searchbox.html with heading removed.
+#}
+{%- if pagename != "search" and builder != "singlehtml" %}
+<div id="searchbox" style="display: none" role="search">
+  <div class="searchformwrapper">
+    <form class="search" action="{{ pathto('search') }}" method="get">
+      <input type="text" name="q" aria-labelledby="searchlabel"
+        placeholder="Search"/>
+      <input type="submit" value="{{ _('Go') }}" />
+    </form>
+  </div>
+</div>
+<script type="text/javascript">$('#searchbox').show(0);</script>
+{%- endif %}
diff --git a/doc/en/_themes/flask/static/flasky.css_t b/doc/en/_themes/flask/static/flasky.css_t
index 6b593da29..d56dbc3d8 100644
--- a/doc/en/_themes/flask/static/flasky.css_t
+++ b/doc/en/_themes/flask/static/flasky.css_t
@@ -106,14 +106,14 @@ div.sphinxsidebar h3,
 div.sphinxsidebar h4 {
     font-family: {{ header_font }};
     color: #444;
-    font-size: 24px;
+    font-size: 21px;
     font-weight: normal;
-    margin: 0 0 5px 0;
+    margin: 16px 0 0 0;
     padding: 0;
 }
 
 div.sphinxsidebar h4 {
-    font-size: 20px;
+    font-size: 18px;
 }
 
 div.sphinxsidebar h3 a {
diff --git a/doc/en/conf.py b/doc/en/conf.py
index 71692e00f..1a6ef7ca8 100644
--- a/doc/en/conf.py
+++ b/doc/en/conf.py
@@ -165,18 +165,18 @@ html_favicon = "img/pytest1favi.ico"
 
 html_sidebars = {
     "index": [
+        "slim_searchbox.html",
         "sidebarintro.html",
         "globaltoc.html",
         "links.html",
         "sourcelink.html",
-        "searchbox.html",
     ],
     "**": [
+        "slim_searchbox.html",
         "globaltoc.html",
         "relations.html",
         "links.html",
         "sourcelink.html",
-        "searchbox.html",
     ],
 }