diff --git a/core/ui/TestCases/DefaultTemplate.tid b/core/ui/TestCases/DefaultTemplate.tid
index 15e25fae2..31926b2de 100644
--- a/core/ui/TestCases/DefaultTemplate.tid
+++ b/core/ui/TestCases/DefaultTemplate.tid
@@ -12,6 +12,8 @@ title: $:/core/ui/testcases/DefaultTemplate
 <div class="tc-testcase-source">
 <$macrocall $name="tabs" tabsList="[<testcaseInfo>jsonget[titles]] -Description -ExpectedResult -[has[plugin-type]]" state=<<state>> default="Output" template="$:/core/ui/testcases/DefaultTemplate/Source"/>
 </div>
+<div class="tc-testcase-divider">
+</div>
 <div class="tc-testcase-output">
 <$testcase-transclude tiddler="Output"/>
 </div>
diff --git a/core/ui/TestCases/DefaultTemplateSource.tid b/core/ui/TestCases/DefaultTemplateSource.tid
index b025a9dfc..3242c8a6c 100644
--- a/core/ui/TestCases/DefaultTemplateSource.tid
+++ b/core/ui/TestCases/DefaultTemplateSource.tid
@@ -1,5 +1,3 @@
 title: $:/core/ui/testcases/DefaultTemplate/Source
 
-<pre>
-<$testcase-view tiddler=<<currentTab>>/>
-</pre>
+<pre><$testcase-view tiddler=<<currentTab>>/></pre>
diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index b63d99d6c..57541d2e6 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -3163,7 +3163,7 @@ select {
 .tc-testcase-wrapper {
 	border: 1px solid <<colour foreground>>;
 	background-color: <<colour muted-foreground>>;
-	border-radius: 3px;
+	border-radius: 6px;
 }
 
 .tc-testcase-header {
@@ -3190,15 +3190,24 @@ select {
 }
 
 .tc-testcase-source {
-	border: 1px solid <<colour background>>;
-	flex: 1 0 50%;
+	flex: 1 0 49%;
 	min-width: 250px;
 }
 
+.tc-testcase-divider {
+	flex: 0 0 2%;
+}
+
+.tc-testcase-source .tc-tab-buttons {
+	padding-top: 0;
+}
+
 .tc-testcase-output {
-	border: 1px solid <<colour background>>;
-	flex: 1 0 50%;
+	border-radius: 3px;
+	border: 1px solid <<colour muted-foreground>>;
+	flex: 1 0 49%;
 	min-width: 250px;
+	padding: 0.25em;
 }