diff --git a/core/ui/EditTemplate/body/default.tid b/core/ui/EditTemplate/body/default.tid
index 9986c4142..6ea0da72c 100644
--- a/core/ui/EditTemplate/body/default.tid
+++ b/core/ui/EditTemplate/body/default.tid
@@ -10,7 +10,7 @@ title: $:/core/ui/EditTemplate/body/default
 
 \function get.style.grid-template-columns()
 [<get.edit-preview-state>!match[yes]then[1fr]]
-:else[<sidebarWidthTiddler>!is[missing]then[calc(100% - ]addsuffix<get.preview.width>addsuffix[) ]addsuffix<get.preview.width>]
+:else[<sidebarWidthTiddler>is[tiddler]then[calc(100% - ]addsuffix<get.preview.width>addsuffix[) ]addsuffix[calc(]addsuffix<get.preview.width>addsuffix[)]]
 :else[[repeat(2, minmax(0px, 1fr))]]
 \end
 
diff --git a/core/wiki/macros/sliders.tid b/core/wiki/macros/sliders.tid
index 29c112fdd..bf382d4c5 100644
--- a/core/wiki/macros/sliders.tid
+++ b/core/wiki/macros/sliders.tid
@@ -6,7 +6,7 @@ code-body: yes
 \import $:/core/procedures/sidebar-resizer
 \function get.resizer.style.position() absolute
 \function get.template-right.width() [<sidebarWidthTiddler>get[text]] :else[[50%]]
-\function get.resizer.style.left() [[calc(100% - ]addsuffix<get.template-right.width>addsuffix[)]]
+\function get.resizer.style.left() [[calc(100% - ]addsuffix<get.template-right.width>addsuffix[ - 3px)]]
 \function get.resizer.style.width() [<sliderWidth>]
 \function set.throttling() no
 \function get.template.left()
@@ -33,7 +33,7 @@ code-body: yes
 		$variable="editor-resizer"
 		template=<<template>>
 		sliderCondition=<<sliderCondition>>
-		eventCatcherClass="tc-one-cell-eventcatcher"
+		eventCatcherClass="tc-editor-preview-eventcatcher"
 		mode=<<mode>>
 	/>
 
diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 4e1692d6a..7bc192b1f 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -1708,7 +1708,7 @@ html body.tc-body.tc-single-tiddler-window {
 	overflow-wrap: anywhere;
 	word-break: normal;
 	border: 1px solid <<colour tiddler-editor-border>>;
-	margin: 4px 0 3px 9px;
+	margin: 4px 0 3px 3px;
 	padding: 3px 3px 3px 3px;
 }
 
diff --git a/themes/tiddlywiki/vanilla/sidebar-resizer.tid b/themes/tiddlywiki/vanilla/sidebar-resizer.tid
index 9335a4b2d..c77f2377e 100644
--- a/themes/tiddlywiki/vanilla/sidebar-resizer.tid
+++ b/themes/tiddlywiki/vanilla/sidebar-resizer.tid
@@ -40,7 +40,7 @@ code-body: yes
 			height: 100%;
 		}
 
-		.tc-edit-texteditor-slider > .tc-sidebar-resizer-pointerdown-eventcatcher.tc-one-cell-eventcatcher {
+		.tc-edit-texteditor-slider > .tc-sidebar-resizer-pointerdown-eventcatcher.tc-editor-preview-eventcatcher {
 			position: absolute;
 			width: 100%;
 			top: 0;