diff --git a/src/vs/workbench/browser/media/floatingPanels.css b/src/vs/workbench/browser/media/floatingPanels.css
index d92b36a5869..e78443892f0 100644
--- a/src/vs/workbench/browser/media/floatingPanels.css
+++ b/src/vs/workbench/browser/media/floatingPanels.css
@@ -156,10 +156,6 @@
 	padding-bottom: var(--vscode-spacing-size40);
 }
 
-.monaco-workbench.floating-panels .activitybar > .content > .composite-bar {
-	margin-top: var(--vscode-spacing-size20);
-}
-
 /*
  * When the status bar is hidden every floating card sits directly against the window
  * bottom edge. Double the bottom margin (4px → 8px) to match the doubled outer gutter
diff --git a/src/vs/workbench/browser/part.ts b/src/vs/workbench/browser/part.ts
index e7b9278318f..0d2e7c4fcb9 100644
--- a/src/vs/workbench/browser/part.ts
+++ b/src/vs/workbench/browser/part.ts
@@ -217,6 +217,8 @@ class PartLayout {
 
 	private static readonly HEADER_HEIGHT = 35;
 	private static readonly TITLE_HEIGHT = 35;
+	// KEEP IN SYNC WITH: styleOverrides/browser/media/padding.css `.style-override .part > .title { height: 32px }`
+	private static readonly TITLE_HEIGHT_STYLE_OVERRIDE = 32;
 	private static readonly Footer_HEIGHT = 35;
 
 	private headerVisible: boolean = false;
@@ -226,10 +228,16 @@ class PartLayout {
 
 	layout(width: number, height: number): ILayoutContentResult {
 
-		// Title Size: Width (Fill), Height (Variable)
+		// Title Size: Width (Fill), Height (Variable).
+		// When the Modern UI style-override is active the title bar is 32 px
+		// (set in padding.css). Mirror that value here so the content area
+		// calculation stays in sync. Uses the same `.closest('.style-override')`
+		// check as EditorTabsControl.tabHeight.
 		let titleSize: Dimension;
 		if (this.options.hasTitle) {
-			titleSize = new Dimension(width, Math.min(height, PartLayout.TITLE_HEIGHT));
+			const isStyleOverride = !!this.contentArea?.closest('.style-override');
+			const titleHeight = isStyleOverride ? PartLayout.TITLE_HEIGHT_STYLE_OVERRIDE : PartLayout.TITLE_HEIGHT;
+			titleSize = new Dimension(width, Math.min(height, titleHeight));
 		} else {
 			titleSize = Dimension.None;
 		}
diff --git a/src/vs/workbench/contrib/styleOverrides/browser/media/activityBar.css b/src/vs/workbench/contrib/styleOverrides/browser/media/activityBar.css
index 72cb2e0dfed..27ce0d6ad50 100644
--- a/src/vs/workbench/contrib/styleOverrides/browser/media/activityBar.css
+++ b/src/vs/workbench/contrib/styleOverrides/browser/media/activityBar.css
@@ -262,7 +262,6 @@
 	box-sizing: border-box;
 	height: 24px;
 	line-height: 24px;
-	margin-bottom: 4px;
 }
 
 .style-override.monaco-workbench .pane-composite-part > .title > .composite-bar-container > .composite-bar > .monaco-action-bar .action-item.icon .action-label::before,
@@ -285,7 +284,6 @@
 	height: 24px;
 	padding: 0;
 	width: 24px;
-	margin-bottom: 4px;
 }
 
 .style-override.monaco-workbench .part.auxiliarybar > .header-or-footer > .composite-bar-container > .composite-bar > .monaco-action-bar .action-item.icon .active-item-indicator,
@@ -303,8 +301,3 @@
 .style-override.monaco-workbench .pane-composite-part.basepanel > .title > .composite-bar-container > .composite-bar > .monaco-action-bar .actions-container {
 	gap: 4px;
 }
-
-.style-override.monaco-workbench .pane-composite-part > .title.has-composite-bar > .title-actions .monaco-action-bar .action-item,
-.style-override.monaco-workbench .pane-composite-part > .title.has-composite-bar > .global-actions .monaco-action-bar .action-item {
-	margin-bottom: 4px;
-}
diff --git a/src/vs/workbench/contrib/styleOverrides/browser/media/padding.css b/src/vs/workbench/contrib/styleOverrides/browser/media/padding.css
index ee21b7b3594..1cd29609a15 100644
--- a/src/vs/workbench/contrib/styleOverrides/browser/media/padding.css
+++ b/src/vs/workbench/contrib/styleOverrides/browser/media/padding.css
@@ -45,16 +45,31 @@
 	width: auto;
 }
 
-/* Tighten the part title bar gutters: flush-left, small right inset. */
+/* Tighten the part title bar gutters: flush-left, small right inset. Reduce height from 35px to 32px.
+ * KEEP IN SYNC WITH: part.ts PartLayout.TITLE_HEIGHT_STYLE_OVERRIDE */
 .style-override.monaco-workbench .part > .title {
+	height: 32px;
 	padding-left: var(--vscode-spacing-size40, 4px);
 	padding-right: var(--vscode-spacing-size40, 4px);
 }
 
+.style-override.monaco-workbench .part > .title > .title-label {
+	line-height: 32px;
+}
+
+.style-override.monaco-workbench .part > .title > .title-actions {
+	height: 32px;
+}
+
 .style-override.monaco-workbench .part.editor > .content .editor-group-container > .title .editor-actions {
 	padding: 0 4px;
 }
 
+.style-override.monaco-workbench .part.editor > .content .editor-group-container > .title .editor-actions .actions-container > li:last-child,
+.style-override.monaco-workbench .part > .title .title-actions .actions-container > li:last-child {
+	margin-right: 0;
+}
+
 /* Inset the part title label (e.g. "Explorer") to align with the content below. */
 .style-override.monaco-workbench .part > .title > .title-label {
 	padding-left: var(--vscode-spacing-size80, 8px);
@@ -68,6 +83,16 @@
 	.agent-session-item .agent-session-title-toolbar .actions-container {
 		gap: 4px;
 	}
+	&.chat-view-location-auxiliarybar {
+		.chat-view-title-inner {
+			padding: var(--vscode-spacing-size40, 4px);
+		}
+	}
+	&.chat-view-location-sidebar, &.chat-view-location-panel {
+		.chat-view-title-inner {
+			padding: 0 var(--vscode-spacing-size40, 4px) 0 var(--vscode-spacing-size80, 8px);
+		}
+	}
 }
 
 .style-override.monaco-workbench .monaco-pane-view .pane > .pane-header > .actions {
@@ -92,5 +117,6 @@
 .style-override.monaco-workbench .part.basepanel.top .composite.title,
 .style-override.monaco-workbench .part.basepanel.left .composite.title,
 .style-override.monaco-workbench .part.basepanel.right .composite.title {
-	padding-right: 0;
+	padding-right: 2px;
 }
+