diff --git a/src/modules/blocks/RenderHtml.tsx b/src/modules/blocks/RenderHtml.tsx
index ce32a428b..672b9e169 100644
--- a/src/modules/blocks/RenderHtml.tsx
+++ b/src/modules/blocks/RenderHtml.tsx
@@ -1,14 +1,14 @@
 import * as React from 'react';
 
 import type { SxProps } from '@mui/joy/styles/types';
-import { Box, Button, IconButton, Tooltip, Typography } from '@mui/joy';
+import { Box, Button, Tooltip, Typography } from '@mui/joy';
 import ContentCopyIcon from '@mui/icons-material/ContentCopy';
 import WebIcon from '@mui/icons-material/Web';
 
 import { copyToClipboard } from '~/common/util/clipboardUtils';
 
 import type { HtmlBlock } from './blocks';
-import { overlayButtonsSx } from './code/RenderCode';
+import { OverlayButton, overlayButtonsSx } from './code/RenderCode';
 
 
 // this is used by the blocks parser (for full text detection) and by the Code component (for inline rendering)
@@ -99,14 +99,14 @@ export function RenderHtml(props: { htmlBlock: HtmlBlock, sx?: SxProps }) {
         {/* External HTML Buttons */}
         <Box className='overlay-buttons' sx={{ ...overlayButtonsSx, p: 1.5 }}>
           <Tooltip title={showHTML ? 'Hide' : 'Show Web Page'} variant='solid'>
-            <IconButton variant={showHTML ? 'solid' : 'outlined'} color='danger' onClick={() => setShowHTML(!showHTML)}>
+            <OverlayButton variant={showHTML ? 'solid' : 'outlined'} color='danger' onClick={() => setShowHTML(!showHTML)}>
               <WebIcon />
-            </IconButton>
+            </OverlayButton>
           </Tooltip>
           <Tooltip title='Copy Code' variant='solid'>
-            <IconButton variant='outlined' onClick={handleCopyToClipboard}>
+            <OverlayButton variant='outlined' onClick={handleCopyToClipboard}>
               <ContentCopyIcon />
-            </IconButton>
+            </OverlayButton>
           </Tooltip>
         </Box>
 
diff --git a/src/modules/blocks/RenderImage.tsx b/src/modules/blocks/RenderImage.tsx
index a52d313be..f6f4927a1 100644
--- a/src/modules/blocks/RenderImage.tsx
+++ b/src/modules/blocks/RenderImage.tsx
@@ -12,7 +12,7 @@ import { GoodTooltip } from '~/common/components/GoodTooltip';
 import { Link } from '~/common/components/Link';
 
 import type { ImageBlock } from './blocks';
-import { overlayButtonsSx } from './code/RenderCode';
+import { OverlayButton, overlayButtonsSx } from './code/RenderCode';
 
 
 const mdImageReferenceRegex = /^!\[([^\]]*)]\(([^)]+)\)$/;
@@ -128,24 +128,24 @@ export const RenderImage = (props: {
         <Box className='overlay-buttons' sx={{ ...overlayButtonsSx, pt: 0.5, px: 0.5, gap: 0.5 }}>
           {!!props.onRunAgain && (
             <GoodTooltip title='Draw again'>
-              <IconButton variant='outlined' onClick={props.onRunAgain}>
+              <OverlayButton variant='outlined' onClick={props.onRunAgain}>
                 <ReplayIcon />
-              </IconButton>
+              </OverlayButton>
             </GoodTooltip>
           )}
 
           {!!alt && (
             <GoodTooltip title={infoOpen ? 'Hide Prompt' : 'Show Prompt'}>
-              <IconButton variant={infoOpen ? 'solid' : 'soft'} onClick={() => setInfoOpen(open => !open)}>
+              <OverlayButton variant={infoOpen ? 'solid' : 'outlined'} onClick={() => setInfoOpen(open => !open)}>
                 <InfoOutlinedIcon />
-              </IconButton>
+              </OverlayButton>
             </GoodTooltip>
           )}
 
           <GoodTooltip title='Open in new tab'>
-            <IconButton variant='soft' component={Link} href={url} download={alt || 'image'} target='_blank'>
+            <OverlayButton variant='outlined' component={Link} href={url} download={alt || 'image'} target='_blank'>
               <OpenInNewIcon />
-            </IconButton>
+            </OverlayButton>
           </GoodTooltip>
         </Box>
       </Sheet>
diff --git a/src/modules/blocks/code/ButtonCodePen.tsx b/src/modules/blocks/code/ButtonCodePen.tsx
index e591786ea..69310bf07 100644
--- a/src/modules/blocks/code/ButtonCodePen.tsx
+++ b/src/modules/blocks/code/ButtonCodePen.tsx
@@ -1,11 +1,13 @@
 import * as React from 'react';
 
-import { IconButton, Tooltip } from '@mui/joy';
+import { Tooltip } from '@mui/joy';
 
 import { Brand } from '~/common/app.config';
 import { CodePenIcon } from '~/common/components/icons/3rdparty/CodePenIcon';
 import { prettyTimestampForFilenames } from '~/common/util/timeUtils';
 
+import { OverlayButton } from './RenderCode';
+
 
 // CodePen is a web-based HTML, CSS, and JavaScript code editor
 const _languages = ['html', 'css', 'javascript', 'json', 'typescript'];
@@ -48,9 +50,9 @@ const handleOpenInCodePen = (code: string, language: string) => {
 export function ButtonCodePen(props: { code: string, language: string }): React.JSX.Element {
   return (
     <Tooltip title='Open in CodePen' variant='solid'>
-      <IconButton variant='outlined' color='neutral' onClick={() => handleOpenInCodePen(props.code, props.language)}>
+      <OverlayButton variant='outlined' onClick={() => handleOpenInCodePen(props.code, props.language)}>
         <CodePenIcon />
-      </IconButton>
+      </OverlayButton>
     </Tooltip>
   );
 }
\ No newline at end of file
diff --git a/src/modules/blocks/code/ButtonJSFiddle.tsx b/src/modules/blocks/code/ButtonJSFiddle.tsx
index f55e1aa45..9119d943a 100644
--- a/src/modules/blocks/code/ButtonJSFiddle.tsx
+++ b/src/modules/blocks/code/ButtonJSFiddle.tsx
@@ -1,6 +1,8 @@
 import * as React from 'react';
 
-import { IconButton, Tooltip } from '@mui/joy';
+import { Tooltip } from '@mui/joy';
+
+import { OverlayButton } from './RenderCode';
 
 
 // JSFiidle is a web-based HTML, CSS, and JavaScript code editor
@@ -49,9 +51,9 @@ const handleOpenInJsFiddle = (code: string, language: string) => {
 export function ButtonJsFiddle(props: { code: string, language: string }): React.JSX.Element {
   return (
     <Tooltip title='Open in JSFiddle' variant='solid'>
-      <IconButton onClick={() => handleOpenInJsFiddle(props.code, props.language)}>
+      <OverlayButton variant='outlined' onClick={() => handleOpenInJsFiddle(props.code, props.language)}>
         JS
-      </IconButton>
+      </OverlayButton>
     </Tooltip>
   );
 }
\ No newline at end of file
diff --git a/src/modules/blocks/code/ButtonStackBlitz.tsx b/src/modules/blocks/code/ButtonStackBlitz.tsx
index 7ad30a4d7..6b88c8c61 100644
--- a/src/modules/blocks/code/ButtonStackBlitz.tsx
+++ b/src/modules/blocks/code/ButtonStackBlitz.tsx
@@ -1,11 +1,13 @@
 import * as React from 'react';
 
-import { IconButton, Tooltip } from '@mui/joy';
+import { Tooltip } from '@mui/joy';
 
 import { Brand } from '~/common/app.config';
 import { StackBlitzIcon } from '~/common/components/icons/3rdparty/StackBlitzIcon';
 import { prettyTimestampForFilenames } from '~/common/util/timeUtils';
 
+import { OverlayButton } from './RenderCode';
+
 
 const _languages = [
   'typescript',
@@ -77,9 +79,9 @@ const handleOpenInStackBlitz = (code: string, language: string, title?: string)
 export function ButtonStackBlitz(props: { code: string, language: string, title?: string }): React.JSX.Element {
   return (
     <Tooltip title='Open in StackBlitz' variant='solid'>
-      <IconButton variant='outlined' color='neutral' onClick={() => handleOpenInStackBlitz(props.code, props.language, props.title)}>
+      <OverlayButton variant='outlined' onClick={() => handleOpenInStackBlitz(props.code, props.language, props.title)}>
         <StackBlitzIcon />
-      </IconButton>
+      </OverlayButton>
     </Tooltip>
   );
 }
diff --git a/src/modules/blocks/code/RenderCode.tsx b/src/modules/blocks/code/RenderCode.tsx
index 896056657..7a9a34aec 100644
--- a/src/modules/blocks/code/RenderCode.tsx
+++ b/src/modules/blocks/code/RenderCode.tsx
@@ -2,7 +2,7 @@ import * as React from 'react';
 import { useQuery } from '@tanstack/react-query';
 
 import type { SxProps } from '@mui/joy/styles/types';
-import { Box, ButtonGroup, IconButton, Sheet, Tooltip, Typography } from '@mui/joy';
+import { Box, ButtonGroup, IconButton, Sheet, styled, Tooltip, Typography } from '@mui/joy';
 import ContentCopyIcon from '@mui/icons-material/ContentCopy';
 import FitScreenIcon from '@mui/icons-material/FitScreen';
 import HtmlIcon from '@mui/icons-material/Html';
@@ -19,11 +19,13 @@ import { ButtonStackBlitz, isStackBlitzSupported } from './ButtonStackBlitz';
 import { heuristicIsHtml, IFrameComponent } from '../RenderHtml';
 import { patchSvgString, RenderCodeMermaid } from './RenderCodeMermaid';
 
+
 export function getPlantUmlServerUrl(): string {
   // set at nextjs build time
   return process.env.NEXT_PUBLIC_PLANTUML_SERVER_URL || 'https://www.plantuml.com/plantuml/svg/';
 }
 
+
 async function fetchPlantUmlSvg(plantUmlCode: string): Promise<string | null> {
   // Get the PlantUML server from inline env var
   let plantUmlServerUrl = getPlantUmlServerUrl();
@@ -64,13 +66,19 @@ async function fetchPlantUmlSvg(plantUmlCode: string): Promise<string | null> {
 }
 
 
+export const OverlayButton = styled(IconButton)(({ theme, variant }) => ({
+  backgroundColor: variant === 'outlined' ? theme.palette.background.surface : undefined,
+  '--Icon-fontSize': theme.fontSize.lg,
+})) as typeof IconButton;
+
+
 export const overlayButtonsSx: SxProps = {
   position: 'absolute', top: 0, right: 0, zIndex: 2, /* top of message and its chips */
   display: 'flex', flexDirection: 'row', gap: 1,
   opacity: 0, transition: 'opacity 0.2s cubic-bezier(.17,.84,.44,1)',
   // buttongroup: background
   '& > div > button': {
-    backgroundColor: 'background.surface',
+    // backgroundColor: 'background.surface',
     // backdropFilter: 'blur(12px)',
   },
 };
@@ -206,53 +214,63 @@ function RenderCodeImpl(props: RenderCodeImplProps) {
 
         {/* Buttons */}
         <Box className='overlay-buttons' sx={{ ...overlayButtonsSx, p: 0.5 }}>
+          {/* Show HTML */}
           {isHTML && (
             <Tooltip title={optimizeLightweight ? null : renderHTML ? 'Hide' : 'Show Web Page'}>
-              <IconButton variant={renderHTML ? 'solid' : 'soft'} color='danger' onClick={() => setShowHTML(!showHTML)}>
-                <HtmlIcon />
-              </IconButton>
-            </Tooltip>
-          )}
-          {isMermaid && (
-            <Tooltip title={optimizeLightweight ? null : renderMermaid ? 'Show Code' : 'Render Mermaid'}>
-              <IconButton variant={renderMermaid ? 'solid' : 'soft'} onClick={() => setShowMermaid(!showMermaid)}>
-                <SchemaIcon />
-              </IconButton>
-            </Tooltip>
-          )}
-          {isPlantUML && (
-            <Tooltip title={optimizeLightweight ? null : renderPlantUML ? 'Show Code' : 'Render PlantUML'}>
-              <IconButton variant={renderPlantUML ? 'solid' : 'soft'} onClick={() => setShowPlantUML(!showPlantUML)}>
-                <SchemaIcon />
-              </IconButton>
+              <OverlayButton variant={renderHTML ? 'solid' : 'outlined'} color='danger' onClick={() => setShowHTML(!showHTML)}>
+                <HtmlIcon sx={{ fontSize: 'xl2' }} />
+              </OverlayButton>
             </Tooltip>
           )}
+
+          {/* Show SVG */}
           {isSVG && (
             <Tooltip title={optimizeLightweight ? null : renderSVG ? 'Show Code' : 'Render SVG'}>
-              <IconButton variant={renderSVG ? 'solid' : 'soft'} onClick={() => setShowSVG(!showSVG)}>
+              <OverlayButton variant={renderSVG ? 'solid' : 'outlined'} onClick={() => setShowSVG(!showSVG)}>
                 <ShapeLineOutlinedIcon />
-              </IconButton>
+              </OverlayButton>
             </Tooltip>
           )}
-          {((isMermaid && showMermaid) || (isPlantUML && showPlantUML && !plantUmlError) || (isSVG && showSVG && canScaleSVG)) && (
-            <Tooltip title={optimizeLightweight ? null : fitScreen ? 'Original Size' : 'Fit Screen'}>
-              <IconButton variant={fitScreen ? 'solid' : 'soft'} onClick={() => setFitScreen(on => !on)}>
-                <FitScreenIcon />
-              </IconButton>
-            </Tooltip>
+
+          {/* Show Diagrams */}
+          {(isMermaid || isPlantUML) && (
+            <ButtonGroup aria-label='Diagram'>
+              {/* Toggle rendering */}
+              <Tooltip title={optimizeLightweight ? null : (renderMermaid || renderPlantUML) ? 'Show Code' : 'Render Mermaid'}>
+                <OverlayButton variant={(renderMermaid || renderPlantUML) ? 'solid' : 'outlined'} onClick={() => {
+                  if (isMermaid) setShowMermaid(on => !on);
+                  if (isPlantUML) setShowPlantUML(on => !on);
+                }}>
+                  <SchemaIcon />
+                </OverlayButton>
+              </Tooltip>
+
+              {/* Fit-To-Screen */}
+              {((isMermaid && showMermaid) || (isPlantUML && showPlantUML && !plantUmlError) || (isSVG && showSVG && canScaleSVG)) && (
+                <Tooltip title={optimizeLightweight ? null : fitScreen ? 'Original Size' : 'Fit Screen'}>
+                  <OverlayButton variant={fitScreen ? 'solid' : 'outlined'} onClick={() => setFitScreen(on => !on)}>
+                    <FitScreenIcon />
+                  </OverlayButton>
+                </Tooltip>
+              )}
+            </ButtonGroup>
           )}
+
+          {/* New Code Window Buttons */}
           {(canJSFiddle || canCodePen || canStackBlitz) && (
-            <ButtonGroup aria-label='Open code in external editors' sx={{ cornerRadius: 'md' }}>
+            <ButtonGroup aria-label='Open code in external editors'>
               {canJSFiddle && <ButtonJsFiddle code={blockCode} language={inferredCodeLanguage!} />}
               {canCodePen && <ButtonCodePen code={blockCode} language={inferredCodeLanguage!} />}
               {canStackBlitz && <ButtonStackBlitz code={blockCode} title={blockTitle} language={inferredCodeLanguage!} />}
             </ButtonGroup>
           )}
+
+          {/* Copy */}
           {props.noCopyButton !== true && (
             <Tooltip title={optimizeLightweight ? null : 'Copy Code'}>
-              <IconButton variant='soft' onClick={handleCopyToClipboard}>
+              <OverlayButton variant='outlined' onClick={handleCopyToClipboard}>
                 <ContentCopyIcon />
-              </IconButton>
+              </OverlayButton>
             </Tooltip>
           )}
         </Box>