diff --git a/web/src/components/MemoActionMenu/MemoShareImageDialog.tsx b/web/src/components/MemoActionMenu/MemoShareImageDialog.tsx
index 3427a41de..6308e50f1 100644
--- a/web/src/components/MemoActionMenu/MemoShareImageDialog.tsx
+++ b/web/src/components/MemoActionMenu/MemoShareImageDialog.tsx
@@ -6,7 +6,13 @@ import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, D
 import { useTranslate } from "@/utils/i18n";
 import { useMemoViewContext } from "../MemoView/MemoViewContext";
 import MemoShareImagePreview from "./MemoShareImagePreview";
-import { buildMemoShareImageFileName, createMemoShareImageBlob, getMemoShareDialogWidth, getMemoSharePreviewWidth } from "./memoShareImage";
+import {
+  buildMemoShareImageFileName,
+  createMemoShareImageBlob,
+  getMemoShareDialogWidth,
+  getMemoSharePreviewWidth,
+  getMemoShareRenderWidth,
+} from "./memoShareImage";
 
 interface MemoShareImageDialogProps {
   open: boolean;
@@ -21,6 +27,7 @@ const MemoShareImageDialog = ({ open, onOpenChange }: MemoShareImageDialogProps)
 
   const previewWidth = useMemo(() => getMemoSharePreviewWidth(cardWidth), [cardWidth]);
   const dialogWidth = useMemo(() => getMemoShareDialogWidth(previewWidth), [previewWidth]);
+  const previewRenderWidth = useMemo(() => getMemoShareRenderWidth(previewWidth, dialogWidth), [dialogWidth, previewWidth]);
 
   const createShareBlob = useCallback(async () => {
     const preview = previewRef.current;
@@ -81,31 +88,47 @@ const MemoShareImageDialog = ({ open, onOpenChange }: MemoShareImageDialogProps)
 
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
-      <DialogContent size="full" className="md:w-auto md:max-w-none" style={{ width: `${dialogWidth}px` }}>
-        <DialogHeader>
-          <DialogTitle className="flex items-center gap-2">
-            <ImageIcon className="h-4 w-4" />
-            {t("memo.share.image-title")}
-          </DialogTitle>
-          <DialogDescription>{t("memo.share.image-description", { width: previewWidth })}</DialogDescription>
-        </DialogHeader>
+      <DialogContent
+        size="full"
+        className="min-h-0 overflow-hidden !gap-0 !p-0 md:w-auto md:max-w-none"
+        style={{ width: `${dialogWidth}px` }}
+      >
+        <div className="flex min-h-0 flex-1 flex-col overflow-hidden">
+          <DialogHeader className="shrink-0 border-b border-border/60 px-4 py-3 sm:px-5">
+            <DialogTitle className="flex items-center gap-2 text-base font-medium">
+              <ImageIcon className="h-4 w-4 text-muted-foreground" />
+              {t("memo.share.image-title")}
+            </DialogTitle>
+            <DialogDescription className="text-xs">{t("memo.share.image-description", { width: previewRenderWidth })}</DialogDescription>
+          </DialogHeader>
 
-        <div className="overflow-auto p-1 sm:p-2">
-          <MemoShareImagePreview ref={previewRef} width={previewWidth} />
-        </div>
+          <div className="relative flex min-h-0 flex-1 items-start justify-center overflow-auto bg-muted/20 px-4 py-3 sm:px-5 sm:py-4">
+            <MemoShareImagePreview ref={previewRef} width={previewRenderWidth} />
+          </div>
 
-        <DialogFooter>
-          {supportsNativeShare && (
-            <Button variant="outline" onClick={handleNativeShare} disabled={isRendering}>
-              {isRendering ? <Loader2Icon className="mr-2 h-4 w-4 animate-spin" /> : <Share2Icon className="mr-2 h-4 w-4" />}
-              {t("memo.share.image-share")}
+          <DialogFooter className="shrink-0 border-t border-border/60 px-4 py-3 sm:px-5">
+            {supportsNativeShare && (
+              <Button
+                variant="ghost"
+                className="text-muted-foreground hover:bg-muted/60 hover:text-foreground"
+                onClick={handleNativeShare}
+                disabled={isRendering}
+              >
+                {isRendering ? <Loader2Icon className="mr-2 h-4 w-4 animate-spin" /> : <Share2Icon className="mr-2 h-4 w-4" />}
+                {t("memo.share.image-share")}
+              </Button>
+            )}
+            <Button
+              variant="outline"
+              className="border-border/70 text-muted-foreground hover:bg-muted/60 hover:text-foreground"
+              onClick={handleDownload}
+              disabled={isRendering}
+            >
+              {isRendering ? <Loader2Icon className="mr-2 h-4 w-4 animate-spin" /> : <DownloadIcon className="mr-2 h-4 w-4" />}
+              {t("memo.share.image-download")}
             </Button>
-          )}
-          <Button onClick={handleDownload} disabled={isRendering}>
-            {isRendering ? <Loader2Icon className="mr-2 h-4 w-4 animate-spin" /> : <DownloadIcon className="mr-2 h-4 w-4" />}
-            {t("memo.share.image-download")}
-          </Button>
-        </DialogFooter>
+          </DialogFooter>
+        </div>
       </DialogContent>
     </Dialog>
   );
diff --git a/web/src/components/MemoActionMenu/MemoShareImagePreview.tsx b/web/src/components/MemoActionMenu/MemoShareImagePreview.tsx
index e86617cc3..4a6144dd0 100644
--- a/web/src/components/MemoActionMenu/MemoShareImagePreview.tsx
+++ b/web/src/components/MemoActionMenu/MemoShareImagePreview.tsx
@@ -34,18 +34,11 @@ const MemoShareImagePreview = forwardRef<HTMLDivElement, { width: number }>(({ w
   }, [memo.attachments]);
 
   return (
-    <div
-      ref={ref}
-      className="relative overflow-hidden rounded-[24px] border border-border/50 bg-linear-to-br from-background via-muted/15 to-background p-2.5 sm:p-3"
-      style={{ width }}
-    >
-      <div className="pointer-events-none absolute -top-16 right-0 h-32 w-32 rounded-full bg-sky-500/8 blur-3xl" />
-      <div className="pointer-events-none absolute -bottom-20 -left-10 h-36 w-36 rounded-full bg-amber-400/8 blur-3xl" />
-
-      <div className="relative overflow-hidden rounded-[20px] border border-border/60 bg-background/98 p-4 shadow-sm shadow-foreground/5 sm:p-5">
+    <div ref={ref} className="overflow-hidden rounded-xl border border-border/50 bg-background p-2 sm:p-2.5" style={{ width }}>
+      <div className="overflow-hidden rounded-lg border border-border/60 bg-background p-4 sm:p-5">
         <div className="flex items-start gap-3">
           <div className="flex min-w-0 items-center gap-2.5">
-            <UserAvatar avatarUrl={avatarUrl} className="h-9 w-9 rounded-2xl" />
+            <UserAvatar avatarUrl={avatarUrl} className="h-8 w-8 rounded-xl" />
             <div className="min-w-0">
               <div className="truncate text-[13px] font-semibold text-foreground">{displayName}</div>
               {formattedDisplayTime && <div className="truncate text-xs text-muted-foreground">{formattedDisplayTime}</div>}
@@ -65,7 +58,7 @@ const MemoShareImagePreview = forwardRef<HTMLDivElement, { width: number }>(({ w
               <div
                 key={item.id}
                 className={cn(
-                  "relative overflow-hidden rounded-[18px] border border-border/70 bg-muted/40",
+                  "relative overflow-hidden rounded-md border border-border/70 bg-muted/30",
                   visualItems.length === 1 ? "aspect-[4/3]" : "aspect-square",
                   visualItems.length === 3 && index === 0 && "col-span-2 aspect-[2.2/1]",
                 )}
diff --git a/web/src/components/MemoActionMenu/memoShareImage.ts b/web/src/components/MemoActionMenu/memoShareImage.ts
index 92b744d60..d239df1c5 100644
--- a/web/src/components/MemoActionMenu/memoShareImage.ts
+++ b/web/src/components/MemoActionMenu/memoShareImage.ts
@@ -1,6 +1,8 @@
 import { toBlob } from "html-to-image";
 
 const WINDOW_HORIZONTAL_MARGIN = 32;
+const PREVIEW_HORIZONTAL_PADDING_IN_DIALOG = 40;
+const PREVIEW_WIDTH_BOOST_IN_DIALOG = 48;
 
 export const MEMO_SHARE_IMAGE_CONFIG = {
   dialogExtraWidth: 80,
@@ -75,6 +77,11 @@ export const getMemoShareDialogWidth = (previewWidth: number) => {
   return Math.min(previewWidth + MEMO_SHARE_IMAGE_CONFIG.dialogExtraWidth, viewportWidth);
 };
 
+export const getMemoShareRenderWidth = (previewWidth: number, dialogWidth: number) => {
+  const maxRenderWidth = Math.max(MEMO_SHARE_IMAGE_CONFIG.minWidth, dialogWidth - PREVIEW_HORIZONTAL_PADDING_IN_DIALOG);
+  return clamp(previewWidth + PREVIEW_WIDTH_BOOST_IN_DIALOG, MEMO_SHARE_IMAGE_CONFIG.minWidth, maxRenderWidth);
+};
+
 export const getMemoSharePreviewAvatarUrl = (avatarUrl?: string) => (isExportableImageUrl(avatarUrl) ? avatarUrl : undefined);
 
 export const createMemoShareImageBlob = async (node: HTMLElement) => {
diff --git a/web/src/components/MemoDetailSidebar/MemoDetailSidebar.tsx b/web/src/components/MemoDetailSidebar/MemoDetailSidebar.tsx
index c944bca6b..585ba6d89 100644
--- a/web/src/components/MemoDetailSidebar/MemoDetailSidebar.tsx
+++ b/web/src/components/MemoDetailSidebar/MemoDetailSidebar.tsx
@@ -1,7 +1,7 @@
 import { create } from "@bufbuild/protobuf";
 import { timestampDate } from "@bufbuild/protobuf/wkt";
 import { isEqual } from "lodash-es";
-import { CheckCircleIcon, Code2Icon, HashIcon, ImageIcon, LinkIcon, type LucideIcon, Share2Icon } from "lucide-react";
+import { CheckCircleIcon, ChevronRightIcon, Code2Icon, HashIcon, ImageIcon, LinkIcon, type LucideIcon, Share2Icon } from "lucide-react";
 import { useMemo, useState } from "react";
 import { Button } from "@/components/ui/button";
 import useCurrentUser from "@/hooks/useCurrentUser";
@@ -40,6 +40,9 @@ const PROPERTY_BADGE_CLASSES =
 const TAG_BADGE_CLASSES =
   "inline-flex items-center gap-1 px-1 rounded-md border border-border/60 bg-muted/60 text-sm text-muted-foreground hover:bg-muted hover:text-foreground/80 transition-colors cursor-pointer";
 
+const SHARE_ACTION_ROW_CLASSES =
+  "h-auto min-h-0 w-full justify-between rounded-none px-2 py-1.5 text-xs font-normal leading-tight text-muted-foreground transition-colors hover:bg-muted/40 hover:text-muted-foreground focus-visible:ring-offset-0 gap-1.5";
+
 const MemoDetailSidebar = ({ memo, className, onShareImageOpen }: Props) => {
   const t = useTranslate();
   const currentUser = useCurrentUser();
@@ -67,17 +70,24 @@ const MemoDetailSidebar = ({ memo, className, onShareImageOpen }: Props) => {
 
       {(canManageShares || onShareImageOpen) && (
         <SidebarSection label={t("memo.share.section-label")}>
-          <div className="flex flex-col gap-2">
+          <div className="overflow-hidden rounded-md border border-border/50 bg-muted/20">
             {onShareImageOpen && (
-              <Button variant="outline" className="w-full justify-start gap-2" onClick={onShareImageOpen}>
-                <ImageIcon className="w-4 h-4" />
-                {t("memo.share.open-image")}
+              <Button variant="ghost" size="sm" className={SHARE_ACTION_ROW_CLASSES} onClick={onShareImageOpen}>
+                <span className="flex min-w-0 flex-1 items-center gap-2">
+                  <ImageIcon className="size-3.5 shrink-0 text-muted-foreground/90" />
+                  <span className="truncate">{t("memo.share.open-image")}</span>
+                </span>
+                <ChevronRightIcon className="size-3.5 shrink-0 text-muted-foreground/35" />
               </Button>
             )}
+            {onShareImageOpen && canManageShares && <div className="border-t border-border/50" />}
             {canManageShares && (
-              <Button variant="outline" className="w-full justify-start gap-2" onClick={() => setSharePanelOpen(true)}>
-                <Share2Icon className="w-4 h-4" />
-                {t("memo.share.open-panel")}
+              <Button variant="ghost" size="sm" className={SHARE_ACTION_ROW_CLASSES} onClick={() => setSharePanelOpen(true)}>
+                <span className="flex min-w-0 flex-1 items-center gap-2">
+                  <Share2Icon className="size-3.5 shrink-0 text-muted-foreground/90" />
+                  <span className="truncate">{t("memo.share.open-panel")}</span>
+                </span>
+                <ChevronRightIcon className="size-3.5 shrink-0 text-muted-foreground/35" />
               </Button>
             )}
           </div>