diff --git a/packages/app/src/agent-stream/view.tsx b/packages/app/src/agent-stream/view.tsx
index 58174eae19..d5e5e5d479 100644
--- a/packages/app/src/agent-stream/view.tsx
+++ b/packages/app/src/agent-stream/view.tsx
@@ -63,6 +63,7 @@ import {
   prepareToolCallHistory,
   projectToolCallDetailLevel,
 } from "@/tool-calls/detail-level/projection";
+import { formatThinkingText } from "@/utils/thinking-text-formatter";
 import { OverviewToolCallGroupView } from "@/tool-calls/detail-level/overview/view";
 import { type AgentStreamRenderModel, buildAgentStreamRenderModel } from "./model";
 import { resolveStreamRenderStrategy } from "./strategy-resolver";
@@ -661,22 +662,42 @@ const AgentStreamViewComponent = forwardRef<AgentStreamViewHandle, AgentStreamVi
       [agentId, client, handleInlinePathPress, resolvedServerId, toast, workspaceRoot],
     );
 
+    const latestThoughtId = useMemo(() => {
+      const head = projectedToolCalls.head;
+      for (let i = head.length - 1; i >= 0; i -= 1) {
+        if (head[i]?.kind === "thought") {
+          return head[i]?.id ?? null;
+        }
+      }
+      const tail = projectedToolCalls.tail;
+      for (let i = tail.length - 1; i >= 0; i -= 1) {
+        if (tail[i]?.kind === "thought") {
+          return tail[i]?.id ?? null;
+        }
+      }
+      return null;
+    }, [projectedToolCalls.head, projectedToolCalls.tail]);
+
     const renderThoughtItem = useCallback(
       (layoutItem: StreamLayoutItem, item: Extract<StreamItem, { kind: "thought" }>) => {
+        const isLastThought = item.id === latestThoughtId;
+        const isExpanded =
+          autoExpandReasoning === "expanded" ||
+          (autoExpandReasoning === "expand_last" && isLastThought);
         return (
           <ToolCallSlot
             itemId={item.id}
             onInlineDetailsExpandedChangeByItemId={setInlineDetailsExpanded}
             toolName="thinking"
-            args={item.text}
+            args={formatThinkingText(item.text)}
             status={item.status === "ready" ? "completed" : "executing"}
             isLastInSequence={layoutItem.isLastInToolSequence}
-            defaultExpanded={autoExpandReasoning}
-            forceInline={autoExpandReasoning}
+            defaultExpanded={isExpanded}
+            forceInline={isExpanded}
           />
         );
       },
-      [autoExpandReasoning, setInlineDetailsExpanded],
+      [autoExpandReasoning, latestThoughtId, setInlineDetailsExpanded],
     );
 
     const renderSingleToolCallItem = useCallback(
diff --git a/packages/app/src/components/message.tsx b/packages/app/src/components/message.tsx
index 8058320f99..dc032c44fb 100644
--- a/packages/app/src/components/message.tsx
+++ b/packages/app/src/components/message.tsx
@@ -3061,6 +3061,11 @@ export const ToolCall = memo(function ToolCall({
 }: ToolCallProps) {
   const { openToolCall } = useToolCallSheet();
   const [isExpanded, setIsExpanded] = useState(defaultExpanded ?? false);
+  const [prevDefaultExpanded, setPrevDefaultExpanded] = useState(defaultExpanded);
+  if (prevDefaultExpanded !== defaultExpanded) {
+    setPrevDefaultExpanded(defaultExpanded);
+    setIsExpanded(defaultExpanded ?? false);
+  }
 
   const isMobile = useIsCompactFormFactor();
   const shouldRenderInline = !isMobile || forceInline;
diff --git a/packages/app/src/components/tool-call-details.tsx b/packages/app/src/components/tool-call-details.tsx
index 41006c4f2e..988f2ea185 100644
--- a/packages/app/src/components/tool-call-details.tsx
+++ b/packages/app/src/components/tool-call-details.tsx
@@ -1,8 +1,10 @@
-import React, { useMemo, type ReactNode } from "react";
+import React, { useCallback, useMemo, useRef, type ReactNode } from "react";
 import {
   View,
   Text,
   ScrollView as RNScrollView,
+  type NativeScrollEvent,
+  type NativeSyntheticEvent,
   type StyleProp,
   type ViewStyle,
 } from "react-native";
@@ -21,6 +23,8 @@ import { HighlightedLines } from "./highlighted-content";
 import { DiffViewer } from "./diff-viewer";
 import { getCodeInsets } from "./code-insets";
 import { isWeb } from "@/constants/platform";
+import { formatThinkingText } from "@/utils/thinking-text-formatter";
+import { MarkdownRenderer } from "./markdown/renderer";
 
 const ScrollView = isWeb ? RNScrollView : GHScrollView;
 
@@ -490,13 +494,34 @@ function FetchDetailSection({ url, result, ds }: FetchDetailProps) {
 }
 
 function ScrollablePlainTextSection({ text, ds }: { text: string; ds: DetailStyles }) {
+  const scrollRef = useRef<RNScrollView | GHScrollView | null>(null);
+  const isNearBottomRef = useRef(true);
+
+  const handleScroll = useCallback((event: NativeSyntheticEvent<NativeScrollEvent>) => {
+    const { layoutMeasurement, contentOffset, contentSize } = event.nativeEvent;
+    const paddingToBottom = 32;
+    const isBottom =
+      layoutMeasurement.height + contentOffset.y >= contentSize.height - paddingToBottom;
+    isNearBottomRef.current = isBottom;
+  }, []);
+
+  const handleContentSizeChange = useCallback(() => {
+    if (isNearBottomRef.current) {
+      scrollRef.current?.scrollToEnd({ animated: false });
+    }
+  }, []);
+
   return (
     <View style={styles.section}>
       <ScrollView
+        ref={scrollRef as never}
         style={ds.scrollAreaStyle}
         contentContainerStyle={styles.scrollContent}
         nestedScrollEnabled
         showsVerticalScrollIndicator
+        onScroll={handleScroll}
+        scrollEventThrottle={16}
+        onContentSizeChange={handleContentSizeChange}
       >
         <Text selectable style={styles.plainText}>
           {text}
@@ -506,6 +531,42 @@ function ScrollablePlainTextSection({ text, ds }: { text: string; ds: DetailStyl
   );
 }
 
+function ScrollableMarkdownSection({ text, ds }: { text: string; ds: DetailStyles }) {
+  const scrollRef = useRef<RNScrollView | GHScrollView | null>(null);
+  const isNearBottomRef = useRef(true);
+
+  const handleScroll = useCallback((event: NativeSyntheticEvent<NativeScrollEvent>) => {
+    const { layoutMeasurement, contentOffset, contentSize } = event.nativeEvent;
+    const paddingToBottom = 32;
+    const isBottom =
+      layoutMeasurement.height + contentOffset.y >= contentSize.height - paddingToBottom;
+    isNearBottomRef.current = isBottom;
+  }, []);
+
+  const handleContentSizeChange = useCallback(() => {
+    if (isNearBottomRef.current) {
+      scrollRef.current?.scrollToEnd({ animated: false });
+    }
+  }, []);
+
+  return (
+    <View style={styles.section}>
+      <ScrollView
+        ref={scrollRef as never}
+        style={ds.scrollAreaStyle}
+        contentContainerStyle={styles.scrollContent}
+        nestedScrollEnabled
+        showsVerticalScrollIndicator
+        onScroll={handleScroll}
+        scrollEventThrottle={16}
+        onContentSizeChange={handleContentSizeChange}
+      >
+        <MarkdownRenderer text={text} compact enableHtmlish={false} />
+      </ScrollView>
+    </View>
+  );
+}
+
 interface SearchDetail {
   query?: string;
   content?: string;
@@ -582,7 +643,13 @@ function buildUnknownSections(detail: UnknownDetail, ds: DetailStyles, t: TFunct
     typeof detail.input === "string" && detail.output === null ? detail.input : null;
 
   if (plainInputText !== null) {
-    return [<ScrollablePlainTextSection key="unknown-plain-text" text={plainInputText} ds={ds} />];
+    return [
+      <ScrollableMarkdownSection
+        key="unknown-markdown-text"
+        text={formatThinkingText(plainInputText)}
+        ds={ds}
+      />,
+    ];
   }
 
   const sectionsFromTopLevel = [
diff --git a/packages/app/src/hooks/use-settings/storage.test.ts b/packages/app/src/hooks/use-settings/storage.test.ts
index 87fdd300f1..fa34d4a8d8 100644
--- a/packages/app/src/hooks/use-settings/storage.test.ts
+++ b/packages/app/src/hooks/use-settings/storage.test.ts
@@ -385,6 +385,50 @@ describe("appearance settings", () => {
     expect(result.toolCallDetailLevel).toBe("detailed");
   });
 
+  it("loads thinking display detail enum values or migrates legacy boolean values", async () => {
+    const depsTrue = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: true }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsTrue)).autoExpandReasoning).toBe("expanded");
+
+    const depsFalse = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: false }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsFalse)).autoExpandReasoning).toBe("collapsed");
+
+    const depsActive = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: "expand_active" }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsActive)).autoExpandReasoning).toBe("expand_last");
+
+    const depsLast = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: "expand_last" }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsLast)).autoExpandReasoning).toBe("expand_last");
+
+    const depsExpanded = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: "expanded" }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsExpanded)).autoExpandReasoning).toBe("expanded");
+
+    const depsInvalid = makeDeps({
+      storage: createInMemoryKeyValueStorage({
+        [APP_SETTINGS_KEY]: JSON.stringify({ autoExpandReasoning: "invalid" }),
+      }),
+    });
+    expect((await loadAppSettingsFromStorage(depsInvalid)).autoExpandReasoning).toBe("collapsed");
+  });
+
   it("migrates the enabled compact tool call preference to overview", async () => {
     const deps = makeDeps({
       storage: createInMemoryKeyValueStorage({
diff --git a/packages/app/src/hooks/use-settings/storage.ts b/packages/app/src/hooks/use-settings/storage.ts
index 0b7a733de0..30c09b074b 100644
--- a/packages/app/src/hooks/use-settings/storage.ts
+++ b/packages/app/src/hooks/use-settings/storage.ts
@@ -27,6 +27,7 @@ export type ServiceUrlBehavior = "ask" | "in-app" | "external";
 export type WorkspaceTitleSource = "title" | "branch";
 /** What a sidebar workspace row shows in the space to the right of its title. */
 export type SidebarWorkspaceTrailing = "diff" | "timestamp" | "none";
+export type ThinkingDisplayDetail = "collapsed" | "expand_last" | "expanded";
 export type ToolCallDetailLevel = "overview" | "detailed";
 
 const VALID_THEMES = new Set<string>(THEME_OPTIONS.map((option) => option.name));
@@ -39,6 +40,11 @@ const VALID_SIDEBAR_WORKSPACE_TRAILINGS = new Set<SidebarWorkspaceTrailing>([
   "none",
 ]);
 const VALID_TOOL_CALL_DETAIL_LEVELS = new Set<ToolCallDetailLevel>(["overview", "detailed"]);
+const VALID_THINKING_DISPLAY_DETAILS = new Set<ThinkingDisplayDetail>([
+  "collapsed",
+  "expand_last",
+  "expanded",
+]);
 export const DEFAULT_TERMINAL_SCROLLBACK_LINES = 10_000;
 export const MIN_TERMINAL_SCROLLBACK_LINES = 0;
 export const MAX_TERMINAL_SCROLLBACK_LINES = 1_000_000;
@@ -66,7 +72,7 @@ export interface AppSettings {
   sidebarWorkspaceTrailing: SidebarWorkspaceTrailing;
   sidebarRowItems: SidebarRowItems;
   sidebarChecksDisplay: SidebarChecksDisplay;
-  autoExpandReasoning: boolean;
+  autoExpandReasoning: ThinkingDisplayDetail;
   toolCallDetailLevel: ToolCallDetailLevel;
   chatOutlineEnabled: boolean;
   vimKeybindings: boolean;
@@ -103,7 +109,9 @@ const StoredAppSettingsSchema = z.strictObject({
   sidebarWorkspaceTrailing: z.enum(["diff", "timestamp", "none"]).optional(),
   sidebarRowItems: SidebarRowItemsSchema.optional(),
   sidebarChecksDisplay: z.enum(["iconAndText", "icon", "none"]).optional(),
-  autoExpandReasoning: z.boolean().optional(),
+  autoExpandReasoning: z
+    .union([z.enum(["collapsed", "expand_last", "expand_active", "expanded"]), z.boolean()])
+    .optional(),
   toolCallDetailLevel: z.enum(["overview", "detailed"]).optional(),
   compactToolCalls: z.boolean().optional(),
   chatOutlineEnabled: z.boolean().optional(),
@@ -133,7 +141,7 @@ export const DEFAULT_CLIENT_SETTINGS: AppSettings = {
   sidebarWorkspaceTrailing: "diff",
   sidebarRowItems: DEFAULT_SIDEBAR_ROW_ITEMS,
   sidebarChecksDisplay: DEFAULT_SIDEBAR_CHECKS_DISPLAY,
-  autoExpandReasoning: false,
+  autoExpandReasoning: "collapsed",
   toolCallDetailLevel: "detailed",
   chatOutlineEnabled: true,
   vimKeybindings: false,
@@ -242,6 +250,25 @@ export function normalizeAppSettings(value: unknown): AppSettings {
   };
 }
 
+function parseThinkingDisplayDetail(stored: StoredAppSettings): ThinkingDisplayDetail | null {
+  if (stored.autoExpandReasoning !== undefined) {
+    if (stored.autoExpandReasoning === "expand_active") {
+      // COMPAT(autoExpandReasoningExpandActive): migrated to expand_last in v0.4.0.
+      return "expand_last";
+    }
+    if (
+      typeof stored.autoExpandReasoning === "string" &&
+      VALID_THINKING_DISPLAY_DETAILS.has(stored.autoExpandReasoning as ThinkingDisplayDetail)
+    ) {
+      return stored.autoExpandReasoning as ThinkingDisplayDetail;
+    }
+    if (typeof stored.autoExpandReasoning === "boolean") {
+      return stored.autoExpandReasoning ? "expanded" : "collapsed";
+    }
+  }
+  return null;
+}
+
 function parseToolCallDetailLevel(stored: StoredAppSettings): ToolCallDetailLevel | null {
   if (stored.toolCallDetailLevel !== undefined) {
     if (
@@ -362,8 +389,9 @@ function pickAppSettings(stored: StoredAppSettings): Partial<AppSettings> {
     result.codeFontSize = codeFontSize;
   }
   Object.assign(result, pickBooleanAppSettings(stored));
-  if (typeof stored.autoExpandReasoning === "boolean") {
-    result.autoExpandReasoning = stored.autoExpandReasoning;
+  const thinkingDisplayDetail = parseThinkingDisplayDetail(stored);
+  if (thinkingDisplayDetail !== null) {
+    result.autoExpandReasoning = thinkingDisplayDetail;
   }
   const toolCallDetailLevel = parseToolCallDetailLevel(stored);
   if (toolCallDetailLevel !== null) {
diff --git a/packages/app/src/i18n/resources/ar.ts b/packages/app/src/i18n/resources/ar.ts
index 9236429686..eeb163a45c 100644
--- a/packages/app/src/i18n/resources/ar.ts
+++ b/packages/app/src/i18n/resources/ar.ts
@@ -1845,8 +1845,14 @@ export const ar: TranslationResources = {
         accessibilityLabel: "خطوط التمرير Terminal",
       },
       autoExpandReasoning: {
-        label: "عرض التفكير دائماً",
-        description: "إظهار تفكير الوكيل وخطوات الاستدلال بشكل كامل بشكل افتراضي",
+        label: "عرض التفكير",
+        description: "كيفية ظهور كتل التفكير في المخطط الزمني",
+        accessibilityLabel: "تحديد عرض التفكير ({{value}})",
+        options: {
+          collapsed: "مطوي",
+          expandLast: "توسيع الأخير",
+          expanded: "توسيع دائماً",
+        },
       },
       toolCallDetail: {
         label: "عرض استدعاءات الأدوات",
diff --git a/packages/app/src/i18n/resources/en.ts b/packages/app/src/i18n/resources/en.ts
index c12ab440de..3440e70a09 100644
--- a/packages/app/src/i18n/resources/en.ts
+++ b/packages/app/src/i18n/resources/en.ts
@@ -1900,8 +1900,14 @@ export const en = {
         accessibilityLabel: "Terminal scrollback lines",
       },
       autoExpandReasoning: {
-        label: "Always expand reasoning",
-        description: "Show agent thinking and chain-of-thought blocks fully expanded by default",
+        label: "Thinking display",
+        description: "How agent thinking and chain-of-thought blocks appear in the timeline",
+        accessibilityLabel: "Select thinking display ({{value}})",
+        options: {
+          collapsed: "Collapsed",
+          expandLast: "Expand Last",
+          expanded: "Always expand",
+        },
       },
       toolCallDetail: {
         label: "Tool call display",
diff --git a/packages/app/src/i18n/resources/es.ts b/packages/app/src/i18n/resources/es.ts
index f28516005a..d4afc44a9e 100644
--- a/packages/app/src/i18n/resources/es.ts
+++ b/packages/app/src/i18n/resources/es.ts
@@ -1891,9 +1891,14 @@ export const es: TranslationResources = {
         accessibilityLabel: "Líneas del historial de terminal",
       },
       autoExpandReasoning: {
-        label: "Siempre expandir razonamiento",
-        description:
-          "Mostrar los bloques de pensamiento y razonamiento del agente totalmente expandidos de forma predeterminada",
+        label: "Visualización de pensamiento",
+        description: "Cómo aparecen los bloques de pensamiento del agente en la cronología",
+        accessibilityLabel: "Seleccionar visualización de pensamiento ({{value}})",
+        options: {
+          collapsed: "Plegado",
+          expandLast: "Expandir último",
+          expanded: "Expandir siempre",
+        },
       },
       toolCallDetail: {
         label: "Visualización de llamadas a herramientas",
diff --git a/packages/app/src/i18n/resources/fr.ts b/packages/app/src/i18n/resources/fr.ts
index 0bda488b2a..d4ae5129ac 100644
--- a/packages/app/src/i18n/resources/fr.ts
+++ b/packages/app/src/i18n/resources/fr.ts
@@ -1894,8 +1894,14 @@ export const fr: TranslationResources = {
         accessibilityLabel: "Lignes de défilementTerminal",
       },
       autoExpandReasoning: {
-        label: "Toujours afficher le raisonnement",
-        description: "Afficher le raisonnement de l'agent entièrement développé par défaut",
+        label: "Affichage de la réflexion",
+        description: "Comment les blocs de réflexion apparaissent dans la chronologie",
+        accessibilityLabel: "Sélectionner l'affichage de la réflexion ({{value}})",
+        options: {
+          collapsed: "Réduit",
+          expandLast: "Développer le dernier",
+          expanded: "Toujours développer",
+        },
       },
       toolCallDetail: {
         label: "Affichage des appels d’outils",
diff --git a/packages/app/src/i18n/resources/ja.ts b/packages/app/src/i18n/resources/ja.ts
index c20a905be4..cc75a7d753 100644
--- a/packages/app/src/i18n/resources/ja.ts
+++ b/packages/app/src/i18n/resources/ja.ts
@@ -1860,8 +1860,14 @@ export const ja: TranslationResources = {
         accessibilityLabel: "ターミナルスクロールバック行数",
       },
       autoExpandReasoning: {
-        label: "常に思考プロセスを展開",
-        description: "デフォルトでAIのエージェント思考・推論ブロックを完全に展開して表示します",
+        label: "思考プロセスの表示",
+        description: "タイムラインでの思考ブロックの表示方法",
+        accessibilityLabel: "思考プロセスの表示を選択 ({{value}})",
+        options: {
+          collapsed: "折りたたむ",
+          expandLast: "最新のみ展開",
+          expanded: "常に展開",
+        },
       },
       toolCallDetail: {
         label: "ツール呼び出しの表示",
diff --git a/packages/app/src/i18n/resources/ko.ts b/packages/app/src/i18n/resources/ko.ts
index 99f4278337..837715e930 100644
--- a/packages/app/src/i18n/resources/ko.ts
+++ b/packages/app/src/i18n/resources/ko.ts
@@ -1856,8 +1856,14 @@ export const ko: TranslationResources = {
         accessibilityLabel: "터미널 스크롤백 줄 수",
       },
       autoExpandReasoning: {
-        label: "추론 항상 펼치기",
-        description: "에이전트의 사고 및 추론 블록을 기본적으로 모두 펼쳐 표시합니다.",
+        label: "사고 과정 표시",
+        description: "타임라인에 에이전트 사고 블록이 표시되는 방식",
+        accessibilityLabel: "사고 과정 표시 선택({{value}})",
+        options: {
+          collapsed: "접음",
+          expandLast: "마지막 항목만 펼치기",
+          expanded: "항상 펼치기",
+        },
       },
       toolCallDetail: {
         label: "도구 호출 표시",
diff --git a/packages/app/src/i18n/resources/pt-BR.ts b/packages/app/src/i18n/resources/pt-BR.ts
index f0a09e4d81..5900d76d73 100644
--- a/packages/app/src/i18n/resources/pt-BR.ts
+++ b/packages/app/src/i18n/resources/pt-BR.ts
@@ -1875,9 +1875,14 @@ export const ptBR: TranslationResources = {
         accessibilityLabel: "Linhas do scrollback do terminal",
       },
       autoExpandReasoning: {
-        label: "Sempre expandir raciocínio",
-        description:
-          "Mostrar os blocos de pensamento e raciocínio do agente totalmente expandidos por padrão",
+        label: "Exibição de pensamento",
+        description: "Como os blocos de pensamento aparecem na linha do tempo",
+        accessibilityLabel: "Selecionar exibição de pensamento ({{value}})",
+        options: {
+          collapsed: "Recolhido",
+          expandLast: "Expandir último",
+          expanded: "Sempre expandir",
+        },
       },
       toolCallDetail: {
         label: "Exibição de chamadas de ferramentas",
diff --git a/packages/app/src/i18n/resources/ru.ts b/packages/app/src/i18n/resources/ru.ts
index 430a1448c3..10cda60ae4 100644
--- a/packages/app/src/i18n/resources/ru.ts
+++ b/packages/app/src/i18n/resources/ru.ts
@@ -1879,9 +1879,14 @@ export const ru: TranslationResources = {
         accessibilityLabel: "Линии прокрутки Terminal",
       },
       autoExpandReasoning: {
-        label: "Всегда разворачивать размышления",
-        description:
-          "По умолчанию показывать блоки размышлений и логики агента полностью развернутыми",
+        label: "Отображение мышления",
+        description: "Как блоки рассуждений агента отображаются в таймлайне",
+        accessibilityLabel: "Выбор отображения мышления ({{value}})",
+        options: {
+          collapsed: "Свернуто",
+          expandLast: "Разворачивать последний",
+          expanded: "Всегда разворачивать",
+        },
       },
       toolCallDetail: {
         label: "Отображение вызовов инструментов",
diff --git a/packages/app/src/i18n/resources/zh-CN.ts b/packages/app/src/i18n/resources/zh-CN.ts
index 333fd8a0c1..ea6a5ab1e4 100644
--- a/packages/app/src/i18n/resources/zh-CN.ts
+++ b/packages/app/src/i18n/resources/zh-CN.ts
@@ -1823,8 +1823,14 @@ export const zhCN: TranslationResources = {
         accessibilityLabel: "终端回滚行数",
       },
       autoExpandReasoning: {
-        label: "始终展开推理过程",
-        description: "默认情况下完全展开 AI 的思考和推理过程",
+        label: "思考过程显示",
+        description: "智能体思考过程在时间线中的显示方式",
+        accessibilityLabel: "选择思考过程显示方式（{{value}}）",
+        options: {
+          collapsed: "折叠",
+          expandLast: "仅展开最新",
+          expanded: "始终展开",
+        },
       },
       toolCallDetail: {
         label: "工具调用显示",
diff --git a/packages/app/src/screens/settings/appearance/appearance-section.tsx b/packages/app/src/screens/settings/appearance/appearance-section.tsx
index 8dfda23538..114558c7b5 100644
--- a/packages/app/src/screens/settings/appearance/appearance-section.tsx
+++ b/packages/app/src/screens/settings/appearance/appearance-section.tsx
@@ -172,13 +172,44 @@ function ThemeRow({ value, onChange }: ThemeRowProps) {
   );
 }
 
+const THINKING_DISPLAY_DETAILS: readonly AppSettings["autoExpandReasoning"][] = [
+  "collapsed",
+  "expand_last",
+  "expanded",
+];
+
+function getThinkingDisplayDetailLabel(
+  t: TFunction,
+  value: AppSettings["autoExpandReasoning"],
+): string {
+  const optionKey = value === "expand_last" ? "expandLast" : value;
+  return t(`settings.general.autoExpandReasoning.options.${optionKey}`);
+}
+
+interface ThinkingDisplayMenuItemProps {
+  value: AppSettings["autoExpandReasoning"];
+  selected: boolean;
+  onChange: (value: AppSettings["autoExpandReasoning"]) => void;
+}
+
+function ThinkingDisplayMenuItem({ value, selected, onChange }: ThinkingDisplayMenuItemProps) {
+  const { t } = useTranslation();
+  const handleSelect = useCallback(() => onChange(value), [onChange, value]);
+  return (
+    <DropdownMenuItem selected={selected} onSelect={handleSelect}>
+      {getThinkingDisplayDetailLabel(t, value)}
+    </DropdownMenuItem>
+  );
+}
+
 interface AutoExpandReasoningRowProps {
-  value: boolean;
-  onChange: (value: boolean) => void;
+  value: AppSettings["autoExpandReasoning"];
+  onChange: (value: AppSettings["autoExpandReasoning"]) => void;
 }
 
 function AutoExpandReasoningRow({ value, onChange }: AutoExpandReasoningRowProps) {
   const { t } = useTranslation();
+  const selectedLabel = getThinkingDisplayDetailLabel(t, value);
   return (
     <View style={settingsStyles.row}>
       <View style={settingsStyles.rowContent}>
@@ -189,7 +220,27 @@ function AutoExpandReasoningRow({ value, onChange }: AutoExpandReasoningRowProps
           {t("settings.general.autoExpandReasoning.description")}
         </Text>
       </View>
-      <Switch value={value} onValueChange={onChange} />
+      <DropdownMenu>
+        <DropdownMenuTrigger
+          style={dropdownTriggerStyle}
+          accessibilityLabel={t("settings.general.autoExpandReasoning.accessibilityLabel", {
+            value: selectedLabel,
+          })}
+        >
+          <Text style={styles.triggerText}>{selectedLabel}</Text>
+          <ThemedChevronDown size={ICON_SIZE.sm} uniProps={mutedColorMapping} />
+        </DropdownMenuTrigger>
+        <DropdownMenuContent side="bottom" align="end" width={200}>
+          {THINKING_DISPLAY_DETAILS.map((option) => (
+            <ThinkingDisplayMenuItem
+              key={option}
+              value={option}
+              selected={value === option}
+              onChange={onChange}
+            />
+          ))}
+        </DropdownMenuContent>
+      </DropdownMenu>
     </View>
   );
 }
@@ -496,7 +547,7 @@ export function AppearanceSection() {
   );
 
   const handleAutoExpandReasoningChange = useCallback(
-    (autoExpandReasoning: boolean) => {
+    (autoExpandReasoning: AppSettings["autoExpandReasoning"]) => {
       void updateSettings({ autoExpandReasoning });
     },
     [updateSettings],
diff --git a/packages/app/src/styles/markdown-styles.test.ts b/packages/app/src/styles/markdown-styles.test.ts
index 44ae3791f2..3b4e976569 100644
--- a/packages/app/src/styles/markdown-styles.test.ts
+++ b/packages/app/src/styles/markdown-styles.test.ts
@@ -68,6 +68,9 @@ describe("createMarkdownStyles", () => {
     expect(styles.ordered_list_icon).toMatchObject({
       userSelect: "text",
     });
+    expect(styles.strong).toMatchObject({
+      fontWeight: darkTheme.fontWeight.bold,
+    });
   });
 
   it("uses the mono font-size token directly for inline and block code", () => {
diff --git a/packages/app/src/styles/markdown-styles.ts b/packages/app/src/styles/markdown-styles.ts
index d7f78fb2ae..089b634004 100644
--- a/packages/app/src/styles/markdown-styles.ts
+++ b/packages/app/src/styles/markdown-styles.ts
@@ -126,7 +126,7 @@ export function createMarkdownStyles(theme: Theme) {
 
     strong: {
       ...webSelectableTextStyle,
-      fontWeight: theme.fontWeight.medium,
+      fontWeight: theme.fontWeight.bold,
     },
 
     em: {
diff --git a/packages/app/src/utils/thinking-text-formatter.test.ts b/packages/app/src/utils/thinking-text-formatter.test.ts
new file mode 100644
index 0000000000..d24c481f37
--- /dev/null
+++ b/packages/app/src/utils/thinking-text-formatter.test.ts
@@ -0,0 +1,61 @@
+import { describe, expect, it } from "vitest";
+import { formatThinkingText } from "./thinking-text-formatter";
+
+describe("formatThinkingText", () => {
+  it("handles empty or invalid inputs", () => {
+    expect(formatThinkingText("")).toBe("");
+    expect(formatThinkingText(null as unknown as string)).toBe("");
+    expect(formatThinkingText(undefined as unknown as string)).toBe("");
+  });
+
+  it("separates adjacent bold titles without newlines", () => {
+    expect(formatThinkingText("**title****title2**")).toBe("**title**\n\n**title2**");
+    expect(formatThinkingText("**title1****title2****title3**")).toBe(
+      "**title1**\n\n**title2**\n\n**title3**",
+    );
+  });
+
+  it("separates adjacent bold titles separated only by spaces", () => {
+    expect(formatThinkingText("**title1** **title2**")).toBe("**title1**\n\n**title2**");
+    expect(formatThinkingText("**title1**   **title2**")).toBe("**title1**\n\n**title2**");
+  });
+
+  it("separates numbered headers", () => {
+    expect(formatThinkingText("**1. Analyze goal****2. Execute plan**")).toBe(
+      "**1. Analyze goal**\n\n**2. Execute plan**",
+    );
+  });
+
+  it("handles in-progress streaming where second bold tag is opened", () => {
+    expect(formatThinkingText("**title1****title2")).toBe("**title1**\n\n**title2");
+    expect(formatThinkingText("**title1****")).toBe("**title1**\n\n**");
+  });
+
+  it("preserves regular markdown bold within prose without altering intended formatting", () => {
+    const prose = "This function uses **foo** and **bar** as arguments.";
+    expect(formatThinkingText(prose)).toBe(prose);
+
+    const uppercaseProse = "I need to inspect **AgentStreamView** before editing it.";
+    expect(formatThinkingText(uppercaseProse)).toBe(uppercaseProse);
+
+    const afterPunctuation =
+      'I looked at config.json, which had key "version". **Note** that this is deprecated.';
+    expect(formatThinkingText(afterPunctuation)).toBe(afterPunctuation);
+  });
+
+  it("preserves fenced code blocks and inline code completely intact", () => {
+    const codeWithBold = "```python\ndef foo():\n\n\n    # check **a****b**\n```";
+    expect(formatThinkingText(codeWithBold)).toBe(codeWithBold);
+
+    const inlineCode = "Use `**bold**` inside inline code.";
+    expect(formatThinkingText(inlineCode)).toBe(inlineCode);
+
+    const streamingCodeBlock = "```typescript\nconst x = **test**;\n";
+    expect(formatThinkingText(streamingCodeBlock)).toBe(streamingCodeBlock);
+  });
+
+  it("preserves already well-spaced thinking blocks without adding excess newlines", () => {
+    const wellSpaced = "**Title 1**\n\nSome thought text.\n\n**Title 2**\n\nMore thought text.";
+    expect(formatThinkingText(wellSpaced)).toBe(wellSpaced);
+  });
+});
diff --git a/packages/app/src/utils/thinking-text-formatter.ts b/packages/app/src/utils/thinking-text-formatter.ts
new file mode 100644
index 0000000000..6f95d164da
--- /dev/null
+++ b/packages/app/src/utils/thinking-text-formatter.ts
@@ -0,0 +1,26 @@
+/**
+ * Normalizes thinking and reasoning text emitted by models (e.g. Codex, OpenAI reasoning models)
+ * where bold headers (like **title**) may be streamed without separating newlines,
+ * producing jammed headers like `**title1****title2**`.
+ */
+export function formatThinkingText(text: string): string {
+  if (!text || typeof text !== "string") {
+    return "";
+  }
+
+  // Preserve code blocks (including in-progress streaming code blocks) and inline code spans
+  const parts = text.split(/(```[\s\S]*?(?:```|$)|`[^`\n]+`)/g);
+
+  return parts
+    .map((part, index) => {
+      // Odd indices are code blocks or inline code spans - leave them completely intact
+      if (index % 2 === 1) {
+        return part;
+      }
+
+      // Separate adjacent bold blocks (e.g. **title1****title2** or **title1** **title2**)
+      // Also handles streaming when the second bold tag is opened: **title1****streaming...
+      return part.replace(/(\*\*[^*\s\n](?:[^*\n]*?[^*\s\n])?\*\*)\s*(?=\*\*)/g, "$1\n\n");
+    })
+    .join("");
+}