FN-8426: adapt Planning Mode for compact layouts

Make Planning Mode usable on mobile, tablet, and short-height layouts.

- Collapse compact Planning interviews into selectable question, plan, and history surfaces.
- Keep Sessions navigation synchronized so returning from the session list restores a visible interview pane.
- Document and test mobile, tablet, and short-landscape behavior.

Files changed:
 .../fn-8426-planning-mobile-tablet-layout.md       |  7 ++
 MOBILE.md                                          |  2 +-
 docs/dashboard-guide.md                            |  2 +-
 .../dashboard/app/components/PlanningModeModal.css | 94 ++++++++++++++++++++--
 .../dashboard/app/components/PlanningModeModal.tsx | 51 +++++++++++-
 .../__tests__/PlanningModeModal.css.test.ts        | 17 ++++
 .../PlanningModeModal.planning-flow.test.tsx       | 36 +++++++++
 .../__tests__/PlanningModeModal.test-helpers.ts    | 23 ++++++
 8 files changed, 220 insertions(+), 12 deletions(-)

Fusion-Task-Id: FN-8426

Fusion-Task-Lineage: 489d6f92-326c-4780-bc85-d28967c7ab35

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-8426-planning-mobile-tablet-layout.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Make Planning Mode usable on mobile and tablet with progressive interview layout.
+category: fix
+dev: Reflows FN-8400/FN-8420 three-pane Planning Mode via viewport progressive disclosure (incl. short landscape); no API contract change.

MOBILE.md

@@ -101,7 +101,7 @@ gesture delivery enabled across `cap sync` regenerations.
 
 ### Planning Mode
 
-Planning Mode opens directly into the composer pane on mobile when no planning sessions exist, avoiding an empty-sidebar dead end. On desktop/tablet the split view is unaffected. Once sessions are saved, mobile shows the session list as usual and the user can navigate between list and detail panes; active interviews keep the running plan reachable beside the answered-question history.
+Planning Mode opens directly into the composer pane on mobile when no planning sessions exist, avoiding an empty-sidebar dead end. Desktop keeps its three-pane interview (answered history, current question, and running plan) when there is room. Mobile, phone-class short landscape, and tablet use a progressive interview: **Question** is the default full-width surface, while labeled **Running plan** and **Answered questions** controls switch to those surfaces without stacking three panes. **Sessions** and the mobile back control always return to the saved-session list; **Validate plan** remains on the Running plan surface. Once sessions are saved, mobile shows the session list as usual and the user can navigate between list and detail panes.
 
 ### Chat and Quick Chat mobile scroll/readability behavior
 

docs/dashboard-guide.md

@@ -529,7 +529,7 @@ When an active Planning AI generation appears stuck, Planning Mode automatically
 Use **New session** to restart planning with a different idea.
 
 <!-- FNXC:PlanningMode 2026-07-18-16:00: Planning Mode is an infinite, user-controlled interview. Each answer updates the running plan and produces another context-aware high-impact question; only Validate plan finalizes it. -->
-Planning Mode keeps the running plan visible beside answered-question history and the current question; you can rename a session and keep asking high-impact, context-aware questions until you choose **Validate plan**. The running title, description, and deliverables are available throughout the interview—including while the next question is generating or a recoverable error is shown; use **Sessions** to return to the saved-session list. The AI never ends an interview on its own. Selection questions provide alternatives with pros and cons plus an **Other** free-text choice, whose wording follows your input language and whose answer steers the next question. You may edit an earlier answer by question ID without losing later answers; Planning re-derives the running plan and appends a fresh next question.
+Planning Mode keeps the running plan visible beside answered-question history and the current question on desktop; you can rename a session and keep asking high-impact, context-aware questions until you choose **Validate plan**. On tablet, mobile, and phone-class short landscape, the interview switches between labeled **Question**, **Running plan**, and **Answered questions** surfaces so the current question stays usable instead of competing with three columns. **Sessions** (and mobile Back) return to the saved-session list, while **Validate plan** remains available on the Running plan surface. The running title, description, and deliverables are available throughout the interview—including while the next question is generating or a recoverable error is shown. The AI never ends an interview on its own. Selection questions provide alternatives with pros and cons plus an **Other** free-text choice, whose wording follows your input language and whose answer steers the next question. You may edit an earlier answer by question ID without losing later answers; Planning re-derives the running plan and appends a fresh next question.
 
 Choose **Validate plan** when the running plan is ready for task creation. Validation is durable and is required before **Create task**, **Create tasks**, or **Start breakdown**; those actions reject unvalidated sessions.
 

packages/dashboard/app/components/PlanningModeModal.css

@@ -537,6 +537,55 @@ The New session button must look EXACTLY like Missions' primary sidebar create b
   .planning-modal-body--split {
     flex-direction: column;
   }
+
+  /*
+  FNXC:PlanningModeMobileTablet 2026-07-20-09:30:
+  The compact interview class is shared by width-mobile, tablet, and short CSS shells.
+  Only one interview surface is visible at once, so a short landscape viewport cannot retain
+  desktop's three competing columns. Non-phone short screens use this same class as the explicit
+  mismatch guard for the compound shell query.
+  */
+  .planning-modal-body--compact-interview {
+    flex-direction: column;
+  }
+
+  .planning-compact-pane-switcher {
+    display: flex;
+    flex: 0 0 auto;
+    gap: var(--space-sm);
+    padding: var(--space-sm) var(--space-md);
+    overflow-x: auto;
+    border-bottom: 1px solid var(--border);
+    background: var(--surface);
+  }
+
+  .planning-compact-pane-switcher .btn {
+    flex: 1 0 auto;
+    min-height: calc(var(--space-md) * 2.25);
+    justify-content: center;
+  }
+
+  .planning-modal-body--compact-interview .planning-sidebar,
+  .planning-modal-body--compact-interview .planning-detail,
+  .planning-modal-body--compact-interview .planning-running-plan {
+    width: 100%;
+    flex: 1 1 auto;
+    min-height: 0;
+    border: 0;
+  }
+
+  .planning-modal-body--compact-interview .planning-running-plan {
+    border-top: 0;
+  }
+
+  .planning-modal-body--compact-question .planning-sidebar,
+  .planning-modal-body--compact-question .planning-running-plan,
+  .planning-modal-body--compact-plan .planning-sidebar,
+  .planning-modal-body--compact-plan .planning-detail,
+  .planning-modal-body--compact-history .planning-detail,
+  .planning-modal-body--compact-history .planning-running-plan {
+    display: none;
+  }
   .planning-sidebar {
     width: 100%;
     border-right: none;
@@ -1447,6 +1496,45 @@ FNXC:PlanningMode 2026-06-25-09:20:
 Tablet embedded Planning keeps the desktop two-pane shell, so the summary footer must absorb the narrower detail pane instead of relying on the mobile full-width stack. Allow the three labeled actions to wrap inside the pane while preserving the desktop left/right grouping when space is available.
 */
 @media (min-width: 769px) and (max-width: 1024px) {
+  /* FNXC:PlanningModeMobileTablet 2026-07-20-09:30: tablet uses the same one-surface interview switcher rather than compressing three fixed panes beside the project navigation. */
+  .planning-modal-body--compact-interview {
+    flex-direction: column;
+  }
+
+  .planning-compact-pane-switcher {
+    display: flex;
+    flex: 0 0 auto;
+    gap: var(--space-sm);
+    padding: var(--space-sm) var(--space-lg);
+    overflow-x: auto;
+    border-bottom: 1px solid var(--border);
+    background: var(--surface);
+  }
+
+  .planning-compact-pane-switcher .btn {
+    flex: 1 0 auto;
+    min-height: calc(var(--space-md) * 2.25);
+    justify-content: center;
+  }
+
+  .planning-modal-body--compact-interview .planning-sidebar,
+  .planning-modal-body--compact-interview .planning-detail,
+  .planning-modal-body--compact-interview .planning-running-plan {
+    width: 100%;
+    flex: 1 1 auto;
+    min-height: 0;
+    border: 0;
+  }
+
+  .planning-modal-body--compact-question .planning-sidebar,
+  .planning-modal-body--compact-question .planning-running-plan,
+  .planning-modal-body--compact-plan .planning-sidebar,
+  .planning-modal-body--compact-plan .planning-detail,
+  .planning-modal-body--compact-history .planning-detail,
+  .planning-modal-body--compact-history .planning-running-plan {
+    display: none;
+  }
+
   .planning-summary-actions {
     flex-wrap: wrap;
     align-items: flex-start;
@@ -1858,12 +1946,6 @@ Tablet embedded Planning keeps the desktop two-pane shell, so the summary footer
     font-size: 16px;
   }
 
-  .planning-running-plan {
-    flex-basis: auto;
-    border-top: 1px solid var(--border);
-    border-left: 0;
-  }
-
   /* Confirm buttons: mobile-friendly sizing */
   .planning-confirm-group {
     flex-direction: column;

packages/dashboard/app/components/PlanningModeModal.tsx

@@ -56,7 +56,7 @@ import { CustomModelDropdown } from "./CustomModelDropdown";
 import { ConversationHistory } from "./ConversationHistory";
 import { MailboxMessageContent } from "./MailboxMessageContent";
 import { OnboardingDisclosure } from "./OnboardingDisclosure";
-import { useViewportMode } from "../hooks/useViewportMode";
+import { isShortViewport, useViewportMode } from "../hooks/useViewportMode";
 import { useMobileKeyboard } from "../hooks/useMobileKeyboard";
 import { useNavigationHistoryContext } from "../hooks/useNavigationHistory";
 import { useMobileScrollLock } from "../hooks/useMobileScrollLock";
@@ -512,6 +512,16 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
   useModalResizePersist(modalRef, isOpen && resizePersistEnabled, "fusion:planning-modal-size");
   const viewportMode = useViewportMode();
   const isMobile = viewportMode === "mobile";
+  /*
+  FNXC:PlanningModeMobileTablet 2026-07-20-09:30:
+  Active interviews use progressive disclosure below desktop, plus every short CSS shell viewport.
+  `viewportMode === "mobile"` preserves the phone-class short-landscape contract from
+  isMobileViewport(); isShortViewport additionally guards non-phone short shells so CSS never
+  collapses three panes while JavaScript leaves their controls inaccessible. This is intentionally
+  temporary while a keyboard is open, rather than a global viewport-mode change.
+  */
+  const isCompactInterview = viewportMode !== "desktop" || isShortViewport();
+  const [compactInterviewPane, setCompactInterviewPane] = useState<"question" | "plan" | "history">("question");
   const { addToast } = useToast();
   const { pushNav } = useNavigationHistoryContext();
 
@@ -2235,8 +2245,23 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
               {selectedSessionId && (view.type === "question" || view.type === "loading" || view.type === "error") && activeSessionTitle && <button type="button" className="btn-icon" aria-label={t("planning.renameSession", "Rename session")} onClick={() => { setSessionTitleDraft(activeSessionTitle); setIsRenamingSession(true); }}><Pencil /></button>}</>
             )}
           </div>
-          {selectedSessionId && (view.type === "question" || view.type === "loading" || view.type === "error") && !isMobile && (
+          {/*
-            <button type="button" className="btn" onClick={() => setShowSessionList((current) => !current)}>
+          FNXC:PlanningModeMobileTablet 2026-07-20-09:12:
+          When the viewport cannot fit three interview panes, operators must still be able to return
+          to the session list and then back to the active question. Keep the list and detail state
+          synchronized on both transitions so a second Sessions press cannot leave the question pane
+          hidden by the mobile list CSS.
+          */}
+          {selectedSessionId && (view.type === "question" || view.type === "loading" || view.type === "error") && (
+            <button
+              type="button"
+              className="btn"
+              onClick={() => {
+                const showList = !showSessionList;
+                setShowSessionList(showList);
+                if (isCompactInterview) setMobileShowDetail(!showList);
+              }}
+            >
               {t("planning.sessions", "Sessions")}
             </button>
           )}
@@ -2252,6 +2277,10 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
         <div
           className={`planning-modal-body planning-modal-body--split ${
             mobileShowDetail ? "planning-modal-body--show-detail" : "planning-modal-body--show-list"
+          } ${
+            selectedSessionId && !showSessionList && (view.type === "question" || view.type === "loading" || view.type === "error") && isCompactInterview
+              ? `planning-modal-body--compact-interview planning-modal-body--compact-${compactInterviewPane}`
+              : ""
           }`}
         >
           {selectedSessionId && !showSessionList && (view.type === "question" || view.type === "loading" || view.type === "error") ? (
@@ -2283,7 +2312,7 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
           FNXC:Planning 2026-06-23-02:00:
           Sidebar resize handle — parity with MissionManager's mission-manager__sidebar-resize-handle. Rendered only on desktop (sidebar stacks on mobile). Pointer-drag and arrow-key resize both clamp + persist width.
           */}
-          {!isMobile && (
+          {viewportMode === "desktop" && !isShortViewport() && (
             <div
               className="planning-sidebar-resize-handle"
               role="separator"
@@ -2298,6 +2327,20 @@ export function PlanningModeModal({ isOpen, onClose, onTaskCreated, onTasksCreat
             />
           )}
 
+          {selectedSessionId && !showSessionList && (view.type === "question" || view.type === "loading" || view.type === "error") && isCompactInterview && (
+            <nav className="planning-compact-pane-switcher" aria-label={t("planning.interviewPanels", "Planning interview panels")}>
+              <button type="button" className={`btn ${compactInterviewPane === "question" ? "btn-primary" : ""}`} aria-pressed={compactInterviewPane === "question"} onClick={() => setCompactInterviewPane("question")}>
+                {t("planning.question", "Question")}
+              </button>
+              <button type="button" className={`btn ${compactInterviewPane === "plan" ? "btn-primary" : ""}`} aria-pressed={compactInterviewPane === "plan"} onClick={() => setCompactInterviewPane("plan")}>
+                {t("planning.runningPlan", "Running plan")}
+              </button>
+              <button type="button" className={`btn ${compactInterviewPane === "history" ? "btn-primary" : ""}`} aria-pressed={compactInterviewPane === "history"} onClick={() => setCompactInterviewPane("history")}>
+                {t("planning.answeredQuestions", "Answered questions")}
+              </button>
+            </nav>
+          )}
+
           <div className="planning-detail">
           {error && <div className="form-error planning-error">{error}</div>}
           {/*

packages/dashboard/app/components/__tests__/PlanningModeModal.css.test.ts

@@ -69,6 +69,23 @@ describe("PlanningModeModal CSS responsive action contract", () => {
     expect(embeddedRule).toMatch(/max-height\s*:\s*100%\s*;/);
   });
 
+  it("uses the compact interview switcher for mobile, short landscape, and tablet instead of crushing three panes", () => {
+    const css = loadPlanningCss();
+    const shortShellCss = getMediaBlocks(css, MOBILE_PLANNING_SHELL_QUERY).join("\n");
+    const tabletCss = getMediaBlocks(css, TABLET_SUMMARY_ACTIONS_QUERY).join("\n");
+
+    expect(findRule(shortShellCss, ".planning-modal-body--compact-interview")).toMatch(/flex-direction\s*:\s*column\s*;/);
+    expect(findRule(shortShellCss, ".planning-compact-pane-switcher")).toMatch(/display\s*:\s*flex\s*;/);
+    expect(findRule(shortShellCss, ".planning-compact-pane-switcher .btn")).toMatch(/min-height\s*:\s*calc\(var\(--space-md\) \* 2\.25\)\s*;/);
+    expect(shortShellCss).toContain(".planning-modal-body--compact-question .planning-running-plan");
+    expect(shortShellCss).toContain(".planning-modal-body--compact-plan .planning-detail");
+    expect(shortShellCss).toContain(".planning-modal-body--compact-history .planning-detail");
+    expect(findRule(tabletCss, ".planning-modal-body--compact-interview")).toMatch(/flex-direction\s*:\s*column\s*;/);
+    expect(tabletCss).toContain(".planning-modal-body--compact-question .planning-running-plan");
+
+    expectSomeRule(css, ".planning-running-plan", /flex\s*:\s*0 1 24rem\s*;/);
+  });
+
   it("keeps the mobile sessions list scrolling above the bottom-pinned New session footer", () => {
     const css = loadPlanningCss();
     const mobileShellCss = getMediaBlocks(css, MOBILE_PLANNING_SHELL_QUERY).join("\n");

packages/dashboard/app/components/__tests__/PlanningModeModal.planning-flow.test.tsx

@@ -61,6 +61,7 @@ import {
   mockTaskDetail,
   MockEventSource,
   getMediaBlocks,
+  mockShortLandscapePhone,
   mockViewport,
 } from "./PlanningModeModal.test-helpers";
 
@@ -3612,6 +3613,41 @@ describe("PlanningModeModal", () => {
     });
   });
 
+  it("uses progressive interview controls on tablet and short-landscape phone sessions", async () => {
+    for (const viewport of ["tablet", "short-landscape"] as const) {
+      if (viewport === "tablet") mockViewport("tablet");
+      else mockShortLandscapePhone();
+      mockFetchAiSession.mockResolvedValueOnce({
+        id: `session-${viewport}`,
+        type: "planning",
+        status: "awaiting_input",
+        title: "Responsive planning session",
+        inputPayload: JSON.stringify({ initialPlan: "Responsive plan prompt" }),
+        conversationHistory: "[]",
+        result: JSON.stringify(mockSummary),
+        thinkingOutput: "",
+        projectId: null,
+        currentQuestion: JSON.stringify(mockQuestion),
+      });
+
+      const rendered = render(<PlanningModeModal isOpen={true} onClose={mockOnClose} onTaskCreated={mockOnTaskCreated} onTasksCreated={vi.fn()} tasks={mockTasks} resumeSessionId={`session-${viewport}`} />);
+      await screen.findByText("What is the scope?");
+      expect(screen.getByRole("button", { name: "Question" })).toHaveAttribute("aria-pressed", "true");
+      expect(screen.getByRole("button", { name: "Running plan" })).toBeDefined();
+      expect(screen.getByRole("button", { name: "Answered questions" })).toBeDefined();
+      expect(screen.getByRole("button", { name: "Next question" })).toBeDefined();
+
+      fireEvent.click(screen.getByRole("button", { name: "Sessions" }));
+      expect(await screen.findByRole("complementary", { name: "Planning sessions" })).toBeDefined();
+      fireEvent.click(screen.getByRole("button", { name: "Sessions" }));
+      expect(rendered.container.querySelector(".planning-modal-body")).toHaveClass("planning-modal-body--show-detail", "planning-modal-body--compact-question");
+      expect(screen.getByRole("button", { name: "Next question" })).toBeVisible();
+      fireEvent.click(screen.getByRole("button", { name: "Running plan" }));
+      expect(screen.getByRole("button", { name: "Validate plan" })).toBeDefined();
+      rendered.unmount();
+    }
+  });
+
   describe.each(["desktop", "mobile"] as const)("single interview action on %s", (viewport) => {
     it("keeps only Next question and the localized Other input affordance", async () => {
       mockViewport(viewport);

packages/dashboard/app/components/__tests__/PlanningModeModal.test-helpers.ts

@@ -200,4 +200,27 @@ export function mockViewport(mode: "mobile" | "desktop" | "tablet") {
   });
 }
 
+/*
+FNXC:PlanningModeMobileTablet 2026-07-20-09:30:
+Short-landscape Planning tests must exercise the wide CSS viewport plus phone-class physical screen
+combination. Returning mobile mode mirrors getViewportMode() after isMobileViewport() accepts that
+phone-class short-height exception; width-only mocks cannot cover the historical desync.
+*/
+export function mockShortLandscapePhone() {
+  mockUseViewportMode.mockReturnValue("mobile");
+  Object.defineProperty(window, "screen", {
+    configurable: true,
+    value: { width: 844, height: 390 },
+  });
+  Object.defineProperty(window, "matchMedia", {
+    writable: true,
+    value: vi.fn().mockImplementation((query: string) => ({
+      matches: query === "(max-height: 480px)" || query === "(max-width: 768px), (max-height: 480px)",
+      media: query,
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+    })),
+  });
+}
+
 export type { Task, TaskDetail, PlanningQuestion, PlanningSummary, MergeResult };