diff --git a/e2e/workbench.spec.ts b/e2e/workbench.spec.ts
index 7c028f2e..3d3968c3 100644
--- a/e2e/workbench.spec.ts
+++ b/e2e/workbench.spec.ts
@@ -27,3 +27,55 @@ test("stripe buttons toggle tool windows", async ({ workbench: page }) => {
   await stripe.getByRole("button", { name: "Problems", exact: true }).click();
   await expect(problems).toBeHidden();
 });
+
+for (const reducedMotion of ["no-preference", "reduce"] as const) {
+  test(`project opening advances simulated progress with ${reducedMotion} motion`, async ({ workbench: page }) => {
+    await page.emulateMedia({ reducedMotion });
+    await page.evaluate(async () => {
+      const path = "/src/platform/project.ts";
+      const { useProject } = await import(/* @vite-ignore */ path);
+      useProject.setState({ opening: true, openingPath: "/work/large-project" });
+    });
+    const progress = page.locator("[data-project-opening]").getByRole("progressbar");
+    await expect(progress).toBeVisible();
+    for (const theme of ["light", "dark"]) {
+      await page.evaluate((theme) => (document.documentElement.dataset.theme = theme), theme);
+      const frames = await progress.evaluate((track) => {
+        const fill = track.firstElementChild!;
+        const animation = fill.getAnimations()[0];
+        if (!animation) throw new Error("Loading progress has no activity indicator");
+        animation.pause();
+        const duration = Number(animation.effect!.getComputedTiming().duration);
+        return [0, 0.25, 0.5, 0.75, 1, 1.5, 2].map((phase) => {
+          animation.currentTime = duration * phase;
+          const outer = track.getBoundingClientRect();
+          const inner = fill.getBoundingClientRect();
+          const style = getComputedStyle(fill);
+          return {
+            trackWidth: outer.width,
+            fillWidth: inner.width,
+            height: inner.height,
+            left: inner.left - outer.left,
+            right: outer.right - inner.right,
+            opacity: Number(style.opacity),
+            color: style.backgroundColor,
+          };
+        });
+      });
+      for (const frame of frames) {
+        expect(frame.height).toBeGreaterThan(0);
+        expect(frame.fillWidth).toBeGreaterThan(0);
+        expect(frame.fillWidth).toBeLessThan(frame.trackWidth);
+        expect(frame.left).toBeGreaterThanOrEqual(-0.5);
+        expect(frame.right).toBeGreaterThanOrEqual(-0.5);
+        expect(frame.opacity).toBeGreaterThanOrEqual(0.6);
+        expect(frame.color).not.toBe("rgba(0, 0, 0, 0)");
+      }
+      const widths = frames.map((frame) => frame.fillWidth);
+      expect(widths[0]).toBeLessThan(widths[1]!);
+      for (let i = 1; i < widths.length; i++) expect(widths[i]).toBeGreaterThanOrEqual(widths[i - 1]!);
+      expect(widths[4]! / frames[4]!.trackWidth).toBeCloseTo(0.92, 2);
+      expect(widths[6]).toBeCloseTo(widths[4]!, 2);
+    }
+  });
+}
diff --git a/public/splash.css b/public/splash.css
index 2414c529..ecb40b61 100644
--- a/public/splash.css
+++ b/public/splash.css
@@ -22,8 +22,8 @@ body,
   flex-direction: column;
   align-items: center;
   justify-content: center;
-  gap: 14px;
-  padding-bottom: 38px;
+  gap: var(--splash-gap, 14px);
+  padding-bottom: var(--splash-offset, 38px);
   box-sizing: border-box;
   color: var(--fg-muted, var(--boot-fg, #6c707e));
   -webkit-user-select: none;
@@ -40,8 +40,8 @@ body,
   color: var(--fg-muted, var(--boot-fg, #8c8f95));
 }
 .splash-logo {
-  width: 56px;
-  height: 56px;
+  width: var(--splash-logo-size, 56px);
+  height: var(--splash-logo-size, 56px);
 }
 /* 15px Inter: 2048 units per em, the line box from ascender to descender. */
 .splash-wordmark {
@@ -49,8 +49,8 @@ body,
   height: 18.15px;
 }
 .splash-bar {
-  width: 120px;
-  height: 2px;
+  width: var(--splash-bar-width, 120px);
+  height: var(--splash-bar-height, 2px);
   border-radius: 1px;
   overflow: hidden;
   background: rgb(127 127 127 / 0.18);
@@ -63,7 +63,8 @@ body,
   height: 100%;
   background: var(--boot-accent, var(--accent, #3871e1));
   transform-origin: left;
-  animation: splash-fill 4s cubic-bezier(0.1, 0.7, 0.3, 1) both;
+  animation: splash-fill var(--splash-progress-duration, 4s)
+    var(--splash-progress-easing, cubic-bezier(0.1, 0.7, 0.3, 1)) both;
 }
 /* Settings window: a dialog, not a launch. Only the bar, and only if loading takes a while. */
 :root[data-window="settings"] .splash {
diff --git a/src/platform/actions.ts b/src/platform/actions.ts
index 19f3ed32..2b561ad5 100644
--- a/src/platform/actions.ts
+++ b/src/platform/actions.ts
@@ -122,6 +122,11 @@ export function allActions(): Action[] {
 }
 
 export function isActionEnabled(action: Action, ctx: ContextKeys = getContext()): boolean {
+  if (
+    ctx.projectOpening &&
+    !["app.quit", "window.next", "window.previous", "window.toggleFullScreen"].includes(action.id)
+  )
+    return false;
   return evaluateWhen(action.when, ctx);
 }
 
diff --git a/src/platform/locales/en.json b/src/platform/locales/en.json
index d63d811c..42b99e00 100644
--- a/src/platform/locales/en.json
+++ b/src/platform/locales/en.json
@@ -49,6 +49,7 @@
   "app.lightEdit.openProject": "Open as Project",
   "app.lightEdit.openProjectTooltip": "Open {folder} as a project",
   "app.log.failed": "Cannot show the log",
+  "app.project.opening": "Opening {name}…",
   "app.title.default": "OpenIDEA",
   "app.unsaved.body": "{count, plural, one {# file has} other {# files have}} unsaved changes in {project}. Save before closing?",
   "app.unsaved.discard": "Don't Save",
diff --git a/src/platform/locales/zh.json b/src/platform/locales/zh.json
index 79f8adec..20801b94 100644
--- a/src/platform/locales/zh.json
+++ b/src/platform/locales/zh.json
@@ -49,6 +49,7 @@
   "app.lightEdit.openProject": "作为项目打开",
   "app.lightEdit.openProjectTooltip": "将 {folder} 作为项目打开",
   "app.log.failed": "无法显示日志",
+  "app.project.opening": "正在打开 {name}…",
   "app.title.default": "OpenIDEA",
   "app.unsaved.body": "{project} 中有 {count} 个文件尚未保存。关闭前是否保存？",
   "app.unsaved.discard": "不保存",
diff --git a/src/platform/project.test.ts b/src/platform/project.test.ts
index 6675236e..c226cef2 100644
--- a/src/platform/project.test.ts
+++ b/src/platform/project.test.ts
@@ -1,5 +1,70 @@
-import { describe, expect, it } from "vitest";
-import { relativeDir } from "./project";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { getContext } from "./context";
+import { executeAction, isActionKeyEnabled, registerAction } from "./actions";
+import { commands } from "./ipc";
+import { openProject, relativeDir, useProject } from "./project";
+import { confirmProjectTrust } from "./projectTrust";
+
+vi.mock("./projectTrust", () => ({ confirmProjectTrust: vi.fn(async () => {}) }));
+vi.mock("./ipc", async (original) => ({
+  ...(await original<typeof import("./ipc")>()),
+  commands: { openProject: vi.fn(), projectCurrent: vi.fn() },
+}));
+
+type BackendProject = NonNullable<Awaited<ReturnType<typeof commands.projectCurrent>>>;
+const old: BackendProject = {
+  root: "/old",
+  name: "old",
+  trusted: true,
+  isGit: false,
+  settings: {} as BackendProject["settings"],
+};
+const next: BackendProject = { ...old, root: "/new", name: "new" };
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  useProject.setState({ project: old, settings: old.settings, lightEdit: false, opening: false, openingPath: null });
+});
+afterEach(() => useProject.setState({ project: null, settings: null, opening: false, openingPath: null }));
+
+it("shows the target while opening and blocks actions from both menus and shortcuts", async () => {
+  let finish!: (value: Awaited<ReturnType<typeof commands.openProject>>) => void;
+  vi.mocked(commands.openProject).mockReturnValue(new Promise((resolve) => (finish = resolve)));
+  const opening = openProject(next.root);
+  await Promise.resolve();
+  expect(useProject.getState()).toMatchObject({ project: old, opening: true, openingPath: next.root });
+  const run = vi.fn();
+  const action = { id: "test.projectMutation", title: "test", run };
+  const dispose = registerAction(action);
+  try {
+    expect(isActionKeyEnabled(action)).toBe(false);
+    expect(await executeAction(action.id)).toBe(false);
+    expect(run).not.toHaveBeenCalled();
+    expect(isActionKeyEnabled({ ...action, id: "app.quit" })).toBe(true);
+    finish({ status: "ok", data: next });
+    await opening;
+    expect(useProject.getState()).toMatchObject({ project: next, opening: false, openingPath: null });
+    expect(getContext().projectOpening).toBe(false);
+    expect(await executeAction(action.id)).toBe(true);
+  } finally {
+    dispose();
+  }
+});
+
+it.each([old, null, next])("reconciles a failed open with the backend's remaining project: %s", async (current) => {
+  vi.mocked(commands.openProject).mockRejectedValue(new Error("cannot open project"));
+  vi.mocked(commands.projectCurrent).mockResolvedValue(current && { ...current });
+  await expect(openProject(next.root)).rejects.toThrow("cannot open project");
+  expect(useProject.getState()).toMatchObject({ project: current, opening: false, openingPath: null });
+  if (current === old) expect(useProject.getState().project).toBe(old);
+});
+
+it("leaves the current project alone when trust is cancelled", async () => {
+  vi.mocked(confirmProjectTrust).mockRejectedValueOnce(new Error("cancelled"));
+  await expect(openProject(next.root)).rejects.toThrow("cancelled");
+  expect(commands.openProject).not.toHaveBeenCalled();
+  expect(useProject.getState()).toMatchObject({ project: old, opening: false, openingPath: null });
+});
 
 describe("relativeDir", () => {
   it("is empty for files directly in the project root", () => {
diff --git a/src/platform/project.ts b/src/platform/project.ts
index 4c009b02..2aed87fc 100644
--- a/src/platform/project.ts
+++ b/src/platform/project.ts
@@ -1,6 +1,7 @@
 /** The project open in this window. */
 import { confirmProjectTrust } from "./projectTrust";
 import { create } from "zustand";
+import { setContext } from "./context";
 import { call, commands, type ProjectInfo, type Settings } from "./ipc";
 import { isVirtualUri, virtualContainer, virtualName, virtualParent } from "./virtualDocs";
 
@@ -9,6 +10,7 @@ interface ProjectState {
   /** Effective settings (project-layered when a project is open). */
   settings: Settings | null;
   opening: boolean;
+  openingPath: string | null;
   /** LightEdit: this window edits loose files without a project (`project` stays null). */
   lightEdit: boolean;
 }
@@ -17,9 +19,12 @@ export const useProject = create<ProjectState>(() => ({
   project: null,
   settings: null,
   opening: false,
+  openingPath: null,
   lightEdit: false,
 }));
 
+useProject.subscribe((s) => setContext("projectOpening", s.openingPath !== null));
+
 let leaveGuard: (() => Promise<boolean>) | null = null;
 
 /** Installs the check run before this window leaves its project (unsaved changes). */
@@ -50,13 +55,21 @@ export function startupLaunchHandled(): Promise<void> {
 
 export async function openProject(path: string): Promise<ProjectInfo> {
   await confirmProjectTrust(path, "local");
-  useProject.setState({ opening: true });
+  useProject.setState({ opening: true, openingPath: path });
   try {
     const project = await call(commands.openProject(path));
     useProject.setState({ project, settings: project.settings, lightEdit: false });
     return project;
+  } catch (error) {
+    // Opening may fail after the backend has already closed the old project.
+    if (useProject.getState().project) {
+      const project = await commands.projectCurrent().catch(() => null);
+      if (project?.root !== useProject.getState().project?.root)
+        useProject.setState({ project, ...(project ? { settings: project.settings } : {}), lightEdit: false });
+    }
+    throw error;
   } finally {
-    useProject.setState({ opening: false });
+    useProject.setState({ opening: false, openingPath: null });
   }
 }
 
diff --git a/src/styles/tokens.css b/src/styles/tokens.css
index 6d27f313..a572274a 100644
--- a/src/styles/tokens.css
+++ b/src/styles/tokens.css
@@ -18,6 +18,13 @@ html {
   --space-2: 8px;
   --space-3: 12px;
   --space-4: 16px;
+  --splash-logo-size: 56px;
+  --splash-bar-width: 120px;
+  --splash-bar-height: 2px;
+  --splash-gap: 14px;
+  --splash-offset: 38px;
+  --splash-progress-duration: 4s;
+  --splash-progress-easing: cubic-bezier(0.1, 0.7, 0.3, 1);
   /* surfaces */
   --bg-app: #191a1c;
   --bg-elev: #212326;
diff --git a/src/workbench/Workbench.module.css b/src/workbench/Workbench.module.css
index 48723829..7993b2b9 100644
--- a/src/workbench/Workbench.module.css
+++ b/src/workbench/Workbench.module.css
@@ -1,4 +1,5 @@
 .workbench {
+  position: relative;
   height: 100%;
   display: flex;
   flex-direction: column;
@@ -6,6 +7,90 @@
   background: var(--bg-app);
   color: var(--fg);
 }
+
+.content {
+  display: contents;
+}
+.content[inert] {
+  visibility: hidden;
+}
+.opening {
+  position: absolute;
+  inset: 0;
+  z-index: var(--z-panel);
+  display: flex;
+  flex-direction: column;
+  background: var(--bg-frame);
+}
+.openingBody {
+  flex: 1;
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: var(--splash-gap);
+  padding: var(--space-4) var(--space-4) var(--splash-offset);
+  color: var(--fg-muted);
+  text-align: center;
+  animation: opening-in var(--dur-slow) ease-out both;
+}
+.openingBrand {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: var(--splash-gap);
+  font-size: var(--fs-input-large);
+  font-weight: 500;
+  line-height: 1.21;
+}
+.openingLogo {
+  width: var(--splash-logo-size);
+  height: var(--splash-logo-size);
+}
+.openingProgress {
+  width: var(--splash-bar-width);
+  height: var(--splash-bar-height);
+  flex-shrink: 0;
+  border-radius: calc(var(--splash-bar-height) / 2);
+  background: color-mix(in srgb, var(--fg-muted) 24%, transparent);
+}
+.opening .openingProgress > div {
+  left: 0;
+  width: 100%;
+  opacity: 1;
+  background: var(--accent);
+  transform-origin: left;
+  animation: opening-progress var(--splash-progress-duration) var(--splash-progress-easing) both;
+}
+.openingTitle {
+  max-width: 100%;
+  overflow-wrap: anywhere;
+  font-size: var(--fs-small);
+}
+.openingPath {
+  max-width: 100%;
+  overflow-wrap: anywhere;
+  font-size: var(--fs-tiny);
+}
+@keyframes opening-in {
+  from {
+    opacity: 0;
+  }
+}
+@keyframes opening-progress {
+  from {
+    transform: scaleX(0.04);
+  }
+  to {
+    transform: scaleX(0.92);
+  }
+}
+@media (prefers-reduced-motion: reduce) {
+  .openingBody {
+    animation: none;
+  }
+}
 /* Islands frame; the project colour washes in from the top-left corner (IDEA project gradient). */
 .framed {
   background:
diff --git a/src/workbench/Workbench.test.tsx b/src/workbench/Workbench.test.tsx
index f8f8f717..2ebf6fcd 100644
--- a/src/workbench/Workbench.test.tsx
+++ b/src/workbench/Workbench.test.tsx
@@ -325,6 +325,41 @@ describe("tool window split areas", () => {
 });
 
 describe("workbench shell", () => {
+  it("covers the old project with the opening target and keeps its views mounted and inert", async () => {
+    const { useProject } = await import("@/platform/project");
+    const { Workbench } = await import("./Workbench");
+    const dispose = registerToolWindow({
+      id: "project",
+      title: "Project",
+      icon: "folder",
+      anchor: "left",
+      component: () => <input aria-label="old project input" />,
+    });
+    useProject.setState({
+      project: { root: "/old", name: "old", trusted: true, isGit: false, settings: {} },
+      opening: false,
+      openingPath: null,
+    });
+    loadToolWindowLayout("/old");
+    const { unmount } = render(<Workbench />);
+    const input = screen.getByRole("textbox", { name: "old project input" });
+    try {
+      act(() => useProject.setState({ opening: true, openingPath: "/work/new-project" }));
+      expect(screen.getByRole("status", { name: "Opening new-project…" })).toBeVisible();
+      expect(screen.getByText("/work/new-project")).toBeVisible();
+      expect(input.closest("[inert]")).not.toBeNull();
+      expect(input).toBeInTheDocument();
+      act(() => useProject.setState({ opening: false, openingPath: null }));
+      expect(screen.queryByText("Opening new-project…")).toBeNull();
+      expect(input.closest("[inert]")).toBeNull();
+      expect(screen.getByRole("textbox", { name: "old project input" })).toBe(input);
+    } finally {
+      unmount();
+      dispose();
+      useProject.setState({ project: null, opening: false, openingPath: null });
+    }
+  });
+
   it("renders the welcome view without a project and the frame with one", async () => {
     const { useProject } = await import("@/platform/project");
     const { Workbench } = await import("./Workbench");
diff --git a/src/workbench/Workbench.tsx b/src/workbench/Workbench.tsx
index 56c55c83..9b5c832c 100644
--- a/src/workbench/Workbench.tsx
+++ b/src/workbench/Workbench.tsx
@@ -6,6 +6,9 @@
  */
 import { useEditorRegistry } from "@/editor/api";
 import { basename, useProject } from "@/platform/project";
+import { useT } from "@/platform/i18n";
+import { ProgressBar } from "@/ui";
+import projectMark from "../../src-tauri/icons/source/openidea-mark.svg";
 import { useDistractionFree } from "./distractionFree";
 import { EditorArea } from "./EditorArea";
 import { OverlayHost } from "./OverlayHost";
@@ -37,11 +40,33 @@ function LightEditFrame() {
   );
 }
 
+function ProjectOpening({ path }: { path: string }) {
+  const t = useT();
+  const label = t("app.project.opening", { name: basename(path) });
+  return (
+    <div className={styles.opening} data-project-opening>
+      <TitleBar bare />
+      <div className={styles.openingBody} role="status" aria-label={label}>
+        <div className={styles.openingBrand} aria-hidden="true">
+          <img className={styles.openingLogo} src={projectMark} alt="" draggable={false} />
+          <span>OpenIDEA</span>
+        </div>
+        <ProgressBar className={styles.openingProgress} aria-label={label} />
+        <div className={styles.openingTitle}>{label}</div>
+        <div className={styles.openingPath} title={path}>
+          {path}
+        </div>
+      </div>
+    </div>
+  );
+}
+
 export function Workbench() {
   useApplyTheme();
   const banners = useContributions((s) => s.workbenchBanners);
   const project = useProject((s) => s.project);
   const lightEdit = useProject((s) => s.lightEdit);
+  const openingPath = useProject((s) => s.openingPath);
   const root = project?.root ?? null;
   const distractionFree = useDistractionFree((s) => s.active);
   const frame = project ? styles.framed : lightEdit ? styles.lightEditFrame : undefined;
@@ -51,22 +76,25 @@ export function Workbench() {
       className={frame ? `${styles.workbench} ${frame}` : styles.workbench}
       style={project ? projectColorVars(project.name) : undefined}
     >
-      {project ? (
-        <>
-          {/* Distraction Free Mode keeps the bar for the traffic lights and window dragging only. */}
-          <TitleBar bare={distractionFree} />
-          {!distractionFree && <WindowGroupTabs />}
-          {[...banners.values()].map(({ id, component: Banner }) => (
-            <Banner key={id} />
-          ))}
-          <ToolWindowLayout key={root} editor={<EditorArea />} />
-          {!distractionFree && <StatusBar />}
-        </>
-      ) : lightEdit ? (
-        <LightEditFrame />
-      ) : (
-        <Welcome />
-      )}
+      <div className={styles.content} inert={openingPath !== null} aria-hidden={openingPath ? true : undefined}>
+        {project ? (
+          <>
+            {/* Distraction Free Mode keeps the bar for the traffic lights and window dragging only. */}
+            <TitleBar bare={distractionFree} />
+            {!distractionFree && <WindowGroupTabs />}
+            {[...banners.values()].map(({ id, component: Banner }) => (
+              <Banner key={id} />
+            ))}
+            <ToolWindowLayout key={root} editor={<EditorArea />} />
+            {!distractionFree && <StatusBar />}
+          </>
+        ) : lightEdit ? (
+          <LightEditFrame />
+        ) : (
+          <Welcome />
+        )}
+      </div>
+      {openingPath && <ProjectOpening path={openingPath} />}
       <OverlayHost />
       <WindowResizeHandles />
     </div>