diff --git a/apps/desktop/src/components/editor/EditorSettingsDialog.vue b/apps/desktop/src/components/editor/EditorSettingsDialog.vue
index 88e1c1df30..d5dd4dd75b 100644
--- a/apps/desktop/src/components/editor/EditorSettingsDialog.vue
+++ b/apps/desktop/src/components/editor/EditorSettingsDialog.vue
@@ -239,6 +239,7 @@ import { DEFAULT_DATA_GRID_FONT_FAMILY, DEFAULT_UI_FONT_FAMILY, normalizeCustomF
 import { buildFontFamilyOptions, displayFontFamily, isPresetFontFamily, loadSystemFontNames } from "@/lib/app/fontFamilyOptions";
 import { buildAppSupportInfoRows, formatAppSupportInfoForClipboard, type AppSupportInfoLabels } from "@/lib/app/supportInfo";
 import { useUiFontFamilyPreview } from "@/composables/useUiFontFamilyPreview";
+import { useMeasuredWidth } from "@/composables/useMeasuredWidth";
 import { DateTimePatterns, normalizeSupportedDateTimePattern } from "@/lib/dataGrid/columnFormatter";
 import { MAX_RESULT_PAGE_SIZE, MIN_RESULT_PAGE_SIZE } from "@/lib/dataGrid/paginationPageSize";
 import { MAX_QUERY_RESULT_MAX_ROWS } from "@/lib/dataGrid/queryResultRowLimit";
@@ -2187,7 +2188,21 @@ function formatShortcutPill(shortcut: string): string {
 }
 
 const shortcutPressShortcutLabel = computed(() => t("settings.shortcutPressShortcut"));
-const shortcutPressShortcutInputWidth = computed(() => `${shortcutPressShortcutLabel.value.length + 2}em`);
+// #9144: `label.length + 2em` under-sizes CJK placeholders wherever the
+// environment's fallback font advances wider than 1em (user report: 15px/char
+// at a 13px font → the last glyph clipped mid-stroke). Measure a hidden mirror
+// span carrying the same box + typography classes as the capture inputs
+// instead; the char-count formula only survives as the pre-measurement
+// fallback. The +2px cushion absorbs sub-pixel rounding differences between
+// the mirror span and the real input.
+const shortcutPressShortcutInputWidth = ref(`${shortcutPressShortcutLabel.value.length + 2}em`);
+const shortcutPlaceholderMirrorRef = ref<HTMLElement | null>(null);
+const shortcutPlaceholderMirrorWidth = useMeasuredWidth(shortcutPlaceholderMirrorRef, 0, [shortcutPressShortcutLabel]);
+watch(shortcutPlaceholderMirrorWidth, (width) => {
+  if (width > 0) {
+    shortcutPressShortcutInputWidth.value = `${Math.ceil(width) + 2}px`;
+  }
+});
 
 function focusShortcutInput(actionId: ShortcutActionId) {
   editingShortcutId.value = actionId;
@@ -9724,6 +9739,13 @@ LIMIT 100;</pre
       :confirm-label="t('common.delete')"
       @confirm="templateDeleteConfirm && confirmDeleteTemplate(templateDeleteConfirm)"
     />
+
+    <!-- Hidden mirror of the shortcut-capture placeholder: measured to size
+         the capture inputs (#9144). Carries the same box + typography classes
+         as those inputs (font-mono text-[13px] font-semibold px-2.5 border) so
+         its border-box width is exactly what they need, including font-fallback
+         advances and letter-spacing that char-count arithmetic cannot predict. -->
+    <span ref="shortcutPlaceholderMirrorRef" aria-hidden="true" class="invisible pointer-events-none absolute top-0 left-0 h-0 max-w-64 overflow-hidden whitespace-pre rounded-[6px] border px-2.5 font-mono text-[13px] font-semibold">{{ shortcutPressShortcutLabel }}</span>
   </component>
 </template>
 
diff --git a/apps/desktop/src/components/editor/__tests__/EditorSettingsDialog.shortcutCaptureInputWidth.spec.ts b/apps/desktop/src/components/editor/__tests__/EditorSettingsDialog.shortcutCaptureInputWidth.spec.ts
new file mode 100644
index 0000000000..5e012ffb1a
--- /dev/null
+++ b/apps/desktop/src/components/editor/__tests__/EditorSettingsDialog.shortcutCaptureInputWidth.spec.ts
@@ -0,0 +1,74 @@
+// @vitest-environment happy-dom
+// Source-assertion regression for #9144: the shortcut-capture input width must
+// come from measuring a hidden mirror span (same box + typography as the real
+// inputs), not from `label.length + 2em` char-count arithmetic — CJK fallback
+// fonts can advance wider than 1em and clip the last placeholder glyph. The
+// dialog cannot be mounted (a 10k-line SFC whose imports pull the whole
+// editor + stores), so this follows the same `?raw` pattern as
+// EditorSettingsDialog.mcpQueryTimeout.integration.spec.ts.
+import { describe, expect, it } from "vitest";
+import dialogSource from "../EditorSettingsDialog.vue?raw";
+
+function templateOnly(): string {
+  // The root <template> block, not the first "</template>" — this SFC is full
+  // of nested slot <template> elements, so the first closing tag (and the
+  // naive slice up to it) lands inside the template and misses most of it.
+  return dialogSource.slice(dialogSource.search(/^<template>$/m), dialogSource.lastIndexOf("</template>"));
+}
+
+describe("EditorSettingsDialog shortcut capture input width (#9144)", () => {
+  it("mounts exactly one hidden mirror span carrying the shared typography/box classes", () => {
+    const template = templateOnly();
+
+    // The ref token appears exactly once in the template: the mirror span.
+    // (The two script occurrences are the ref declaration and the
+    // useMeasuredWidth call.)
+    expect(template.match(/shortcutPlaceholderMirrorRef/g)).toHaveLength(1);
+    expect(dialogSource.match(/shortcutPlaceholderMirrorRef/g)).toHaveLength(3);
+
+    // Same box + typography classes as the capture inputs so the measured
+    // border-box width includes padding, border, letter-spacing and
+    // fallback-font advances. Asserted against the span's own tag (not the
+    // whole template) — the capture inputs share these classes, so a
+    // template-wide match would pass even with the span stripped.
+    const spanTag = template.match(/<span ref="shortcutPlaceholderMirrorRef"[^>]*>/)?.[0];
+    expect(spanTag).toBeTruthy();
+    for (const cls of ["font-mono", "text-[13px]", "font-semibold", "px-2.5", "border", "whitespace-pre", "invisible"]) {
+      expect(spanTag).toContain(cls);
+    }
+
+    // The label must be interpolated in-band with the span tags, not as
+    // template text between newlines — whitespace-pre would otherwise widen
+    // the measured box.
+    expect(template).toMatch(/<span ref="shortcutPlaceholderMirrorRef"[^>]*>\{\{ shortcutPressShortcutLabel \}\}<\/span>/);
+  });
+
+  it("binds all three capture inputs to the measured width ref", () => {
+    // Two width bindings gate on the row-level editing state (formatter table
+    // + shortcuts table), one on the SQL-shortcut dialog editing state. Each
+    // conditional token appears in exactly one kind of binding.
+    expect(dialogSource.match(/editingShortcutId === definition\.id \? shortcutPressShortcutInputWidth/g)).toHaveLength(2);
+    expect(dialogSource.match(/editingSqlShortcutInputId === 'dialog' \? shortcutPressShortcutInputWidth/g)).toHaveLength(1);
+
+    // Account for every usage of the width ref: 1 fallback initializer,
+    // 1 watcher application, 3 capture-input bindings.
+    expect(dialogSource.match(/shortcutPressShortcutInputWidth/g)).toHaveLength(5);
+  });
+
+  it("wires the measured width to the shared mirror ref with the label as revalidate source", () => {
+    expect(dialogSource).toContain("useMeasuredWidth(shortcutPlaceholderMirrorRef, 0, [shortcutPressShortcutLabel])");
+
+    // The applied width adds a ~2px cushion and rounds up so sub-pixel
+    // rounding never under-sizes.
+    expect(dialogSource).toContain("${Math.ceil(width) + 2}px");
+  });
+
+  it("keeps the char-count formula only as the ref fallback initializer", () => {
+    // The legacy `length + 2em` estimate survives solely as the pre-measurement
+    // initializer of the ref.
+    expect(dialogSource).toContain("shortcutPressShortcutInputWidth = ref(`${shortcutPressShortcutLabel.value.length + 2}em`)");
+
+    // No computed re-derives the width from char count anymore.
+    expect(dialogSource).not.toMatch(/computed\(\(\) => `\$\{shortcutPressShortcutLabel\.value\.length \+ 2\}em`\)/);
+  });
+});
diff --git a/apps/desktop/src/composables/__tests__/useMeasuredWidth.spec.ts b/apps/desktop/src/composables/__tests__/useMeasuredWidth.spec.ts
new file mode 100644
index 0000000000..041f992426
--- /dev/null
+++ b/apps/desktop/src/composables/__tests__/useMeasuredWidth.spec.ts
@@ -0,0 +1,129 @@
+// @vitest-environment happy-dom
+import { createApp, defineComponent, h, nextTick, ref } from "vue";
+import type { Ref, WatchSource } from "vue";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { useMeasuredWidth } from "../useMeasuredWidth";
+
+function createHarness(revalidateSources: WatchSource[] = []) {
+  const targetRef = ref<HTMLElement | null>(null);
+  let widthRef: Ref<number> | undefined;
+  const app = createApp(
+    defineComponent({
+      setup() {
+        widthRef = useMeasuredWidth(targetRef, 42, revalidateSources);
+        return () => h("div");
+      },
+    }),
+  );
+  app.mount(document.createElement("div"));
+  return { targetRef, widthRef: widthRef!, unmount: () => app.unmount() };
+}
+
+/** A bare element whose getBoundingClientRect reports the given width. */
+function elementOfWidth(width: number): HTMLElement {
+  const element = document.createElement("span");
+  Object.defineProperty(element, "getBoundingClientRect", {
+    configurable: true,
+    value: () => ({ width, height: 0, top: 0, left: 0, bottom: 0, right: 0, x: 0, y: 0, toJSON: () => ({}) }),
+  });
+  return element;
+}
+
+async function flush(ticks = 5) {
+  for (let i = 0; i < ticks; i += 1) {
+    await nextTick();
+  }
+}
+
+describe("useMeasuredWidth", () => {
+  beforeEach(() => {
+    document.body.innerHTML = "";
+  });
+
+  afterEach(() => {
+    document.body.innerHTML = "";
+  });
+
+  it("keeps the fallback while no element is attached", async () => {
+    const { targetRef, widthRef } = createHarness();
+    expect(targetRef.value).toBeNull();
+    await flush();
+    expect(widthRef.value).toBe(42);
+  });
+
+  it("measures the element once attached", async () => {
+    const { targetRef, widthRef } = createHarness();
+
+    targetRef.value = elementOfWidth(90);
+    await flush();
+    expect(widthRef.value).toBe(90);
+  });
+
+  it("ignores a zero-width measurement instead of clobbering the previous width", async () => {
+    const flag = ref(0);
+    const { targetRef, widthRef } = createHarness([() => flag.value]);
+
+    targetRef.value = elementOfWidth(90);
+    await flush();
+    expect(widthRef.value).toBe(90);
+
+    // Zero width means "not laid out yet" (or display:none ancestry), never
+    // "the text is zero pixels wide" — must not replace a usable width. Bump
+    // the revalidate source so a re-measure actually runs against the
+    // zero-width stub.
+    Object.defineProperty(targetRef.value!, "getBoundingClientRect", {
+      configurable: true,
+      value: () => ({ width: 0, height: 0, top: 0, left: 0, bottom: 0, right: 0, x: 0, y: 0, toJSON: () => ({}) }),
+    });
+    flag.value += 1;
+    await flush();
+    expect(widthRef.value).toBe(90);
+  });
+
+  it("re-measures when a revalidate source changes (ResizeObserver-unavailable path)", async () => {
+    const flag = ref(0);
+    const { targetRef, widthRef } = createHarness([() => flag.value]);
+
+    targetRef.value = elementOfWidth(70);
+    await flush();
+    expect(widthRef.value).toBe(70);
+
+    // A locale swap changed the text: the element resized without moving, so
+    // only the source watch picks it up.
+    Object.defineProperty(targetRef.value!, "getBoundingClientRect", {
+      configurable: true,
+      value: () => ({ width: 91, height: 0, top: 0, left: 0, bottom: 0, right: 0, x: 0, y: 0, toJSON: () => ({}) }),
+    });
+    flag.value += 1;
+    await flush();
+    expect(widthRef.value).toBe(91);
+  });
+
+  it("re-binds and re-measures when the target element is swapped", async () => {
+    const { targetRef, widthRef } = createHarness();
+
+    targetRef.value = elementOfWidth(90);
+    await flush();
+    expect(widthRef.value).toBe(90);
+
+    targetRef.value = elementOfWidth(120);
+    await flush();
+    expect(widthRef.value).toBe(120);
+  });
+
+  it("stays inert after unmount (observer disconnected, no stray throws)", async () => {
+    const { targetRef, unmount } = createHarness();
+
+    targetRef.value = elementOfWidth(90);
+    await flush();
+    expect(targetRef.value).not.toBeNull();
+
+    unmount();
+    // Mutating the stub and flushing must not throw once the app is gone.
+    Object.defineProperty(targetRef.value!, "getBoundingClientRect", {
+      configurable: true,
+      value: () => ({ width: 200, height: 0, top: 0, left: 0, bottom: 0, right: 0, x: 0, y: 0, toJSON: () => ({}) }),
+    });
+    await flush();
+  });
+});
diff --git a/apps/desktop/src/composables/useMeasuredWidth.ts b/apps/desktop/src/composables/useMeasuredWidth.ts
new file mode 100644
index 0000000000..6f0c08dff6
--- /dev/null
+++ b/apps/desktop/src/composables/useMeasuredWidth.ts
@@ -0,0 +1,62 @@
+import { nextTick, onUnmounted, ref, watch, type Ref, type WatchSource } from "vue";
+
+/**
+ * Measured border-box width (CSS pixels) of a mirror element.
+ *
+ * Measuring primitive for widths that char-count arithmetic cannot predict:
+ * bind the returned ref to a template ref and it tracks the element's real
+ * laid-out width — including font-fallback advances, letter-spacing, and
+ * sub-pixel rounding. Motivated by #9144, where the zh-CN shortcut-capture
+ * placeholder advanced 15px/char on a machine whose CJK fallback font renders
+ * wider than 1em, so a `label.length + 2em` width clipped the last glyph.
+ *
+ * The width starts at `fallback` so callers render a sane size before the
+ * first measurement lands (and in environments without real layout, e.g.
+ * happy-dom). Zero-width measurements are ignored: they mean "not laid out
+ * yet" (or `display: none` ancestry), never "the text is zero pixels wide",
+ * and must not clobber a usable width. `revalidateSources` covers content
+ * changes that resize the element without moving it (e.g. a locale swap)
+ * for environments where ResizeObserver is unavailable.
+ */
+export function useMeasuredWidth(targetRef: Ref<HTMLElement | null>, fallback = 0, revalidateSources: WatchSource[] = []): Ref<number> {
+  const width = ref(fallback);
+  let resizeObserver: ResizeObserver | undefined;
+
+  function measure() {
+    const element = targetRef.value;
+    if (!element) {
+      return;
+    }
+    const measured = element.getBoundingClientRect().width;
+    if (measured > 0) {
+      width.value = measured;
+    }
+  }
+
+  if (revalidateSources.length > 0) {
+    watch(revalidateSources, () => {
+      void nextTick(measure);
+    });
+  }
+
+  watch(
+    targetRef,
+    (element) => {
+      resizeObserver?.disconnect();
+      resizeObserver = undefined;
+      if (element && typeof ResizeObserver !== "undefined") {
+        resizeObserver = new ResizeObserver(measure);
+        resizeObserver.observe(element);
+      }
+      void nextTick(measure);
+    },
+    { flush: "post" },
+  );
+
+  onUnmounted(() => {
+    resizeObserver?.disconnect();
+    resizeObserver = undefined;
+  });
+
+  return width;
+}