diff --git a/task-launcher/src/utils/detectInput.ts b/task-launcher/src/utils/detectInput.ts
new file mode 100644
index 000000000..79a7db84f
--- /dev/null
+++ b/task-launcher/src/utils/detectInput.ts
@@ -0,0 +1,71 @@
+type InputType = 'touch' | 'mouse' | 'keyboard' | 'unknown';
+
+interface InputCapability {
+  touch: boolean;
+  mouse: boolean;
+  primary: InputType;
+}
+
+interface InputDetector {
+  capability: InputCapability;
+  getCurrentInput: () => InputType | null;
+}
+
+export function setupInputDetection(): InputDetector {
+  const mq = (query: string): boolean =>
+    window.matchMedia(query).matches;
+
+  // --- Capability snapshot
+  const capability: InputCapability = {
+    touch:
+      navigator.maxTouchPoints > 0 ||
+      mq('(any-pointer: coarse)'),
+
+    mouse: mq('(any-pointer: fine)'),
+
+    primary: mq('(pointer: coarse)')
+      ? 'touch'
+      : mq('(pointer: fine)')
+      ? 'mouse'
+      : 'unknown'
+  };
+
+  let lastTouchTime = 0;
+  let currentInput: InputType | null = null;
+
+  const setInput = (type: InputType) => {
+    if (currentInput === type) return;
+    currentInput = type;
+    document.documentElement.dataset.input = type;
+  };
+
+  // --- Interaction detection
+  window.addEventListener(
+    'touchstart',
+    () => {
+      lastTouchTime = Date.now();
+      setInput('touch');
+    },
+    { passive: true }
+  );
+
+  window.addEventListener('mousemove', () => {
+    // Ignore fake mouse events after touch
+    if (Date.now() - lastTouchTime < 500) return;
+    setInput('mouse');
+  });
+
+  window.addEventListener('keydown', () => {
+    setInput('keyboard');
+  });
+
+  // --- Initial guess
+  if (capability.primary !== 'unknown') {
+    setInput(capability.primary);
+  }
+
+  return {
+    capability,
+    getCurrentInput: () => currentInput
+  };
+}
\ No newline at end of file