fix(reply-modal): blur TeX button when preview closes

Blur the TeX preview trigger on close so Escape does not leave a
lingering focus outline or tooltip on the button.

src/components/reply-modal/__tests__/reply-modal.test.tsx

@@ -544,6 +544,33 @@ describe('ReplyModal', () => {
     expect(texPreview?.textContent).toContain('tex_preview_title');
   });
 
+  it('clears TeX button focus after closing the TeX preview with Escape', async () => {
+    testState.directoryByAddress['science-and-math.bso'] = {
+      address: 'science-and-math.bso',
+      directoryCode: 'sci',
+      features: {},
+      title: '/sci/ - Science & Math',
+    };
+    testState.communities['science-and-math.bso'] = { address: 'science-and-math.bso' };
+
+    await renderReplyModal('/sci/thread/post-1', 'science-and-math.bso');
+
+    const texButton = container.querySelector<HTMLButtonElement>('button[aria-label="preview_tex_equations"]');
+    expect(texButton).toBeTruthy();
+
+    await act(async () => {
+      texButton?.focus();
+      texButton?.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+    });
+    expect(document.activeElement).toBe(texButton);
+
+    await act(async () => {
+      document.dispatchEvent(new KeyboardEvent('keydown', { bubbles: true, cancelable: true, key: 'Escape' }));
+    });
+
+    expect(document.activeElement).not.toBe(texButton);
+  });
+
   it('shows a flag selector on flag boards and publishes the default geographic request', async () => {
     await renderReplyModal('/pol/thread/post-1', 'politically-incorrect.bso');
 

src/components/reply-modal/reply-modal.module.css

@@ -58,17 +58,11 @@
   text-decoration: none;
 }
 
-.texButton:hover,
-.texButton:focus-visible {
+.texButton:hover {
   color: var(--button-desktop-text-color-hover);
   text-decoration: none;
 }
 
-.texButton:focus-visible {
-  outline: 1px dotted currentColor;
-  outline-offset: 1px;
-}
-
 .texButton sub {
   font-size: 80%;
   pointer-events: none;

src/components/reply-modal/reply-modal.tsx

@@ -127,7 +127,13 @@ const ReplyModal = ({ closeModal, showReplyModal, parentCid, parentNumber, threa
   const [isBbcodePreviewing, setIsBbcodePreviewing] = useState(false);
   const [bbcodePreviewContent, setBbcodePreviewContent] = useState('');
   const [showTexPreview, setShowTexPreview] = useState(false);
-  const closeTexPreview = useCallback(() => setShowTexPreview(false), []);
+  const texButtonRef = useRef<HTMLButtonElement>(null);
+  // Blur in the close handler so the TeX button doesn't keep a lingering focus state
+  // (focus-visible promotion on Escape, focus-triggered tooltip) after the preview closes.
+  const closeTexPreview = useCallback(() => {
+    setShowTexPreview(false);
+    texButtonRef.current?.blur();
+  }, []);
 
   const checkContentLengthRef = useRef(
     debounce((content: string, t: TFunction, options: string, directoryCode: string | undefined) => {
@@ -550,6 +556,7 @@ const ReplyModal = ({ closeModal, showReplyModal, parentCid, parentNumber, threa
         {showTexButton && !isMobile && (
           <Tooltip content={t('preview_tex_equations')} className={styles.texButtonTooltip}>
             <button
+              ref={texButtonRef}
               type='button'
               className={styles.texButton}
               onClick={(e) => {