apps/web/e2e/a11y.spec.ts

@@ -120,11 +120,22 @@ async function expectNoHorizontalScroll(page: Page, label: string): Promise<void
   const report = await page.evaluate(() => {
     const doc = document.documentElement;
     const limit = doc.clientWidth;
+    /** Content inside its own scroll container is allowed to be wider than
+     *  the viewport — that is the prescribed remedy, not the defect. Only
+     *  what pushes the PAGE is a finding. */
+    const insideScroller = (el: HTMLElement): boolean => {
+      for (let node = el.parentElement; node && node !== doc; node = node.parentElement) {
+        const overflowX = getComputedStyle(node).overflowX;
+        if (overflowX === 'auto' || overflowX === 'scroll' || overflowX === 'hidden') return true;
+      }
+      return false;
+    };
+
     const offenders: string[] = [];
     for (const el of Array.from(document.querySelectorAll<HTMLElement>('body *'))) {
       const rect = el.getBoundingClientRect();
       // 1 px Toleranz gegen Subpixel-Rundung.
-      if (rect.width > 0 && rect.right > limit + 1) {
+      if (rect.width > 0 && rect.right > limit + 1 && !insideScroller(el)) {
         const cls =
           el.className && typeof el.className === 'string'
             ? `.${el.className.trim().split(/\s+/).join('.')}`
@@ -134,7 +145,7 @@ async function expectNoHorizontalScroll(page: Page, label: string): Promise<void
         );
       }
     }
-    return { scrollWidth: doc.scrollWidth, clientWidth: limit, offenders: offenders.slice(0, 12) };
+    return { scrollWidth: doc.scrollWidth, clientWidth: limit, offenders: offenders.slice(0, 20) };
   });
   expect(
     { overflowBy: report.scrollWidth - report.clientWidth, offenders: report.offenders },

apps/web/src/styles/base.css

@@ -4014,6 +4014,12 @@ ul[data-type='task_list'] li p:last-of-type {
     position: static;
     width: 100%;
     overflow-x: auto;
+    /* THE reflow fix (issue #301). As a flex child the nav defaults to
+       `min-width: auto`, i.e. the min-content width of the whole jump
+       strip — so it pushed the column wider than the viewport and its own
+       `overflow-x: auto` never got the chance to scroll anything. Measured
+       at 320px: 417px of page-level overflow, all of it these links. */
+    min-width: 0;
   }
 
   .settings-nav ul {