XS✔ ◾ Fix #785: make the Settings nav scrollbar visible across OSes

src/ui/src/components/settings/SettingsDialog.tsx

@@ -214,7 +214,7 @@ export function SettingsDialog() {
             className="flex-1 min-w-0 h-full overflow-hidden"
           >
             <ScrollArea className="h-full">
-              <div className="pb-4 pr-1">
+              <div className="pb-4 pr-3">
                 {activeTab?.id === "general" && (
                   <GeneralSettingsPanel isActive={open && activeTabId === "general"} />
                 )}

src/ui/src/components/settings/SettingsNav.test.tsx

@@ -118,3 +118,24 @@ describe("SettingsNav (#803) keyboard navigation", () => {
     expect(buttons[0]).toHaveAttribute("tabindex", "-1");
   });
 });
+
+describe("SettingsNav (#785) scrollable when window height is reduced", () => {
+  it("renders the tablist inside a scroll-area viewport, not a plain overflow div", () => {
+    // #785: the nav previously scrolled via a bare `overflow-y-auto` div, whose
+    // scrollbar is the OS/browser's native one — which can render with zero
+    // visible width (observed on Linux/GTK themes) or stay hidden until
+    // scrolled (macOS default), leaving no visible affordance that more tabs
+    // exist below the fold. The tablist must live inside the shared
+    // `ScrollArea` (the same styled-scrollbar component the settings panel
+    // uses) so it gets a visible, cross-OS-consistent scrollbar whenever its
+    // content overflows.
+    render(<SettingsNav tabs={tabs} activeTabId="general" onSelect={vi.fn()} />);
+
+    const tablist = screen.getByRole("tablist", { name: "Settings sections" });
+    const viewport = tablist.closest('[data-slot="scroll-area-viewport"]');
+    expect(viewport).not.toBeNull();
+
+    const scrollAreaRoot = viewport?.closest('[data-slot="scroll-area"]');
+    expect(scrollAreaRoot).not.toBeNull();
+  });
+});

src/ui/src/components/settings/SettingsNav.tsx

@@ -1,4 +1,5 @@
 import { type KeyboardEvent, useEffect, useRef, useState } from "react";
+import { ScrollArea } from "../ui/scroll-area";
 import { SettingsNavHealthIndicator } from "./SettingsNavHealthIndicator";
 import type { SettingsHealthMap } from "./settings-health";
 import { nextRovingIndex } from "./settings-nav-keys";
@@ -23,7 +24,7 @@ interface SettingsNavProps {
  * Keyboard-accessible Settings options list.
  *
  * Fixes #803:
- *  - `min-h-0` lets the nav shrink inside its flex row so `overflow-y-auto`
+ *  - `min-h-0` lets the nav shrink inside its flex row so the scroll container
  *    actually engages and every tab (e.g. "Account") stays reachable instead of
  *    overflowing and being clipped.
  *  - Roving-tabindex + Up/Down/Home/End arrow navigation (the list previously
@@ -35,6 +36,16 @@ interface SettingsNavProps {
  *    was vetoed by the unsaved-changes guard (where `activeIndex` doesn't change
  *    and the resync effect below wouldn't fire). A later Arrow press then steps
  *    from where the user visibly is, not a stale keyboard position.
+ *
+ * Fixes #785:
+ *  - The list previously scrolled via plain `overflow-y-auto`, which relies on
+ *    the OS/browser's native scrollbar. That scrollbar can render with zero
+ *    visible width (seen on Linux/GTK themes, and macOS's default
+ *    hidden-until-scroll setting), leaving no visual affordance that the list
+ *    has more content below the fold even though wheel/trackpad scrolling
+ *    mechanically works. Wrapping the tablist in the same `ScrollArea` used by
+ *    the settings panel gives it the app's styled, always-visible scrollbar
+ *    thumb consistently across OSes, matching AC3/AC4/AC5.
  */
 export function SettingsNav({ tabs, activeTabId, panelId, onSelect, tabHealth }: SettingsNavProps) {
   const activeIndex = Math.max(
@@ -61,40 +72,42 @@ export function SettingsNav({ tabs, activeTabId, panelId, onSelect, tabHealth }:
   };
 
   return (
-    <div
-      aria-label="Settings sections"
-      role="tablist"
-      aria-orientation="vertical"
-      onKeyDown={handleKeyDown}
-      className="w-48 flex flex-col gap-1 flex-shrink-0 overflow-y-auto pr-1 min-h-0"
-    >
-      {tabs.map((tab, index) => {
-        const isActive = tab.id === activeTabId;
-        const health = tabHealth?.[tab.id];
-        return (
-          <button
-            key={tab.id}
-            ref={(el: HTMLButtonElement | null) => {
-              buttonsRef.current[index] = el;
-            }}
-            type="button"
-            role="tab"
-            aria-selected={isActive}
-            aria-controls={panelId}
-            tabIndex={index === focusIndex ? 0 : -1}
-            onFocus={() => setFocusIndex(index)}
-            onClick={() => onSelect(tab.id)}
-            className={`group relative flex items-center justify-between gap-2 text-left px-3 py-2.5 rounded-md transition-colors border border-transparent ${
-              isActive
-                ? "bg-white/10 border-white/20 text-white"
-                : "text-white/80 hover:bg-white/5 hover:text-white"
-            }`}
-          >
-            <div className="text-sm font-medium">{tab.label}</div>
-            {health ? <SettingsNavHealthIndicator health={health} /> : null}
-          </button>
-        );
-      })}
-    </div>
+    <ScrollArea type="auto" className="w-48 h-full flex-shrink-0 min-h-0">
+      <div
+        aria-label="Settings sections"
+        role="tablist"
+        aria-orientation="vertical"
+        onKeyDown={handleKeyDown}
+        className="flex flex-col gap-1 pr-3"
+      >
+        {tabs.map((tab, index) => {
+          const isActive = tab.id === activeTabId;
+          const health = tabHealth?.[tab.id];
+          return (
+            <button
+              key={tab.id}
+              ref={(el: HTMLButtonElement | null) => {
+                buttonsRef.current[index] = el;
+              }}
+              type="button"
+              role="tab"
+              aria-selected={isActive}
+              aria-controls={panelId}
+              tabIndex={index === focusIndex ? 0 : -1}
+              onFocus={() => setFocusIndex(index)}
+              onClick={() => onSelect(tab.id)}
+              className={`group relative flex items-center justify-between gap-2 text-left px-3 py-2.5 rounded-md transition-colors border border-transparent ${
+                isActive
+                  ? "bg-white/10 border-white/20 text-white"
+                  : "text-white/80 hover:bg-white/5 hover:text-white"
+              }`}
+            >
+              <div className="text-sm font-medium">{tab.label}</div>
+              {health ? <SettingsNavHealthIndicator health={health} /> : null}
+            </button>
+          );
+        })}
+      </div>
+    </ScrollArea>
   );
 }