diff --git a/docs/superpowers/specs/2026-05-21-mypass-design.md b/docs/superpowers/specs/2026-05-21-mypass-design.md
index ee4f869..9a22033 100644
--- a/docs/superpowers/specs/2026-05-21-mypass-design.md
+++ b/docs/superpowers/specs/2026-05-21-mypass-design.md
@@ -34,14 +34,15 @@ MyPassCore (Swift Package)
 ├── Entry / Group / Attachment — value-type models
 ├── TOTPGenerator         — RFC 6238 TOTP from otp:// custom field
 ├── VaultSession          — owns the live KDBXDatabase; lock/unlock lifecycle
-└── KeychainStore         — read/write master password in shared Keychain group
+├── KeychainStore         — read/write master password in shared Keychain group
+└── KeePassIconMapper     — approximates KeePass's standard iconIndex (0-68) as SF Symbols
 
 MyPass (Main App Target)  ──links──► MyPassCore
 ├── UnlockView
-├── GroupBrowserView
+├── EntryListView         — flat, filterable entry list (see UI Navigation)
+├── GroupFilterView       — sidebar: multi-select group tree, filters EntryListView
 ├── EntryDetailView
 ├── EntryEditView
-├── SearchView
 ├── FileBookmarkService   — security-scoped bookmark management
 ├── BiometricAuthService  — LAContext wrapper
 └── ClipboardService      — copy with 30 s expiry
@@ -135,28 +136,59 @@ struct TOTPConfig {
 
 ## UI Navigation
 
-### iOS — NavigationStack
+**Revised 2026-09-19** — replaces the original group-drilling design (see git history for the prior version). The main area now shows a flat, filterable list of entries instead of requiring the user to navigate into groups one at a time; groups become a filter, not a place you browse into.
+
+### Shared structure (iOS + macOS — same component, one implementation)
 
 ```
-UnlockView
-  └─► GroupBrowserView (root group)
-        ├─► GroupBrowserView (subgroup, pushed recursively)
-        └─► EntryDetailView
-              └─► EntryEditView (sheet)
+NavigationSplitView(columnVisibility:)
+├── sidebar: GroupFilterView         — multi-select group tree (see below)
+└── detail:  NavigationStack
+              └─► EntryListView (flat, filtered)
+                    └─► EntryDetailView
+                          └─► EntryEditView (sheet)
 ```
 
-- Search bar at the top of every `GroupBrowserView` filters entries globally across all groups
-- Swipe-to-delete on entries; toolbar `+` button adds an entry in the current group
-- Tapping a password field in `EntryDetailView` copies to clipboard (clears after 30 s)
-- TOTP code displays with a countdown ring and refreshes automatically
+`NavigationSplitView` is used on **both** platforms instead of maintaining separate iOS/macOS navigation code. On iPhone-width layouts it automatically collapses the sidebar into an overlay; on iPad/Mac it can sit persistently alongside the detail column. This behavior is built into the component — no platform-specific branching needed for it.
 
-### macOS — NavigationSplitView (3 columns)
+- **Hamburger button** (leading toolbar item, `"line.3.horizontal"`) toggles `columnVisibility` between `.all` and `.detailOnly`, showing/hiding the sidebar.
+- **Search icon** (trailing toolbar item, `"magnifyingglass"`) toggles a `.searchable()` bar over `EntryListView`; tapping again hides it and clears the query.
+- Swipe-to-delete on entry rows; toolbar `+` button opens `EntryEditView` for a new entry (see "Add-entry flow" below).
+- Tapping a password field in `EntryDetailView` copies to clipboard (clears after 30 s).
+- TOTP code displays with a countdown ring and refreshes automatically.
+- Keyboard shortcuts (macOS): `⌘C` copies password, `⌘⌥C` copies TOTP code, `⌘E` opens edit sheet.
 
-| Sidebar | Middle | Detail |
-|---|---|---|
-| Group tree (expandable) | Entry list for selected group + search bar | Entry fields + Edit button |
+### Entry list (`EntryListView`)
 
-Keyboard shortcuts: `⌘C` copies password, `⌘⌥C` copies TOTP code, `⌘E` opens edit sheet.
+Flat list, one row per entry across the whole vault (or the filtered subset — see below). Each row:
+
+```
+[icon]  Title
+        username · Group > Subgroup > Sub-subgroup
+```
+
+- **Icon:** always shown, mapped from the entry's `iconIndex` via `KeePassIconMapper` (an approximate SF Symbol per KeePass's standard 0–68 icon palette; unmapped indices fall back to `"key.fill"`). The data model has no custom-icon-image support yet — only the standard palette index — so this is a best-effort visual match, not pixel-accurate.
+- **Breadcrumb:** full ancestor path excluding the vault's top-level `root` group (e.g. an entry directly in `root > Work > Email` shows as `Work > Email`, not `Root > Work > Email` — the root node isn't a meaningful group to the user). Truncated in the middle if too long for the row. Computed by a tree-flattening helper (`VaultViewModel.flatEntries: [(entry: Entry, groupPath: [Group])]`) that walks the vault once per access, since entries don't natively carry a back-reference to their parent group. An entry stored directly in the root group (no breadcrumb) just shows the username line with nothing after it.
+
+### Group filter (`GroupFilterView`, the sidebar)
+
+A tree of all groups (never entries), each row a `DisclosureGroup` with a leading checkbox-style tap target (`circle` / `checkmark.circle.fill`) — a real `Toggle` isn't used here since it would conflict with the disclosure triangle's own tap target.
+
+- Selecting a group selects it and its entire subgroup subtree (recursive select-down); deselecting a parent deselects the whole subtree too.
+- Selection state (`Set<UUID>`) lives in `GroupFilterViewModel`, separate from `VaultViewModel` — the sidebar's tree-interaction concerns (expand/collapse, checkbox propagation) are distinct from list-filtering concerns. `ContentView` wires the resulting set into `VaultViewModel.selectedGroupIds`.
+- Empty selection = no filter (show everything). A "Clear filter" affordance resets it.
+
+### Filtering: group selection and search combine with AND
+
+`VaultViewModel.displayedEntries` applies, in order: (1) group filter — keep only entries whose direct parent group ID is in `selectedGroupIds` (or all entries if empty), then (2) search filter — substring match on title/username/URL, same as the existing behavior. Both active at once narrows the result to their intersection (e.g. select "Work", then search "email" → only Work entries matching "email").
+
+### Add-entry flow
+
+Flattening removes the implicit "current group" that group-drilling used to provide. `EntryEditView` gets an explicit **group picker field** (listing the group tree by full path) instead, defaulting to: the sole selected filter group if exactly one is active, otherwise the vault's root group. The user can change it before saving. `EntryEditViewModel.groupId` becomes a real, always-present field rather than the previous optional-with-silent-failure.
+
+### Dark mode
+
+No new work needed — the codebase already uses only semantic SwiftUI colors (`.secondary`, `.tint`, system backgrounds) with zero hardcoded color values, which follow the system appearance automatically. No in-app override setting for now; this may become a settings item later.
 
 ---
 
@@ -226,15 +258,20 @@ Entry URL field is matched against the `serviceIdentifier` using host comparison
 - `TOTPGenerator`: known test vectors from RFC 6238
 - `ProtectedString`: obfuscation / reveal symmetry
 - AutoFill URL matching: table-driven tests covering exact match, subdomain, no-URL entries
+- `KeePassIconMapper`: known indices map to expected symbols, unmapped indices fall back correctly
 
 ### `MyPassTests` (integration)
 - Unlock flow with a test KDBX fixture
 - Add / edit / delete entry persisted to file
+- Tree-flattening helper: entries paired with correct full `groupPath`, including nested subgroups
+- Group-filter subtree selection: selecting a parent group selects all descendant subgroup IDs; deselecting a parent deselects the whole subtree
+- Group filter + search combine as AND: narrowing by group then searching returns only the intersection
 
 ### `MyPassUITests`
-- Unlock → browse groups → view entry detail → copy password
-- Add entry → verify it appears in list
+- Unlock → view flat entry list → tap entry → view detail → copy password
+- Add entry → verify it appears in list with the group picker's chosen group
 - Search: query returns expected entries
+- Group filter: selecting a group in the sidebar narrows the list; selecting a parent with subgroups includes descendant entries
 
 ---