From e6eb3dd8496ed9b5a2cc27c3a3bca7c2bd28e6e0 Mon Sep 17 00:00:00 2001
From: Codeman maintainer <noreply@anthropic.com>
Date: Wed, 7 Oct 2026 03:51:26 +0200
Subject: [PATCH] style(tiles): no CSS hides dividers and slots that a zoom
 never leaves

`.tile-grid--zoomed .tile-divider` and `.tile-grid--zoomed .tile-slot` hid
elements that do not exist while a tile is zoomed: _applyTileLayout toggles
the zoomed class in the same pass that syncs zero dividers and zero slots,
and it is the only place either is created. Both rules are gone.

The dividers test asserted the CSS rule; it now asserts what the user sees
(no divider elements while zoomed, two again on restore), and
tile-grid-entry-points gains the same check for the empty slot of three
tiles in a 2x2. Both fail if the zoom stops removing them.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 src/web/public/styles.css           |  8 --------
 test/tile-grid-dividers.test.ts     | 10 +++++-----
 test/tile-grid-entry-points.test.ts |  9 +++++++++
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index aca95c6d..e972d6f8 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -19557,10 +19557,6 @@ html[data-session-list="sidebar"][data-sidebar="collapsed"] .btn-sidebar-toggle
   background: var(--accent, #4a9eff);
 }
 
-.tile-grid.tile-grid--zoomed .tile-divider {
-  display: none;
-}
-
 /* While a divider drags: the resize cursor everywhere and no text selection
    (mirrors body.split-pane-resizing). */
 body.tile-grid-resizing,
@@ -19592,10 +19588,6 @@ body.tile-grid-resizing--row * {
   opacity: 0.6;
 }
 
-.tile-grid.tile-grid--zoomed .tile-slot {
-  display: none;
-}
-
 /* A tab dragged over a tile (replace it) or an empty slot (add it). */
 .tile.tile--drop-target,
 .tile-slot.tile--drop-target {
diff --git a/test/tile-grid-dividers.test.ts b/test/tile-grid-dividers.test.ts
index 4071c8f7..9f3e7604 100644
--- a/test/tile-grid-dividers.test.ts
+++ b/test/tile-grid-dividers.test.ts
@@ -12,8 +12,6 @@
  *
  * Real code via the shared vm harness (test/mocks/tile-grid-vm.ts). Port: N/A.
  */
-import { readFileSync } from 'node:fs';
-import { resolve } from 'node:path';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import {
   FakeEl,
@@ -204,11 +202,13 @@ describe('fractions on fewer columns', () => {
 });
 
 describe('zoomed', () => {
-  it('shows no dividers', () => {
+  it('has no dividers while a tile fills the grid, and gets them back on restore', () => {
     const app = grid(['s-a', 's-b', 's-c', 's-d']);
+    const dividerEls = () => section.children.filter((el) => el.className.startsWith('tile-divider'));
     app.zoomTile('s-a');
     expect(app._tileGrid.dividers.size).toBe(0);
-    const css = readFileSync(resolve(import.meta.dirname, '../src/web/public/styles.css'), 'utf8');
-    expect(css).toMatch(/\.tile-grid\.tile-grid--zoomed \.tile-divider\s*\{\s*display: none;/);
+    expect(dividerEls()).toHaveLength(0);
+    app.zoomTile('s-a');
+    expect(dividerEls()).toHaveLength(2);
   });
 });
diff --git a/test/tile-grid-entry-points.test.ts b/test/tile-grid-entry-points.test.ts
index fe4b56b4..2c181677 100644
--- a/test/tile-grid-entry-points.test.ts
+++ b/test/tile-grid-entry-points.test.ts
@@ -120,6 +120,15 @@ describe('dragging a tab onto an empty slot', () => {
     app.openTileGrid(['s-a', 's-b']);
     expect(slots()).toHaveLength(0);
   });
+
+  it('a zoomed grid has no slot; restoring the grid brings it back', () => {
+    const app = makeGridApp(IDS);
+    app.openTileGrid(IDS);
+    app.zoomTile('s-a');
+    expect(slots()).toHaveLength(0);
+    app.zoomTile('s-a');
+    expect(slots()).toHaveLength(1);
+  });
 });
 
 describe('Ctrl/Cmd+click on a tab', () => {