From 870449fa4db66ccb4e55668226661ac18e0084f1 Mon Sep 17 00:00:00 2001
From: judy <judy@symbolstar.local>
Date: Fri, 26 Jun 2026 17:15:04 +0800
Subject: [PATCH] =?UTF-8?q?fix(web/style):=20=E9=BC=A0=E6=A0=87=20hover=20?=
 =?UTF-8?q?post-list=20=E6=97=B6=E6=BB=9A=E5=8A=A8=E6=9D=A1=E5=8D=A0?=
 =?UTF-8?q?=E4=BD=8D=E5=AF=BC=E8=87=B4=E5=86=85=E5=AE=B9=E5=B7=A6=E5=8F=B3?=
 =?UTF-8?q?=E6=8A=96=E5=8A=A8?=
MIME-Version: 1.0
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PR #93 把 #post-list 的 scrollbar 改成 hover 时显示，通过 hover 切换
scrollbar-width: none → auto 实现。但这个切换在 Firefox 和 Chromium
都会真正占走 ~10px 布局宽度，鼠标移进 post-list 内容左移 10px、移走
再右移回来，肉眼可见的抖动。

修法：scrollbar-gutter: stable 永远预留 gutter，bar 仍然只在 hover
时画。视觉上跟之前完全一致（默认空、hover 出现），但布局宽度恒定，
鼠标进出零 reflow。

(原本是跟 PR #106 keyed-diff 一起修的，但 #106 在 scrollbar 改动 push
上去之前就 merge 了，所以这里单独再开一个 PR。)
---
 CHANGELOG.md  | 1 +
 web/style.css | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index af2e518..0243958 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,7 @@ auto-generated notes — but stable semver tags must pass.
 ## Unreleased
 
 - Thread view no longer flickers on every refresh. The post list is now diffed in place (keyed by post id), so unchanged posts keep their existing DOM nodes — SSE bursts, the 8s poll fallback, and cross-tab broadcasts can all fire together without repainting the column. When SSE is healthy the per-thread poll is suppressed entirely.
+- Post column no longer shifts left/right when the pointer hovers the thread view. The Slack-style hover-reveal scrollbar now reserves its gutter at all times, so toggling the bar in/out doesn't reflow the column.
 - _Add entries here as they ship. They get cut into the next `v<semver>` section at release time._
 
 <!--
diff --git a/web/style.css b/web/style.css
index 6722574..34b4e5b 100644
--- a/web/style.css
+++ b/web/style.css
@@ -1382,6 +1382,12 @@ body.squad-collapsed #squad-list::-webkit-scrollbar { display: none; }  /* WebKi
   /* Hide scrollbar chrome by default — cleaner reading surface; bar
      reappears on :focus-within for keyboard users (a11y). */
   scrollbar-width: none;
+  /* Always reserve the scrollbar gutter on the right so the Slack-style
+     hover-reveal scrollbar below doesn't reflow the post column when the
+     pointer enters/leaves. Without this, toggling scrollbar-width from
+     `none` to `auto` on :hover physically pushes content ~10px left, then
+     back — the user-reported "闪" when the cursor moves over post-list. */
+  scrollbar-gutter: stable;
 }
 #post-list::-webkit-scrollbar { display: none; }
 /* Show scrollbar when the user hovers the messages pane (Slack-style: bar