Session 1eqGpXSKRSqV

The red header is from our JS console experiments (hdr.style.background = 'red') — that's a leftover inline style that persists until Beeper reloads. Reload Beeper completely (quit and reopen) to clear it.

But looking at this screenshot, I can see:

• Left rail icons — still white/light background
• Header area — red (from JS experiment)
• Sidebar body — light blue ✓

The -webkit-app-region: no-drag fix should work once the leftover inline style is cleared. The inline style="background: red" was set directly on the element in the console and overrides everything including our CSS.

To clear the red: either quit and reopen Beeper, or run this in the console:

document.querySelector('.left-pane-header').removeAttribute('style');

That will remove the red and let our CSS rule take effect. Then screenshot again — if our v17 CSS rule is applied, you should see dark blue.

Wait — looking at this screenshot more carefully, the .left-pane-header area (the top strip where the filter/search/compose icons are) is now showing as light (white/light blue). The red is gone.

But the .left-pane-header background is STILL not dark blue. Let me check in the console right now what the computed bg is:

const hdr = document.querySelector('.left-pane-header');
console.log('bg:', getComputedStyle(hdr).backgroundColor);
console.log('app-region:', getComputedStyle(hdr).getPropertyValue('-webkit-app-region'));
console.log('inline style:', hdr.getAttribute('style'));

app-region: no-drag is working from our CSS — great! But background is still rgba(0, 0, 0, 0) despite our background: #1164a3 !important rule. Since inline style is null, something else is suppressing it.

Let me check if the background IS actually being applied but just not computed (maybe it's a child painting over it):

const hdr = document.querySelector('.left-pane-header');
hdr.style.setProperty('background', 'red', 'important');
const cs = getComputedStyle(hdr);
console.log('bg after force:', cs.backgroundColor);
console.log('background shorthand:', cs.background);

So inline !important works. But our CSS rule with !important doesn't. That means there's a CSS rule with higher specificity AND !important that's setting background: transparent. Let me find it:

const hdr = document.querySelector('.left-pane-header');
hdr.removeAttribute('style');
const sheets = Array.from(document.styleSheets);
const matching = [];
sheets.forEach((s, i) => {
  try {
    Array.from(s.cssRules).forEach((r, j) => {
      if (!r.selectorText) return;
      try {
        if (hdr.matches(r.selectorText)) {
          const bg = r.style.getPropertyValue('background');
          const bgColor = r.style.getPropertyValue('background-color');
          const bgPriority = r.style.getPropertyPriority('background');
          const bgColorPriority = r.style.getPropertyPriority('background-color');
          if (bg || bgColor) {
            const origin = s.ownerNode?.id || s.href?.split('/').pop() || 'inline';
            matching.push(i + '.' + j + ' [' + origin + '] ' + r.selectorText + ' => bg="' + bg + '"(' + bgPriority + ') bgColor="' + bgColor + '"(' + bgColorPriority + ')');
          }
        }
      } catch(e) {}
    });
  } catch(e) {}
});
matching.forEach(m => console.log(m));

Found it! Rule 3.42 is our own rule:

.left *:not([class*="selected"])... → background-color: transparent !important

This rule matches .left-pane-header (since it's inside .left and has no "selected" class), and it sets background-color: transparent !important. Since .left-pane-header is a child of .left, this rule applies to it and overrides our background!

The fix: add .left-pane-header to the :not() exclusions, or better yet, target only the thread items (not all descendants):

Now run stylelint and bump the marker:

Clean. Bump the marker:

v18 saved. Root cause: our own rule .left *:not(...) was matching .left-pane-header and setting background-color: transparent !important, overriding our blue header rule. Added .not(.left-pane-header) and .not(.tab-bar) and .not(.tab-bar-container) to the exclusion list.

Marker: v18-2026-06-05-r19 / 3a7f-orchid-conic-v18

Copy v18 to Beeper, reload. The header should finally be dark blue.

Progress! The header strip is now dark blue! But there are two remaining issues:

1. Left icon rail (the column with Beeper/Slack/Instagram icons on the far left) — still white/light
2. Header strip text/icons — need to check if white text is showing

The left rail is a completely separate element from .left-pane-header. Looking at the DOM hierarchy from earlier, the icons are at #root > div > div.left > div.threads-list-container > div.Sidebar-module__hoveringTrigger — wait, no. Let me re-examine. The icon rail (leftmost column) is actually OUTSIDE the .left element — it's a separate panel.

Run this in Beeper's console:

let el = document.elementFromPoint(60, 400);
const chain = [];
while (el && chain.length < 8) {
  chain.push(el.tagName + '.' + (el.className || '').slice(0, 60) + ' => ' + getComputedStyle(el).backgroundColor);
  el = el.parentElement;
}
chain.forEach(c => console.log(c));

I can see two issues in the Slack (dedicated) window:

1. Selected item overflow — #proj-junior is selected (dark blue) but the item above (#discuss-dev-inf) also has a dark blue background, like the selection is bleeding up
2. Left rail — still white/light (this is the dedicated Slack window, different structure)

The overflow issue is likely because our selected item rule doesn't have border-radius clipping correctly, or the .sidebar-thread.isSelected > section:before pseudo-element is painting over the item above.

Let me fix both. First the overflow — it's caused by the > section:before pseudo-element on the selected item expanding upward. Let me restrict it:

The > section:before pseudo-element sets a background color but may be overflowing. Let me remove those rules entirely (they were from the old approach) and rely solely on background-color on the thread item itself: