bug(desktop): v2.10.0 map popup header/close button misplaced; CSS override fixes until reopen #9481

Environment

• Official Windows desktop release v2.10.0 (Tauri / WebView2)
• Desktop dashboard in German; observed on multiple map overlays (conflict-zone 'KYIV', cyber threat 'Dragonfly')
• Issue occurs when clicking an icon/zone on the map and opening an informational .map-popup.

Actual behavior

The popup content/body renders normally, but the title bar and close button are visually displaced above and left of the popup, with much of the title bar clipped/overlaid. Closing via Escape works; close button can be hit in an unexpected position, and the popup body can still scroll. Reopening reproduces.

When testing the first affected conflict-zone popup in DevTools:

popup (getBoundingClientRect): left=632, top=781, width=360, height=560
popup .popup-header: left=461, top=759, width=343, height=45
popup .popup-close: left=766, top=769, width=24, height=24
popup.scrollLeft=0; popup.scrollTop=0
popup.scrollWidth=343; popup.clientWidth=343
elementFromPoint(closeButtonCenter).tagName = BUTTON

The positions clearly put the header to the left/above the parent rectangle even when the popup's own scroll offsets are 0. Resetting scroll offsets made no difference.

Confirmed temporary workaround

While the popup is open, apply the following styles to its .popup-header only:

header.style.setProperty('position', 'static', 'important');
header.style.setProperty('transform', 'none', 'important');
header.style.setProperty('translate', 'none', 'important');
header.style.setProperty('margin', '0', 'important');
header.style.setProperty('inset', 'auto', 'important');

This immediately restores the complete title bar and aligns the close (×) icon at the right edge. New popups are freshly created DOM nodes, so a session-only MutationObserver applying the same style overrides to each new .map-popup:not(.map-popup-sheet) .popup-header reproduces a good layout across repeated openings of several popup types.

This is diagnostic evidence of a CSS layout/positioning problem, not proof that position: sticky by itself is the root cause; which of the overrides is essential remains to be isolated.

Expected

The desktop map popup title bar should be entirely inside the top edge of its own popup, with the close control aligned on the upper right, on repeated opening and when the content is long.

Code pointers

• src/components/MapPopup.ts: show() constructs .map-popup, positions and appends it to document.body; hide() discards it; Escape handler works.
• src/styles/main.css: .map-popup { position: fixed; overflow-y:auto; }; .popup-header { display:flex; position:sticky; top:0; }; .popup-close button styles.
• Please check the interaction between position:sticky, any inherited transforms/zoom/scale, and the scroll container in the packaged WebView2 release. A fix should preserve sticky behavior if possible and cover desktop popup reopen flows in a regression test.

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