The top bar packs three zones onto one row: the view-mode toggle, the editor
actions (Compile/Run/Stop/...), and the canvas controls (board selector,
Serial, Scope, zoom, Add) portaled in from SimulatorCanvas. The editor zone
was flex:1 min-width:0 while the canvas zone was fixed-width, so when the bar
narrowed - mainly when the right-docked AI chat opens - the editor zone shrank
below its own buttons and painted them over the board selector / Serial /
Scope. The existing collapse logic was keyed to the viewport (@media 768px),
so it never fired on a wide screen with the chat open.
Make the shared bar a container-query context and collapse every zone by the
bar's own width instead of the viewport: view-mode labels drop to icons first,
then Serial/Scope/Add labels and the board selector ellipsizes, then the
component count and finally the zoom buttons (wheel-zoom still works). Floor
the editor zone at its collapsed content width so it can never underflow and
overlap; past that the lower-priority canvas controls yield toward the right
edge instead. Verified across bar widths 660-1140px with the AI chat open:
overlap eliminated, dropdown menus still render un-clipped.
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