[Bug]: GUI dropdown menu overlap

[Wenz-jam]

Self checks

• I have searched existing issues, including closed issues.
• I have read the Contributing Guide.
• This is a bug report, not a question, feature request, or usage discussion.
• I will include logs, screenshots, or command output where they help reproduce the issue.
• I have removed secrets, private paths, tokens, and other sensitive information from the report.

ECOS Studio version

d486592

Affected area

GUI

How did you get ECOS Studio?

Source checkout with pnpm run dev

Where are you running ECOS Studio?

Native Linux desktop

Environment

Ubuntu25.04

ECC, PDK, and resource context

N/A – no ECC/PDK/resource context involved.

Steps to reproduce

1. Launch the application using any method:
   • Run pnpm run dev
   • Or run make gui
   • Or run ./ECOS-Studio_*.AppImage
2. Click on Backend Design in the main interface.
3. Click on the File or Help button in the top bar to open the dropdown menu.

Expected behavior

The dropdown menu should appear above all UI elements, including the back button (screenshot attached).

Actual behavior

The dropdown menu is blocked/covered by the back button (screenshot attached).

Logs, screenshots, or recordings

N/A

Additional context

Relevant Code Structure

<div class="topbar-left z[10]">
    <div class="menu-items">
        <div class="dropdown-menu z-[1000]"></div>
    </div>
</div>
<div class="app-main">
    <button class="z[20]">
        Back to ECOS
    </button>
</div>

The dropdown menu’s z-index: 1000 is confined within .topbar-left’s stacking context (z-index: 10). The back button resides in a separate stacking context that is painted above .topbar-left, causing the button to obscure the menu.

Fix

Raise .topbar-left’s z-index to a higher value (e.g., 30) or remove it entirely so the dropdown’s stacking context no longer loses to the back button’s container.