Nextcloud Desktop UI Customization

I have brand-ready design references and now need the Nextcloud desktop client adapted to match them. The scope is strictly visual: applying a custom theme and colour palette, swapping in a full set of new icons/illustrations, and adjusting the window layout so key elements line up with the mock-ups I will supply.

You will work against the latest stable Nextcloud desktop source, so familiarity with its Qt/C++ codebase, QML styling and SVG asset pipelines is important. A short read-me describing the build steps for Windows, macOS and Linux should accompany the final pull request or patch set so my in-house team can continue maintenance without friction.

Deliverables
• Fork or patch of the official client implementing the theme, icons and layout tweaks
• All graphic assets exported in vector and @2x raster formats, organised by platform folders
• Build and installation instructions confirmed on at least one OS (the others may remain untested but should compile)

Acceptance criteria
1. Visual appearance matches the provided mock-ups pixel-for-pixel on the target OS.
2. No regressions in sync functionality or existing settings panels.
3. CI pipeline passes the existing unit tests.

If you enjoy making open-source apps look first-class, this should be a straightforward but satisfying project.

A complete handover of the project with details of codes that were changed, you will guide us the relevant information to change in future by ourself.