Fix: Remove deprecated css argument from Blocks() for Gradio 4–6 compatibility

[Ahmadalzin95]

Summary

This PR fixes a compatibility issue with newer Gradio versions (>= 4.x).

In main_demo, gradio.Blocks is currently called with a css keyword argument:

with gradio.Blocks(css=""".gradio-container {margin: 0 !important; min-width: 100%};""", title="DUSt3R Demo") as demo:

In Gradio>=4, Blocks no longer accepts a css keyword, which results in:

TypeError: BlockContext.init() got an unexpected keyword argument 'css'

Fix

The fix simply moves the css argument from the Blocks constructor to demo.launch, which is supported in both Gradio 3 and >=4:

with gradio.Blocks(title="DUSt3R Demo") as demo:
    ...
demo.launch(
    share=False,
    server_name=server_name,
    server_port=server_port,
    css=""".gradio-container {margin: 0 !important; min-width: 100%};""",
)

Notes

Tested locally with:

• Python 3.11
• torch 2.5.1
• gradio 6.0.1

This change remains backward-compatible with Gradio 3.x and 4.x, because the launch(css=...) argument is supported across versions, while css= in Blocks() has been removed in Gradio 4+.