✨(frontend) add default background to left panel for better accessibi…

[Ovgodd]

Purpose

Fix visual accessibility issue caused by missing background color in the custom LeftPanel used in DOCS.

issue : 896

Proposal

• Add default background color to the LeftPanel used in DOCS
• Ensure alignment with UI Kit behavior, which already defines a background color
• Improve accessibility for users applying custom styles (e.g., via Stylus extension)

Note: The LeftPanel from the UI Kit has default background color but DOCS uses a custom implementation of a LeftPanel.

[github-actions]

Size Change: +11 B (0%)

Total Size: 3.65 MB

Filename	Size	Change
apps/impress/out/_next/static/ad1f5b13/_buildManifest.js	0 B	-865 B (removed)	🏆
apps/impress/out/_next/static/bf7d6635/_buildManifest.js	866 B	+866 B (new file)	🆕

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