[Documentation Update]: Making UI of sign in page more attractive

[dhairyagothi]

Is there an existing issue for this?

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Issue Description

fixing css of Sign in page

Suggested Change

css change of sign in page

Rationale

No response

Urgency

High

Record

• I have read the Contributing Guidelines
• I'm a GSSOC'24 contributor
• I have starred the repository

[malvika-sinha]

I want to resolve the issue, kindly assign me the task