Front-end Login page Design

Dependencies: #7
Related Issues: #6

User Story

As a doctor,
I want to log in with a verified account,
so that I can have access to patient information.

[x] The login page shall contain username and password input boxes and a login button, and the password shall be masked.
[x] The web page shall provide a prompt when an error occurs.
[x] The front-end UI design shall is responsive and compatible with both desktop and mobile browsers.
[x] The front-end UI design shall conform to operational logic, good visuals, and a unified style.
[x] The front-end UI design shall primarily be designed using the Tailwind CSS framework.