Website Functionality Enhancement

I need to update the functionality and features of my website, specifically the user login/logout system.

Requirements:
- Implement a secure user login/logout feature.
- Create a user role system with an admin role.

Ideal Skills and Experience:
- Experience in web development, particularly with user authentication.
- Knowledge of role-based access control.
- Familiarity with security protocols to protect user data.

Please ensure the update is seamless and does not disrupt the existing user experience.