Flipkart Machine coding round

The task was to build a static email application with the following core functionalities:

• Layout: A two-panel interface – a left sidebar for the inbox and a larger right panel for detailed email viewing.
• Data: We were provided with hardcoded email data by the interviewer.
• Inbox View (Left Panel): A scrollable list displaying individual emails.
  • Click Interaction: Selecting an email in the list should:
    • Open its detailed view in the right panel.
    • Visually mark the email as "read" in the list (background changing to a light grey).
  • Visual States:
    • Currently Reading: The selected email in the list should have a subtle yellow background.
    • Read: Previously opened emails in the list should have a light grey background.
    • Unread: All unopened emails should have a white background.
• Email Detail View (Right Panel): Upon selecting an email, the right panel should display:
  • Sender information.
  • Timestamp of the email.
  • A button to "Mark as Unread," which would revert its visual state in the left panel and its read status.
• Persistence: Both the "delete email" and "mark as read/unread" actions should persist across multiple hypothetical visits to the application.

Bonus Challenge:

• Implement a search bar at the top to filter the displayed emails.

All of the code should be written in HTML, CSS and Vanilla JavaScript.