I want you to act as a web developer and please write some code for me to create a real-time search feature for the website.

I want you to act as a web developer and please write some code for me to create a real-time search feature for the website.
Search bar:
An input field with a “Magnifying Glass” icon, featuring a simple design.
There is a distinct visual feedback when gaining focus (e.g., the border changes color).
Result dropdown panel:
Located below the search bar, with a white background and some shadowing. The z-index should be higher than that of any other content on the page.
If results are found, display a list of matching items; if no results are found, display a message indicating “No relevant results found.”
The panel needs to support a maximum height restriction. If it exceeds this limit, internal scrolling should be implemented to prevent obscuring page content.