Improve visibility of reply indicator bar in chat UI

Problem

When a user selects Reply on a message, a reply indicator bar appears above the typing area. However, the current visual styling makes this bar difficult to notice because it uses colors that are very similar to both the typing window and the surrounding chat background. (On all "offical" themes.) As a result, it is not always clear that the user is currently replying to a specific message. If the user starts a reply, pauses, and then returns to the conversation later, they may forget that reply mode is active and accidentally send a message as a reply to the wrong person/message.

Proposed solution

The reply indicator should be visually distinct from the typing area and chat background, so it is immediately clear when reply mode is active. This could be improved by increasing the contrast, adding a more visible border, accent color, or background shade, making the “replying to…” state more prominent, and ensuring that the cancel/close reply button is easy to see. A clearer visual state would reduce mistakes and improve the overall chat experience.