Chat and Input UI Fixes and Improvements

[Cdddo]

Chat and Input UI Fixes and Improvements

This commit improves the appearance of the chat panel and input area below it.

Chat Messages Enhancements:

• Improved the chat message colors: the user message is a darker grey, error and warning are slightly darker and less saturated, and the AI response has been changed from green to the same dark grey as the user
• Increased chat message padding and reduced corner radius to improve overall chat appearance
• Removed utility message indent to align the messages, providing a cleaner look
• Limited the max-width of the chat message containers to maintain a readable line-length

Input Area Enhancements:

• Made the input section background color match the chat's background, making for a sleeker look
• Reduced the chat buttons corner radius (making them rounded rectangles instead of circles, to match the rest of the UI)
• Removed unnecessary scaling on hover of the user message input field and the submit / voice buttons
• Reduced opacity of the placeholder text, making it subtler

Fixes:

• Don't override chat scrollbar color to maintain consistent colors in the UI
• Consolidated conflicting duplicate input-section layout rules