SaaS Clean Chat Conversation

Act like a frontend developer with 15 years of experience. I want the exact same UI with 95-99% similarity.

Platform: This is a RESPONSIVE design — it should work on both mobile and desktop. Use mobile layout patterns (bottom nav, stacked content) for mobile, and desktop layout patterns (sidebar/nav bar, wider content areas) for web.

Design a chat screen with a header showing avatar, name and online status, alternating incoming and outgoing message bubbles with timestamps, and a rounded input bar with an attach icon and a send button.

Visual style — SaaS Clean:
Crisp white cards with a single vivid brand accent, 8px radius, a subtle 1px border plus a barely-visible shadow, and clean geometric sans (Inter-style). Small rounded-square icon badges with tinted backgrounds. Confident, trustworthy, modern product design.

Color palette — Emerald Slate:
Background #FFFFFF, surfaces #F7FAF9. Text #131B18. Accent emerald #0D9488.

Typography — use these exact font families:
- Headings / display: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", sans-serif

Commit fully to this style — it should be unmistakable at a glance. Use realistic content, not placeholder text. Keep animations smooth (200ms ease-out).