Single frame at 375 × 760. RAG-grounded chat thread on a phone — full-height scrollable conversation, citation chips beneath each AI answer, sticky input bar pinned to bottom.
Full-height chat: user bubbles right-aligned (brand-700 / white text), AI bubbles left-aligned (white / border) with a small AI avatar. Citation chips sit inside each AI bubble below a dashed separator — file icon + filename, tappable, brand-50 background. Input bar is pinned bottom: pill-shaped text field, mic, and a brand-700 send button. Header drops the desktop title row in favor of an eyebrow + h1 + "+ New chat" link aligned right.