Why: during a run nothing was rendered (the assistant message only lands
at completion, so the LiveState projection never hit the screen), and
white-space:pre-wrap on .part-text turned marked's inter-block newlines
into blank lines, giving ordered lists a huge per-item gap. A latent
race also wiped thinking/tool/phase state that arrived before the send
POST resolved, and thinking text ran inline with the answer.
Evidence: headless playwright against the mock backend shows the live
bar, an expanded thinking panel, tool chips and incremental text with a
blinking cursor mid-run; list item gaps measure 2.1px with
white-space:normal; make test (frontend 9 tests) green.
Impact: users watch thinking, tool calls and the answer stream in real
time; markdown typography (lists, tables, quotes, headings) is compact;
terminal runs fold the process trail behind a summary.
Refs: feature/chat-live-quality task card.
Why: .chat is a column-flex item of .main without min-height:0, so its
content-based automatic minimum height grew past the viewport; .chat-body
never overflowed (never scrolled) and the input bar was pushed off-screen.
Evidence: headless Chromium on mock serve, 1024x620: before .chat=2130px
and input-bar bottom=717 (>viewport), chat-body scrollable=false; after
.chat=620, chat-body clientH 501 / scrollH 2011 with wheel scroll moving
600px up and back to bottom, input-bar bottom=620. Variants (empty
conversation, single short message, 1024x400, 720x600) keep the input
visible. Full combo make test green.
Impact: chat page was unusable beyond one screen of content; single CSS
rule chain, no behavior change elsewhere.
Refs: Agent-System-Dev task card feature/chat-scroll-fix.
weichen