:root {
  --bg: #f2f5f6; --panel: #ffffff; --ink: #14202b; --muted: #5d6c78;
  --line: #d8e0e4; --accent: #0f6f68; --accent-ink: #ffffff; --err: #a6342b;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f171d; --panel: #17222a; --ink: #e6edf1; --muted: #90a1ad;
          --line: #27363f; --accent: #3fb5aa; --accent-ink: #06201d; --err: #f08a80; }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body { background: var(--bg); color: var(--ink);
  font: 16px/1.55 "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif; }
.app { max-width: 780px; height: 100%; margin: 0 auto; display: flex; flex-direction: column; padding: 0 16px; }
.bar { display: flex; align-items: center; justify-content: space-between; padding: 16px 0 12px; border-bottom: 1px solid var(--line); }
.bar h1 { font-size: 1.15rem; font-weight: 600; margin: 0; }
.bar-actions { display: flex; gap: 8px; }
.banner { margin-top: 12px; padding: 10px 14px; border: 1px solid var(--err); color: var(--err); border-radius: 8px; font-size: .92rem; }
.log { flex: 1; overflow-y: auto; padding: 20px 0; display: flex; flex-direction: column; gap: 12px; }
.empty { margin: auto; color: var(--muted); }
.msg { max-width: 85%; padding: 10px 14px; border-radius: 12px; white-space: pre-wrap; overflow-wrap: anywhere; }
.msg.user { align-self: flex-end; background: var(--ink); color: var(--bg); border-bottom-right-radius: 4px; }
.msg.agent { align-self: flex-start; background: var(--panel); border: 1px solid var(--line); border-bottom-left-radius: 4px; }
.msg.error { align-self: flex-start; border: 1px solid var(--err); color: var(--err); background: transparent; }
.msg.pending { color: var(--muted); }
.composer { display: flex; gap: 8px; padding: 12px 0 16px; border-top: 1px solid var(--line); }
textarea, input { font: inherit; color: var(--ink); background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; }
textarea { flex: 1; resize: none; max-height: 160px; }
textarea:focus-visible, input:focus-visible, .btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn { font: inherit; font-weight: 500; border-radius: 8px; padding: 9px 16px; border: 1px solid var(--line); cursor: pointer; background: var(--panel); color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.ghost { background: transparent; }
.btn:disabled { opacity: .55; cursor: not-allowed; }
dialog { border: 1px solid var(--line); border-radius: 12px; background: var(--panel); color: var(--ink); width: min(440px, 92vw); padding: 22px; }
dialog::backdrop { background: rgba(0,0,0,.45); }
dialog h2 { margin: 0 0 6px; font-size: 1.1rem; }
.hint { color: var(--muted); font-size: .88rem; margin: 0 0 14px; }
label { display: block; font-size: .9rem; font-weight: 500; margin-bottom: 12px; }
label input { display: block; width: 100%; margin-top: 4px; font-weight: 400; }
.opt { color: var(--muted); font-weight: 400; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 8px; }