:root {
  --bg: #fbfaf7;
  --fg: #1a1a1a;
  --muted: #6a6a6a;
  --border: #e3e0d8;
  --accent: #1f6feb;
  --user-bg: #eef3ff;
  --assistant-bg: #fff;
  --status: #8a8a8a;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.55;
}

.login {
  max-width: 420px;
  margin: 10vh auto;
  padding: 32px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
}
.login h1 { margin-top: 0; font-size: 24px; }
.login .lede { color: var(--muted); }
.login form { display: flex; flex-direction: column; gap: 14px; }
.login label { display: flex; flex-direction: column; gap: 4px; font-size: 14px; color: var(--muted); }
.login input {
  font-size: 16px; padding: 10px 12px;
  border: 1px solid var(--border); border-radius: 8px;
  background: #fff;
}
.login button {
  font-size: 15px; padding: 10px 14px;
  background: var(--accent); color: #fff; border: 0; border-radius: 8px;
  cursor: pointer;
}
.login .notice { color: var(--muted); }
.login .error { color: #b91c1c; font-size: 14px; }

.topbar {
  display: flex; align-items: center; gap: 14px;
  padding: 10px 16px;
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
}
.topbar .title { font-weight: 600; }
.topbar .who { color: var(--muted); font-size: 13px; }
.topbar form { margin-left: auto; }
.topbar form + form { margin-left: 8px; }
.topbar button.link {
  background: transparent; border: 0; color: var(--accent);
  cursor: pointer; padding: 4px 6px; font-size: 13px;
}

.thread {
  max-width: 820px;
  margin: 0 auto;
  padding: 24px 16px 140px;
  display: flex; flex-direction: column; gap: 16px;
}

.bubble {
  padding: 12px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  max-width: 100%;
}
.bubble.user {
  background: var(--user-bg);
  align-self: flex-end;
  max-width: 80%;
}
.bubble.user p { margin: 0; white-space: pre-wrap; }
.bubble.assistant {
  background: var(--assistant-bg);
  align-self: stretch;
}
.bubble.assistant .status {
  color: var(--status); font-size: 13px; font-style: italic;
  min-height: 0;
}
.bubble.assistant .status:not(:empty) {
  margin-bottom: 8px;
}
.bubble.assistant .content { margin: 0; }
.bubble.assistant .content p:first-child { margin-top: 0; }
.bubble.assistant .content p:last-child { margin-bottom: 0; }
.bubble.assistant .content table {
  border-collapse: collapse; margin: 8px 0;
}
.bubble.assistant .content th, .bubble.assistant .content td {
  border: 1px solid var(--border); padding: 4px 8px;
}
.bubble.assistant .content code {
  background: #f3f1ec; padding: 1px 5px; border-radius: 4px;
  font-size: 0.92em;
}
.bubble.assistant .content a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: rgba(31,111,235,0.4);
  text-underline-offset: 2px;
}
.bubble.assistant .sources {
  margin-top: 12px;
  border-top: 1px solid var(--border);
  padding-top: 8px;
  font-size: 13px;
}
.bubble.assistant .sources summary {
  cursor: pointer;
  color: var(--muted);
}
.bubble.assistant .sources ul {
  margin: 8px 0 0 0;
  padding-left: 18px;
}
.bubble.assistant .sources a { color: var(--accent); }

#composer {
  position: fixed; bottom: 0; left: 0; right: 0;
  background: #fff; border-top: 1px solid var(--border);
  padding: 12px 16px;
  display: flex; gap: 10px;
  z-index: 10;
}
#composer textarea {
  flex: 1;
  resize: vertical; min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--border); border-radius: 8px;
  font: inherit;
  background: #fff;
}
#composer button {
  font-size: 15px; padding: 0 18px;
  background: var(--accent); color: #fff; border: 0; border-radius: 8px;
  cursor: pointer; align-self: flex-end; min-height: 44px;
}