:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --text: #1f2328;
  --muted: #6b7280;
  --border: #e5e7eb;
  --accent: #4f46e5;
  --user-bg: #4f46e5;
  --user-text: #ffffff;
  --bot-bg: #f1f2f6;
  --error: #dc2626;
  --ok: #16a34a;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --panel: #171a21;
    --text: #e6e8eb;
    --muted: #9aa1ac;
    --border: #262a33;
    --bot-bg: #222631;
  }
}
* { box-sizing: border-box; margin: 0; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100vh;
  display: flex;
  justify-content: center;
}
.app {
  width: 100%;
  max-width: 760px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}
.header {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}
.avatar {
  width: 40px; height: 40px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  display: grid; place-items: center;
  font-weight: 700; font-size: 14px;
}
.header h1 { font-size: 17px; }
.status { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 6px; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
.dot.ok { background: var(--ok); }
.dot.error { background: var(--error); }
.messages {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.msg {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 14px;
  line-height: 1.45;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.msg.user { align-self: flex-end; background: var(--user-bg); color: var(--user-text); border-bottom-right-radius: 4px; }
.msg.bot { align-self: flex-start; background: var(--bot-bg); border-bottom-left-radius: 4px; }
.msg.typing { color: var(--muted); font-style: italic; }
.msg.error { color: var(--error); }
.composer {
  display: flex;
  gap: 10px;
  padding: 14px 20px;
  border-top: 1px solid var(--border);
}
.composer textarea {
  flex: 1;
  resize: none;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
  max-height: 140px;
}
.composer textarea:focus { outline: 2px solid var(--accent); border-color: transparent; }
.composer button {
  padding: 0 20px;
  border: none;
  border-radius: 12px;
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.composer button:disabled { opacity: .5; cursor: not-allowed; }
.footer { text-align: center; font-size: 12px; color: var(--muted); padding: 0 0 12px; }
@media (max-width: 600px) {
  .msg { max-width: 90%; }
  .messages, .composer { padding-left: 12px; padding-right: 12px; }
}
.reset {
  margin-left: auto;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
}
.reset:hover { color: var(--text); border-color: var(--muted); }