:root {
  --bg: #0e1116;
  --panel: #161b22;
  --panel-2: #1c2230;
  --border: #2a313c;
  --text: #d6dde6;
  --muted: #8b949e;
  --accent: #4c8dff;
  --user: #1f6feb;
  --ok: #3fb950;
  --err: #f85149;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

body {
  display: flex;
  flex-direction: column;
  max-width: 860px;
  margin: 0 auto;
}

header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { font-size: 16px; font-weight: 600; letter-spacing: .2px; }
.brand .tag { font-size: 12px; color: var(--muted); }
.dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); }

.conn { font-size: 12px; color: var(--muted); }
.conn.ok { color: var(--ok); }
.conn.err { color: var(--err); }

#chat {
  flex: 1;
  overflow-y: auto;
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.msg {
  max-width: 78%;
  padding: 10px 14px;
  border-radius: 12px;
  white-space: pre-wrap;
  word-wrap: break-word;
}

.msg.user {
  align-self: flex-end;
  background: var(--user);
  color: #fff;
  border-bottom-right-radius: 3px;
}

.msg.assistant {
  align-self: flex-start;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-bottom-left-radius: 3px;
}

.msg.system {
  align-self: center;
  background: transparent;
  border: 1px dashed var(--border);
  color: var(--muted);
  font-size: 13px;
}

.msg.status {
  align-self: flex-start;
  color: var(--muted);
  font-style: italic;
  font-size: 13px;
  background: transparent;
}

#composer {
  display: flex;
  gap: 10px;
  padding: 14px 20px;
  border-top: 1px solid var(--border);
  background: var(--panel);
}

#input {
  flex: 1;
  resize: none;
  max-height: 160px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}
#input:focus { outline: none; border-color: var(--accent); }

#send {
  padding: 0 20px;
  border: 0;
  border-radius: 10px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}
#send:hover { filter: brightness(1.1); }
#send:disabled { opacity: .5; cursor: default; }