:root {
  --bg: #0b0f14;
  --panel: rgba(255,255,255,0.06);
  --panel2: rgba(255,255,255,0.10);
  --text: rgba(255,255,255,0.92);
  --muted: rgba(255,255,255,0.65);
  --border: rgba(255,255,255,0.12);
  --radius: 16px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

.app {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: block;
}

.brandName {
  font-weight: 700;
}

.brandTag {
  font-size: 12px;
  color: var(--muted);
}

.actions {
  display: flex;
  gap: 8px;
}

button {
  background: var(--panel2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 10px;
  cursor: pointer;
}

.panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.messages {
  flex: 1;
  padding: 14px;
  overflow-y: auto;
}

.bubble {
  max-width: 85%;
  padding: 10px 12px;
  border-radius: 12px;
  margin-bottom: 10px;
  border: 1px solid var(--border);
  white-space: pre-wrap;
}

.bubble.user {
  margin-left: auto;
  background: var(--panel2);
}

.bubble.bot {
  background: rgba(0,0,0,0.20);
}

.composer {
  display: flex;
  gap: 10px;
  padding: 12px;
  border-top: 1px solid var(--border);
}

textarea {
  flex: 1;
  resize: none;
  padding: 10px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(0,0,0,0.25);
  color: var(--text);
  font-size: 14px;
}

@media (max-width: 700px) {
  textarea { font-size: 16px; }
}