@media (max-width: 600px) {
  .bubble { max-width: 85%; }
  .app {
    max-width: 100%;
    height: 100vh;
    height: 100dvh;
    height: var(--app-h, 100dvh);
    margin: 0;
    border-radius: 0;
    box-shadow: none;
  }
  .icon-btn { width: 44px; height: 44px; }
  .icon-btn svg { width: 20px; height: 20px; }
  .send-btn { width: 44px; height: 44px; }
  .mic-btn { width: 44px; height: 44px; }
  .composer-input {
    font-size: 16px;
    padding: 12px 14px;
  }
  .composer {
    padding: 10px 12px;
    padding-bottom: calc(10px + env(safe-area-inset-bottom));
    gap: 8px;
  }
  .header { padding: 10px 14px; }
}