html, body { background: #F5F7FA; }

#rkb-install-hint {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: calc(12px + env(safe-area-inset-bottom));
  z-index: 2147483647;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 8px 12px 16px;
  border-radius: 12px;
  background: #0175C2;
  color: #fff;
  font: 15px/1.35 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  box-shadow: 0 6px 24px rgba(0, 0, 0, .25);
}

#rkb-install-hint span { flex: 1; }

#rkb-install-hint button {
  flex: none;
  width: 36px;
  height: 36px;
  border: 0;
  border-radius: 18px;
  background: rgba(255, 255, 255, .18);
  color: #fff;
  font-size: 22px;
  line-height: 36px;
  cursor: pointer;
}