/* 站群静态包补充样式（仅静态演示用，套模板时可删） */
.to-top {
  position: fixed; right: 28px; bottom: 40px; z-index: 60;
  width: 44px; height: 44px; border: 0; border-radius: 50%;
  background: rgba(22, 58, 112, .82); color: #fff; font-size: 20px; line-height: 44px;
  cursor: pointer; opacity: 0; visibility: hidden; transition: .25s;
}
.to-top.on { opacity: 1; visibility: visible; }
.to-top:hover { background: #163a70; }
@media (max-width: 640px) { .to-top { right: 16px; bottom: 24px; } }