.gkbtt-button {
  position: fixed;
  right: 22px;
  bottom: 24px;
  z-index: 9998;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 58px;
  height: 58px;
  padding: 0;
  border: 1px solid #2d78c4;
  border-radius: 50%;
  background: #2d78c4;
  box-shadow: 0 8px 18px rgba(45, 120, 196, .24);
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity .2s ease, transform .2s ease, box-shadow .2s ease;
}

.gkbtt-button.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.gkbtt-button:hover {
  background: #1f67ad;
  border-color: #1f67ad;
  box-shadow: 0 10px 24px rgba(45, 120, 196, .34);
  transform: translateY(-2px);
}

.gkbtt-button span {
  display: block;
  width: 14px;
  height: 14px;
  margin-top: 6px;
  border-top: 3px solid #fff;
  border-left: 3px solid #fff;
  transform: rotate(45deg);
}

.gkbtt-button::after {
  content: "";
  position: absolute;
  width: 3px;
  height: 22px;
  margin-top: 7px;
  border-radius: 999px;
  background: #fff;
}

@media (max-width: 768px) {
  .gkbtt-button {
    right: 14px;
    bottom: 18px;
    width: 52px;
    height: 52px;
  }
}