.zalo {
  position: fixed;
  bottom: 68px;
  left: 29px;
  z-index: 999;
}
.zalo-chat {
  position: relative;
  display: block;
  margin: 0;
  width: 1em;
  height: 1em;
  font-size: 100px;
}
.zalo-chat::after {
  position: absolute;
  content: "";
  width: 0.5em;
  height: 0.5em;
  background: url(./Zalo.svg);
  background-position: 50% 50%;
  background-repeat: no-repeat;
  background-size: contain;
  filter: drop-shadow(3px 5px 2px rgb(0 0 0 / 20%));
}