.side-bar {
  position: fixed;
  bottom: 10px;
  left: 10px;
  z-index: 1000;
}
.side-bar > ul > li > a {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: tomato;
  align-items: center;
  justify-content: center;
  display: flex;
  position: relative;
  z-index: 1;
}

.side-bar > ul > li:not(:last-child) {
  width: 55px;
  height: 55px;
  border-radius: 50%;
  background-color: #ffbe45;
  border: 1px solid #ccc;
  align-items: center;
  justify-content: center;
  display: flex;
  margin-bottom: 5px;
  position: relative;
}
.side-bar > ul > li:last-child {
  width: 55px;
  height: 55px;
  border-radius: 50%;
  align-items: center;
  justify-content: center;
  display: flex;
  margin-bottom: 5px;
  position: relative;
  cursor: pointer;
}
#zalo-icon,
#phone-icon {
  background-color: tomato;
  width: 35px;
  height: 35px;
  border-radius: 50%;
}
#mess-icon {
  background-color: tomato;
  width: 50px;
  height: 50px;
  border-radius: 50%;
}
#to-top-icon {
  width: 50px;
  height: 50px;
  border-radius: 50%;
}
.scroll-to-top {
  cursor: pointer;
}
.side-bar > ul > li:last-child > a {
  background-color: #fff;
  display: none;
}
.animation-zoom {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 55px;
  height: 55px;
  border: 1px solid red;
  border-radius: 50%;
  animation: zoom 1.5s infinite;
  z-index: 0;
}

@keyframes zoom {
  0% {
    transform: translate(-50%, -50%) scale(1);
  }
  50% {
    transform: translate(-50%, -50%) scale(1.1);
  }
  100% {
    transform: translate(-50%, -50%) scale(1);
  }
}