skype_loader.css

body {
  background-color: #02aff1;
}

#center {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  font-family: "Lato", sans-serif;
  font-weight: 600;
  font-size: 16px;
  color: #fff;
  text-align: center;
  -webkit-font-smoothing: antialiased;
  background-color: rgba(0,0,0,0.9);
  z-index: 99999999999;
}

.skype-loader {
  width: 80px;
  height: 80px;
  position: relative;
  margin: auto;
  top: 50%
}

.skype-loader .dot {
  position: absolute;
  top: 0;
  left: 0;
  width: 80px;
  height: 80px;

  animation: 1.7s dotrotate cubic-bezier(0.775, 0.005, 0.310, 1.000) infinite;
}

.skype-loader .dot:nth-child(1) {
  animation-delay: 0.2s;
}

.skype-loader .dot:nth-child(2) {
  animation-delay: 0.35s;
}

.skype-loader .dot:nth-child(3) {
  animation-delay: 0.45s;
}

.skype-loader .dot:nth-child(4) {
  animation-delay: 0.55s;
}

.skype-loader .dot:after, .skype-loader .dot .first {
  content: "";
  position: absolute;
  width: 8px;
  height: 8px;
  background: white;
  border-radius: 50%;
  left: 50%;
  margin-left: -4px;
}

.skype-loader .dot .first {
  background: #fff;
  margin-top: -4px;
  animation: 1.7s dotscale cubic-bezier(0.775, 0.005, 0.310, 1.000) infinite;
  animation-delay: 0.2s;
}

@keyframes dotrotate { 
  from { transform: rotate(0deg); } 
  to { transform: rotate(360deg); }
}

@keyframes dotscale { 
  0%, 10% { width: 16px; height: 16px; margin-left: -8px;  margin-top: -4px; } 
  50% { width: 8px; height: 8px; margin-left: -4px; margin-top: 0; }
  90%, 100% { width: 16px; height: 16px;  margin-left: -8px;  margin-top: -4px; }
}

skype_loader.html

<div id="center">
  
  <div class="skype-loader">
    <div class="dot">
      <div class="first"></div>
    </div>
    <div class="dot"></div>
    <div class="dot"></div>
    <div class="dot"></div>
  </div>
  
</div>