<div class="tiles">
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
  <div class="tile"></div>
</div>
// Variables.
$tile-bg: #cfcfdf;

// Styles.
.tiles {
  left: 50%;
  position: absolute;
  top: 50%;
  transform: translateY(-50%) translateX(-50%);
  width: 330px;
}

.tile {
  animation: 1s ease 0s pulse infinite;
  background: $tile-bg;
  border-radius: 4px;
  float: left;
  height: 75px;
  margin: 5px;
  width: 100px;
}

// Loop from 1-9.
@for $i from 1 through 9 {
  .tile {
    
    // :nth-child(1-9) 
    &:nth-child(#{$i}) {
      
      // Delay the animation. Delay increases as items loop.
      animation-delay: $i * (1s / 18);
    }
  }
}

@keyframes pulse {
  0% {
    background: $tile-bg;
    transform: scale(1);
  }
  
  25% {
    background: darken($tile-bg, 10%);
    transform: scale(1.015);
  }
  
  50% {
    background: $tile-bg;
    transform: scale(1);
  }
}

html {
  height: 100%;
  width: 100%;
}

body {
  height: 100%;
  margin: 0;
  padding: 0;
  position: relative;
  text-align: center;
  width: 100%;
}

External CSS

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External JavaScript

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