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CSS

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HTML 

              
                <div class="loader">
  <div class="heart"></div>
  <div class="heart"></div>
  <div class="heart"></div>
</div>
!

CSS 

              
                *, *:before, *:after {
  box-sizing: border-box;
}

.loader {
  width: 50px;
  height: 24px;
  padding: 4px 0;
  background: #222;
  border-top: 2px solid #111;
  border-bottom: 2px solid #111;
  position: fixed;
  left: 50%; top: 50%;
  transform: translate(-50%, -50%) scale(2);
  // scaling it for a better view
  
  &::before,
  &::after {
    content: '';
    position: absolute;
    top: 0;
    height: 2px;
    width: 2px;
  }
  
  &::before {
    box-shadow: //left border
                -2px  0px 0 #111,
                -4px  2px 0 #111,
                -6px  4px 0 #111,
                -6px  6px 0 #111,
                -6px  8px 0 #111,
                -6px 10px 0 #111,
                -6px 12px 0 #111,
                -6px 14px 0 #111,
                -4px 16px 0 #111,
                -2px 18px 0 #111,
                //left lg vertical line
                -2px  2px 0 #222,
                -2px  4px 0 #222,
                -2px  6px 0 #222,
                -2px  8px 0 #222,
                -2px 10px 0 #222,
                -2px 12px 0 #222,
                -2px 14px 0 #222,
                -2px 16px 0 #222,
                //left md vertical line
                -4px  4px 0 #222,
                -4px  6px 0 #222,
                -4px  8px 0 #222,
                -4px 10px 0 #222,
                -4px 12px 0 #222,
                -4px 14px 0 #222;    
  }
  
  &::after {
    right: 0;
    box-shadow: //left border
                2px  0px 0 #111,
                4px  2px 0 #111,
                6px  4px 0 #111,
                6px  6px 0 #111,
                6px  8px 0 #111,
                6px 10px 0 #111,
                6px 12px 0 #111,
                6px 14px 0 #111,
                4px 16px 0 #111,
                2px 18px 0 #111,
                //left lg vertical line
                2px  2px 0 #222,
                2px  4px 0 #222,
                2px  6px 0 #222,
                2px  8px 0 #222,
                2px 10px 0 #222,
                2px 12px 0 #222,
                2px 14px 0 #222,
                2px 16px 0 #222,
                //left md vertical line
                4px  4px 0 #222,
                4px  6px 0 #222,
                4px  8px 0 #222,
                4px 10px 0 #222,
                4px 12px 0 #222,
                4px 14px 0 #222; 
  }  
}

.heart {
    display: inline-block;
    vertical-align: top;
    margin-left: 12px;
    height: 2px;
    width: 2px;
    box-shadow: 
      6px  2px 0 #fff,
      //
      2px  0px 0 #fff,
      4px  0px 0 #fff,
      0px  2px 0 #fff,
      0px  4px 0 #fff,
      2px  6px 0 #fff,
      4px  8px 0 #fff,
      6px  10px 0 #fff,
      //
      8px  0px 0 #fff,
      10px  0px 0 #fff,
      12px  2px 0 #fff,
      12px  4px 0 #fff,
      10px  6px 0 #fff,
      8px  8px 0 #fff;
  
  &::before,
  &::after {
    content: '';
    position: absolute;
    height: 2px; width: 2px;
    visibility: hidden;
    animation: ani 3s/*duration*/ 2s/*delay*/  infinite;
  }
  
  &::before {
    box-shadow: 
      2px  2px 0 #e03800,
      2px  4px 0 #e03800,
      4px  2px 0 #e03800,
      4px  4px 0 #e03800,
      4px  6px 0 #e03800,
      6px  4px 0 #e03800,
      6px  6px 0 #e03800,
      6px  8px 0 #e03800;  
  }
  
  &::after {
    box-shadow: 
      8px  2px 0 #e03800,
      8px  4px 0 #e03800,
      8px  6px 0 #e03800,
      10px  2px 0 #e03800,
      10px  4px 0 #e03800;
  }   
  
  &:nth-child(1) {
    margin: 0;
    &::before {
      animation-timing-function: steps(9);
    }
    &::after {
      animation-timing-function: steps(8);
    }     
  }
  
  &:nth-child(2) {
    &::before {
       animation-timing-function: steps(7);
    }
    &::after {
        animation-timing-function: steps(6);
    }     
  }
  
  &:nth-child(3) {
    &::before {
       animation-timing-function: steps(5);
    }
    &::after {
       animation-timing-function: steps(4);
    }     
  }
  
}

@keyframes ani {
  to {visibility: visible;} 
}
!

JS 

              
                // https://catalin.red/gamespot-loading-hearts/
// As seen on http://www.gamespot.com/
!
999px

Console