A Pen by Josh.

index.html

<span class="loader"><span class="loader-inner"></span></span>

Loading-Square.markdown

Loading Square

This square spins and fills. It wants to be cool like all of the other squares.

A Pen by Josh on CodePen.

License.

style.css

body, html {
    height: 100%;
    text-align: center;
}

body {
  background-color: #D2312B;
}

.loader {
  display: inline-block;
  width: 30px;
  height: 30px;
  position: relative;
  border: 4px solid #FBFBFB;
  top: 50%;
  animation: loader 4s infinite ease;
}

.loader-inner {
  vertical-align: top;
  display: inline-block;
  width: 100%;
  background-color: #FBFBFB;
  animation: loader-inner 4s infinite ease-in;
}

@keyframes loader {
  0% {
    transform: rotate(0deg);
  }
  
  25% {
    transform: rotate(180deg);
  }
  
  50% {
    transform: rotate(180deg);
  }
  
  75% {
    transform: rotate(360deg);
  }
  
  100% {
    transform: rotate(360deg);
  }
}

@keyframes loader-inner {
  0% {
    height: 0%;
  }
  
  25% {
    height: 0%;
  }
  
  50% {
    height: 100%;
  }
  
  75% {
    height: 100%;
  }
  
  100% {
    height: 0%;
  }
}