CSS Spinner

HTML

<div class="crabbly_spinner"></div>

CSS

.crabbly_spinner {
    position: relative;
    width: 25px;
    height: 25px;
    -webkit-animation: crabbly_spinner infinite .75s linear;
       -moz-animation: crabbly_spinner infinite .75s linear;
         -o-animation: crabbly_spinner infinite .75s linear;
            animation: crabbly_spinner infinite .75s linear;
    border: 2px solid rgba(125, 125, 125, 0.9);
    border-top-color: rgba(0, 0, 0, .1);
    border-right-color: rgba(0, 0, 0, .1);
    border-bottom-color: rgba(0, 0, 0, .1);
    border-radius: 100%;
}

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