.progress-bar { position: relative; height: 160px; width: 160px; }
.progress-bar div { position: absolute; height: 160px; width: 160px; border-radius: 50%;}
.progress-bar div span { position: absolute; font-size: 40px; line-height: 130px; height: 130px; width: 130px;left: 15px; top: 15px;text-align: center;border-radius: 50%; background-color: #d3451d; font-family: 'Swell'; color: #fff; }
.progress-bar .rotate { clip: rect(0 80px 160px 0); }
.progress-bar .left { clip: rect(0 80px 160px 0); opacity: 1; }
.progress-bar .right { clip: rect(0 80px 160px 0); transform: rotate(180deg); opacity: 0; }

@keyframes toggle {  
  0% { opacity: 0; }
  100% { opacity: 1;}
}