Vòng kết nối tiến trình CSS [đã đóng]

.wrapper {
  width: 100px; /* Set the size of the progress bar */
  height: 100px;
  position: absolute; /* Enable clipping */
  clip: rect(0px, 100px, 100px, 50px); /* Hide half of the progress bar */
}
/* Set the sizes of the elements that make up the progress bar */
.circle {
  width: 80px;
  height: 80px;
  border: 10px solid green;
  border-radius: 50px;
  position: absolute;
  clip: rect(0px, 50px, 100px, 0px);
}
/* Using the data attributes for the animation selectors. */
/* Base settings for all animated elements */
div[data-anim~=base] {
  -webkit-animation-iteration-count: 1;  /* Only run once */
  -webkit-animation-fill-mode: forwards; /* Hold the last keyframe */
  -webkit-animation-timing-function:linear; /* Linear animation */
}

.wrapper[data-anim~=wrapper] {
  -webkit-animation-duration: 0.01s; /* Complete keyframes asap */
  -webkit-animation-delay: 3s; /* Wait half of the animation */
  -webkit-animation-name: close-wrapper; /* Keyframes name */
}

.circle[data-anim~=left] {
  -webkit-animation-duration: 6s; /* Full animation time */
  -webkit-animation-name: left-spin;
}

.circle[data-anim~=right] {
  -webkit-animation-duration: 3s; /* Half animation time */
  -webkit-animation-name: right-spin;
}
/* Rotate the right side of the progress bar from 0 to 180 degrees */
@-webkit-keyframes right-spin {
  from {
    -webkit-transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(180deg);
  }
}
/* Rotate the left side of the progress bar from 0 to 360 degrees */
@-webkit-keyframes left-spin {
  from {
    -webkit-transform: rotate(0deg);
  }
  to {
    -webkit-transform: rotate(360deg);
  }
}
/* Set the wrapper clip to auto, effectively removing the clip */
@-webkit-keyframes close-wrapper {
  to {
    clip: rect(auto, auto, auto, auto);
  }
}

<div class="wrapper" data-anim="base wrapper">
  <div class="circle" data-anim="base left"></div>
  <div class="circle" data-anim="base right"></div>
</div>

@import url(http://fonts.googleapis.com/css?family=Josefin+Sans:100,300,400);
    
.arc1 {
    width: 160px;
    height: 160px;
    background: #00a0db;
    -webkit-transform-origin: -31% 61%;
    margin-left: -30px;
    margin-top: 20px;
    -webkit-transform: translate(-54px,50px);
    -moz-transform: translate(-54px,50px);
    -o-transform: translate(-54px,50px);
}
.arc2 {
    width: 160px;
    height: 160px;
    background: #00a0db;
    -webkit-transform: skew(45deg,0deg);
    -moz-transform: skew(45deg,0deg);
    -o-transform: skew(45deg,0deg);
    margin-left: -180px;
    margin-top: -90px;
    position: absolute;
    -webkit-transition: all .5s linear;
    -moz-transition: all .5s linear;
    -o-transition: all .5s linear;
}

.arc-container:hover .arc2 {
    margin-left: -50px;
    -webkit-transform: skew(-20deg,0deg);
    -moz-transform: skew(-20deg,0deg);
    -o-transform: skew(-20deg,0deg);
}

.arc-wrapper {
    width: 150px;
    height: 150px;
    border-radius:150px;
    background: #424242;
    overflow:hidden;
    left: 50px;
    top: 50px;
    position: absolute;
}
.arc-hider {
    width: 150px;
    height: 150px;
    border-radius: 150px;
    border: 50px solid #e9e9e9;
    position:absolute;
    z-index:5;
    box-shadow:inset 0px 0px 20px rgba(0,0,0,0.7);
}

.arc-inset  {
    font-family: "Josefin Sans";
    font-weight: 100;
    position: absolute;
    font-size: 413px;
    margin-top: -64px;
    z-index: 5;
    left: 30px;
    line-height: 327px;
    height: 280px;
    -webkit-mask-image: -webkit-linear-gradient(top, rgba(0,0,0,1), rgba(0,0,0,0.2));
}
.arc-lowerInset {
    font-family: "Josefin Sans";
    font-weight: 100;
    position: absolute;
    font-size: 413px;
    margin-top: -64px;
    z-index: 5;
    left: 30px;
    line-height: 327px;
    height: 280px;
    color: white;
    -webkit-mask-image: -webkit-linear-gradient(top, rgba(0,0,0,0.2), rgba(0,0,0,1));
}
.arc-overlay {
    width: 100px;
    height: 100px;
    background-image: linear-gradient(bottom, rgb(217,217,217) 10%, rgb(245,245,245) 90%, rgb(253,253,253) 100%);
    background-image: -o-linear-gradient(bottom, rgb(217,217,217) 10%, rgb(245,245,245) 90%, rgb(253,253,253) 100%);
    background-image: -moz-linear-gradient(bottom, rgb(217,217,217) 10%, rgb(245,245,245) 90%, rgb(253,253,253) 100%);
    background-image: -webkit-linear-gradient(bottom, rgb(217,217,217) 10%, rgb(245,245,245) 90%, rgb(253,253,253) 100%);

    padding-left: 32px;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    line-height: 100px;
    font-family: sans-serif;
    font-weight: 400;
    text-shadow: 0 1px 0 #fff;
    font-size: 22px;
    border-radius: 100px;
    position: absolute;
    z-index: 5;
    top: 75px;
    left: 75px;
    box-shadow:0px 0px 20px rgba(0,0,0,0.7);
}
.arc-container {
    position: relative;
    background: #e9e9e9;
    height: 250px;
    width: 250px;
}

<div class="arc-container">
    <div class="arc-hider"></div>
    <div class="arc-inset">
        o
    </div>
    <div class="arc-lowerInset">
        o
    </div>
    <div class="arc-overlay">
        35%
    </div>
    <div class="arc-wrapper">
        <div class="arc2"></div>
        <div class="arc1"></div>
    </div>
</div>