<div class="circle-bar">
    <div class="circle-bar-left"></div>
    <div class="circle-bar-right"></div>
    <div class="mask">
        <span class="percent">33%</span>
    </div>
</div>

.circle-bar {
    background-image: linear-gradient(#7affaf, #7a88ff);
    width: 182px;
    height: 182px;
    position: relative;
}
.circle-bar-left {
    background-color: #e9ecef;
    width: 182px;
    height: 182px;
    clip: rect(0, 91px, auto, 0);
}
.circle-bar-right {
    background-color: #e9ecef;
    width: 182px;
    height: 182px;
    clip: rect(0, auto, auto, 91px);
    transform: rotate(118.8deg);
}
.mask {
    width: 140px;
    height: 140px;
    background-color: #fff;
    text-align: center;
    line-height: 0.2em;
    color: rgba(0, 0, 0, 0.5);
    position: absolute;
    left: 21px;
    top: 21px;
}
.mask > span {
    display: block;
    font-size: 44px;
    line-height: 150px;
}
/*所有的后代都水平垂直居中，这样就是同心圆了*/
.circle-bar * {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    margin: auto;
}
/*自身以及子元素都是圆*/
.circle-bar,
.circle-bar > * {
    border-radius: 50%;
}