太极图

<div class="taiji"></div>

.taiji {
140px;
height: 280px;
border-radius: 100%;
/* background-color: red; */
border: 2px solid black;
border-left: 140px solid black;
position: relative;
}

.taiji::before {
content: "";
position: absolute;
right: 50%;
top: 0;
40px;
height: 40px;
border-radius: 100%;
background: black;
border: 50px solid #ffffff;
}

.taiji::after {
content: "";
position: absolute;
right: 50%;
bottom: 0;
40px;
height: 40px;
border-radius: 100%;
background: #fff;
border: 50px solid black;
}

1.

.taiji {
140px;
height: 280px;
border-radius: 100%;
/* background-color: red; */
border: 2px solid black;
border-left: 140px solid black;
position: relative;
}

2.将两个图形定位到相应的位置

.taiji::before {
content: "";
position: absolute;
right: 50%;
top: 0;
40px;
height: 40px;
border-radius: 100%;
background: black;
border: 50px solid #ffffff;
}

.taiji::after {
content: "";
position: absolute;
right: 50%;
bottom: 0;
40px;
height: 40px;
border-radius: 100%;
background: #fff;
border: 50px solid black;
}