1、html代码

<div class="panel">
  <div class="row">
    <span class="item"></span>
    <span class="item"></span>
  </div>
  <div class="row">
    <span class="item"></span>
  </div>
  <div class="row">
    <span class="item"></span>
    <span class="item"></span>
  </div>
</div>

2、css代码

.panel {
  width: 300px;
  height: 300px;
  border-radius: 10px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  border: 1px solid #000000;
}
.row {
  display: flex;
  justify-content: space-around;
}
.row:nth-child(2) {
  align-self: center;
}
.item {
  width: 30px;
  height: 30px;
  border-radius: 50px;
  border: 1px solid #000000;
  background-color: #000000;
}

3、效果图