您可以使用以下多个元素进行黑客攻击:

null

.d1 {
  width: 100px;
  height: 100px;
  background-color: #00f;
}

.wrapper {
  width: 100px;
  height: 20px;
  background-color: #fff;
  margin-top: -20px;
}

.d2 {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background-color: #00f;
}

.wrapper2 {
  width: 100px;
  height: 10px;
  background-color: #00f;
  margin-top: -20px;
  position: absolute;
}

<div class="d1"></div>
<div class="wrapper">
  <div class="d2"></div>
</div>
<div class="wrapper2"></div>