CSS3实现一个粒子动效的按钮

以下是一个使用CSS3实现的粒子动效按钮的示例代码：

HTML:

<div class="particles-button">
  <button class="btn">点击我</button>
</div>

CSS:

.particles-button {
  position: relative;
  width: 150px;
  height: 50px;
}
 
.btn {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0;
  z-index: 10;
}
 
.particles-button:after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, #ff6e7f, #bfe9ff);
  z-index: 1;
  transition: opacity 0.5s ease;
  opacity: 0;
}
 
.particles-button:before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: transparent;
  z-index: 2;
  transition: background-size 0.5s ease;
  background-image: radial-gradient(circle at center, #fff 0%, rgba(255, 255, 255, 0) 70%), radial-gradient(circle at center, #fff 0%, rgba(255, 255, 255, 0) 70%);
  background-size: 10% 10%, 20% 20%;
  background-position: 0 0, 10px 10px;
}
 
.btn:hover + .particles-button:after {
  opacity: 1;
}
 
.btn:hover + .particles-button:before {
  background-size: 50% 50%, 100% 100%;
}

这段代码使用伪元素 :before 和 :after 来创建按钮的背景和动态效果。当鼠标悬停在按钮上时，这些伪元素的样式通过 CSS 过渡效果发生变化，从而形成粒子动效。