页面的head部分的样式主要是两部分，一个是触发按钮的样式，另一是模态窗的样式，代码如下：

html, body {
  height: 100%;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  background-color: #FAFAFB;
  color: slategrey;
  font-family: 'Microsoft YaHei','Lantinghei SC','Open Sans',Arial,'Hiragino Sans GB','STHeiti','WenQuanYi Micro Hei','SimSun',sans-serif;
}

a.button {
  text-decoration: none;
  text-align: center;
  text-shadow: 0 1px 0 #fff;
  color: #00a2ff;
  font-weight: 500;
  padding: 8px 15px 8px 15px;
  border: 1px solid rgba(26, 53, 71, 0.1);
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  transition: .25s;
  background: linear-gradient(white, ghostwhite);
}
a.button:hover {
  border: 1px solid rgba(26, 53, 71, 0.2);
  background: white;
}

.wrapper {
  width: 600px;
  height: 100%;
  margin: auto;
  text-align: center;
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
  align-items: center;
  justify-content: center;
}

.overlay {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0.7);
  transition: opacity .5s;
  visibility: hidden;
  opacity: 0;
}
.overlay:target {
  visibility: visible;
  opacity: 1;
}

.modal {
  width: 80%;
  position: relative;
  margin: auto;
  padding: 1.5rem;
  background: #fff;
  border-radius: 4px;
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  transition: .5s;
  opacity: 0;
}
.modal .content {
  margin-top: 1rem;
  text-align: justify;
}
.modal .content a {
  max-width: 60%;
  margin: auto;
  display: block;
}

.overlay:target > .modal {
  transform: translateY(30%) scale(0.9);
  transition-timing-function: cubic-bezier(0.8, 0, 0, 1.5);
  opacity: 1;
}

h2 {
  text-align: center;
  margin-top: 2rem;
  color: #00a2ff;
}

a.close {
  position: absolute;
  top: 15px;
  right: 13px;
  width: 24px;
  height: 24px;
  text-decoration: none;
  text-align: center;
  font-size: 24px;
  line-height: 22px;
  color: lightslategrey;
  background-color: lightgrey;
  border-radius: 50%;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  transition: .25s;
}
a.close:hover {
  background-color: tomato;
  color: white;
}

页面的body部分跟样式类型，也是分成两个部分的，一个是按钮容器，一个是模态窗的容器，都很容易看懂的，代码如下：

<div class="wrapper">
  <a class="button" href="#pop">纯CSS模态窗</a>
</div>

<div id="pop" class="overlay">
  <div class="modal">
    <h2>吸引力法则</h2>
    <a class="close" href="#">&times;</a>
    <div class="content">
      第二步是信念。<br/><br/>
      你要相信你已经拥有它了。要有一种<strong>毫不动摇的信念，</strong>就是我的说法。<br/><br/>
      要相信还没有实现的事，“你的愿望就是我的命令”。<br/><br/>
      宇宙就会开始运作安排，从而满足你心中的愿望。<br/><br/>
      <br/><a class="button" href="#">关闭</a><br/>
    </div>
  </div>
</div>