使用后无法为按钮设置动画：属性

Question

我试图了解伪元素，但似乎无法使用简单的按钮动画来处理它。

悬停时，我希望面板从下到上。类似于this page上的按钮（第1行，第2个按钮）。

根据我的理解，使用.btn:after会在每个.btn课程后添加任何css 。但那为什么这不起作用呢？

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.btn {
    border: 1px solid #65bb39;
    color: #fff;
    background-color: #65bb39;
    cursor: pointer;
    padding: 25px 80px;
    display: inline-block;
    margin: 15px 30px;
    text-transform: uppercase;
    outline: none;
    position: relative;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
}
.btn:after {
    content: '';
    position: absolute;
    z-index: -1;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
    border: 1px solid #65bb39;
    background-color: #fff;
}
*, *:after, *:before {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}

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<div class="text">
  <span class="btn">Test</span>
</div>

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悬停时，我希望边框转为#65bb39，挡块填充白色（从下到上）。

当然，对before和after的任何反馈表示赞赏！

Answer 1

因此需要在btn中添加悬停状态：之后然后在两个状态之间转换css。请参阅下面的代码段。

*, *:after, *:before {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}


.btn {
    color: #fff;
    cursor: pointer;
    padding: 25px 80px;
    display: inline-block;
    margin: 15px 30px;
    text-transform: uppercase;
    position: relative;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
}

.btn:hover{
    color: #65bb39;
}

.btn:after, .btn:before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 0;
    color: #65bb39;
    -webkit-transition: all 0.3s;
    -moz-transition: all 0.3s;
    transition: all 0.3s;
    border: 1px solid #65bb39;
    background-color: #fff;
}

.btn:before {
  z-index: -2;
  background-color: #65bb39;
  height: 100%;
}

.btn:after {
  z-index: -1;
}

.btn:hover:after {    
    height: 100%;
}

<div class="btn">Test</div>

Answer 2

我认为这就是你要找的东西：

body,
html {
  height: 100%;
  width: 100%;
  margin: 0;
  
  display: flex;
  justify-content: center;
  align-items: center;
}

a {
  color: white;
  text-decoration: none;
  font-weight: bold;
  font-size: 1.25em;
  text-align: center;
  line-height: 75px;
}

.button {
  height: 75px;
  width: 200px;
  position: absolute;
  border: 1px solid #65bb39;
  background: transparent;
  transition: all .3s ease-in-out;
}
  .button::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: #65bb39;
    z-index: -1;
    transition: all .3s ease-in-out;
  }

.button:hover {
  color: #65bb39;
}
  .button:hover::after {
    height: 0%;
  }
    .button:hover::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      height: 100%;
      width: 100%;
      background: white;
      z-index: -2;
    }

<a href="#" class="button">Button</a>

Answer 3

你去了：

.btn {
  border: 3px solid #65bb39;
  background: none;
  color: #65bb39;
  cursor: pointer;
  padding: 25px 80px;
  display: inline-block;
  margin: 15px 30px;
  text-transform: uppercase;
  outline: none;
  position: relative;
  transition: all 0.3s;
}

.btn:hover {
  color: #FFFFFF;
}

.btn:after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 0;
  width: 100%;
  background: #65bb39;
  z-index: -1;
  transition: all 0.3s;
}

.btn:hover:after {
  height: 100%;
}

*,
*:after,
*:before {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

<div class="text">
  <span class="btn">Test</span>
</div>

Answer 4

试试这个

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.btn {
  border: 2px solid #65bb39;
  background: none;
  color: #fff;
  cursor: pointer;
  padding: 25px 80px;
  display: inline-block;
  margin: 15px 30px;
  text-transform: uppercase;
  outline: none;
  position: relative;
  transition: all 0.3s;
}

.btn:hover {
  color: #65bb39;
}

.btn:after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  background: #65bb39;
  z-index: -1;
  transition: all 0.4s;
}

.btn:hover:after {
  height: 0%;
}

*,
*:after,
*:before {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

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<div class="text"><span class="btn">Test</span></div>

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