html - HTML，CSS-将按钮对准页面中心

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How to vertically align div on page with flexbox [duplicate]
（4个答案）
两年前关闭。
我想把我的按钮对准页面的中心。我能在CSS中知道怎么做吗。

button {
  background-color: #6495ED;
  color: white;
  padding: 16px 25px;
  margin: 0 auto;
  border: none;
  cursor: pointer;
  width: 100%;
  border-radius: 8px;
  display: block;
  position: middle;
}

<button type="button" onclick="document.getElementById('id01').style.display='block'" style="width: auto;">User Login</button>
<br><br><br>
<button type="button" onclick="document.getElementById('id02').style.display='block'" style="width:auto; ">Admin Login</button>

最佳答案

如果flexbox是一个选项，您可以添加：

body {
  margin: 0;
  height: 100vh; // stretch body to the whole page
  display: flex; // define a flex container
  flex-direction: column; // arrange items in column
  justify-content: center; // align vertically center
}

（注意position: middle无效）
请参见下面的演示：

body {
  margin: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

button {
  background-color: #6495ED;
  color: white;
  padding: 16px 25px;
  margin: 0 auto;
  border: none;
  cursor: pointer;
  width: 100%;
  border-radius: 8px;
}

<button type="button" onclick="document.getElementById('id01').style.display='block'" style="width: auto;">User Login</button>
<br><br><br>
<button type="button" onclick="document.getElementById('id02').style.display='block'" style="width:auto; ">Admin Login</button>