sunzsh/flex-transition-demo.html

## flex-transition-demo.html
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    body, html {
      height: 100%;
      margin: 0;
    }
    .wrapper {
      display: flex;
      flex-direction: column;
      height: 100%;
      overflow: hidden;
      background-color: linen;
    }
    .item {
      text-align: center;
      flex-grow: 0;
      transition: flex-grow .3s;
      position: relative;
    }
    .title {
      background-color: rgb(150, 181, 183);
      color: rgb(4, 43, 46);
      height: 44px;
      line-height: 44px;
      border-top:rgb(125, 157, 160) solid 1px;
    }
    .active {
      flex-grow: 1;
    }
    .content {
      position: absolute;
      top: 44px;
      left: 0;
      width: 100%;
      overflow: auto;
    }
  </style>
</head>
<body>
  <div class="wrapper">
    <div class="item">
      <div class="title">111</div>
      <div class="content">
        asdkfjasldfkjas;ldf
        asdflkajsdfl
      </div>
    </div>
    <div class="item active">
      <div class="title">222</div>
      <div class="content">
        1231
      </div>
    </div>
    <div class="item">
      <div class="title">333</div>
      <div class="content">
        43laksdjflaskdj
      </div>
    </div>
  </div>
  <script>
    const items = document.querySelectorAll('.title');
    items.forEach(item => {
      item.addEventListener('click', () => {
        document.querySelector('.active').classList.remove('active');
        item.parentElement.classList.toggle('active');
      });
    });
  </script>
</body>
</html>
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
	<style>
	body, html {
	height: 100%;
	margin: 0;
	}
	.wrapper {
	display: flex;
	flex-direction: column;
	height: 100%;
	overflow: hidden;
	background-color: linen;
	}
	.item {
	text-align: center;
	flex-grow: 0;
	transition: flex-grow .3s;
	position: relative;
	}
	.title {
	background-color: rgb(150, 181, 183);
	color: rgb(4, 43, 46);
	height: 44px;
	line-height: 44px;
	border-top:rgb(125, 157, 160) solid 1px;
	}
	.active {
	flex-grow: 1;
	}
	.content {
	position: absolute;
	top: 44px;
	left: 0;
	width: 100%;
	overflow: auto;
	}
	</style>
	</head>
	<body>
	<div class="wrapper">
	<div class="item">
	<div class="title">111</div>
	<div class="content">
	asdkfjasldfkjas;ldf
	asdflkajsdfl
	</div>
	</div>
	<div class="item active">
	<div class="title">222</div>
	<div class="content">
	1231
	</div>
	</div>
	<div class="item">
	<div class="title">333</div>
	<div class="content">
	43laksdjflaskdj
	</div>
	</div>
	</div>
	<script>
	const items = document.querySelectorAll('.title');
	items.forEach(item => {
	item.addEventListener('click', () => {
	document.querySelector('.active').classList.remove('active');
	item.parentElement.classList.toggle('active');
	});
	});
	</script>
	</body>
	</html>