效果图
以下是源码
<!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>简单的手风琴二级菜单</title>
<style>
* {
padding: 0;
margin: 0;
box-sizing: border-box;
font-family: 'Space Mono', monospace;
}
body {
display: flex;
justify-content: center;
}
.wrapper {
width: 600px;
margin: 10vh auto;
}
h1 {
margin-bottom: 20px;
text-align: center;
}
input {
display: none;
}
label {
display: flex;
width: 100%;
height: 50px;
cursor: pointer;
border: 3px solid #3E474F;
user-select: none;
}
label div:first-child {
width: 100%;
line-height: 45px;
margin-left: 10px;
font-size: 1.2em;
}
.cross {
margin-right: 15px;
margin-top: 3px;
}
.cross::before,
.cross::after {
content: '';
border-top: 2px solid #3E474F;
width: 15px;
display: block;
margin-top: 18px;
transition: .3s;
}
.cross::after {
transform: rotate(90deg);
margin-top: -2px;
}
input:checked ~ label .cross::before {
transform: rotate(180deg);
}
input:checked ~ label .cross::after {
transform: rotate(0deg);
}
.content {
box-sizing: border-box;
font-size: 0.9em;
margin: 10px 10px;
max-height: 0px;
overflow: hidden;
transition: max-height,.5s;
}
input:checked ~ .content {
max-height: 400px;
transition: max-height,1s;
}
.SecondaryMenus {
margin-top: 20px;
max-height: 0;
overflow: hidden;
transition: max-height,.5s;
}
.SecondaryMenus label {
border: none;
box-shadow: none;
margin: 0;
}
input:checked ~ .SecondaryMenus {
max-height: 400px;
border-bottom: 2px solid #3E474F;
transition: 1s;
}
</style>
</head>
<body>
<div class="wrapper">
<h1>Accordion secndary menu</h1>
<div class="wrap-1">
<input type="radio" id="tab-1" name="tabs">
<label for="tab-1">
<div>First level menu - one</div>
<div class="cross"></div>
</label>
<div class="content">
One kind of loneliness is that when you close your eyes, you can recall the
temperature, conversation, action, and details of the story. When you open your eyes, you feel that they
never happened. It is because life has a lot of passing, no intersection of loneliness, so we have to
start each time, good farewell.
</div>
</div>
<div class="wrap-2">
<input type="radio" id="tab-2" name="tabs">
<label for="tab-2">
<div>First level menu - two</div>
<div class="cross"></div>
</label>
<div class="content">
Youth, is a gorgeous dream, there will always be empty one day, but no matter how
lonely, thank you have accompanied me that moved.
</div>
</div>
<div class="wrap-3">
<input type="radio" id="tab-3" name="tabs">
<label for="tab-3">
<div>First level menu - three</div>
<div class="cross"></div>
</label>
<div class="SecondaryMenus">
<div class="SecondaryMenu-wrap">
<input type="radio" id="SecondaryMenu-1" name="SecondaryMenu">
<label for="SecondaryMenu-1">
<div>SecondaryMenu - one</div>
<div class="cross"></div>
</label>
<div class="content">
In infinite time, limited life, we are chasing the sun and the moon, chasing
the dream. Looking
back, we are far away from that pure dream.
</div>
</div>
<div class="SecondaryMenu-wrap">
<input type="radio" id="SecondaryMenu-2" name="SecondaryMenu">
<label for="SecondaryMenu-2">
<div>SecondaryMenu - two</div>
<div class="cross"></div>
</label>
<div class="content">
We, one day, will become me, because the happiness ahead will let you go, and
the footprints you
left are the basis for my stay.
</div>
</div>
</div>
</div>
</div>
</body>
</html>