HTML
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>CSS Expandable Menu</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="main">
<input type="checkbox">
<span></span>
<span></span>
<span></span>
<div class="menu">
<li><a href="#">Home</a></li>
<li><a href="#">Design</a></li>
<li><a href="#">Development</a></li>
<li><a href="#">SEO</a></li>
<li><a href="#">Contact</a></li>
</div>
</div>
</body>
</html>CSS
body {
margin: 0;
padding: 0;
min-height: 100vh;
background-color: #FF4D50;
font-family: 'Open Sans', Verdana, Geneva, Tahoma, sans-serif;
}
body, .main, .menu {
display: flex;
justify-content: center;
align-items: center;
}
.main {
position: relative;
background-color: #fff;
padding: 20px;
transition: 0.5s;
border-radius: 50px;
overflow: hidden;
box-shadow: 0 8px 15px rgba(0,0,0,.2);
}
.menu {
margin: 0;
padding: 0;
width: 0;
overflow: hidden;
transition: 0.5s;
}
.main input:checked ~ .menu {
width: 500px;
}
.menu li {
list-style: none;
margin: 0 10px;
}
.menu li a {
text-decoration: none;
color: #666;
text-transform: uppercase;
font-weight: 600;
transition: 0.5s;
}
.menu li a:hover {
color: #161919;
}
.main input {
width: 40px;
height: 40px;
cursor: pointer;
opacity: 0;
}
.main span {
position: absolute;
left: 30px;
width: 30px;
height: 4px;
border-radius: 50px;
background-color: #666;
pointer-events: none;
transition: 0.5s;
}
.main input:checked ~ span {
background-color: #FF4D50;
}
.main span:nth-child(2) {
transform: translateY(-8px);
}
.main input:checked ~ span:nth-child(2) {
transform: translateY(0) rotate(-45deg);
}
.main span:nth-child(3) {
transform: translateY(8px);
}
.main input:checked ~ span:nth-child(3) {
transform: translateY(0) rotate(45deg);
}
.main input:checked ~ span:nth-child(4) {
display: none;
}