HTML
<div id="accordion">
<form>
<label>
<input type="radio" name="btn" checked />
<div>
<div>カテゴリー１</div>
<ul>
<li><a href="#">サブカテゴリー１</a></li>
<li><a href="#">サブカテゴリー２</a></li>
<li><a href="#">サブカテゴリー３</a></li>
</ul>
</div>
</label>
<label>
<input type="radio" name="btn" />
<div>
<div>カテゴリー２</div>
<ul>
<li><a href="#">サブカテゴリー１</a></li>
<li><a href="#">サブカテゴリー２</a></li>
<li><a href="#">サブカテゴリー３</a></li>
</ul>
</div>
</label>
<label>
<input type="radio" name="btn" />
<div>
<div>カテゴリー３</div>
<ul>
<li><a href="#">サブカテゴリー１</a></li>
<li><a href="#">サブカテゴリー２</a></li>
<li><a href="#">サブカテゴリー３</a></li>
</ul>
</div>
</label>
<label>
<input type="radio" name="btn" />
<div>
<div>カテゴリー４</div>
<ul>
<li><a href="#">サブカテゴリー１</a></li>
<li><a href="#">サブカテゴリー２</a></li>
<li><a href="#">サブカテゴリー３</a></li>
</ul>
</div>
</label>
<label>
<input type="radio" name="btn" />
<div>
<div>カテゴリー５</div>
<ul>
<li><a href="#">サブカテゴリー１</a></li>
<li><a href="#">サブカテゴリー２</a></li>
<li><a href="#">サブカテゴリー３</a></li>
</ul>
</div>
</label>
</form>
</div>
CSS
@font-face {
font-family: 'Typicons';
src: url('fonts/typicons-regular-webfont.eot');
src: url('fonts/typicons-regular-webfont.eot?#iefix') format('embedded-opentype'),
url('fonts/typicons-regular-webfont.woff') format('woff'),
url('fonts/typicons-regular-webfont.ttf') format('truetype'),
url('fonts/typicons-regular-webfont.svg#TypiconsRegular') format('svg');
font-weight: normal;
font-style: normal;
}
#accordion{
position:relative;
width: 500px;
margin: 0 auto;
padding: 0;
border-top: 15px solid #1b4958;
border-bottom: 15px solid #1b4958;
border-radius: 3px;
font-size: 16px;
line-height: 1;
}
#accordion input{
position:absolute;
height: 0;
padding:0;
}
#accordion div div{
position: relative;
padding: 15px 10px 12px 40px;
border-top: 1px solid #d4ebf2;
border-bottom: 1px solid #86c5da;
background: #add8e6;
}
#accordion label:first-child div div{
border-top: 0;
}
#accordion label:last-child div div{
border-bottom: 0;
}
#accordion div div:hover{
background: #a0d2e2;
cursor: pointer;
}
#accordion div div:before{
position:absolute;
top: 13px;
left:10px;
color: #2f7f99;
font: 24px/100% 'Typicons';
content: "\0023";
}
#accordion div div:after{
position:absolute;
top: 15px;
right:10px;
color: #2f7f99;
font: 20px 'Typicons';
content: "7";
-moz-transition: .3s;
-webkit-transition: .3s;
-o-transition: .3s;
-ms-transition: .3s;
transition: .3s;
}
#accordion input:checked + div div:after{
top: 12px;
right: 15px;
-moz-transform: rotate(90deg);
-webkit-transform: rotate(90deg);
-o-transform: rotate(90deg);
-ms-transform: rotate(90deg);
transform: rotate(90deg);
}
#accordion ul{
list-style: none;
margin: 0;
background: #e1f1f6;
}
#accordion ul li a{
display: block;
overflow: hidden;
height: 0;
padding: 0px 70px;
color: #333;
text-decoration: none;
-moz-transition: .3s;
-webkit-transition: .3s;
-o-transition: .3s;
-ms-transition: .3s;
transition: .3s;
}
#accordion input:checked + div ul li a{
position:relative;
background: none;
line-height: 1;
height: 16px;
padding: 13px 70px;
border-top: 1px solid #fff;
border-bottom: 1px solid #a0d2e2;
}
#accordion input:checked + div ul li:first-child a{
border-top: 0;
box-shadow: 0 7px 7px -7px rgba(0,0,0,.5) inset;
}
#accordion input:checked + div ul li:last-child a{
border-bottom: 0;
}
#accordion input:checked + div ul li a:hover{
background: #d4ebf2;
border-top-color: #eef7fa;
}
#accordion input:checked + div ul li a:before{
position: absolute;
top: 16px;
left: 45px;
color: #2f7f99;
font:16px/100% 'Typicons';
content: "x";
-moz-transition: .3s;
-webkit-transition: .3s;
-o-transition: .3s;
-ms-transition: .3s;
transition: .3s;
}