<div class="menu">
    <label for="menu_bar01">MENU01</label>
    <input type="checkbox" id="menu_bar01" class="accordion" />
    <ul id="links01">
        <li><a href="">Link01</a></li>
        <li><a href="">Link02</a></li>
        <li><a href="">Link03</a></li>
        <li><a href="">Link04</a></li>
    </ul>
    <label for="menu_bar02">MENU02</label>
    <input type="checkbox" id="menu_bar02" class="accordion" />
    <ul id="links02">
        <li><a href="">Link01</a></li>
        <li><a href="">Link02</a></li>
        <li><a href="">Link03</a></li>
        <li><a href="">Link04</a></li>
    </ul>
</div>
.menu {
	max-width: 400px;
	margin: 0 auto;
	padding: 0;
}

.menu a {
  display: block;
  padding: 10px;
	text-decoration: none;
	color: #000;
  line-height: 1;
}

label {
  display: block;
  margin: 0 0 2px 0;
	padding :12px;
  line-height: 1;
	color :#fff;
  background :#007bbb;
	cursor :pointer;
}

input {
	display: none;
}

.menu ul {
	margin: 0;
	padding: 0;
  background :#f4f4f4;
	list-style: none;
}

.menu li {
  max-height: 0;
  overflow-y: hidden;
  -webkit-transition: all 0.5s;
	-moz-transition: all 0.5s;
	-ms-transition: all 0.5s;
	-o-transition: all 0.5s;
	transition: all 0.5s;
}

#menu_bar01:checked ~ #links01 li,
#menu_bar02:checked ~ #links02 li {
	max-height: 46px;
  opacity: 1;
}

External CSS

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External JavaScript

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