/*
<div class="main">
<input type="checkbox" />
<div></div>
</div>*/
.main {
position: relative
}
.main > div {
width: 200px;
height: 200px;
background: #f00;
}
input {
width: 100%;
height: 100%;
position: absolute;
top: 0;
left: 0;
opacity: 0;
}
input:checked + div {
background: #000
}