<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title></title>
</head>
<body>
<input type="checkbox">
<div class="box">Чекбокс1</div>
<input type="checkbox">
<div class="box">Чекбокс2</div>
<input type="checkbox">
<div class="box">Чекбокс3</div>
<input type="checkbox">
<div class="box">Чекбокс4</div>
</body>
<style>
input:not(:checked) + div {
display: none
}
input::checked + div {
display: block
}
</style>
</html>