Chkolnik,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.hot{
border: 1px dashed Gray; padding: 5px; height: 200px; width: 100px ;
background-color: #00BFFF;
float: left;
transition: all 3s ease;
}
.hot:nth-of-type(2)
{
height : 300px; background-color: #FF69B4;
}
.hot:nth-of-type(1)
{
height : 100px; background-color: #FFD700;
}
</style>
<script>
window.addEventListener("DOMContentLoaded", function() {
var divs = document.querySelectorAll(".hot"),
height = [].reduce.call(divs, function(height, div) {
return div.scrollHeight > height ? div.scrollHeight : height
}, 0);
[].forEach.call(divs, function(el) {
el.style.height = height + "px"
})
});
</script>
</head>
<body>
<div class="hot"></div>
<div class="hot"></div>
<div class="hot"></div>
</body>
</html>