AntonMs,
FlexBox?
<!DOCTYPE html>
<html lang="ru">
<head>
<meta charset="UTF-8">
<title>Demo</title>
</head>
<body>
<div id="items">
<div class="item item1"></div>
<div class="item item2"></div>
<div class="item item3"></div>
</div>
<style type="text/css">
#items {
width: 60px;
background-color: #eee;
border: 2px solid #ccc;
display: flex;
align-items: flex-end;
}
.item{
width: 10px;
height: 50px;
margin: 5px 5px 0 5px;
background-color: #333;
}
.item1{
height: 35px;
}
.item2{
height: 20px;
}
</style>
</body>
</html>
Строки 20 и 21.