#container {
position: fixed;
height: 100%;
left: 0px;
right: 0px;
top: 0px;
width: 10%;
background-color: blue;
}
#container>div {}
<html>
<div id="container">
<div>up</div>
<div>down</div>
<div>left</div>
<div>right</div>
</div>
</html>
Is there a way to ensure that each of the div elements within #container are displayed inside yellow boxes that match the length of the container, regardless of the number of divs present?