<div class="content">
<div class="cube cube1">text</div>
<div class="cube cube2">text</div>
<div class="cube cube3">text</div>
</div>
.cube {
position:relative;
display:inline-block;
height:50px;
width:75px;
top:250px;
left:500px;
}
@media screen and (max-width:768px) {
.cube {display:block;}
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
.cube {
position: relative;
display: inline-block;
height: 50px;
width: 75px;
top: 250px;
left: 500px;
background-color: blue;
color: white;
text-align: center;
line-height: 50px;
font-family: Arial, sans-serif;
font-size: 14px;
}
</style>
</head>
<body>
<div class="content">
<div class="cube cube1">text</div>
<div class="cube cube2">text</div>
<div class="cube cube3">text</div>
</div>
</body>
</html>