<!DOCTYPE html>
<html>
<head>
    <style>
        .box {
            margin: 10px;
            width: 100px;
            height: 100px;
            background-color: blue;
        }
    </style>
</head>
<body>
    <div class="box" style="transform: scale(80%)"></div>
    <div class="box" style="transform: scale(80%, 0.8)"></div>
    <div class="box" style="transform: scale(calc(100% * 0.8), 0.8)"></div>
    <div class="box" style="scale: 80%"></div>
    <div class="box" style="scale: calc(100% * 0.8)"></div>
</body>
</html>