lecture 3,padding

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Lecture 3</title>
</head>
<style>
    .box {
        width: 400px;
        height: 400px;
        background: lightblue;
        border: 10px solid black;
        padding-left: 40px;
        padding-left: 15px;
    }
    .first-box {
        width: 100%;
        height: 50%;
        background: orange;
    }
</style>
<body>
    <div class="box"></div>
    <div class="first-box"></div>
</body>
</html>