68.client.html

<!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>Document</title>
    <style>
        .rect {
            position: relative;
            width: 800px;
            height: 600px;
            background-color: rgb(248, 232, 232);
            border: 1px solid black;
        }

        .ball {
            position: absolute;
            width: 150px;
            height: 150px;
            border-radius: 50%;
            background-color: rgb(245, 216, 52);
            text-align: center;
            border: 1px solid black;
            left: 100px;
            top: 100px;
        }
    </style>
</head>

<body>
    <div class="rect">
        <div class="ball"></div>
    </div>
    <div id="info"></div>
    <script>
        const rect = document.querySelector(".rect");
        const ball = document.querySelector(".ball");
        const info = document.querySelector("#info");


        rect.addEventListener("mousemove", function (event) {
            info.innerText = `
            client: ${event.clientX}, ${event.clientY},
            page: ${event.pageX}, ${event.pageY},
            offset: ${event.offsetX}, ${event.offsetY}`;
        });
    </script>
</body>

</html>