<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>制作计算器</title>
    <link rel="stylesheet" href="index.css">
</head>
<body>
    <div class="calculator">
        <div class="buttons">
            <h2 id="value"></h2>
            <span id="Clear">Clear</span>
            <span>/</span>
            <span>*</span>
            <span>7</span>
            <span>8</span>
            <span>9</span>
      