CSS box-shadow 示例

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>CSS box-shadow 示例</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      padding: 20px;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
    }

    h1 {
      text-align: center;
      color: white;
      text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
      margin-bottom: 40px;
    }