HTML/CSS 在线运行工具

HTML 代码

<!DOCTYPE html>
<html>
<head>
  <title>测试页面</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      background: linear-gradient(to right, #ff9966, #ff5e62);
      margin: 0;
      padding: 20px;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
    }
    
    .container {
      text-align: center;
      background: white;
      padding: 40px;
      border-radius: 15px;
      box-shadow: 0 10px 30px rgba(0,0,0,0.2);
      max-width: 600px;
    }
    
    h1 {
      color: #2c3e50;
      margin-bottom: 30px;
    }
    
    .btn {
      background: linear-gradient(to right, #3498db, #2c3e50);
      color: white;
      border: none;
      padding: 15px 40px;
      border-radius: 30px;
      cursor: pointer;
      font-size: 18px;
      transition: all 0.3s;
    }
    
    .btn:hover {
      transform: scale(1.05);
      box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    }
  </style>
</head>
<body>
  <div class="container">
    <h1>欢迎使用在线代码运行工具</h1>
    <p>这是一个即时预览的HTML/CSS运行环境</p>
    <button class="btn">点击测试</button>
  </div>
</body>
</html>

CSS 代码