<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Image Gallery</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            background-color: #f0f2f5;
        }
        .container {
            max-width: 900px;
            margin: 50px auto;
            padding: 20px;
            background-color: white;
            border-radius: 8px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
        h1 {
            color: #333;
            text-align: center;
        }
        .gallery {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
            gap: 15px;
        }
        .gallery img {
            width: 100%;
            height: auto;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.2);
        }
        .gallery img:hover {
            opacity: 0.8;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>Image Gallery</h1>
        <div class="gallery">
            <img src="https://via.placeholder.com/200" alt="Image 1">
            <img src="https://via.placeholder.com/200" alt="Image 2">
            <img src="https://via.placeholder.com/200" alt="Image 3">
            <img src="https://via.placeholder.com/200" alt="Image 4">
            <img src="https://via.placeholder.com/200" alt="Image 5">
            <img src="https://via.placeholder.com/200" alt="Image 6">
        </div>
    </div>
</body>
</html>