### 2. `styles.css` (CSS文件)

```css
/* 全局样式 */
body {
    font-family: Arial, sans-serif;
    background: url('game_background.jpg') no-repeat center center fixed;
    background-size: cover;
    color: white;
    margin: 0;
    padding: 0;
}

/* 顶部导航栏 */
header {
    background: rgba(0, 0, 0, 0.7);
    padding: 20px;
}

nav ul {
    list-style: none;
    text-align: center;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-size: 18px;
}

/* 主页部分 */
.hero {
    text-align: center;
    padding: 100px 0;
    background: rgba(0, 0, 0, 0.5);
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero p {
    font-size: 24px;
}

/* 功能介绍部分 */
#features {
    padding: 50px 0;
    text-align: center;
    background-color: rgba(0, 0, 0, 0.7);
}

#features h2 {
    font-size: 36px;
    margin-bottom: 20px;
}

#features ul {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 40px;
}

#features li {
    width: 150px;
    text-align: center;
}

#features img {
    width: 100%;
    height: auto;
    margin-bottom: 10px;
}

/* 外挂演示部分 */
#demo {
    padding: 50px 0;
    text-align: center;
    background-color: rgba(0, 0, 0, 0.7);
}

#demo video {
    width: 80%;
    max-width: 800px;
}

/* 购买链接部分 */
#buy {
    padding: 50px 0;
    text-align: center;
    background-color: rgba(0, 0, 0, 0.7);
}

#buy h2 {
    font-size: 36px;
    margin-bottom: 20px;
}

#buy p {
    font-size: 20px;
    margin-bottom: 20px;
}

button {
    background-color: #ff4500;
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    cursor: pointer;
    border-radius: 5px;
}

button:hover {
    background-color: #e03e00;
}

/* 用户评价部分 */
#reviews {
    padding: 50px 0;
    text-align: center;
    background-color: rgba(0, 0, 0, 0.7);
}

#reviews h2 {
    font-size: 36px;
    margin-bottom: 20px;
}

#reviews blockquote {
    font-size: 18px;
    margin: 20px 0;
    border-left: 4px solid #ff4500;
    padding-left: 20px;
}

/* 底部 */
footer {
    text-align: center;
    padding: 20px;
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
}
```