/* 全局样式 */
body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(to bottom, #003366, #4da6ff);
    color: #ffffff;
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3 {
    font-weight: bold;
    text-align: center;
    margin-top: 2rem;
}

p {
    margin-bottom: 1rem;
    padding: 0 1rem;
}

pre {
    background: rgba(0, 0, 0, 0.7);
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1rem;
}

code {
    color: #33ff99;
    font-size: 0.9rem;
}

table {
    width: 90%;
    margin: 1rem auto;
    border-collapse: collapse;
    background: rgba(0, 0, 0, 0.5);
}

th, td {
    border: 1px solid #ffffff;
    padding: 0.5rem;
    text-align: center;
}

/* 导航栏 */
nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: linear-gradient(to right, #003366, #0066cc);
    z-index: 1000;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    padding: 0.5rem 0;
}

nav ul li {
    margin: 0 1rem;
}

nav ul li a {
    color: #ffffff;
    text-decoration: none;
    font-size: 1rem;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: #33ff99;
}

/* 模块样式 */
.module {
    padding: 4rem 1rem;
    text-align: center;
    background-size: cover;
    background-position: center;
}

.module:nth-child(odd) {
    background: linear-gradient(to bottom, #003366, #4da6ff);
}

.module:nth-child(even) {
    background: linear-gradient(to bottom, #0066cc, #4da6ff);
}

.module h2 {
    margin-bottom: 1rem;
}

.module img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
}

/* 按钮样式 */
button {
    background: linear-gradient(to right, #00cc66, #33ff99);
    color: #003366;
    border: none;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 1rem;
}

button:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 8px rgba(0, 204, 102, 0.5);
}

/* 响应式设计 */
@media (max-width: 768px) {
    nav ul {
        flex-direction: column;
    }

    nav ul li {
        margin: 0.5rem 0;
    }

    .module {
        padding: 2rem 1rem;
    }

    pre {
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    h1, h2, h3 {
        font-size: 1.5rem;
    }

    button {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}