/* 基础样式定义 */
:root {
    --primary-color: #1e3c72;
    --secondary-color: #2a5298;
    --accent-color: #6a11cb;
    --background-gradient: linear-gradient(135deg, #1e3c72, #2a5298, #6a11cb, #2575fc);
    --button-gradient: linear-gradient(45deg, #00c6ff, #0072ff);
    --button-hover-gradient: linear-gradient(45deg, #005bea, #00c6ff);
    --font-primary: 'Montserrat', sans-serif;
    --font-secondary: 'Roboto', sans-serif;
    --text-color: #ffffff;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

/* 全局样式 */
body {
    margin: 0;
    padding: 0;
    font-family: var(--font-primary);
    background: var(--background-gradient);
    color: var(--text-color);
    line-height: 1.6;
}

/* 容器样式 */
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px 0;
}

/* 模块化布局 */
.module {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 40px;
    box-shadow: 0 4px 6px var(--shadow-color);
}

/* 标题样式 */
h1, h2, h3, h4 {
    font-family: var(--font-secondary);
    color: #ffffff;
}

h1 {
    font-size: 2.5em;
    margin-bottom: 20px;
}

h2 {
    font-size: 2em;
    margin-bottom: 15px;
}

h3 {
    font-size: 1.75em;
    margin-bottom: 10px;
}

h4 {
    font-size: 1.5em;
    margin-bottom: 8px;
}

/* 段落样式 */
p {
    font-size: 16px;
    margin-bottom: 15px;
}

/* 按钮样式 */
.button {
    background: var(--button-gradient);
    border: none;
    padding: 10px 20px;
    border-radius: 25px;
    color: #fff;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.3s ease;
    font-size: 16px;
}

.button:hover {
    background: var(--button-hover-gradient);
    transform: scale(1.05);
}

/* 图片样式 */
img.decorative {
    width: 100%;
    max-width: 320px;
    border-radius: 15px;
    box-shadow: 0 4px 6px var(--shadow-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img.decorative:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 8px var(--shadow-color);
}

/* 网格布局 */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(30, 60, 114, 0.9);
    padding: 15px 0;
    z-index: 1000;
    box-shadow: 0 2px 4px var(--shadow-color);
}

.navbar ul {
    list-style: none;
    display: flex;
    justify-content: center;
    margin: 0;
    padding: 0;
}

.navbar li {
    margin: 0 15px;
}

.navbar a {
    color: #ffffff;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s ease;
}

.navbar a:hover {
    color: #00c6ff;
}

/* 章节导航样式 */
.chapter-nav {
    position: fixed;
    right: 20px;
    top: 100px;
    background: rgba(42, 82, 152, 0.8);
    padding: 10px;
    border-radius: 10px;
}

.chapter-nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.chapter-nav li {
    margin-bottom: 10px;
}

.chapter-nav a {
    color: #ffffff;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.chapter-nav a:hover {
    color: #6a11cb;
}

/* 加载动画样式 */
.loader {
    border: 8px solid rgba(255, 255, 255, 0.3);
    border-top: 8px solid #00c6ff;
    border-radius: 50%;
    width: 60px;
    height: 60px;
    animation: spin 1s linear infinite;
    margin: 50px auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 响应式调整 */
@media (max-width: 768px) {
    .navbar ul {
        flex-direction: column;
    }
    .chapter-nav {
        position: static;
        margin-top: 20px;
    }
}