/* 全局样式设置，定义基本字体、背景色和文字颜色 */
body {
    margin: 0;
    padding: 0;
    background-color: #1E1E1E; /* 深色背景 */
    color: #FFFFFF; /* 白色文字 */
    font-family: 'Roboto', sans-serif; /* 无衬线字体 */
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: #121212;
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

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

.navbar li {
    position: relative;
    margin-left: 20px;
}

.navbar a {
    color: #FFFFFF;
    text-decoration: none;
    padding: 8px 12px;
    transition: background-color 0.3s ease, color 0.3s ease;
    border-radius: 4px;
}

.navbar a:hover {
    background-color: #0D6EFD;
    color: #FFFFFF;
}

/* 多级菜单样式 */
.navbar li:hover > ul {
    display: block;
}

.navbar ul ul {
    display: none;
    position: absolute;
    top: 40px;
    left: 0;
    background-color: #2E2E2E;
    padding: 10px 0;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

.navbar ul ul li {
    margin: 0;
}

.navbar ul ul a {
    padding: 8px 20px;
    white-space: nowrap;
}

.navbar ul ul a:hover {
    background-color: #0D6EFD;
}

/* 主要内容区域样式 */
.container {
    max-width: 1200px;
    margin: 100px auto 50px auto; /* 顶部预留导航栏空间 */
    padding: 0 15px;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.section {
    background-color: #2E2E2E;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.7);
    animation: fadeIn 1s ease-in-out;
}

.section h2, .section h3, .section h4 {
    color: #0D6EFD; /* 辅助色用于标题 */
}

.section p {
    font-size: 16px;
    color: #B0B0B0; /* 浅灰色文字 */
}

.section pre {
    background-color: #1E1E1E;
    padding: 15px;
    border-radius: 6px;
    overflow-x: auto;
    margin-top: 15px;
}

.section code {
    color: #0D6EFD;
    font-family: 'Courier New', Courier, monospace;
}

/* 图片样式 */
img.decorative {
    width: 100%;
    max-width: 320px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.5);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

img.decorative:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.7);
}

/* 代码块样式 */
.code-block {
    background-color: #1E1E1E;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin-top: 20px;
}

.code-block code {
    color: #0D6EFD;
    font-family: 'Courier New', Courier, monospace;
    font-size: 14px;
}

/* 导航系统样式 */
.nav-sidebar {
    position: fixed;
    top: 70px;
    left: 20px;
    background-color: #2E2E2E;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.7);
}

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

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

.nav-sidebar a {
    color: #FFFFFF;
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-sidebar a:hover {
    color: #0D6EFD;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar ul {
        flex-direction: column;
        background-color: #121212;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        display: none;
    }
    .navbar ul.show {
        display: flex;
    }
    .navbar li {
        margin: 10px 0;
    }
    .nav-sidebar {
        display: none;
    }
    .container {
        margin: 80px auto 20px auto;
    }
}

@media (max-width: 480px) {
    .section {
        padding: 20px;
    }
    .navbar {
        padding: 10px 20px;
    }
}

/* 按钮样式 */
.btn-primary {
    background-color: #0D6EFD;
    border: none;
    color: #FFFFFF;
    padding: 10px 20px;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn-primary:hover {
    background-color: #0B5ED7;
}

/* 过渡与动画 */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 提示文本样式 */
.note {
    background-color: #0D6EFD;
    color: #FFFFFF;
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 20px;
    text-align: center;
}

/* 折叠区域样式 */
.collapsible {
    background-color: #2E2E2E;
    color: #FFFFFF;
    cursor: pointer;
    padding: 10px 20px;
    border: none;
    text-align: left;
    outline: none;
    font-size: 16px;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

.active, .collapsible:hover {
    background-color: #0D6EFD;
}

.content {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    background-color: #1E1E1E;
    border-radius: 4px;
}

.content p {
    color: #B0B0B0;
}

/* 页脚样式 */
.footer {
    background-color: #121212;
    padding: 30px;
    text-align: center;
    color: #B0B0B0;
    border-top: 1px solid #2E2E2E;
}

.footer a {
    color: #0D6EFD;
    text-decoration: none;
    margin: 0 10px;
}

.footer a:hover {
    color: #0B5ED7;
}

/* 视觉焦点样式 */
.focus {
    background-color: #6A0DAD;
    color: #FFFFFF;
    padding: 5px 10px;
    border-radius: 4px;
}

/* 高亮文本样式 */
.highlight {
    background: linear-gradient(45deg, #0D6EFD, #6A0DAD);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* 输入框样式 */
input[type="text"], textarea {
    width: 100%;
    padding: 10px;
    margin-top: 6px;
    margin-bottom: 16px;
    resize: vertical;
    border: none;
    border-radius: 4px;
    background-color: #2E2E2E;
    color: #FFFFFF;
}

/* 表格样式 */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

table, th, td {
    border: 1px solid #0D6EFD;
}

th, td {
    padding: 12px;
    text-align: left;
}

th {
    background-color: #0D6EFD;
    color: #FFFFFF;
}

tr:nth-child(even) {
    background-color: #2E2E2E;
}

/* 媒体查询示例 */
@media (max-width: 768px) {
    .navbar ul {
        flex-direction: column;
    }
    .navbar ul.show {
        display: flex;
    }
}