:root[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f7f9;
    --bg-tertiary: #edf2f7;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --border-color: #e2e8f0;
    --accent-color: #4f46e5;
    --accent-hover: #4338ca;
    --nav-bg: #2c3e50;
    --sidebar-bg: #f8f9fa;
    --video-bg: #ffffff;
    --nav-item-bg: #34495e;
    --nav-item-text: #ffffff;
    --nav-item-hover: #3498db;
    --nav-item-active: #2980b9;
}

:root[data-theme="dark"] {
    --bg-primary: #1a1a1a;
    --bg-secondary: #242424;
    --bg-tertiary: #2d2d2d;
    --text-primary: #e5e5e5;
    --text-secondary: #a0a0a0;
    --border-color: #363636;
    --accent-color: #4f46e5;
    --accent-hover: #6366f1;
    --nav-bg: #262626;
    --sidebar-bg: #1a1a1a;
    --video-bg: #242424;
    --nav-item-bg: #404040;
    --nav-item-text: #ffffff;
    --nav-item-hover: #525252;
    --nav-item-active: #4f46e5;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
}

/* 顶部导航栏 */
.top-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    background-color: var(--nav-bg);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    backdrop-filter: blur(8px);
}

.nav-content {
    max-width: 1920px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-left {
    display: flex;
    align-items: center;
}

.nav-menu {
    display: flex;
    gap: 16px;
    align-items: center;
}

.nav-item {
    color: var(--nav-item-text);
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 17px;
    transition: all 0.2s;
    margin: 0 8px;
    background-color: var(--nav-item-bg);
    border: 1px solid transparent;
}

.nav-item:hover {
    background-color: var(--nav-item-hover);
    color: white;
    transform: translateY(-2px);
}

.nav-item.active {
    background-color: var(--nav-item-active);
    color: white;
    font-weight: 600;
}

/* 主容器 */
.main-container {
    display: flex;
    margin-top: 70px;
    height: calc(100vh - 70px);
}

/* 左侧边栏 */
.course-sidebar {
    width: 300px;
    background-color: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    height: 100%;
    overflow: hidden;
    flex-shrink: 0;
}

.course-menu {
    height: 100%;
    display: flex;
    flex-direction: column;
}

.course-header {
    padding: 16px;
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.course-header h2 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--text-primary);
}

.course-sections {
    flex: 1;
    overflow-y: auto;
    padding: 16px;
}

/* 课程章节样式 */
.course-section {
    margin-bottom: 16px;
}

.section-header {
    padding: 14px 18px;
    background-color: var(--bg-primary);
    border-radius: 4px;
    margin-bottom: 4px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 16px;
    font-weight: 500;
}

.section-header:hover {
    background-color: var(--bg-tertiary);
}

.section-lessons {
    padding-left: 12px;
}

.lesson-item {
    padding: 12px 16px 12px 32px;
    margin: 2px 0;
    position: relative;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    background-color: var(--bg-secondary);
}

.lesson-item:hover {
    background-color: var(--bg-tertiary);
}

.lesson-item.active {
    background-color: var(--accent-color);
    color: white;
}

.lesson-item::before {
    content: '▶';
    position: absolute;
    left: 12px;
    font-size: 12px;
    color: var(--text-secondary);
}

.lesson-item.active::before {
    content: '▶';
    color: white;
}

/* 主内容区域 */
.content-area {
    flex: 1;
    overflow-y: auto;
    background-color: var(--bg-primary);
}

/* 视频播放区域 */
.video-section {
    max-width: 1000px;
    margin: 0 auto;
    padding: 32px;
}

.course-player {
    display: none;
}

.course-player.active {
    display: block;
}

.video-container {
    position: relative;
    width: 100%;
    padding-top: 56.25%; /* 16:9 宽高比 */
    background-color: var(--video-bg);
    border-radius: 8px;
    overflow: hidden;
}

.video-container iframe, .video-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.course-info {
    padding: 24px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    margin-top: 24px;
}

.course-info h1 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-primary);
}

.course-meta {
    display: flex;
    gap: 16px;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.course-description {
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-secondary);
    margin: 15px 0;
    padding: 10px;
    background-color: var(--bg-secondary);
    border-radius: 4px;
}

.course-files {
    margin: 20px 0;
    padding: 10px;
    background-color: var(--bg-secondary);
    border-radius: 4px;
}

.course-files h3 {
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 18px;
    color: var(--text-primary);
}

.file-item {
    display: flex;
    align-items: center;
    padding: 8px 12px;
    margin-bottom: 5px;
    background-color: var(--bg-primary);
    border-radius: 4px;
    color: var(--text-primary);
    text-decoration: none;
    transition: background-color 0.3s ease;
}

.file-item:hover {
    background-color: var(--accent-color);
    color: white;
}

.file-icon {
    font-size: 20px;
    margin-right: 10px;
}

.file-name {
    flex: 1;
    font-weight: 500;
}

.file-size {
    font-size: 14px;
    opacity: 0.8;
}



/* 主题切换按钮 */
#themeToggle {
    background: transparent;
    border: 1px solid var(--border-color);
    padding: 10px 16px;
    border-radius: 6px;
    cursor: pointer;
    color: var(--text-primary);
    transition: all 0.2s;
    font-size: 16px;
}

#themeToggle:hover {
    background-color: var(--bg-tertiary);
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* 将主题切换按钮移到右边 */
.nav-controls {
    position: absolute;
    right: 24px;
}

/* 添加视频教程容器样式 */
.video-tutorial-container {
    display: flex;
    width: 100%;
    height: 100%;
}

/* 添加编辑器容器样式 */
.editor-container {
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
}

/* 实用工具容器样式 */
.tools-container {
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
    overflow-y: auto;
    padding: 24px;
}

.tools-grid {
    max-width: 1200px;
    margin: 0 auto;
}

.tools-header {
    margin-bottom: 32px;
    text-align: center;
}

.tools-header h2 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.tools-filter {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 24px;
}

.filter-btn {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

.tools-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.tool-card {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 20px;
    transition: transform 0.2s;
    cursor: pointer;
}

.tool-card:hover {
    transform: translateY(-4px);
}

.tool-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.tool-card .description {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

.tool-card .meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: var(--text-secondary);
}

.tool-card .tag {
    background: var(--bg-tertiary);
    padding: 4px 8px;
    border-radius: 4px;
}

/* 导航链接容器样式 */
.nav-links-container {
    width: 100%;
    height: 100%;
    background-color: var(--bg-primary);
    overflow-y: auto;
    padding: 32px;
}

.nav-links-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    gap: 32px;
}

.nav-section {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 24px;
}

.nav-section-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.nav-links {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.nav-link-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    text-decoration: none;
    transition: transform 0.2s;
}

.nav-link-card:hover {
    transform: translateY(-2px);
    background: var(--accent-color);
}

.nav-link-card:hover .nav-link-info h3,
.nav-link-card:hover .nav-link-info p {
    color: white;
}

.nav-link-icon {
    font-size: 24px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 8px;
}

.nav-link-info h3 {
    color: var(--text-primary);
    font-size: 16px;
    margin-bottom: 4px;
}

.nav-link-info p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* 添加课程内容样式 */
.course-content {
    margin-top: 20px;
    display: grid;
    gap: 24px;
}

.course-content h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

/* 课程重点样式 */
.course-highlights ul {
    list-style: none;
    padding: 0;
}

.course-highlights li {
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
    color: var(--text-secondary);
}

.course-highlights li::before {
    content: '•';
    position: absolute;
    left: 8px;
    color: var(--accent-color);
}

/* 课程文件样式 */
.course-files {
    background: var(--bg-secondary);
    border-radius: 8px;
    padding: 16px;
}

.file-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 12px;
    background: var(--bg-primary);
    border-radius: 6px;
    text-decoration: none;
    color: var(--text-primary);
    transition: all 0.2s;
}

.file-item:hover {
    background: var(--bg-tertiary);
    transform: translateX(4px);
}

.file-icon {
    font-size: 20px;
    margin-right: 12px;
}

.file-name {
    flex: 1;
}

.file-size {
    color: var(--text-secondary);
    font-size: 14px;
}