/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* 基础样式 - 防止页面横向拉伸 */
html {
    overflow-x: hidden;
}
body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
    max-width: 100vw; /* 限制最大宽度为视口宽度 */
    overflow-x: hidden; /* 隐藏横向向滚动条 */
}
body.dark-mode {
    background-color: #1e1e2e;
    color: #e0e0e0;
}

/* 容器样式 */
.note-container {
    width: 100%;
    margin: 0 auto;
    padding: 20px;
}

/* 头部样式 */
.note-header {
    display: flex;
    flex-direction: column; /* 纵向排列：标题 → 计时器 → 主题按钮 */
    align-items: center; /* 所有子元素水平居中 */
    padding: 20px 0;
    border-bottom: 1px solid #e0e0e0;
    margin-bottom: 30px;
}
body.dark-mode .note-header {
    border-bottom-color: #333;
}

.note-header h1 {
    font-size: 24px;
    color: #2c3e50;
    display: flex;
    align-items: center;
    margin-bottom: 12px; /* 标题与计时器的垂直间距 */
    text-align: center; /* 确保标题文字本身居中（应对长标题） */
}
body.dark-mode .note-header h1 {
    color: #ffffff;
}
.note-header h1 i {
    margin-right: 10px;
    color: #3498db;
}
/* 主题按钮样式：增加与计时器的间距 */
.theme-toggle {
    margin-top: 12px; /* 计时器与主题按钮的垂直间距 */
}
.theme-toggle button {
    background: none;
    border: none;
    font-size: 20px;
    color: #7f8c8d;
    cursor: pointer;
    transition: color 0.3s;
}
.theme-toggle button:hover {
    color: #3498db;
}

/* 主体内容区 - 网格布局 */
.note-content {
    display: grid;
    grid-template-columns: 180px 250px 1fr;
    gap: 30px;
    margin-bottom: 50px;
}

/* 学科选择区 */
.subject-section h2 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #2c3e50;
}
body.dark-mode .subject-section h2 {
    color: #ffffff;
}
.subject-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-height: 500px;
    overflow-y: auto;
    align-items: flex-start;
}
/* 学科按钮样式 - 优化横向占用空间 */
.subject-btn {
    padding: 12px 15px;
    border: none;
    border-radius: 8px;
    background-color: #ffffff;
    color: #333;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    text-align: left;
    white-space: nowrap;
    flex-shrink: 0;
}
body.dark-mode .subject-btn {
    background-color: #2d2d44;
    color: #e0e0e0;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}
.subject-btn.active {
    background-color: #3498db;
    color: #ffffff;
    box-shadow: 0 4px 8px rgba(52, 152, 219, 0.3);
}
.subject-btn:hover:not(.active) {
    background-color: #f1f5f9;
    transform: translateY(-2px);
}
body.dark-mode .subject-btn:hover:not(.active) {
    background-color: #3a3a56;
}

/* 章节列表区 */
.chapter-section h2 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #2c3e50;
}
body.dark-mode .chapter-section h2 {
    color: #ffffff;
}
.chapter-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 600px;
    overflow-y: auto;
    padding-right: 10px;
    width: 100%;
}
/* 滚动条样式优化 */
.chapter-list::-webkit-scrollbar,
.subject-buttons::-webkit-scrollbar {
    width: 6px;
}
.chapter-list::-webkit-scrollbar-thumb,
.subject-buttons::-webkit-scrollbar-thumb {
    background-color: #bdc3c7;
    border-radius: 3px;
}
body.dark-mode .chapter-list::-webkit-scrollbar-thumb,
body.dark-mode .subject-buttons::-webkit-scrollbar-thumb {
    background-color: #4a4a6a;
}


/* 章节项样式 */
.chapter-item {
    padding: 10px 12px;
    border-radius: 6px;
    background-color: #ffffff;
    color: #333;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
body.dark-mode .chapter-item {
    background-color: #2d2d44;
    color: #e0e0e0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.chapter-item:hover {
    background-color: #f8f9fa;
    transform: translateX(5px);
}
body.dark-mode .chapter-item:hover {
    background-color: #3a3a56;
}
.chapter-item.active {
    background-color: #e3f2fd;
    border-left: 3px solid #3498db;
}
body.dark-mode .chapter-item.active {
    background-color: #343458;
    border-left-color: #4dabf5;
}

/* 目录容器样式 */
.notes-toc {
    margin: 0 0 25px 0;
    padding: 20px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    background-color: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
}
body.dark-mode .notes-toc {
    background-color: #2d2d44;
    border-color: #444;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}


/* 目录标题 */
.toc-title {
    margin: 0 0 18px 0;
    font-size: 18px; /* 增大标题字体 */
    color: #2c3e50;
    font-weight: 600;
    padding-bottom: 10px;
    /* 移除下边框（原下划线由边框实现） */
    border-bottom: none; /* 将原有的 border-bottom: 2px solid #f0f0f0; 改为 none */
    display: flex;
    align-items: center;
}

.toc-title::before {
    content: "📚";
    margin-right: 8px;
}

/* 目录列表：清除默认样式，优化间距 */
.toc-item {
    margin: 8px 0; /* 项间距适中，避免拥挤 */
    line-height: 1.5; /* 与笔记内容行高一致 */
}
.toc-item:hover {
    transform: translateX(4px);
}
/* 目录项 */
.toc-item {
    margin: 6px 0;
    line-height: 1.6;
    transition: transform 0.2s ease;
}

/* 目录链接：无下划线，颜色贴近笔记文本 */
.toc-link {
    color: #34495e;
    text-decoration: none !important; /* 强制去除下划线 */
    font-size: 15px;
    padding: 4px 6px;
    border-radius: 4px;
    display: inline-block;
    transition: all 0.2s ease;
}

/* 链接hover状态：用颜色变化代替下划线 */
.toc-link:hover {
    color: #2980b9;
    background-color: #f5f7fa;
}
/* 平滑滚动（让跳转更友好） */
html {
    scroll-behavior: smooth;
}
/* 目录列表 */
.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}







/* 笔记分隔线（可选优化） */
.note-separator {
    height: 1px;
    background-color: #eee;
    margin: 20px 0;
}


/* 笔记内容区 - 基础自适应优化 */
.note-display-wrapper {
    overflow-x: auto;
    scrollbar-width: thin;
    width: 100%;
}

.note-display {
    background-color: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    padding: 30px;
    min-height: 600px;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box; /* 新增：确保padding不增加宽度 */
}
body.dark-mode .note-display {
    background-color: #2d2d44;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

/* 笔记占位符 */
.note-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: #95a5a6;
    text-align: center;
    padding: 50px;
}
body.dark-mode .note-placeholder {
    color: #7f8c8d;
}
.note-placeholder i {
    font-size: 60px;
    margin-bottom: 20px;
}
.note-placeholder p {
    font-size: 18px;
}

/* 笔记内容区域 */
.note-content-area {
    display: none;
}
.note-title {
    font-size: 24px;
    color: #2c3e50;
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid #e0e0e0;
}
/* 同时修改暗黑模式下的样式 */
body.dark-mode .toc-title {
    color: #ecf0f1;
    border-bottom: none; /* 移除暗黑模式下的下边框 */
}
.note-meta {
    display: flex;
    align-items: center;
    color: #7f8c8d;
    font-size: 14px;
    margin-bottom: 25px;
}
.note-meta i {
    margin-right: 5px;
}

/* 笔记正文样式 - 解除固定最小宽度 */
.note-body {
    font-size: 16px;
    line-height: 1.8;
    width: 100%;
    word-wrap: break-word;
    word-break: break-all; /* 新增：强制所有长内容换行 */
}
.note-body p {
    margin-bottom: 20px;
    word-break: break-all; /* 新增：段落文本强制换行 */
}
.note-body a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.2s;
    word-break: break-all; /* 新增：长链接强制换行 */
}
.note-body a:hover {
    color: #2980b9;
    text-decoration: underline;
}

/* 代码块样式 */
.note-body pre {
    background-color: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    margin: 15px 0;
    overflow-x: auto;
    font-family: 'Consolas', monospace;
    font-size: 12px;
    width: 100%;
    box-sizing: border-box;
}
body.dark-mode .note-body pre {
    background-color: #343458;
}
.note-body code {
    background-color: #f1f1f1;
    padding: 2px 4px;
    border-radius: 4px;
    font-family: 'Consolas', monospace;
    font-size: 12px;
    word-break: break-all;
}

/* 笔记容器样式（参考，确保目录与其协调） */
.single-note {
    margin-bottom: 25px;
    padding: 20px;
    border: 1px solid #e0e0e0;
    border-radius: 4px;
    background-color: #fff;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}
body.dark-mode .single-note {
    background-color: #2d2d44;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* 优化：多笔记时标题序号样式 */
.single-note .note-title {
    color: #3498db;
    border-bottom: 1px solid #f1f5f9;
}
body.dark-mode .single-note .note-title {
    color: #4dabf5;
    border-bottom-color: #3a3a56;
}

body.dark-mode .note-body code {
    background-color: #444466;
}

/* 笔记图片区域 - 手机端自适应 */
.note-images {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin: 15px 0;
    padding: 0; /* 新增：清除内边距避免挤压 */
}
.note-image {
    width: 100%; /* 修改：用100%宽度代替flex:1，避免计算异常 */
    min-width: 100%;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 3px 8px rgba(0,0,0,0.1);
    box-sizing: border-box;
}
.note-image img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    max-width: 100%; /* 新增：兜底防止图片本身宽度过大 */
}
.note-image img:hover {
    transform: scale(1.02);
}

/* 嵌入内容（如视频）- 手机端自适应 */
/* 确保容器不隐藏溢出内容 */
.note-embed {
    margin: 20px 0;
    border-radius: 8px;
    overflow: visible; /* 修改为 visible 避免内容被截断 */
    box-shadow: 0 3px 8px rgba(0,0,0,0.1);
    width: 100%;
    box-sizing: border-box;
}
.note-embed iframe {
    width: 100%;
    min-height: 500px; /* 增加最小高度 */
    max-height: 800px; /* 设置最大高度 */
    height: auto; /* 允许高度自适应内容 */
    border: none;
    overflow: auto; /* 内容过长时显示垂直滚动条 */
}

/* 底部样式 */
.note-footer {
    text-align: center;
    padding: 20px 0;
    color: #7f8c8d;
    border-top: 1px solid #e0e0e0;
}
body.dark-mode .note-footer {
    border-top-color: #333;
}

body.dark-mode .toc-link {
    color: #bdc3c7;
}
body.dark-mode .toc-link:hover {
    color: #3498db;
    background-color: #3a3a56;
}
/* 当前激活的目录项（可选） */
.toc-link.active {
    color: #2980b9;
    font-weight: 500;
    background-color: #eef5fb;
}
body.dark-mode .toc-link.active {
    color: #3498db;
    background-color: #343458;
}


/* 响应式设计 - 大屏适配 */
@media (max-width: 1200px) {
    .note-content {
        grid-template-columns: 160px 220px 1fr;
    }
}

/* 平板适配（992px以下） */
@media (max-width: 992px) {
    .note-content {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto 1fr;
    }
    .subject-section, .chapter-section {
        margin-bottom: 20px;
    }
    .subject-buttons {
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: 15px;
        max-height: none;
        gap: 8px;
    }
    .subject-btn {
        padding: 10px 12px;
        font-size: 13px;
    }
    .chapter-list {
        max-height: 220px;
        flex-direction: row;
        flex-wrap: nowrap;
        overflow-x: auto;
        padding-right: 0;
        padding-bottom: 10px;
        gap: 8px;
    }
    .chapter-item {
        flex: 1 0 calc(33.333% - 8px);
        white-space: normal;
        text-align: center;
        min-height: 80px;
    }
}

/* 小平板/大屏手机（768px以下）- 关键修改：删除min-width，优化视频高度 */
@media (max-width: 768px) {
    .note-container {
        padding: 15px;
    }
    .note-header h1 {
        font-size: 20px;
    }
    .note-display {
        padding: 20px;
        width: 100%;
        box-sizing: border-box;
    }
    .chapter-item {
        flex: 1 0 calc(50% - 8px);
        font-size: 12px;
        padding: 8px 10px;
    }
    .note-embed iframe {
        min-height: 400px;
        max-height: 600px;
        overflow: auto;
    }
    .note-body {
        /* 已删除min-width: 500px，避免溢出 */
        font-size: 15px;
    }
}

/* 小屏手机（576px以下，360px手机触发）- 超小屏优化 */
@media (max-width: 576px) {
    .subject-buttons {
        padding-bottom: 12px;
        gap: 6px;
    }
    .subject-btn {
        padding: 8px 10px;
        font-size: 12px;
    }
    .note-container {
        padding: 8px 5px; /* 减少左右padding，增加可用宽度 */
    }
    .note-content {
        gap: 15px;
    }
    .note-header {
        padding: 15px 0;
        margin-bottom: 20px;
    }
    .note-header h2.subtitle {
        font-size: 14px;
        line-height: 1.5;
        padding: 0 10px;
    }
    .chapter-list {
        flex-direction: column;
        max-height: 250px;
        overflow-y: auto;
    }
    .chapter-item {
        flex: 1 0 100%;
        white-space: nowrap;
        min-height: auto;
        text-align: left;
    }
    .note-title {
        font-size: 18px; /* 缩小标题字体 */
        margin-bottom: 12px;
        padding-bottom: 12px;
    }
    .note-image {
        min-width: 100%;
    }
    .note-embed iframe {
        height: 160px; /* 超小屏视频高度 */
        overflow: auto;
    }
    .note-display {
        padding: 10px 8px; /* 减少内边距 */
        min-height: 350px; /* 降低最小高度 */
    }
    .note-body {
        font-size: 14px;
        line-height: 1.6;
    }
    .single-note {
        padding: 10px; /* 减少单篇笔记内边距 */
        margin-bottom: 20px;
    }
}