:root {
    --primary-color: #3498db;
    --primary-light: #e3f2fd;
    --secondary-color: #2ecc71;
    --accent-color: #e74c3c;
    --light-color: #f9f9f9;
    --dark-color: #2c3e50;
    --border-color: #e1e5e9;
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-heavy: 0 8px 24px rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

#page-knowledge iframe {
    border: 2px solid rgba(0, 0, 0, 0);
    outline: 2px solid #000000;
}

/* 首页样式 */
#page-knowledge .home-page {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 90vh;
    padding: 20px;
    background: rgba(0, 0, 0, 0);
}

#page-knowledge .logo {
    text-align: center;
    margin-bottom: 50px;
    max-width: 800px;
}

#page-knowledge .logo h1 {
    font-size: 2.8rem;
    background: linear-gradient(135deg, var(--dark-color) 0%, var(--primary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 15px;
    letter-spacing: -0.5px;
}

#page-knowledge .logo p {
    font-size: 1.1rem;
    color: #64748b;
    line-height: 1.6;
}

#page-knowledge .subjects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    max-width: 900px;
    width: 100%;
    margin-bottom: 50px;
}

#page-knowledge .subject-btn {
    font-family: "fillet";
    background: white;
    border: none;
    border-radius: var(--radius-lg);
    padding: 32px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-light);
    position: relative;
    overflow: hidden;
}

#page-knowledge .subject-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    opacity: 0;
    transition: var(--transition);
}

#page-knowledge .subject-btn:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-heavy);
}

#page-knowledge .subject-btn:hover::before {
    opacity: 1;
}

#page-knowledge .subject-btn i {
    font-size: 2.8rem;
    margin-bottom: 18px;
}

#page-knowledge .subject-btn h3 {
    font-size: 1.3rem;
    color: var(--dark-color);
}

#page-knowledge .instructions {
    background: white;
    padding: 20px 25px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
    max-width: 900px;
    width: 100%;
}

#page-knowledge .instructions p {
    margin: 8px 0;
    color: #64748b;
    display: flex;
    align-items: center;
    gap: 10px;
}

#page-knowledge .instructions i {
    color: var(--primary-color);
}

#page-knowledge .chinese {
    color: #e74c3c;
}

#page-knowledge .math {
    color: #3498db;
}

#page-knowledge .english {
    color: #2ecc71;
}

#page-knowledge .physics {
    color: #9b59b6;
}

#page-knowledge .chemistry {
    color: #e67e22;
}

/* 切换动画 */
#page-knowledge .transition-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--dark-color) 100%);
    z-index: 2000;
    display: none;
    justify-content: center;
    align-items: center;
    opacity: 0;
    transition: opacity 0.5s ease;
}

#page-knowledge .transition-text {
    color: white;
    font-size: 1.8rem;
    display: flex;
    align-items: center;
    gap: 15px;
}

/* 知识点页面 */
#page-knowledge .knowledge-page {
    display: none;
    min-height: 100vh;
}

#page-knowledge .page-header {
    display: flex;
    align-items: center;
    padding: 18px 25px;
    background-color: white;
    box-shadow: var(--shadow-light);
    z-index: 100;
    position: sticky;
    top: 0;
    border-bottom: 1px solid var(--border-color);
}

#page-knowledge .header-btns {
    display: flex;
    gap: 12px;
}

#page-knowledge .header-btn {
    background-color: var(--light-color);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1.1rem;
    color: #64748b;
}

#page-knowledge .header-btn:hover {
    background-color: var(--primary-color);
    color: white;
    transform: scale(1.05);
}

#page-knowledge .subject-title {
    margin-left: 25px;
    font-size: 1.4rem;
    color: var(--dark-color);
}

#page-knowledge .page-content {
    display: flex;
    height: calc(100vh - 76px);
}

/* 目录样式 - 美化 */
#page-knowledge .directory-container {
    width: 320px;
    background-color: white;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    overflow: hidden;
}

#page-knowledge .directory-container.hidden {
    width: 0;
    border-right: none;
}

#page-knowledge .directory-header {
    padding: 20px 25px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
}

#page-knowledge .directory-header h3 {
    color: var(--dark-color);
    font-size: 1.1rem;
    letter-spacing: 0.5px;
}

#page-knowledge .directory-list {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
}

#page-knowledge .folder {
    margin-bottom: 6px;
    margin-top: 6px;
}

#page-knowledge .folder-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 16px;
    background-color: #f8fafc;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid #f1f5f9;
}

#page-knowledge .folder-header:hover {
    background-color: #f1f5f9;
    border-color: var(--border-color);
}

#page-knowledge .folder-name {
    display: flex;
    align-items: center;
    gap: 12px;
}

#page-knowledge .folder-name i {
    font-size: 1rem;
    color: var(--primary-color);
}

#page-knowledge .folder-name span {
    font-size: 0.85rem;
    /* 字体变小 */
    color: #1a202c;
    /* 对比度增大，更深 */
}

#page-knowledge .folder-toggle {
    color: #94a3b8;
    font-size: 0.9rem;
    transition: var(--transition);
}

#page-knowledge .folder-content {
    padding-left: 20px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.4s ease;
    position: relative;
    /* 为左侧线定位 */
}

/* 添加左侧线，显示嵌套层级 */
#page-knowledge .folder-content::before {
    content: '';
    position: absolute;
    left: 16px;
    top: 0;
    bottom: 0;
    width: 2px;
    background-color: rgba(128, 128, 128, 1.0);
    display: block;
    opacity: 0.6;
}

#page-knowledge .folder-content.expanded {
    height: auto;
    max-height: 1000px;
}

/* 嵌套文件夹样式 - 更清晰的层级 */
#page-knowledge .folder .folder {
    margin-bottom: 0px;
}

#page-knowledge .folder .folder .folder-header {
    background-color: #f1f5f9;
    padding: 8px 16px;
}

#page-knowledge .folder .folder .folder-name {
    font-size: 0.9rem;
}

#page-knowledge .folder .folder .folder-name i {
    font-size: 0.9rem;
}

#page-knowledge .folder .folder .folder-content {
    padding-left: 16px;
}

/* 知识点项目 */
#page-knowledge .knowledge-item {
    padding: 8px 16px;
    margin: 6px 0;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.8rem;
    /* 字体变小 */
    color: #2d3748;
    /* 对比度增大，更深 */
    border: 1px solid transparent;
    line-height: 1.5;
}

#page-knowledge .knowledge-item:hover {
    background-color: #f1f7ff;
    border-color: #dbeafe;
    color: var(--primary-color);
}

#page-knowledge .knowledge-item.active {
    background-color: var(--primary-light);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

#page-knowledge .knowledge-item i {
    font-size: 0.85rem;
}

/* 知识点内容区域 */
#page-knowledge .knowledge-content {
    flex: 1;
    padding: 30px 40px;
    overflow-y: auto;
    background-color: #f8fafc;
    transition: var(--transition);
}

#page-knowledge .knowledge-content.fullscreen {
    padding: 40px 60px;
}

#page-knowledge .content-title {
    font-size: 2.2rem;
    margin-bottom: 25px;
    color: var(--dark-color);
    padding-bottom: 20px;
    border-bottom: 2px solid var(--primary-color);
    line-height: 1.3;
}

#page-knowledge .content-body {
    line-height: 1.8;
}

#page-knowledge .content-section {
    margin-bottom: 30px;
    background-color: white;
    padding: 30px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
    border: 1px solid var(--border-color);
}

#page-knowledge .content-section h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--dark-color);
}

#page-knowledge .content-section p {
    margin-bottom: 18px;
    font-size: 1.05rem;
    color: #475569;
}

#page-knowledge .content-section ul,
#page-knowledge .content-section ol {
    padding-left: 30px;
    margin-bottom: 20px;
}

#page-knowledge .content-section li {
    margin-bottom: 10px;
    font-size: 1.05rem;
    color: #475569;
}

#page-knowledge .formula {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: var(--radius-md);
    margin: 20px 0;
    text-align: center;
    font-size: 1.3rem;
    border-left: 4px solid var(--primary-color);
}

#page-knowledge .example {
    background-color: #fff8e1;
    border-left: 4px solid #ffc107;
    padding: 20px;
    margin: 20px 0;
    border-radius: var(--radius-md);
}

/* 加载动画 */
#page-knowledge .loader {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top: 3px solid rgba(255, 255, 255, 1.0);
    animation: spin 1s ease-in-out infinite;
}

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

@keyframes fadeIn {
    0% {
        opacity: 0;
    }

    100% {
        opacity: 1;
    }
}

#page-knowledge .fade-in {
    animation: fadeIn 0.5s ease;
}

/* 手机端样式 */
@media (max-width: 768px) {
    #page-knowledge .subjects-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }

    #page-knowledge .page-content {
        flex-direction: column;
    }

    #page-knowledge .directory-container {
        width: 100%;
        height: 0;
        position: fixed;
        top: 0;
        left: 0;
        z-index: 500;
        overflow: hidden;
        box-shadow: var(--shadow-heavy);
    }

    #page-knowledge .directory-container.mobile-open {
        height: 100vh;
        overflow-y: auto;
    }

    #page-knowledge .knowledge-content {
        width: 100%;
        padding: 20px;
    }

    #page-knowledge .subject-btn {
        padding: 25px 15px;
    }

    #page-knowledge .subject-btn i {
        font-size: 2.2rem;
    }

    #page-knowledge .subject-btn h3 {
        font-size: 1.1rem;
    }

    #page-knowledge .logo h1 {
        font-size: 2rem;
    }

    #page-knowledge .content-title {
        font-size: 1.8rem;
    }

    #page-knowledge .content-section {
        padding: 20px;
    }

    #page-knowledge .knowledge-content.fullscreen {
        padding: 20px;
    }

    #page-knowledge .instructions {
        padding: 15px;
    }
}

@media (max-width: 480px) {
    #page-knowledge .subjects-grid {
        grid-template-columns: 1fr;
    }

    #page-knowledge .logo h1 {
        font-size: 1.8rem;
    }

    #page-knowledge .subject-btn i {
        font-size: 2rem;
    }

    #page-knowledge .content-title {
        font-size: 1.6rem;
    }

    #page-knowledge .content-section {
        padding: 15px;
    }
}

/* 空状态 */
#page-knowledge .empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #94a3b8;
}

#page-knowledge .empty-state i {
    font-size: 3rem;
    margin-bottom: 20px;
    opacity: 0.5;
}

#page-knowledge .empty-state h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: #64748b;
}

/* 使用!important覆盖 , 就是好像有点长 */
mjx-container,
mjx-math,
mjx-utext,
mjx-c,
mjx-mtext,
.MJX-TEX,
.MathJax,
.MathJax_CHTML,
.MathJax_SVG,
.mjx-chtml,
.mjx-math,
.mjx-utext,
.mjx-c,
.mjx-mtext,
.MJXc-TeX-unknown-R,
.MJXc-TeX-unknown-I,
.MJXc-TeX-main-R,
.MJXc-TeX-main-I,
.MJXc-TeX-main-B,
.MJXc-TeX-main-BI,
.MJXc-TeX-math-I,
.MJXc-TeX-math-Ix,
.MJXc-TeX-math-Iw,
.MJXc-TeX-ams-R,
.MJXc-TeX-ams-I,
.MJXc-TeX-cal-B,
.MJXc-TeX-cal-Bx,
.MJXc-TeX-frak-R,
.MJXc-TeX-frak-B,
.MJXc-TeX-script-R,
.MJXc-TeX-script-B,
.MJXc-TeX-typewriter-R,
.MJXc-TeX-sans-R,
.MJXc-TeX-sans-B,
.MJXc-TeX-sans-I,
.MJXc-TeX-script-Rw,
.MJXc-TeX-fraktur-R,
.MJXc-TeX-fraktur-B,
[class*="MJXc-"] {
    font-family: MJXc-TeX-math-I, MJXc-TeX-math-Ix, MJXc-TeX-math-Iw,
        MJXc-TeX-main-R, MJXc-TeX-main-I, MJXc-TeX-main-B, MJXc-TeX-main-BI,
        MJXc-TeX-ams-R, MJXc-TeX-ams-I,
        MJXc-TeX-cal-B, MJXc-TeX-cal-Bx,
        MJXc-TeX-frak-R, MJXc-TeX-frak-B,
        MJXc-TeX-script-R, MJXc-TeX-script-B,
        'STIX-Web', 'STIX Two Math', 'Latin Modern Math', 'Cambria Math',
        'Asana Math', 'TeX Gyre Termes Math', 'XITS Math', 'Libertinus Math',
        'DejaVu Math TeX Gyre', 'STIX Math', serif !important;
}