/* ========== 用户侧通用样式（提取自 base.html） ========== */

/* Mermaid 图表容器（皮肤无关） */
.content-body .mermaid {
    display: flex;
    justify-content: center;
    align-items: center;
    background: #ffffff;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    /* 占位阶段不显示，渲染完成后再显示，避免源码闪现 */
    min-height: 60px;
}

/* 渲染占位阶段：保持隐藏（由 JS 在 mermaid.run 完成后移除） */
/* 使用 opacity:0 而非 display:none，确保元素保留布局尺寸供 mermaid 计算 SVG 坐标 */
.content-body .mermaid.mermaid-placeholder {
    opacity: 0;
}

/* 渲染错误态：醒目错误提示卡片，避免源码外露 */
.content-body .mermaid.mermaid-error {
    display: block;
    background: #fff3cd;
    border: 1px solid #ffc107;
    border-radius: 8px;
    padding: 16px;
    color: #856404;
    font-family: 'Courier New', monospace;
    font-size: 0.95rem;
    white-space: pre-wrap;
    margin: 16px 0;
}

.content-body .mermaid svg {
    max-width: 100%;
    height: auto;
}

/* Mermaid 渲染完成后的入场动画（淡入 + 轻微缩放，模拟"展开"） */
@keyframes mermaidFadeIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.content-body .mermaid.mermaid-fade-in {
    animation: mermaidFadeIn 0.4s ease-out both;
    transform-origin: center center;
}

/* 无障碍：尊重 prefers-reduced-motion 用户偏好，关闭动画 */
@media (prefers-reduced-motion: reduce) {
    .content-body .mermaid.mermaid-fade-in {
        animation: none;
    }
}

/* 导航品牌 */
.navbar-brand {
    font-weight: bold;
    color: var(--skin-navbar-brand, #0d6efd) !important;
    display: flex;
    align-items: center;
    gap: 8px;
    margin-left: 4px;
}

.navbar-brand svg {
    width: 48px;
    height: 48px;
}

/* 题目卡片 */
.question-card {
    transition: transform 0.2s;
    border: 1px solid var(--skin-card-border, #e0e0e0);
}

.question-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--skin-card-shadow, 0 4px 12px rgba(0,0,0,0.1));
}

/* 徽章 */
.difficulty-badge {
    font-size: 0.75em;
}

.tag-badge {
    color: #6c757d;
    font-size: 0.875em;
}

.vip-badge {
    background: linear-gradient(45deg, #ffd700, #ffed4e);
    color: #856404;
}

.points-badge {
    background-color: #e3f2fd;
    color: #1976d2;
}

/* Markdown 内容 */
.markdown-content {
    line-height: 1.6;
}

.markdown-content img {
    max-width: 100%;
    height: auto;
    margin: 10px 0;
}

.markdown-content pre {
    background-color: var(--skin-code-bg, #f8f9fa);
    color: var(--skin-code-text, #212529);
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
}

.markdown-content code {
    background-color: var(--skin-code-bg, #e9ecef);
    color: var(--skin-code-text, #212529);
    padding: 2px 4px;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
}

/* 答案区域 */
.answer-section {
    background-color: var(--skin-card-bg, #f8f9fa);
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
}

/* 附件 */
.attachments {
    margin-top: 10px;
}

.attachment-item {
    padding: 8px 12px;
    background-color: var(--skin-alert-info-bg, #e3f2fd);
    border-radius: 5px;
    margin-bottom: 5px;
}

.attachment-item a {
    color: var(--skin-link-color, #1976d2);
    text-decoration: none;
}

.attachment-item a:hover {
    text-decoration: underline;
}

/* Toast 提示容器（位于导航栏下方，避免透明重叠） */
.toast-container {
    position: fixed;
    top: 70px;
    right: 20px;
    z-index: 1050;
}

/* 题目统计与操作 */
.question-stats {
    font-size: 0.9em;
    color: #6c757d;
}

.question-actions {
    margin-top: 15px;
}

/* 加载和空状态 */
.loading-spinner {
    display: none;
    text-align: center;
    padding: 20px;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: var(--skin-muted, #6c757d);
}

.empty-state i {
    font-size: 3em;
    margin-bottom: 15px;
    opacity: 0.5;
}

/* 标签选择器 */
.tag-selector {
    border: 1px solid var(--skin-input-border, #ced4da);
    border-radius: 0.25rem;
    padding: 0.375rem 0.75rem;
    background-color: var(--skin-input-bg, #fff);
    cursor: pointer;
}

.tag-selector:hover {
    border-color: var(--skin-input-focus-border, #80bdff);
    outline: 0;
    box-shadow: var(--skin-input-focus-shadow, 0 0 0 0.2rem rgba(0,123,255,.25));
}

.selected-tags {
    margin-top: 10px;
}

.selected-tag {
    display: inline-block;
    background-color: var(--skin-primary, #007bff);
    color: white;
    padding: 3px 8px;
    border-radius: 3px;
    margin: 2px;
    font-size: 0.85em;
}

.selected-tag .remove-tag {
    margin-left: 5px;
    cursor: pointer;
}

/* AI 反馈框 */
.ai-feedback {
    background-color: var(--skin-alert-warning-bg, #fff3cd);
    border: 1px solid var(--skin-alert-warning-border, #ffeaa7);
    border-radius: 5px;
    padding: 15px;
    margin-top: 15px;
}

.ai-feedback .feedback-header {
    font-weight: bold;
    color: var(--skin-alert-warning-text, #856404);
    margin-bottom: 10px;
}

.ai-suggestions {
    background-color: var(--skin-alert-info-bg, #d1ecf1);
    border: 1px solid var(--skin-alert-info-border, #bee5eb);
    border-radius: 5px;
    padding: 15px;
    margin-top: 10px;
}

.ai-suggestions .suggestions-header {
    font-weight: bold;
    color: var(--skin-alert-info-text, #0c5460);
    margin-bottom: 10px;
}

.ai-highlights {
    background-color: var(--skin-alert-success-bg, #d4edda);
    border: 1px solid var(--skin-alert-success-border, #c3e6cb);
    border-radius: 5px;
    padding: 15px;
    margin-top: 10px;
}

.ai-highlights .highlights-header {
    font-weight: bold;
    color: var(--skin-alert-success-text, #155724);
    margin-bottom: 10px;
}

/* 分数颜色 */
.score-badge {
    font-size: 1.2em;
    font-weight: bold;
}

.score-excellent { color: #28a745; }
.score-good { color: #17a2b8; }
.score-average { color: #ffc107; }
.score-poor { color: #dc3545; }

/* 难度和题目类型颜色 */
.difficulty-easy { color: #28a745; }
.difficulty-medium { color: #ffc107; }
.difficulty-hard { color: #dc3545; }

.question-type-choice { color: #007bff; }
.question-type-qa { color: #6f42c1; }

/* 练习统计 */
.practice-stats {
    background-color: var(--skin-card-bg, #f8f9fa);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
}

.practice-stats h5 {
    color: var(--skin-body-color, #495057);
    margin-bottom: 15px;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--skin-card-border, #e9ecef);
}

.stat-item:last-child {
    border-bottom: none;
}

.stat-label {
    color: #6c757d;
}

.stat-value {
    font-weight: bold;
    color: #495057;
}

/* 证书卡片 */
.certificate-card {
    border: 2px solid #28a745;
    border-radius: 10px;
    padding: 20px;
    text-align: center;
    background: var(--skin-card-bg, linear-gradient(135deg, #fff 0%, #f8f9fa 100%));
    position: relative;
    overflow: hidden;
}

.certificate-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: repeating-linear-gradient(
        45deg,
        transparent,
        transparent 10px,
        rgba(40, 167, 69, 0.1) 10px,
        rgba(40, 167, 69, 0.1) 20px
    );
    animation: certificate-shine 20s linear infinite;
}

@keyframes certificate-shine {
    0% { transform: translateX(-100%) translateY(-100%); }
    100% { transform: translateX(100%) translateY(100%); }
}

.certificate-icon {
    font-size: 3em;
    color: #28a745;
    margin-bottom: 15px;
}

.certificate-title {
    font-size: 1.5em;
    font-weight: bold;
    color: #155724;
    margin-bottom: 10px;
}

.certificate-date {
    color: #6c757d;
    font-size: 0.9em;
}

/* 过滤器 */
.filter-section {
    background-color: var(--skin-card-bg, #f8f9fa);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
}

.filter-title {
    font-weight: bold;
    color: #495057;
    margin-bottom: 15px;
}

/* 题目列表项 */
.question-list-item {
    border-left: 4px solid #007bff;
    padding-left: 15px;
    margin-bottom: 15px;
}

.question-list-item.answered {
    border-left-color: #28a745;
}

.question-list-item.unanswered {
    border-left-color: #6c757d;
}

.question-list-item.correct {
    border-left-color: #28a745;
}

.question-list-item.incorrect {
    border-left-color: #dc3545;
}

.question-list-title {
    font-weight: bold;
    color: #495057;
    margin-bottom: 5px;
}

.question-list-meta {
    font-size: 0.85em;
    color: #6c757d;
}

.question-list-actions {
    margin-top: 10px;
}

/* 分页 */
.pagination-info {
    text-align: center;
    color: #6c757d;
    margin: 20px 0;
}

/* ===== 通用组件微调 ===== */
.btn-group-sm > .btn, .btn-sm { font-size: 0.8rem; }
.card-header .btn-group { margin-left: auto; }
.table-responsive { border-radius: 0.25rem; }
.badge { font-weight: normal; }

/* ===== 按钮 ===== */
.btn { border-radius: var(--skin-btn-radius, 0.375rem); }
.btn-primary {
    background-color: var(--skin-btn-primary-bg, #007bff);
    border-color: var(--skin-btn-primary-bg, #007bff);
    color: var(--skin-btn-primary-text, #ffffff);
}
.btn-primary:hover {
    background-color: var(--skin-btn-primary-hover, #0056b3);
    border-color: var(--skin-btn-primary-hover, #0056b3);
}
.btn-outline-primary {
    color: var(--skin-btn-outline-text, #007bff);
    border-color: var(--skin-btn-outline-border, #007bff);
}
.btn-outline-primary:hover {
    background-color: var(--skin-btn-outline-hover-bg, #ff8c00);
    border-color: var(--skin-btn-outline-hover, #ff8c00);
    color: #fff;
}
.btn-outline-primary:hover i,
.btn-outline-primary:hover .fas,
.btn-outline-primary:hover .far {
    color: #fff;
}
.btn-close { filter: var(--skin-btn-close-filter, none); }

/* ===== 全局滚动偏移：防止 sticky 导航栏遮挡锚点目标 ===== */
html {
    scroll-padding-top: 140px;
}

/* ===== 导航栏 ===== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--skin-navbar-bg, rgba(248, 249, 250, 0.95)) !important;
    backdrop-filter: var(--skin-navbar-backdrop, blur(12px));
    -webkit-backdrop-filter: var(--skin-navbar-backdrop, blur(12px));
    border-bottom: 1px solid var(--skin-navbar-border, rgba(255,255,255,0.3));
    box-shadow: var(--skin-navbar-shadow, 0 2px 8px rgba(0,0,0,0.08));
}
/* 滚动后加深导航栏背景，避免内容穿透显示 */
.navbar.navbar-scrolled {
    background: var(--skin-navbar-bg-scrolled, rgba(248, 249, 250, 0.98)) !important;
    backdrop-filter: var(--skin-navbar-backdrop, blur(12px));
    -webkit-backdrop-filter: var(--skin-navbar-backdrop, blur(12px));
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}
.navbar .nav-link {
    color: var(--skin-navbar-text, rgba(0,0,0,0.55)) !important;
    text-align: center;
    padding-left: 0.6rem;
    padding-right: 0.6rem;
}

/* 平板及以上左侧菜单栏等宽分布（表格布局等效）；宽度不足时菜单文字自动折为两行（每行2字），
   图标固定左侧垂直居中，不收起为汉堡 */
@media (min-width: 768px) {
    .navbar-nav.me-auto .nav-item {
        flex: 1 1 0;
    }
    .navbar-nav.me-auto .nav-link {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 0.2rem;
        width: 100%;
        padding-left: 0.4rem;
        padding-right: 0.4rem;
        font-variant-numeric: tabular-nums; /* 数字等宽（与方块汉字观感一致） */
    }
    /* 文字容器：空间充足时两个2字字段并排单行；不足时自动折行为每段一行（2+2） */
    .navbar-nav.me-auto .nav-text {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        line-height: 1.25;
    }
    .navbar-nav.me-auto .nav-text-part {
        white-space: nowrap; /* 每个2字字段内部不折行 */
    }
    /* 统一左侧菜单图标占位宽度：FontAwesome 各字形宽窄不一（实测 12~20px），
       固定为 1.25em 后所有菜单「图标+文字」内容等宽，折行行为一致 */
    .navbar-nav.me-auto .nav-link i {
        display: inline-block;
        width: 1.25em;
        text-align: center;
        flex: none; /* 折行时图标不收缩 */
    }
}

/* 平板窄档（768~991px，container 仅 720px）：压缩字号/间距，保证菜单文字最多折两行 */
@media (min-width: 768px) and (max-width: 991.98px) {
    .navbar-nav.me-auto .nav-link {
        font-size: 0.85rem;
        padding-left: 0.2rem;
        padding-right: 0.2rem;
    }
    .navbar-nav.me-auto .nav-link i {
        width: 1em;
    }
}

/* 用户下拉按钮：图标 + 姓名/积分双行堆叠 */
.user-dropdown-toggle {
    display: inline-flex !important;
    align-items: center;
    gap: 0.35rem;
}
/* 移动端汉堡菜单中，用户信息与其他菜单项保持居中对齐 */
@media (max-width: 767.98px) {
    .user-dropdown-toggle {
        width: 100%;
        justify-content: center;
    }
}
.user-info-stack {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    line-height: 1.2;
}
.user-info-stack .user-name {
    font-size: 0.85rem;
}
.user-info-stack .badge {
    font-size: 0.65rem;
    padding: 0.15em 0.4em;
}
.navbar .nav-link:hover {
    color: var(--skin-navbar-text-hover, rgba(0,0,0,0.7)) !important;
}
.navbar-toggler {
    border-color: var(--skin-navbar-toggler-border, rgba(0,0,0,0.1));
}
.navbar-dark .navbar-toggler-icon {
    background-image: var(--skin-navbar-toggler-icon-dark, url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255, 255, 255, 0.55%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e"));
}

/* ===== 页脚 ===== */
footer {
    background: var(--skin-footer-bg, #f8f9fa) !important;
    color: var(--skin-footer-text, #6c757d) !important;
}
footer a {
    color: var(--skin-footer-link, #6c757d) !important;
}

/* ===== 卡片 ===== */
.card {
    background: var(--skin-card-bg, #ffffff);
    border-color: var(--skin-card-border, #e0e0e0);
    border-radius: var(--skin-card-radius, 0.375rem);
    box-shadow: var(--skin-card-shadow, 0 2px 8px rgba(0,0,0,0.04));
    backdrop-filter: var(--skin-card-backdrop, none);
    -webkit-backdrop-filter: var(--skin-card-backdrop, none);
}
.card-header {
    background: var(--skin-card-header-bg, #0d6efd);
    color: var(--skin-card-header-text, #ffffff);
    border-bottom-color: var(--skin-card-border, #e0e0e0);
}
/* 卡片头部内标题文字覆盖全局 h* 颜色，使用 card-header 的文字色 */
.card-header h1, .card-header h2, .card-header h3,
.card-header h4, .card-header h5, .card-header h6 {
    color: var(--skin-card-header-text, #ffffff);
}
/* 卡片头部内 .text-muted 覆盖全局 !important，使用 card-header 文字色 */
.card-header .text-muted {
    color: var(--skin-card-header-text, #ffffff) !important;
    opacity: 0.75;
}
.card-header.bg-primary {
    background-color: var(--skin-primary, #0d6efd) !important;
    color: var(--skin-primary-text, #ffffff) !important;
}
.card-footer {
    border-top-color: var(--skin-card-border, #e0e0e0);
}

/* ===== 表单 ===== */
.form-control, .form-select {
    background-color: var(--skin-input-bg, #ffffff);
    border-color: var(--skin-input-border, #ced4da);
    color: var(--skin-input-text, #212529);
    border-radius: var(--skin-input-radius, 0.375rem);
}
.form-control:focus, .form-select:focus {
    border-color: var(--skin-input-focus-border, #80bdff);
    box-shadow: var(--skin-input-focus-shadow, 0 0 0 0.2rem rgba(0,123,255,0.25));
    background-color: var(--skin-input-focus-bg, var(--skin-input-bg, #ffffff));
    /* 显式绑定焦点态文字色，避免 Bootstrap 5.3 在 :focus 时回退到 var(--bs-body-color)
       导致暗色皮肤下出现黑字配暗背景的低对比度问题 */
    color: var(--skin-input-text, #212529);
    /* 覆盖 Chrome 自动填充遗留色，防止 focus 时变黑 */
    -webkit-text-fill-color: var(--skin-input-text, #212529);
}
/* readonly/disabled 输入框：Bootstrap 5.3 用 --bs-secondary-bg（浅灰 #e9ecef）作为其背景，
   特异性高于 .form-control，会覆盖皮肤变量，导致暗色皮肤下出现"亮灰底白字"的低对比度问题。
   这里统一改为皮肤变量 */
.form-control:disabled,
.form-control[readonly],
.form-select:disabled,
.form-select[readonly] {
    background-color: var(--skin-input-bg, #ffffff);
    color: var(--skin-input-text, #212529);
    opacity: 1;
}
.form-control::placeholder { color: var(--skin-input-placeholder, #6c757d); }
/* Chrome 自动填充适配：保持背景与文字色与皮肤一致 */
.form-control:-webkit-autofill,
.form-control:-webkit-autofill:focus,
.form-select:-webkit-autofill,
.form-select:-webkit-autofill:focus {
    -webkit-text-fill-color: var(--skin-input-text, #212529);
    caret-color: var(--skin-input-text, #212529);
    box-shadow: var(--skin-input-focus-shadow, 0 0 0 0.2rem rgba(0,123,255,0.25)),
                0 0 0 1000px var(--skin-input-focus-bg, var(--skin-input-bg, #ffffff)) inset;
    transition: background-color 5000s ease-in-out 0s;
}
.form-label { color: var(--skin-body-color, #212529); }
.form-text { color: var(--skin-muted, #6c757d); }
.form-check-label { color: var(--skin-body-color, #212529); }
.form-select {
    background-image: var(--skin-select-arrow, none);
}
.form-select option {
    background-color: var(--skin-input-bg, #ffffff);
    color: var(--skin-input-text, #212529);
}

/* ===== 模态框 ===== */
.modal-content {
    background: var(--skin-modal-bg, #ffffff);
    border-color: var(--skin-modal-border, rgba(0,0,0,0.175));
    border-radius: var(--skin-modal-radius, 0.3rem);
    backdrop-filter: var(--skin-modal-backdrop, none);
    -webkit-backdrop-filter: var(--skin-modal-backdrop, none);
}
.modal-header {
    background: var(--skin-modal-header-bg, #f8f9fa);
    border-bottom-color: var(--skin-modal-border, rgba(0,0,0,0.175));
    color: var(--skin-body-color, #212529);
}
.modal-footer {
    background: var(--skin-modal-header-bg, #f8f9fa);
    border-top-color: var(--skin-modal-border, rgba(0,0,0,0.175));
}

/* ===== 表格 ===== */
.table {
    --bs-table-bg: var(--skin-table-bg, #ffffff);
    --bs-table-border-color: var(--skin-table-border, #dee2e6);
    color: var(--skin-body-color, #212529);
}
.table thead th {
    background-color: var(--skin-table-head-bg, #f8f9fa) !important;
    color: var(--skin-body-color, #212529) !important;
}
.table-striped > tbody > tr:nth-of-type(odd) > * {
    --bs-table-bg-type: var(--skin-table-stripe, rgba(0,0,0,0.02));
}

/* ===== 链接 ===== */
a:not(.btn):not(.nav-link):not(.navbar-brand):not(.dropdown-item):not(.skin-nav-btn) {
    color: var(--skin-link-color, #0d6efd);
}
a:not(.btn):not(.nav-link):not(.navbar-brand):not(.dropdown-item):not(.skin-nav-btn):hover {
    color: var(--skin-link-hover, #0a58ca);
}

/* ===== 警告框 ===== */
.alert-info {
    background-color: var(--skin-alert-info-bg, #d1ecf1);
    border-color: var(--skin-alert-info-border, #bee5eb);
    color: var(--skin-alert-info-text, #0c5460);
}
.alert-warning {
    background-color: var(--skin-alert-warning-bg, #fff3cd);
    border-color: var(--skin-alert-warning-border, #ffeaa7);
    color: var(--skin-alert-warning-text, #856404);
}
.alert-success {
    background-color: var(--skin-alert-success-bg, #d4edda);
    border-color: var(--skin-alert-success-border, #c3e6cb);
    color: var(--skin-alert-success-text, #155724);
}
.alert-danger {
    background-color: var(--skin-alert-danger-bg, #f8d7da);
    border-color: var(--skin-alert-danger-border, #f5c6cb);
    color: var(--skin-alert-danger-text, #721c24);
}

/* ===== 下拉菜单 ===== */
.dropdown-menu {
    background-color: var(--skin-dropdown-bg, var(--skin-card-bg, #ffffff));
    border-color: var(--skin-dropdown-border, var(--skin-card-border, #e0e0e0));
    border-radius: var(--skin-dropdown-radius, 0.375rem);
    backdrop-filter: var(--skin-dropdown-backdrop, none);
    -webkit-backdrop-filter: var(--skin-dropdown-backdrop, none);
}
.dropdown-item { color: var(--skin-body-color, #212529); }
.dropdown-item:hover {
    background-color: var(--skin-dropdown-item-hover-bg, rgba(0,0,0,0.05));
    color: var(--skin-dropdown-item-hover-text, var(--skin-link-color, #0d6efd));
}
.dropdown-divider {
    border-top-color: var(--skin-dropdown-divider, rgba(0,0,0,0.08));
}

/* ===== 分页 ===== */
.page-link {
    background-color: var(--skin-card-bg, #ffffff);
    border-color: var(--skin-card-border, #dee2e6);
    color: var(--skin-link-color, #0d6efd);
}
.page-link:hover {
    background-color: var(--skin-page-hover-bg, #e9ecef);
    border-color: var(--skin-link-color, #0d6efd);
    color: var(--skin-link-color, #0d6efd);
}
.page-item.active .page-link {
    background-color: var(--skin-primary, #0d6efd);
    border-color: var(--skin-primary, #0d6efd);
    color: var(--skin-primary-text, #ffffff);
}
.page-item.disabled .page-link {
    background-color: var(--skin-page-disabled-bg, #f8f9fa);
    border-color: var(--skin-card-border, #dee2e6);
    color: var(--skin-page-disabled-text, #6c757d);
}

/* ===== 列表组 ===== */
.list-group-item {
    background-color: var(--skin-card-bg, #ffffff);
    border-color: var(--skin-card-border, rgba(0,0,0,0.125));
    color: var(--skin-body-color, #212529);
}

/* ===== 导航标签 ===== */
.nav-tabs { border-bottom-color: var(--skin-nav-tabs-border, #dee2e6); }
.nav-tabs .nav-link { color: var(--skin-muted, #6c757d); }
.nav-tabs .nav-link:hover {
    border-color: var(--skin-nav-tabs-border, #dee2e6);
    color: var(--skin-link-color, #0d6efd);
}
.nav-tabs .nav-link.active {
    background-color: var(--skin-card-bg, #ffffff);
    border-color: var(--skin-nav-tabs-border, #dee2e6);
    color: var(--skin-link-color, #0d6efd);
}

/* ===== 进度条 ===== */
.progress { background-color: var(--skin-progress-bg, #e9ecef); }

/* ===== 输入框组 ===== */
.input-group-text {
    background-color: var(--skin-input-group-bg, #e9ecef);
    border-color: var(--skin-input-border, #ced4da);
    color: var(--skin-body-color, #212529);
}

/* ===== 面包屑 ===== */
.breadcrumb { background: transparent; }
.breadcrumb-item.active { color: var(--skin-muted, #6c757d); }

/* ===== 水平线 ===== */
hr { border-top-color: var(--skin-hr-color, rgba(0,0,0,0.1)); }

/* ===== 标题 ===== */
h1, h2, h3, h4, h5, h6 {
    color: var(--skin-heading-color, var(--skin-body-color, #212529));
}
.position-title { color: var(--skin-body-color, #212529) !important; }

/* ===== 通用工具类覆盖 ===== */
.text-muted { color: var(--skin-muted, #6c757d) !important; }
.text-dark { color: var(--skin-body-color, #212529) !important; }
.text-primary { color: var(--skin-primary, #007bff) !important; }
.bg-light { background-color: var(--skin-bg-light, #f8f9fa) !important; }
.bg-white { background-color: var(--skin-card-bg, #ffffff) !important; }
.bg-primary { background-color: var(--skin-primary, #007bff) !important; }
.border-primary { border-color: var(--skin-primary, #007bff) !important; }

/* ===== 代码块 ===== */
pre, .markdown-content pre {
    background-color: var(--skin-code-bg, #f8f9fa);
    color: var(--skin-code-text, #212529);
    border: 1px solid var(--skin-code-border, transparent);
}
code, .markdown-content code {
    background-color: var(--skin-code-inline-bg, var(--skin-code-bg, #e9ecef));
    color: var(--skin-code-text, #212529);
}
/* hljs 高亮后：行内 code 使用透明背景让 token 颜色显现 */
.markdown-content code.hljs,
.markdown-content code.hljs * {
    background: transparent;
}
/* hljs 块级 code：保留浅色背景并由 hljs 主题控制 token 颜色 */
.markdown-content pre code.hljs,
.markdown-content pre code.hljs * {
    background: transparent;
}

/* ===== 文章/招聘详情页覆盖 ===== */
.article-header, .article-content,
.detail-header, .detail-content {
    background: var(--skin-article-bg, rgba(255,255,255,0.72)) !important;
    backdrop-filter: var(--skin-article-backdrop, blur(16px) saturate(140%));
    -webkit-backdrop-filter: var(--skin-article-backdrop, blur(16px) saturate(140%));
    border: 1px solid var(--skin-article-border, rgba(255,255,255,0.5));
}
.article-card, .recruitment-card {
    background: var(--skin-article-bg, rgba(255,255,255,0.72)) !important;
    backdrop-filter: var(--skin-article-backdrop, blur(16px) saturate(140%));
    -webkit-backdrop-filter: var(--skin-article-backdrop, blur(16px) saturate(140%));
    border: 1px solid var(--skin-article-border, rgba(255,255,255,0.5));
}
.article-title { color: var(--skin-body-color, #212529) !important; }
.article-meta {
    color: var(--skin-muted, #6c757d) !important;
    border-top-color: var(--skin-card-border, #dee2e6) !important;
    border-bottom-color: var(--skin-card-border, #dee2e6) !important;
}
.content-body { color: var(--skin-body-color, #212529); }
.content-body h1, .content-body h2, .content-body h3,
.content-body h4, .content-body h5, .content-body h6 {
    color: var(--skin-body-color, #212529);
}
.content-body blockquote {
    color: var(--skin-muted, #6c757d) !important;
    border-left-color: var(--skin-primary, #0d6efd) !important;
}
.content-body pre { background: var(--skin-code-bg, #f8f9fa) !important; }
.content-body code {
    background: var(--skin-code-inline-bg, var(--skin-code-bg, #e9ecef)) !important;
    color: var(--skin-code-text, #212529) !important;
}
.content-body th { background: var(--skin-table-stripe, rgba(0,0,0,0.02)) !important; }
.content-body th, .content-body td {
    border-color: var(--skin-table-border, #dee2e6) !important;
}
.like-section { border-top-color: var(--skin-card-border, #dee2e6) !important; }
.comment-item { border-bottom-color: var(--skin-card-border, #dee2e6) !important; }
.replies-section { background: var(--skin-table-stripe, rgba(0,0,0,0.02)) !important; }
.reply-item { border-bottom-color: var(--skin-table-border, #dee2e6) !important; }

/* ===== 招聘元信息 ===== */
.recruitment-meta { color: var(--skin-muted, #6c757d) !important; }
.meta-separator { color: var(--skin-muted, #6c757d) !important; opacity: 0.6; }

/* 页面顶部横幅 —— 透明底，与皮肤背景融合 */
.page-header {
    background: transparent;
    color: var(--skin-hero-text, #212529);
    padding: 50px 0 40px;
    margin-bottom: 20px;
}
.page-header h1 {
    font-weight: 700;
    margin: 0;
}
.page-header p {
    color: var(--skin-hero-sub, #6c757d);
    margin: 8px 0 0;
}

/* 右侧浮动按钮组 */
.sidebar-btn-group {
    position: fixed;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

/* 单个按钮 — 始终保持方形 */
.sidebar-btn-item {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 46px;
    height: 46px;
    padding: 0;
    border-radius: 10px 0 0 10px;
    border: none;
    cursor: pointer;
    opacity: 0.8;
    transition: transform 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease, opacity 0.3s ease;
    box-shadow: -2px 2px 8px rgba(0, 0, 0, 0.15);
    text-decoration: none;
    box-sizing: border-box;
}

.sidebar-btn-item:hover {
    opacity: 1;
    transform: translateX(-6px);
    box-shadow: -4px 2px 16px rgba(0, 0, 0, 0.22);
}

/* 图标 */
.sidebar-btn-item .sidebar-icon {
    font-size: 20px;
    transition: transform 0.25s ease;
}

.sidebar-btn-item:hover .sidebar-icon {
    transform: scale(1.15);
}

/* SVG图标（微信/QQ等品牌图标） */
.sidebar-btn-item .sidebar-icon-svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
    transition: transform 0.25s ease;
}

.sidebar-btn-item:hover .sidebar-icon-svg {
    transform: scale(1.15);
}

/* 文字标签 — 悬浮在按钮左侧（无图片时） */
.sidebar-btn-item .sidebar-label {
    position: absolute;
    right: 100%;
    top: 50%;
    transform: translateY(-50%) translateX(-4px);
    white-space: nowrap;
    background: inherit;
    color: inherit;
    padding: 5px 10px;
    border-radius: 6px 0 0 6px;
    font-size: 13px;
    font-weight: 500;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease, transform 0.2s ease;
    box-shadow: -2px 2px 6px rgba(0, 0, 0, 0.12);
}

.sidebar-btn-item:hover .sidebar-label {
    opacity: 1;
    transform: translateY(-50%) translateX(-10px);
}

/* 富媒体悬停面板（有图片时，替代纯文字标签） */
.sidebar-btn-item .sidebar-hover-panel {
    position: absolute;
    right: 54px;
    top: 50%;
    transform: translateY(-50%) translateX(8px);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    background: #fff;
    color: #333;
    padding: 10px;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.18);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s ease, transform 0.2s ease;
    z-index: 999;
    min-width: 140px;
}

.sidebar-btn-item:hover .sidebar-hover-panel {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.sidebar-btn-item .sidebar-hover-panel .sidebar-hover-title {
    font-size: 14px;
    font-weight: 600;
    color: #212529;
    text-align: center;
}

.sidebar-btn-item .sidebar-hover-panel img {
    max-width: 140px;
    max-height: 140px;
    border-radius: 4px;
    border: 1px solid #eee;
}

.sidebar-btn-item .sidebar-hover-panel .sidebar-hover-desc {
    font-size: 12px;
    color: #6c757d;
    text-align: center;
    max-width: 140px;
    line-height: 1.4;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .sidebar-btn-item {
        width: 36px;
        height: 36px;
        border-radius: 8px 0 0 8px;
    }
    .sidebar-btn-item .sidebar-icon,
    .sidebar-btn-item .sidebar-icon-svg {
        width: 16px;
        height: 16px;
        font-size: 16px;
    }
    .sidebar-btn-item .sidebar-label {
        font-size: 11px;
        padding: 4px 8px;
    }
    .sidebar-btn-item .sidebar-hover-panel {
        min-width: 120px;
        padding: 8px;
    }
    .sidebar-btn-item .sidebar-hover-panel img {
        max-width: 100px;
        max-height: 100px;
    }
    .sidebar-btn-item .sidebar-hover-panel .sidebar-hover-title {
        font-size: 12px;
    }
    .sidebar-btn-item .sidebar-hover-panel .sidebar-hover-desc {
        font-size: 11px;
    }

    .question-card {
        margin-bottom: 15px;
    }

    .answer-section {
        padding: 15px;
    }

    .practice-stats {
        padding: 15px;
    }

    .certificate-card {
        padding: 15px;
    }

    .filter-section {
        padding: 15px;
    }

    .toast-container {
        top: 60px;
        right: 10px;
        left: 10px;
    }
}

/* 打印样式 */
@media print {
    .navbar, .btn, .question-actions, .answer-section {
        display: none !important;
    }

    .question-card {
        break-inside: avoid;
        box-shadow: none !important;
        border: 1px solid #000 !important;
    }

    .certificate-card::before {
        display: none;
    }
}

/* 导航图标颜色（由皮肤变量驱动） */
.nav-icon-home { color: var(--skin-nav-icon-home, #007bff); }
.nav-icon-history { color: var(--skin-nav-icon-history, #6f42c1); }
.nav-icon-exams { color: var(--skin-nav-icon-exams, #28a745); }
.nav-icon-articles { color: var(--skin-nav-icon-articles, #fd7e14); }
.nav-icon-recruitments { color: var(--skin-nav-icon-recruitments, #17a2b8); }
.nav-icon-admin { color: var(--skin-nav-icon-admin, #6c757d); }
.nav-icon-video { color: var(--skin-nav-icon-video, #dc3545); }
.nav-icon-courses { color: var(--skin-nav-icon-courses, #6f42c1); }
.nav-icon-user { color: var(--skin-nav-icon-user, #343a40); }
.nav-icon-skin { color: var(--skin-nav-icon-skin, var(--skin-muted, #6c757d)); }

/* ========== Footer 固定在底部（内容不足一页时） ========== */

/* 让 body 成为 flex 容器，最小高度为视口高度 */
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* main 占据剩余空间，推动 footer 到底部 */
main {
    flex: 1 0 auto;
}

/* Toast 皮肤适配 */
.toast {
    background-color: var(--skin-card-bg, #fff);
    border: 1px solid var(--skin-card-border, rgba(0,0,0,.125));
    color: var(--skin-body-color, #212529);
    box-shadow: var(--skin-card-shadow, 0 0.5rem 1rem rgba(0,0,0,.15));
}

.toast-header {
    background-color: var(--skin-card-header-bg, rgba(255,255,255,.85));
    color: var(--skin-card-header-text, #6c757d);
    border-bottom: 1px solid var(--skin-card-border, rgba(0,0,0,.05));
}

.toast-header .btn-close {
    filter: var(--skin-toast-close-filter, none);
}

.toast-body {
    color: var(--skin-body-color, #212529);
}

/* ===== 课程列表页 ===== */

/* 课程卡片 */
.course-card {
    display: flex;
    flex-direction: column;
    transition: transform 0.2s, box-shadow 0.2s;
    border: none;
    border-radius: 12px;
    overflow: hidden;
    background: var(--skin-card-bg, #ffffff);
    box-shadow: var(--skin-card-shadow, 0 2px 8px rgba(0,0,0,0.08));
}
.course-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--skin-card-hover-shadow, 0 8px 24px rgba(0,0,0,0.12));
}

/* 课程封面 */
.course-cover {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}
.course-cover-placeholder {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: var(--skin-primary, #667eea);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--skin-primary-text, white);
    font-size: 3rem;
}

/* 课程价格（语义颜色保持硬编码） */
.course-price {
    font-size: 1.25rem;
    font-weight: bold;
    color: #dc3545;
}
.course-original-price {
    font-size: 0.9rem;
    color: var(--skin-muted, #6c757d);
    text-decoration: line-through;
    margin-left: 0.5rem;
}
.course-free {
    font-size: 1.1rem;
    font-weight: bold;
    color: #28a745;
}

/* 难度徽章（语义颜色保持硬编码） */
.course-difficulty {
    font-size: 0.75rem;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
}
.difficulty-beginner { background: #d4edda; color: #155724; }
.difficulty-intermediate { background: #fff3cd; color: #856404; }
.difficulty-advanced { background: #f8d7da; color: #721c24; }
.difficulty-comprehensive { background: #e2d9f3; color: #563d7c; }

/* 课程元信息 */
.course-instructor {
    font-size: 0.85rem;
    color: var(--skin-muted, #6c757d);
}
.course-meta {
    font-size: 0.8rem;
    color: var(--skin-muted, #adb5bd);
}

/* ===== 课程详情页 ===== */

/* 详情页头部 */
.course-header {
    background: transparent;
    color: var(--skin-body-color, #212529);
    padding: 1.5rem 0;
    margin-bottom: 0.5rem;
}
.course-cover-large {
    width: 100%;
    display: block;  /* 消除 img 默认 baseline 间隙，避免图片下方出现多余空白 */
    border-radius: 12px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}

/* 章节列表 */
.chapter-list {
    list-style: none;
    padding: 0;
}
.chapter-item {
    background: var(--skin-card-bg, #f8f9fa);
    border-radius: 8px;
    margin-bottom: 1rem;
    overflow: hidden;
    border: 1px solid var(--skin-card-border, transparent);
}
.chapter-header {
    padding: 1rem 1.25rem;
    background: var(--skin-card-header-bg, #e9ecef);
    color: var(--skin-card-header-text, inherit);
    font-weight: bold;
    display: flex;
    align-items: center;
}
.chapter-header i {
    margin-right: 0.5rem;
    color: var(--skin-card-header-text, inherit);
    opacity: 0.8;
}

/* 视频列表 */
.video-list {
    list-style: none;
    padding: 0;
}
.video-item {
    padding: 0.75rem 1.25rem;
    border-bottom: 1px solid var(--skin-card-border, #dee2e6);
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    transition: background 0.2s;
}
.video-item:last-child {
    border-bottom: none;
}
.video-item {
    position: relative;
    cursor: pointer;
}
.video-item:hover::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--skin-primary, #0d6efd);
    opacity: 0.12;
    pointer-events: none;
}
.video-item.active {
    background: var(--skin-alert-info-bg, #d1ecf1);
    border-left: 3px solid var(--skin-primary, #0c5460);
}
.video-item.locked {
    opacity: 0.6;
    cursor: not-allowed;
}
.video-info {
    display: flex;
    align-items: center;
    flex: 1;
}
.video-number {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--skin-card-border, #dee2e6);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    margin-right: 0.75rem;
    flex-shrink: 0;
    color: var(--skin-body-color, inherit);
}
.video-item.active .video-number {
    background: var(--skin-primary, #0c5460);
    color: var(--skin-primary-text, white);
}
.video-title {
    flex: 1;
}
.video-duration {
    font-size: 0.8rem;
    color: var(--skin-muted, #6c757d);
    margin-left: 0.5rem;
}

/* 视频行操作按钮 */
.video-actions {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    flex-shrink: 0;
    white-space: nowrap;
    margin-left: 0.75rem;
}
.btn-play-video,
.btn-share-video {
    padding: 0.15rem 0.5rem;
    font-size: 0.75rem;
    line-height: 1.4;
}
.btn-share-video {
    color: var(--skin-muted, #6c757d);
    border-color: var(--skin-card-border, #dee2e6);
}
.btn-share-video:hover {
    color: var(--skin-btn-outline-text, #0d6efd);
    border-color: var(--skin-btn-outline-border, #0d6efd);
    background: var(--skin-btn-outline-hover, rgba(13,110,253,0.08));
}
.video-badge-group {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    margin-left: 0.25rem;
}

/* 分享模态框输入框 */
.share-url-input {
    font-size: 0.85rem !important;
    font-family: monospace;
    background-color: var(--skin-input-bg, #fff) !important;
    color: var(--skin-input-text, #212529) !important;
    border-color: var(--skin-input-border, #ced4da) !important;
}

/* 视频角标（语义颜色保持硬编码） */
.video-badge {
    font-size: 0.7rem;
    padding: 0.15rem 0.5rem;
    border-radius: 0.25rem;
    margin-left: 0.5rem;
}
.badge-free {
    background: #d4edda;
    color: #155724;
}
.badge-encrypted {
    background: #f8d7da;
    color: #721c24;
}

/* 课程视频弹窗：去掉倒角，让播放器贴边 */
#videoModal .modal-content,
#videoModal .modal-header {
    border-radius: 0;
}
#videoModal .modal-header {
    padding: 0;
}
#videoModal .modal-header > * {
    display: flex;
    align-items: center;
}
#videoModal .btn-close {
    margin: 0;
    width: 0.5em;
    height: 0.5em;
}

/* ===== 课程详情 Tab 按钮 ===== */
#courseTab {
    flex-wrap: nowrap;
}
#courseTab .nav-link {
    padding: 0.75rem 1.5rem;
    margin-right: 8px;
    white-space: nowrap;
    background: var(--skin-card-bg, #fff);
    border: 1px solid var(--skin-card-border, #dee2e6);
    border-bottom: none;
    border-radius: 8px 8px 0 0;
    transition: all 0.2s ease;
}
#courseTab .nav-link:hover {
    background: var(--skin-table-stripe, #f0f0f0);
}
#courseTab .nav-link.active {
    background: var(--skin-card-bg, #fff);
    border-color: var(--skin-card-border, #dee2e6);
    font-weight: 600;
    transform: scale(1.08);
    transform-origin: bottom;
    box-shadow: 0 -2px 8px rgba(0,0,0,0.06);
}

/* 移动端：缩小 Tab 内边距确保同行显示 */
@media (max-width: 575px) {
    #courseTab .nav-link {
        padding: 0.6rem 0.8rem;
        font-size: 0.85rem;
    }
}

/* 课程视频弹窗播放器 16:9 容器 */
.modal-video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    background: #000;
}
.modal-video-container iframe,
.modal-video-container video,
.modal-video-container #aliplayer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* 课程信息侧栏 */
.course-meta-info {
    background: var(--skin-card-bg, #f8f9fa);
    border-radius: 8px;
    padding: 1.5rem;
    border: 1px solid var(--skin-card-border, transparent);
}
.course-meta-item {
    display: flex;
    align-items: center;
    margin-bottom: 0.75rem;
}
.course-meta-item:last-child {
    margin-bottom: 0;
}
.course-meta-item i {
    width: 24px;
    color: var(--skin-muted, #6c757d);
}

/* 价格信息框 */
.course-price-box {
    background: var(--skin-card-bg, #ffffff);
    border-radius: var(--skin-card-radius, 12px);
    padding: 1.5rem;
    box-shadow: var(--skin-card-shadow, 0 2px 8px rgba(0,0,0,0.08));
    border: 1px solid var(--skin-card-border, transparent);
}
/* 价格框内操作按钮等宽布局：auto-fit 空间足够时并排、不足时单列堆叠；
   minmax(min(150px,100%),1fr) 保证任意布局下列宽一致，grid 单列时列宽统一两行严格等宽 */
.course-btn-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(min(150px, 100%), 1fr));
    gap: 0.5rem;
}
.course-btn-grid > .btn {
    width: 100%;
}
.course-price-large {
    font-size: 2rem;
    font-weight: bold;
    color: var(--skin-primary, #dc3545);
}
.course-original-price-large {
    font-size: 1.1rem;
    color: var(--skin-muted, #6c757d);
    text-decoration: line-through;
    margin-left: 0.5rem;
}

/* 课程标签（标签徽章） */
.course-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}
.course-tag {
    display: inline-flex;
    align-items: center;
    background: var(--skin-tag-bg, #f0f4ff);
    color: var(--skin-tag-color, #4a6cf7);
    font-size: 0.7rem;
    font-weight: 500;
    padding: 3px 10px;
    border-radius: 10px;
    white-space: nowrap;
    line-height: 1.4;
    letter-spacing: 0.01em;
    border: 1px solid var(--skin-tag-border, #dce4ff);
}
.course-tag-more {
    background: var(--skin-tag-more-bg, #f5f5f5);
    color: var(--skin-tag-more-color, #999);
    border-color: var(--skin-tag-more-border, #e0e0e0);
}
.course-brief-text {
    line-height: 1.5;
}

/* 课程卡片 card-body 撑满 */
.course-card .card-body {
    flex: 1;
}

/* ===== 窄屏（<768px）课程/组合卡片双列排版适配：压缩字号与间距，保留全部元素，卡片自然增高 ===== */
@media (max-width: 767.98px) {
    .course-card .card-body {
        padding: 0.6rem 0.65rem;
    }
    .course-card .card-title {
        font-size: 0.9rem;
        line-height: 1.35;
    }
    .course-card .course-difficulty {
        font-size: 0.65rem;
        padding: 0.15rem 0.5rem;
    }
    .course-card .course-free,
    .course-card .course-price {
        font-size: 0.9rem;
    }
    .course-card .course-instructor {
        font-size: 0.72rem;
    }
    .course-card .course-meta {
        font-size: 0.68rem;
    }
    .course-card .course-tag {
        font-size: 0.6rem;
        padding: 2px 6px;
    }
    .course-card .card-text {
        font-size: 0.75rem;
        line-height: 1.4;
        margin: 0.35rem 0;
    }
    .course-card .btn {
        font-size: 0.78rem;
        padding: 0.3rem 0.4rem;
    }
    .bundle-card .bundle-card-body {
        padding: 0.5rem 0.6rem;
    }
}

/* 课程描述 Markdown 渲染样式（与皮肤无关） */
#courseDescription img {
    max-width: 100%;
    border-radius: 8px;
    margin: 1rem 0;
    /* 修复图片本身边缘有杂色像素的问题 */
    clip-path: inset(0 1px 0 1px);
}
#courseDescription pre {
    background: var(--skin-code-bg, #f4f4f4);
    border-radius: 6px;
    padding: 1rem;
    overflow-x: auto;
}
#courseDescription code {
    font-size: 0.9em;
}
#courseDescription h1, #courseDescription h2, #courseDescription h3,
#courseDescription h4, #courseDescription h5, #courseDescription h6 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}
#courseDescription ul, #courseDescription ol {
    padding-left: 1.5rem;
}
#courseDescription blockquote {
    border-left: 4px solid #dee2e6;
    padding-left: 1rem;
    color: var(--skin-muted, #6c757d);
    margin: 1rem 0;
}
#courseDescription table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}
#courseDescription th, #courseDescription td {
    border: 1px solid #dee2e6;
    padding: 0.5rem;
}

/* 课程描述 Markdown 初始隐藏，渲染后再显示，避免原始文本闪烁 */
#courseDescription {
    visibility: hidden;
}
#courseDescription.rendered {
    visibility: visible;
}

/* ===== Tab 标题栏吸顶（全端） ===== */
#tabHeader {
    position: sticky;
    top: 80px;
    padding-top: 8px;
    z-index: 980;
    /* 皮肤适配背景 + 模糊，确保滚动时 Tab 清晰不穿透 */
    background: var(--skin-tab-header-bg, rgba(255,255,255,0.92));
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-top-left-radius: var(--skin-card-radius, 0.375rem);
    border-top-right-radius: var(--skin-card-radius, 0.375rem);
}

/* 移动端：导航栏折叠后高度不同，略微调整吸顶偏移 */
@media (max-width: 991px) {
    #tabHeader {
        top: 62px;
        padding-top: 6px;
    }
}

/* ===== 文章分页锚点偏移 ===== */
/* 翻页后：浏览器原生滚动行为下，避免内容被顶部导航栏/返回链接遮挡 */
.markdown-paginator-content {
    scroll-margin-top: 100px;
}