/* ===== Header 站点名称静止（禁用滚动时的左右位移动画） ===== */
.md-header__topic:first-child {
  opacity: 1 !important;
  transform: none !important;
  transition: none !important;
}

/* 隐藏滚动后替换显示的页面标题（保持 Helm 始终可见） */
.md-header__topic:nth-child(2) {
  display: none !important;
}

/* ===== 表格美化 ===== */

/* 表格容器 - 响应式横向滚动 */
.md-typeset__scrollwrap {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.md-typeset table:not([class]) {
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  overflow: hidden;
  width: 100%;
  margin: 1.2em 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

/* 表头样式 */
.md-typeset table:not([class]) thead {
  position: sticky;
  top: 0;
  z-index: 1;
}

.md-typeset table:not([class]) th {
  background: linear-gradient(135deg, #4051b5 0%, #5c6bc0 100%);
  color: white;
  font-weight: 600;
  padding: 12px 14px;
  text-align: left;
  border: none;
  border-bottom: 2px solid #303f9f;
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  transition: background 0.2s ease;
}

.md-typeset table:not([class]) th:hover {
  background: linear-gradient(135deg, #3949ab 0%, #5c6bc0 100%);
}

/* 排序指示器 */
.md-typeset table:not([class]) th.sortable::after {
  content: " ⇅";
  opacity: 0.5;
  font-size: 0.8em;
}

.md-typeset table:not([class]) th.sort-asc::after {
  content: " ↑";
  opacity: 1;
}

.md-typeset table:not([class]) th.sort-desc::after {
  content: " ↓";
  opacity: 1;
}

/* 单元格样式 */
.md-typeset table:not([class]) td {
  padding: 10px 14px;
  border: none;
  border-bottom: 1px solid #e8e8e8;
  vertical-align: top;
}

/* 隔行变色 */
.md-typeset table:not([class]) tbody tr:nth-child(odd) {
  background-color: #ffffff;
}

.md-typeset table:not([class]) tbody tr:nth-child(even) {
  background-color: #f8f9fa;
}

/* 鼠标悬停高亮 */
.md-typeset table:not([class]) tbody tr:hover {
  background-color: #e3f2fd !important;
  transition: background-color 0.2s ease;
}

/* 最后一行无边框 */
.md-typeset table:not([class]) tbody tr:last-child td {
  border-bottom: none;
}

/* 表格内链接 */
.md-typeset table:not([class]) a {
  color: #1565c0;
  text-decoration: none;
  border-bottom: 1px dotted #1565c0;
}

.md-typeset table:not([class]) a:hover {
  color: #0d47a1;
  border-bottom-style: solid;
}

/* 响应式：小屏幕优化 */
@media screen and (max-width: 768px) {
  .md-typeset table:not([class]) th,
  .md-typeset table:not([class]) td {
    padding: 10px 12px;
    font-size: 0.9em;
  }
  
  .md-typeset table:not([class]) {
    font-size: 14px;
  }
}

/* ===== 深色模式支持 ===== */
[data-md-color-scheme="slate"] .md-typeset table:not([class]) {
  border-color: #404040;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) th {
  background: linear-gradient(135deg, #37474f 0%, #455a64 100%);
  border-bottom-color: #263238;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) tbody tr:nth-child(odd) {
  background-color: #1e1e1e;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) tbody tr:nth-child(even) {
  background-color: #262626;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) tbody tr:hover {
  background-color: #37474f !important;
}

[data-md-color-scheme="slate"] .md-typeset table:not([class]) td {
  border-bottom-color: #404040;
}

/* ===== 复选框美化 ===== */
.md-typeset .task-list-item input[type="checkbox"] {
  margin-right: 8px;
}

.md-typeset .task-list-item input[type="checkbox"]:checked + span {
  color: #4caf50;
}

/* ===== 左侧导航层次结构 ===== */
/* navigation.tabs 启用后左侧导航只显示当前 tab 内容 */

/* 子目录分组标题（label 元素，无链接）：靛蓝色系，视觉权重 > 文档链接 */
.md-nav--primary label.md-nav__link {
  font-size: 0.68rem;
  font-weight: 700;
  color: #7986cb;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-top: 0.4rem;
}

.md-nav--primary .md-nav__item--nested > .md-nav__link .md-nav__icon {
  color: #7986cb;
}

/* 文档链接（非活跃）：中性灰，清晰可读 */
.md-nav--primary .md-nav__item--nested a.md-nav__link {
  font-size: 0.65rem;
  color: #757575;
  font-weight: 400;
  line-height: 1.5;
}

.md-nav--primary .md-nav__item--nested a.md-nav__link:hover {
  color: #4051b5;
}

/* 一级分区标题（如"学术资料"）：最显眼，最大字号 */
/* 真实 HTML：li.md-nav__item--section > div.md-nav__container > a.md-nav__link */
.md-nav--lifted > .md-nav__list > .md-nav__item--section > .md-nav__container > a.md-nav__link {
  font-size: 0.78rem;
  font-weight: 700;
  color: #4051b5;
  padding-bottom: 0.3rem;
  margin-bottom: 0.1rem;
}

[data-md-color-scheme="slate"] .md-nav--lifted > .md-nav__list > .md-nav__item--section > .md-nav__container > a.md-nav__link {
  color: #7c8aff;
}

/* 二级子目录标题前加 › 符号，并加渐变下划线增强识别度 */
.md-nav--primary .md-nav__item--section > label.md-nav__link .md-ellipsis::before {
  content: '› ';
}

.md-nav--primary .md-nav__item--section > label.md-nav__link {
  background-image: linear-gradient(to right, #7986cb 55%, transparent 100%);
  background-size: 100% 1px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  padding-bottom: 0.25rem;
  margin-bottom: 0.1rem;
}

[data-md-color-scheme="slate"] .md-nav--primary .md-nav__item--section > label.md-nav__link {
  background-image: linear-gradient(to right, #5c6bc0 55%, transparent 100%);
}

/* 当前文档（活跃）：仅颜色+粗体，无背景；保留 Material 默认间距 */
.md-nav--primary .md-nav__item--active > .md-nav__link {
  font-weight: 700 !important;
  color: #4051b5 !important;
  background-color: transparent !important;
  border-radius: 0;
}

/* 深色模式 */
[data-md-color-scheme="slate"] .md-nav--primary label.md-nav__link {
  color: #9fa8da;
}

[data-md-color-scheme="slate"] .md-nav--primary .md-nav__item--nested > .md-nav__link .md-nav__icon {
  color: #9fa8da;
}

[data-md-color-scheme="slate"] .md-nav--primary .md-nav__item--nested a.md-nav__link {
  color: #8a8a8a;
}

[data-md-color-scheme="slate"] .md-nav--primary .md-nav__item--nested a.md-nav__link:hover {
  color: #7c8aff;
}

[data-md-color-scheme="slate"] .md-nav--primary .md-nav__item--active > .md-nav__link {
  color: #7c8aff !important;
}

/* ===== 左侧导航：分类默认折叠（仅展开当前分类，点击可切换） ===== */
/* navigation.sections 默认强制展开所有分类，以下 CSS 覆盖该行为 */
@media screen and (min-width: 76.25em) {
  /* 恢复 label 的鼠标事件（navigation.sections 会设置 pointer-events: none） */
  .md-nav[data-md-level="1"] > .md-nav__list > .md-nav__item--section > label.md-nav__link {
    pointer-events: auto !important;
    cursor: pointer !important;
  }

  /* 所有分类的文章列表默认隐藏（checkbox 控制显示，活跃分类初始 checked=true 故自动展开） */
  .md-nav[data-md-level="1"] > .md-nav__list > .md-nav__item--section > nav.md-nav {
    display: none !important;
  }

  /* 当 toggle checkbox 被选中时（点击展开），显示文章列表 */
  .md-nav[data-md-level="1"] > .md-nav__list > .md-nav__item--section > .md-nav__toggle:checked ~ nav.md-nav {
    display: block !important;
  }

  /* 显示展开/折叠箭头图标（navigation.sections 会隐藏它） */
  .md-nav[data-md-level="1"] > .md-nav__list > .md-nav__item--section > label .md-nav__icon {
    display: inline-flex !important;
  }
}

/* 修复桌面端 lifted 导航模式 */
@media screen and (min-width: 76.25em) {
  .md-nav--lifted > .md-nav__list > .md-nav__item--active > .md-nav__link {
    box-shadow: none;
  }
}

/* 修复侧边栏内边距 */
.md-sidebar__inner {
  padding-top: 0.2rem;
}

/* ===== 1. 右侧目录(TOC)样式 ===== */

.md-sidebar--secondary .md-nav__title {
  font-weight: 700;
  font-size: 0.65rem;
  color: #37474f;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  padding-bottom: 8px;
  border-bottom: 1px solid #e8e8e8;
  margin-bottom: 6px;
}

.md-sidebar--secondary .md-nav__list {
  border-left: 2px solid #e8e8e8;
  margin-left: 2px;
  padding-left: 0;
}

.md-sidebar--secondary .md-nav__link {
  padding: 4px 0 4px 12px;
  margin-left: -2px;
  border-left: 2px solid transparent;
  transition: all 0.15s ease;
  color: #616161;
}

.md-sidebar--secondary .md-nav__link:hover {
  color: #4051b5;
  border-left-color: #bdbdbd;
}

.md-nav__link--passed {
  color: #9e9e9e;
}

.md-nav__link--active[href] {
  font-weight: 700 !important;
  color: #4051b5 !important;
}

[data-md-color-scheme="slate"] .md-nav__link--active[href] {
  color: #7c8aff !important;
}

.md-sidebar--secondary .md-nav__link--active {
  border-left: 2px solid #4051b5 !important;
  padding-left: 12px;
  margin-left: -2px;
  background: rgba(64, 81, 181, 0.06);
  border-radius: 0 4px 4px 0;
  color: #4051b5;
}

[data-md-color-scheme="slate"] .md-sidebar--secondary .md-nav__title {
  color: #b0bec5;
  border-bottom-color: #424242;
}

[data-md-color-scheme="slate"] .md-sidebar--secondary .md-nav__list {
  border-left-color: #424242;
}

[data-md-color-scheme="slate"] .md-sidebar--secondary .md-nav__link {
  color: #90a4ae;
}

[data-md-color-scheme="slate"] .md-sidebar--secondary .md-nav__link:hover {
  color: #7c8aff;
  border-left-color: #616161;
}

[data-md-color-scheme="slate"] .md-sidebar--secondary .md-nav__link--active {
  border-left-color: #7c8aff !important;
  background: rgba(124, 138, 255, 0.08);
  color: #7c8aff;
}

/* ===== 2. 代码块美化 ===== */
.md-typeset pre {
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.md-typeset code {
  border-radius: 4px;
  padding: 0.1em 0.4em;
  background: rgba(64, 81, 181, 0.08);
  font-size: 0.85em;
}

.md-typeset pre code {
  padding: 1em;
  background: transparent;
  font-size: 0.85em;
}

.md-clipboard {
  transition: all 0.2s ease;
}

.md-clipboard:hover {
  color: #4051b5;
  transform: scale(1.1);
}

.md-clipboard--copied,
.md-clipboard--copied:hover {
  color: #4caf50;
}

[data-md-color-scheme="slate"] .md-typeset code {
  background: rgba(255, 255, 255, 0.08);
}

/* ===== 3. 引用块/提示框美化 ===== */
.md-typeset blockquote {
  border-left: 4px solid #4051b5;
  background: linear-gradient(135deg, rgba(64, 81, 181, 0.05) 0%, rgba(92, 107, 192, 0.08) 100%);
  border-radius: 0 8px 8px 0;
  padding: 0.8em 1em;
  margin: 1.2em 0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
}

.md-typeset blockquote p:last-child {
  margin-bottom: 0;
}

[data-md-color-scheme="slate"] .md-typeset blockquote {
  border-left-color: #7c8aff;
  background: linear-gradient(135deg, rgba(124, 138, 255, 0.08) 0%, rgba(124, 138, 255, 0.12) 100%);
}

.md-typeset .admonition,
.md-typeset details {
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: none;
  overflow: hidden;
}

.md-typeset .admonition-title,
.md-typeset summary {
  font-weight: 600;
}

/* ===== 4. 外部链接标识 ===== */
.md-typeset a[href^="http"]:not([href*="wiki-dyw.pages.dev"]):not([href*="wiki.itsail.net"])::after {
  content: " ↗";
  font-size: 0.75em;
  opacity: 0.7;
  vertical-align: super;
}

.md-typeset a[href^="http"]:not([href*="wiki-dyw.pages.dev"]):not([href*="wiki.itsail.net"]):hover::after {
  opacity: 1;
}

.md-nav a[href^="http"]::after,
.md-footer a[href^="http"]::after,
.md-header a[href^="http"]::after {
  content: none !important;
}

/* ===== 5. 阅读体验优化 ===== */
.md-typeset {
  line-height: 1.7;
  font-size: 0.68rem;
}

/* 右侧目录(TOC)字体大小 */
.md-sidebar--secondary .md-nav {
  font-size: 0.62rem;
  line-height: 1.5;
}

/* 嵌套列表样式 - 区分层级 */
.md-typeset ul ul {
  list-style-type: circle;
  margin-top: 0.5em;
  margin-bottom: 0.5em;
}

.md-typeset ul ul ul {
  list-style-type: square;
}

.md-typeset p {
  margin-bottom: 1em;
}

.md-typeset h1 {
  margin-top: 0;
  margin-bottom: 1em;
}

.md-typeset h2 {
  margin-top: 2em;
  margin-bottom: 0.8em;
  padding-bottom: 0.3em;
  border-bottom: 1px solid #e0e0e0;
}

.md-typeset h3 {
  margin-top: 1.5em;
  margin-bottom: 0.6em;
}

[data-md-color-scheme="slate"] .md-typeset h2 {
  border-bottom-color: #404040;
}

/* ===== 布局优化 - 完全自适应方案 (2026-01-31) ===== */

/* 容器 - 移除宽度限制，满屏显示 */
.md-grid {
  max-width: none !important;
  width: 100%;
}

/* 中间阅读区 - 自适应剩余空间 */
.md-content {
  max-width: none !important;
  min-width: 40rem;  /* 640px - 防止过窄 */
  width: 100%;
}

/* 左侧导航栏 */
.md-sidebar--primary {
  width: 12rem;  /* 192px - 适配子目录分组导航 */
}

/* 右侧目录栏 - 增加宽度以容纳长标题 */
.md-sidebar--secondary {
  width: 15rem;  /* 240px - 从11rem增加到15rem */
  padding-right: 2rem;    /* 32px 右侧留白 */
  padding-left: 0.5rem;   /* 8px 左侧平衡 */
}

/* 响应式保护 - 小屏幕不受影响 */
@media screen and (max-width: 1220px) {
  .md-content {
    max-width: none;
    min-width: 0;
  }
  
  .md-grid {
    max-width: 61rem;
  }
}

/* ===== 6. 归档文档折叠区排序符号修复 ===== */
details:not([open]) th.sortable::after {
  content: none;
}

/* ===== 9. MCQ 交互式答题 ===== */

.mcq-score-tracker {
  padding: 0.75rem;
  margin-bottom: 0.75rem;
  border-bottom: 1px solid #e0e0e0;
}

.mcq-score-tracker-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #666;
  margin-bottom: 0.6rem;
  padding: 0 0.25rem;
}

.mcq-score-row {
  display: flex;
  align-items: center;
  justify-content: space-around;
  gap: 0;
}

.mcq-score-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  flex: 1;
}

.mcq-score-sep {
  width: 1px;
  height: 28px;
  background: #e0e0e0;
  flex-shrink: 0;
}

.mcq-score-stat-label {
  font-size: 0.65rem;
  font-weight: 500;
  color: #9e9e9e;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.mcq-score-stat-value {
  font-weight: 700;
  font-size: 1rem;
  color: #37474f;
  line-height: 1.2;
}

.mcq-score-stat-dim {
  font-weight: 400;
  font-size: 0.8rem;
  color: #9e9e9e;
}

.mcq-score-high { color: #2e7d32 !important; }
.mcq-score-mid { color: #e65100 !important; }
.mcq-score-low { color: #c62828 !important; }

[data-md-color-scheme="slate"] .mcq-score-tracker {
  border-bottom-color: #424242;
}

[data-md-color-scheme="slate"] .mcq-score-tracker-title { color: #90a4ae; }
[data-md-color-scheme="slate"] .mcq-score-sep { background: #424242; }
[data-md-color-scheme="slate"] .mcq-score-stat-value { color: #cfd8dc; }

[data-md-color-scheme="slate"] .mcq-score-stat-label { color: #78909c; }

[data-md-color-scheme="slate"] .mcq-score-stat-value { color: #e0e0e0; }

[data-md-color-scheme="slate"] .mcq-score-stat-dim { color: #616161; }

.mcq-exam-submit-wrapper {
  text-align: center;
  margin: 2rem 0;
  padding: 1.5rem;
}

.mcq-exam-submit-btn {
  display: inline-block;
  padding: 12px 48px;
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
  background: #1565c0;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
  letter-spacing: 0.02em;
}

.mcq-exam-submit-btn:hover {
  background: #0d47a1;
  transform: translateY(-1px);
}

.mcq-exam-submit-btn:active {
  transform: translateY(0);
}

.mcq-exam-submit-btn:disabled {
  background: #90a4ae;
  cursor: not-allowed;
  transform: none;
}

[data-md-color-scheme="slate"] .mcq-exam-submit-btn {
  background: #1e88e5;
}

[data-md-color-scheme="slate"] .mcq-exam-submit-btn:hover {
  background: #1565c0;
}

[data-md-color-scheme="slate"] .mcq-exam-submit-btn:disabled {
  background: #546e7a;
}

.mcq-exam-nav {
  padding: 0.75rem;
  position: sticky;
  top: 4rem;
}

.mcq-exam-nav-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #666;
  margin-bottom: 0.75rem;
  padding: 0 0.25rem;
}

.mcq-exam-nav-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}

.mcq-exam-nav-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
}

.mcq-exam-nav-cell:hover {
  transform: scale(1.1);
}

.mcq-exam-nav-unanswered {
  background: #e0e0e0;
  color: #757575;
}

.mcq-exam-nav-answered {
  background: #1565c0;
  color: #fff;
}

.mcq-exam-nav-correct {
  background: #2e7d32;
  color: #fff;
}

.mcq-exam-nav-wrong {
  background: #c62828;
  color: #fff;
}

.mcq-exam-nav-active {
  box-shadow: 0 0 0 2px #1565c0;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-title {
  color: #90a4ae;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-unanswered {
  background: #37474f;
  color: #90a4ae;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-answered {
  background: #1e88e5;
  color: #fff;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-correct {
  background: #388e3c;
  color: #fff;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-wrong {
  background: #d32f2f;
  color: #fff;
}

[data-md-color-scheme="slate"] .mcq-exam-nav-active {
  box-shadow: 0 0 0 2px #42a5f5;
}

.md-typeset .mcq-card {
  border: 1px solid #e0e0e0;
  border-radius: 12px;
  padding: 24px;
  margin: 1.5em 0;
  background: #fff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.md-typeset .mcq-card p {
  margin-bottom: 0.5em;
}

.md-typeset .mcq-card-correct {
  border-color: #a5d6a7;
  box-shadow: 0 1px 4px rgba(76, 175, 80, 0.15);
}

.md-typeset .mcq-card-wrong {
  border-color: #ef9a9a;
  box-shadow: 0 1px 4px rgba(244, 67, 54, 0.15);
}

.mcq-card-header {
  margin-bottom: 8px;
}

.mcq-qnum {
  display: inline-block;
  font-weight: 700;
  font-size: 0.75rem;
  color: #4051b5;
  background: rgba(64, 81, 181, 0.08);
  padding: 2px 10px;
  border-radius: 12px;
  letter-spacing: 0.5px;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-card {
  background: #1e1e1e;
  border-color: #333;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-card-correct {
  border-color: #388e3c;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-card-wrong {
  border-color: #c62828;
}

[data-md-color-scheme="slate"] .mcq-qnum {
  color: #90caf9;
  background: rgba(124, 138, 255, 0.12);
}

.md-typeset .mcq-options {
  margin: 12px 0 4px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.md-typeset .mcq-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border: 2px solid #e8e8e8;
  border-radius: 10px;
  cursor: pointer;
  transition: border-color 0.15s ease, background-color 0.15s ease, box-shadow 0.15s ease, transform 0.15s ease;
  user-select: none;
  line-height: 1.6;
  background: #fafafa;
}

.md-typeset .mcq-option:hover {
  border-color: #4051b5;
  background: rgba(64, 81, 181, 0.04);
  box-shadow: 0 2px 8px rgba(64, 81, 181, 0.1);
}

.md-typeset .mcq-option:focus-visible {
  outline: 2px solid #4051b5;
  outline-offset: 2px;
}

.md-typeset .mcq-radio {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 2px solid #bdbdbd;
  flex-shrink: 0;
  transition: border-color 0.15s ease, background-color 0.15s ease;
  position: relative;
}

.md-typeset .mcq-option:hover .mcq-radio {
  border-color: #4051b5;
}

.md-typeset .mcq-option-letter {
  font-weight: 600;
  color: #616161;
  min-width: 28px;
  flex-shrink: 0;
  transition: color 0.15s ease;
}

.md-typeset .mcq-option-text {
  flex: 1;
}

.md-typeset .mcq-option.mcq-selected {
  border-color: #1565c0;
  background: #e3f2fd;
  opacity: 1;
  cursor: pointer;
}

.md-typeset .mcq-option.mcq-selected .mcq-radio {
  border-color: #1565c0;
  background: #e3f2fd;
}

.md-typeset .mcq-option.mcq-selected .mcq-radio::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 10px;
  height: 10px;
  background: #1565c0;
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.md-typeset .mcq-option.mcq-selected .mcq-option-letter {
  color: #1565c0;
  font-weight: 700;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-selected {
  border-color: #42a5f5;
  background: rgba(66, 165, 245, 0.15);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-selected .mcq-radio {
  border-color: #42a5f5;
  background: rgba(66, 165, 245, 0.15);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-selected .mcq-radio::after {
  background: #42a5f5;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-selected .mcq-option-letter {
  color: #42a5f5;
}

.md-typeset .mcq-answered .mcq-option {
  cursor: default;
  opacity: 0.55;
  background: transparent;
  pointer-events: none;
}

.md-typeset .mcq-answered .mcq-option.mcq-correct,
.md-typeset .mcq-answered .mcq-option.mcq-wrong {
  opacity: 1;
  pointer-events: none;
}

.md-typeset .mcq-option.mcq-correct {
  border-color: #4caf50;
  background: #e8f5e9;
}

.md-typeset .mcq-option.mcq-correct .mcq-radio {
  border-color: #4caf50;
  background: #4caf50;
}

.md-typeset .mcq-option.mcq-correct .mcq-radio::after {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: white;
}

.md-typeset .mcq-option.mcq-correct .mcq-option-letter {
  color: #2e7d32;
  font-weight: 700;
}

.md-typeset .mcq-option.mcq-wrong {
  border-color: #ef5350;
  background: #ffebee;
}

.md-typeset .mcq-option.mcq-wrong .mcq-radio {
  border-color: #ef5350;
  background: #ef5350;
}

.md-typeset .mcq-option.mcq-wrong .mcq-radio::after {
  content: "\00d7";
  color: white;
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
}

.md-typeset .mcq-option.mcq-wrong .mcq-option-letter {
  color: #c62828;
  font-weight: 700;
}

.md-typeset .mcq-result {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 8px;
  margin-top: 12px;
  font-size: 0.9rem;
  animation: mcqFadeIn 0.3s ease;
}

.md-typeset .mcq-result-correct {
  background: #e8f5e9;
  color: #2e7d32;
  border-left: 4px solid #4caf50;
}

.md-typeset .mcq-result-wrong {
  background: #ffebee;
  color: #c62828;
  border-left: 4px solid #ef5350;
}

.mcq-result-icon { font-size: 1.1rem; }

.md-typeset .mcq-card .mcq-explanation {
  animation: mcqFadeIn 0.3s ease;
  margin-top: 12px;
  margin-bottom: 0;
}

@keyframes mcqFadeIn {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option {
  border-color: #3a3a3a;
  background: #252525;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option:hover {
  border-color: #7c8aff;
  background: rgba(124, 138, 255, 0.08);
  box-shadow: 0 2px 8px rgba(124, 138, 255, 0.1);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-radio {
  border-color: #616161;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option:hover .mcq-radio {
  border-color: #7c8aff;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option-letter {
  color: #b0bec5;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-answered .mcq-option {
  background: transparent;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-correct {
  border-color: #388e3c;
  background: rgba(76, 175, 80, 0.12);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-correct .mcq-option-letter {
  color: #81c784;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-wrong {
  border-color: #c62828;
  background: rgba(244, 67, 54, 0.12);
}

[data-md-color-scheme="slate"] .md-typeset .mcq-option.mcq-wrong .mcq-option-letter {
  color: #ef5350;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-result-correct {
  background: rgba(76, 175, 80, 0.12);
  color: #81c784;
  border-left-color: #4caf50;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-result-wrong {
  background: rgba(244, 67, 54, 0.12);
  color: #ef5350;
  border-left-color: #ef5350;
}

.mcq-ask-ai-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-left: 12px;
  padding: 2px 12px;
  font-size: 0.78rem;
  font-weight: 600;
  color: #fff;
  background: #5c6bc0;
  border: none;
  border-radius: 14px;
  cursor: pointer;
  transition: all 0.2s ease;
  vertical-align: middle;
  line-height: 1.6;
}

.mcq-ask-ai-btn:hover {
  background: #3949ab;
  box-shadow: 0 2px 8px rgba(57, 73, 171, 0.35);
  transform: translateY(-1px);
}

.mcq-ask-ai-btn:active {
  transform: translateY(0);
}

.mcq-ask-ai-copied {
  background: #388e3c !important;
}

.mcq-ask-ai-icon {
  font-size: 0.85rem;
}

[data-md-color-scheme="slate"] .mcq-ask-ai-btn {
  background: #7c8aff;
  color: #1a1a1a;
}

[data-md-color-scheme="slate"] .mcq-ask-ai-btn:hover {
  background: #9fa8da;
  box-shadow: 0 2px 8px rgba(124, 138, 255, 0.35);
}

[data-md-color-scheme="slate"] .mcq-ask-ai-copied {
  background: #4caf50 !important;
  color: #fff !important;
}

@media screen and (max-width: 768px) {
  .md-typeset .mcq-card {
    padding: 16px;
    margin: 1em 0;
    border-radius: 10px;
  }

  .md-typeset .mcq-option {
    padding: 10px 12px;
    gap: 10px;
    font-size: 0.9em;
  }

  .mcq-score-section {
    padding: 0 4px;
  }
}


/* ===== 顶栏：始终显示站点名称，滚动时不切换为页面/分区标题 ===== */
/* Material theme 在滚动时会把第二个 .md-header__topic（页面标题）切换为 active，
   隐藏第二个 topic 即可始终保持站点名称可见 */
.md-header__title .md-header__topic ~ .md-header__topic {
  display: none !important;
}
.md-header__title .md-header__topic:first-child {
  opacity: 1 !important;
  max-width: none !important;
}

/* ===== 10. MCQ 题目插图大小限制 ===== */
.md-typeset p > img {
  max-width: min(100%, 480px);
  max-height: 350px;
  object-fit: contain;
  display: block;
  margin: 0.5em auto;
  border-radius: 6px;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
}

/* ===== 11. MCQ 题号与题目合并为一行 ===== */
/* 隐藏独立题号 header — **Q2.** 段落中已含题号，无需重复 */
.mcq-card-header {
  display: none;
}

/* 为 **Q2.** 加徽标样式，与题目内容同行显示 */
.md-typeset .mcq-card > p:first-of-type > strong:first-child {
  display: inline-block;
  color: #4051b5;
  background: rgba(64, 81, 181, 0.08);
  padding: 1px 8px;
  border-radius: 10px;
  font-size: 0.75rem;
  letter-spacing: 0.3px;
  margin-right: 4px;
  vertical-align: middle;
}

[data-md-color-scheme="slate"] .md-typeset .mcq-card > p:first-of-type > strong:first-child {
  color: #90caf9;
  background: rgba(124, 138, 255, 0.12);
}