/* ==================================================================
 * site.css — MD Pages
 * 目录：1 设计变量 / 2 基础 / 3 布局 / 4 侧边栏 / 5 顶栏 / 6 正文
 *       7 代码 / 8 目录大纲 / 9 页脚 / 10 演示模式 / 11 浮层 / 12 响应式 & 打印
 * ================================================================== */

/* ---------------------------------------------------------------- */
/* 1. 设计变量                                                       */
/* ---------------------------------------------------------------- */

:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", "SFMono-Regular", Consolas,
    "Liberation Mono", Menlo, monospace;

  --sidebar-w: 288px;
  --toc-w: 232px;
  --content-max: 780px;
  --topbar-h: 58px;

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #ffffff;
  --bg-soft: #f7f8fa;
  --bg-sidebar: #fafbfc;
  --bg-raised: #ffffff;
  --bg-hover: rgba(15, 23, 42, 0.05);
  --bg-active: rgba(79, 70, 229, 0.09);
  --border: #e7eaef;
  --border-strong: #d6dae2;
  --text: #171a20;
  --text-soft: #3f4653;
  --text-dim: #6b7280;
  --text-faint: #9aa1ad;
  --accent: #4f46e5;
  --accent-text: #4338ca;
  --accent-soft: rgba(79, 70, 229, 0.1);
  --code-bg: #f7f8fa;
  --table-head: #f7f8fa;
  --scrim: rgba(15, 23, 42, 0.32);
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 12px 32px -16px rgba(15, 23, 42, 0.28);
  --slide-bg: #ffffff;
  --slide-fg: #171a20;
  --slide-dim: #5b6472;
  --hl-keyword: #cf222e;
  --hl-title: #8250df;
  --hl-attr: #0550ae;
  --hl-string: #0a3069;
  --hl-built: #953800;
  --hl-comment: #6e7781;
  --hl-tag: #116329;
  --hl-subst: #24292f;
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1218;
  --bg-soft: #12161e;
  --bg-sidebar: #0b0e14;
  --bg-raised: #161b24;
  --bg-hover: rgba(255, 255, 255, 0.055);
  --bg-active: rgba(139, 147, 255, 0.14);
  --border: #222836;
  --border-strong: #2e3746;
  --text: #e9edf4;
  --text-soft: #c4ccd8;
  --text-dim: #8d98a8;
  --text-faint: #66717f;
  --accent: #8b93ff;
  --accent-text: #aab4ff;
  --accent-soft: rgba(139, 147, 255, 0.14);
  --code-bg: #151a23;
  --table-head: #151a23;
  --scrim: rgba(0, 0, 0, 0.6);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.45);
  --shadow-md: 0 16px 40px -18px rgba(0, 0, 0, 0.85);
  --slide-bg: #161b24;
  --slide-fg: #eef2f8;
  --slide-dim: #9aa6b8;
  --hl-keyword: #ff7b72;
  --hl-title: #d2a8ff;
  --hl-attr: #79c0ff;
  --hl-string: #a5d6ff;
  --hl-built: #ffa657;
  --hl-comment: #8b949e;
  --hl-tag: #7ee787;
  --hl-subst: #c9d1d9;
}

/* ---------------------------------------------------------------- */
/* 2. 基础                                                           */
/* ---------------------------------------------------------------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

/* hidden 属性必须永远生效（页面上不少元素显式设置了 display） */
[hidden] {
  display: none !important;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 15px;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow: hidden;
}

::selection {
  background: var(--accent-soft);
  color: var(--text);
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}

svg {
  display: block;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border: 3px solid transparent;
  border-radius: 8px;
  background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-faint);
  background-clip: content-box;
}

/* ---------------------------------------------------------------- */
/* 3. 布局                                                           */
/* ---------------------------------------------------------------- */

.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  height: 100vh;
  height: 100dvh;
}

.main {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
  position: relative;
}

.workspace {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  min-height: 0;
}

.reader {
  flex: 1 1 auto;
  min-width: 0;
  overflow-y: auto;
  overflow-x: hidden;
  outline: none;
  scroll-padding-top: 24px;
}

.doc {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 44px 34px 140px;
}

/* ---------------------------------------------------------------- */
/* 4. 侧边栏                                                         */
/* ---------------------------------------------------------------- */

.sidebar {
  display: flex;
  flex-direction: column;
  min-height: 0;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
}

.sidebar__head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 12px 10px 16px;
  min-height: var(--topbar-h);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1 1 auto;
  min-width: 0;
  padding: 4px 6px;
  border-radius: var(--radius-sm);
  transition: background 0.15s var(--ease);
}

.brand:hover {
  background: var(--bg-hover);
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  color: #fff;
  background: linear-gradient(140deg, #6366f1, #8b5cf6 60%, #ec4899);
  box-shadow: var(--shadow-sm);
  flex: 0 0 auto;
}

.brand__mark svg {
  width: 17px;
  height: 17px;
}

.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  line-height: 1.25;
}

.brand__text strong {
  font-size: 14px;
  font-weight: 650;
  letter-spacing: -0.01em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand__text small {
  font-size: 11.5px;
  color: var(--text-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar__close {
  display: none;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  color: var(--text-dim);
  transition: background 0.15s var(--ease), color 0.15s var(--ease);
  flex: 0 0 auto;
}

.icon-btn svg {
  width: 17px;
  height: 17px;
}

.icon-btn:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.search {
  position: relative;
  display: flex;
  align-items: center;
  margin: 2px 14px 10px;
}

.search__icon {
  position: absolute;
  left: 9px;
  width: 15px;
  height: 15px;
  color: var(--text-faint);
  pointer-events: none;
}

.search__input {
  width: 100%;
  height: 34px;
  padding: 0 32px 0 31px;
  font-size: 13.5px;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
  appearance: none;
}

.search__input::-webkit-search-cancel-button {
  display: none;
}

.search__input::placeholder {
  color: var(--text-faint);
}

.search__input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.search__clear {
  position: absolute;
  right: 6px;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border-radius: 4px;
  color: var(--text-faint);
}

.search__clear svg {
  width: 13px;
  height: 13px;
}

.search__clear:hover {
  background: var(--bg-hover);
  color: var(--text);
}

/* ---- 目录树 ---- */

.tree {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 2px 8px 18px;
  font-size: 13.5px;
}

.tree__placeholder {
  margin: 12px 10px;
  color: var(--text-faint);
  font-size: 13px;
  line-height: 1.6;
}

.tree__list,
.tree__children {
  list-style: none;
  margin: 0;
  padding: 0;
}

.tree__item--dir > .tree__children {
  display: none;
}

.tree__item--dir.is-open > .tree__children {
  display: block;
}

.tree.is-filtering .tree__item--dir > .tree__children {
  display: block;
}

.tree .is-hidden {
  display: none !important;
}

.tree__children {
  position: relative;
  margin-left: 11px;
  padding-left: 9px;
  border-left: 1px solid var(--border);
}

.tree__row {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  min-height: 29px;
  padding: 0 8px 0 4px;
  border-radius: var(--radius-sm);
  color: var(--text-soft);
  font-size: 13.5px;
  line-height: 1.35;
  text-align: left;
  transition: background 0.13s var(--ease), color 0.13s var(--ease);
}

.tree__row:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.tree__row--dir {
  font-weight: 560;
  color: var(--text);
}

.tree__chevron {
  width: 13px;
  height: 13px;
  flex: 0 0 auto;
  color: var(--text-faint);
  transition: transform 0.18s var(--ease);
}

.tree__item--dir.is-open > .tree__row--dir .tree__chevron,
.tree.is-filtering .tree__item--dir > .tree__row--dir .tree__chevron {
  transform: rotate(90deg);
}

.tree__icon {
  width: 15px;
  height: 15px;
  flex: 0 0 auto;
  color: var(--text-faint);
}

.tree__row--dir .tree__icon {
  color: var(--accent);
  opacity: 0.85;
}

.tree__label {
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.tree__count {
  flex: 0 0 auto;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  color: var(--text-faint);
  padding: 0 4px;
  border-radius: 20px;
  background: var(--bg-hover);
}

.tree__row--file.is-active {
  position: relative;
  background: var(--bg-active);
  color: var(--accent-text);
  font-weight: 560;
}

.tree__row--file.is-active .tree__icon {
  color: var(--accent);
  opacity: 1;
}

.tree__row--file.is-active::before {
  content: "";
  position: absolute;
  left: -9px;
  top: 5px;
  bottom: 5px;
  width: 2px;
  border-radius: 2px;
  background: var(--accent);
}

.tree__item--dir:has(> .tree__children .tree__row--file.is-active) > .tree__row--dir {
  color: var(--text);
}

.sidebar__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 12px 10px 16px;
  border-top: 1px solid var(--border);
  font-size: 11.5px;
  color: var(--text-faint);
}

.sidebar__foot-actions {
  display: flex;
  gap: 2px;
}

html[data-theme="light"] .icon-moon,
html[data-theme="dark"] .icon-sun {
  display: none;
}

.scrim {
  position: fixed;
  inset: 0;
  z-index: 40;
  background: var(--scrim);
  backdrop-filter: blur(2px);
}

/* ---------------------------------------------------------------- */
/* 5. 顶栏                                                           */
/* ---------------------------------------------------------------- */

.topbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: var(--topbar-h);
  padding: 0 16px 0 20px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  position: relative;
  z-index: 20;
}

.topbar__menu {
  display: none;
}

.crumbs {
  flex: 1 1 auto;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-dim);
  overflow: hidden;
  white-space: nowrap;
  mask-image: linear-gradient(to right, #000 calc(100% - 24px), transparent);
}

.crumbs__item {
  flex: 0 0 auto;
  max-width: 240px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.crumbs__item--home {
  color: var(--text-dim);
  font-weight: 500;
  padding: 3px 6px;
  margin-left: -6px;
  border-radius: 5px;
}

.crumbs__item--home:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.crumbs__item--current {
  color: var(--text);
  font-weight: 600;
}

.crumbs__sep {
  color: var(--text-faint);
  opacity: 0.6;
  flex: 0 0 auto;
}

.topbar__actions {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 0 0 auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 32px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 560;
  transition: transform 0.12s var(--ease), box-shadow 0.15s var(--ease),
    background 0.15s var(--ease);
}

.btn svg {
  width: 14px;
  height: 14px;
}

.btn--accent {
  margin-left: 6px;
  color: #fff;
  background: linear-gradient(135deg, #4f46e5, #7c3aed);
  box-shadow: 0 6px 16px -8px rgba(79, 70, 229, 0.9);
}

.btn--accent:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 22px -10px rgba(79, 70, 229, 0.95);
}

.btn--accent:active {
  transform: translateY(0);
}

/* ---------------------------------------------------------------- */
/* 6. 正文排版                                                       */
/* ---------------------------------------------------------------- */

.prose {
  font-size: 16px;
  line-height: 1.78;
  color: var(--text);
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.prose > *:first-child {
  margin-top: 0;
}

.prose h1,
.prose h2,
.prose h3,
.prose h4,
.prose h5,
.prose h6 {
  position: relative;
  margin: 2em 0 0.7em;
  font-weight: 650;
  line-height: 1.32;
  letter-spacing: -0.012em;
  scroll-margin-top: 24px;
}

.prose h1 {
  font-size: 1.95em;
  margin-top: 0.2em;
  letter-spacing: -0.02em;
}

.prose h2 {
  font-size: 1.44em;
  padding-bottom: 0.38em;
  border-bottom: 1px solid var(--border);
}

.prose h3 {
  font-size: 1.18em;
}

.prose h4 {
  font-size: 1.02em;
}

.prose h5,
.prose h6 {
  font-size: 0.95em;
  color: var(--text-dim);
}

.prose p {
  margin: 1.05em 0;
}

.prose a {
  color: var(--accent-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2.5px;
  text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent);
  transition: text-decoration-color 0.15s var(--ease), color 0.15s var(--ease);
}

.prose a:hover {
  text-decoration-color: currentColor;
}

.prose .is-external::after {
  content: "↗";
  margin-left: 2px;
  font-size: 0.82em;
  opacity: 0.55;
}

.prose strong {
  font-weight: 640;
  color: var(--text);
}

.prose em {
  font-style: italic;
}

.prose del {
  color: var(--text-dim);
}

.prose ul,
.prose ol {
  margin: 1.05em 0;
  padding-left: 1.5em;
}

.prose li {
  margin: 0.36em 0;
}

.prose li > ul,
.prose li > ol {
  margin: 0.4em 0;
}

.prose li::marker {
  color: var(--text-faint);
}

.prose li.task-item {
  list-style: none;
  margin-left: -1.45em;
  display: flex;
  align-items: flex-start;
  gap: 0.55em;
}

.prose li.task-item > input[type="checkbox"] {
  margin-top: 0.42em;
  width: 14px;
  height: 14px;
  accent-color: var(--accent);
  flex: 0 0 auto;
}

.prose blockquote {
  margin: 1.3em 0;
  padding: 0.1em 1.1em;
  color: var(--text-soft);
  background: var(--bg-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.prose blockquote blockquote {
  margin: 1em 0;
}

.prose blockquote > *:first-child {
  margin-top: 0.9em;
}

.prose blockquote > *:last-child {
  margin-bottom: 0.9em;
}

.prose hr {
  height: 1px;
  margin: 2.6em 0;
  border: none;
  background: var(--border);
}

.prose img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-soft);
}

.prose img.zoomable {
  cursor: zoom-in;
  transition: box-shadow 0.2s var(--ease), transform 0.2s var(--ease);
}

.prose img.zoomable:hover {
  box-shadow: var(--shadow-md);
}

.prose kbd {
  display: inline-block;
  padding: 0.12em 0.42em;
  font-family: var(--font-mono);
  font-size: 0.82em;
  color: var(--text-soft);
  background: var(--bg-raised);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 5px;
}

.prose details {
  margin: 1.2em 0;
  padding: 0.7em 1em;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.prose summary {
  cursor: pointer;
  font-weight: 560;
  color: var(--text);
}

.prose details[open] > summary {
  margin-bottom: 0.7em;
}

.prose .heading__anchor {
  display: inline-block;
  margin-left: 0.3em;
  padding: 0.1em;
  color: var(--text-faint);
  opacity: 0;
  text-decoration: none;
  vertical-align: middle;
  transition: opacity 0.15s var(--ease), color 0.15s var(--ease);
}

.prose .heading:hover .heading__anchor,
.prose .heading__anchor:focus-visible {
  opacity: 1;
}

.prose .heading__anchor:hover {
  color: var(--accent);
}

.prose sup a {
  text-decoration: none;
  font-weight: 600;
}

.prose .footnotes {
  margin-top: 3em;
  padding-top: 1em;
  border-top: 1px solid var(--border);
  font-size: 0.9em;
  color: var(--text-dim);
}

.prose .footnotes h2 {
  font-size: 1em;
  border: none;
  margin-bottom: 0.6em;
}

.prose .md-error {
  padding: 1em;
  color: #b91c1c;
  background: #fef2f2;
  border-radius: var(--radius);
}

/* ---- 表格 ---- */

.table-wrap {
  margin: 1.4em 0;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.94em;
  line-height: 1.6;
}

.prose th,
.prose td {
  padding: 0.62em 0.95em;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.prose th {
  background: var(--table-head);
  font-weight: 620;
  white-space: nowrap;
}

.prose tbody tr:last-child td {
  border-bottom: none;
}

.prose tbody tr:hover {
  background: var(--bg-hover);
}

.prose table code {
  white-space: nowrap;
}

/* ---------------------------------------------------------------- */
/* 7. 代码                                                           */
/* ---------------------------------------------------------------- */

.prose code {
  font-family: var(--font-mono);
  font-size: 0.875em;
}

.prose :not(pre) > code {
  padding: 0.15em 0.4em;
  color: var(--text);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 5px;
  white-space: break-spaces;
}

.code-block {
  margin: 1.4em 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--code-bg);
  overflow: hidden;
}

.code-block__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 0.35em 0.6em 0.35em 0.95em;
  font-size: 11.5px;
  color: var(--text-dim);
  background: var(--bg-soft);
  background: color-mix(in srgb, var(--bg-soft) 60%, var(--code-bg));
  border-bottom: 1px solid var(--border);
}

.code-block__lang {
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  text-transform: lowercase;
}

.code-block__copy {
  padding: 0.28em 0.6em;
  font-size: 11.5px;
  color: var(--text-dim);
  border-radius: 5px;
  transition: background 0.15s var(--ease), color 0.15s var(--ease);
}

.slide .code-block__copy {
  display: none;
}

.code-block__copy:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.code-block pre {
  margin: 0;
  padding: 1em 1.1em;
  overflow-x: auto;
  line-height: 1.65;
}

.code-block pre code {
  font-size: 13px;
  background: none;
  border: none;
  padding: 0;
}

/* highlight.js 主题 */
.hljs {
  color: var(--hl-subst);
  background: transparent;
}

.hljs-doctag,
.hljs-keyword,
.hljs-meta .hljs-keyword,
.hljs-template-tag,
.hljs-template-variable,
.hljs-type,
.hljs-variable.language_ {
  color: var(--hl-keyword);
}

.hljs-title,
.hljs-title.class_,
.hljs-title.class_.inherited__,
.hljs-title.function_ {
  color: var(--hl-title);
}

.hljs-attr,
.hljs-attribute,
.hljs-literal,
.hljs-meta,
.hljs-number,
.hljs-operator,
.hljs-selector-attr,
.hljs-selector-class,
.hljs-selector-id,
.hljs-variable {
  color: var(--hl-attr);
}

.hljs-meta .hljs-string,
.hljs-regexp,
.hljs-string {
  color: var(--hl-string);
}

.hljs-built_in,
.hljs-symbol {
  color: var(--hl-built);
}

.hljs-code,
.hljs-comment,
.hljs-formula {
  color: var(--hl-comment);
  font-style: italic;
}

.hljs-name,
.hljs-quote,
.hljs-selector-pseudo,
.hljs-selector-tag {
  color: var(--hl-tag);
}

.hljs-subst {
  color: var(--hl-subst);
}

.hljs-section {
  color: var(--hl-title);
  font-weight: 600;
}

.hljs-bullet {
  color: var(--hl-attr);
}

.hljs-emphasis {
  font-style: italic;
}

.hljs-strong {
  font-weight: 700;
}

.hljs-addition {
  color: var(--hl-tag);
  background: rgba(46, 160, 67, 0.12);
}

.hljs-deletion {
  color: var(--hl-keyword);
  background: rgba(248, 81, 73, 0.12);
}

/* ---------------------------------------------------------------- */
/* 8. 大纲                                                           */
/* ---------------------------------------------------------------- */

.toc {
  flex: 0 0 var(--toc-w);
  width: var(--toc-w);
  padding: 44px 18px 40px 8px;
  border-left: 1px solid var(--border);
  overflow-y: auto;
  font-size: 12.5px;
}

.toc.is-empty {
  visibility: hidden;
}

.toc__title {
  margin: 0 0 10px 12px;
  font-size: 11px;
  font-weight: 620;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.toc__list {
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--border);
  max-height: calc(100vh - 160px);
  overflow-y: auto;
}

.toc__link {
  position: relative;
  display: block;
  padding: 4px 8px 4px 12px;
  margin-left: -1px;
  border-left: 2px solid transparent;
  color: var(--text-dim);
  line-height: 1.45;
  transition: color 0.15s var(--ease), border-color 0.15s var(--ease);
}

.toc__link:hover {
  color: var(--text);
}

.toc__link--l1 {
  font-weight: 560;
  color: var(--text-soft);
}

.toc__link--l2 {
  padding-left: 12px;
}

.toc__link--l3 {
  padding-left: 24px;
  font-size: 12px;
  color: var(--text-faint);
}

.toc__link.is-active {
  color: var(--accent-text);
  border-left-color: var(--accent);
  font-weight: 560;
}

/* ---------------------------------------------------------------- */
/* 9. 文档页脚 / 欢迎页                                              */
/* ---------------------------------------------------------------- */

.doc-footer {
  margin-top: 4em;
  padding-top: 1.6em;
  border-top: 1px solid var(--border);
}

.doc-footer__meta {
  display: flex;
  gap: 14px;
  font-size: 12px;
  color: var(--text-faint);
  margin-bottom: 18px;
}

.doc-footer__meta span {
  position: relative;
}

.pager {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.pager__link {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-raised);
  transition: border-color 0.15s var(--ease), transform 0.15s var(--ease),
    box-shadow 0.15s var(--ease);
  min-width: 0;
}

.pager__link small {
  font-size: 11.5px;
  color: var(--text-faint);
}

.pager__link strong {
  font-size: 14px;
  font-weight: 570;
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.pager__link--next {
  text-align: right;
  align-items: flex-end;
}

a.pager__link:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.pager__link.is-disabled {
  opacity: 0.45;
  pointer-events: none;
}

.pager__link.is-disabled strong {
  color: var(--text-dim);
  font-weight: 500;
}

.welcome {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 32px;
  background: var(--bg);
}

.welcome__card {
  max-width: 460px;
  text-align: center;
}

.welcome__card h1 {
  margin: 0 0 12px;
  font-size: 26px;
  font-weight: 680;
  letter-spacing: -0.02em;
}

.welcome__card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.7;
}

.welcome__stats {
  margin-top: 16px !important;
  font-size: 12.5px !important;
  color: var(--text-faint) !important;
}

.to-top {
  position: absolute;
  right: 26px;
  bottom: 26px;
  z-index: 15;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  color: var(--text-dim);
  background: var(--bg-raised);
  border: 1px solid var(--border);
  border-radius: 50%;
  box-shadow: var(--shadow-md);
  transition: transform 0.15s var(--ease), color 0.15s var(--ease);
}

.to-top svg {
  width: 17px;
  height: 17px;
}

.to-top:hover {
  color: var(--accent);
  transform: translateY(-2px);
}

/* ---------------------------------------------------------------- */
/* 10. 演示模式                                                      */
/* ---------------------------------------------------------------- */

.deck {
  position: fixed;
  inset: 0;
  z-index: 200;
  background:
    radial-gradient(120% 100% at 50% 0%, #1b2140 0%, #0b0e16 55%, #06080d 100%);
  overflow: hidden;
  user-select: none;
}

.deck__stage {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 26px;
}

.deck__frame {
  position: relative;
}

.deck__viewport {
  position: absolute;
  top: 0;
  left: 0;
  width: 1280px;
  height: 720px;
  transform-origin: top left;
}

.deck__track {
  position: relative;
  width: 1280px;
  height: 720px;
}

.slide {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-radius: 18px;
  background: var(--slide-bg);
  color: var(--slide-fg);
  box-shadow: 0 40px 90px -40px rgba(0, 0, 0, 0.9), 0 0 0 1px rgba(255, 255, 255, 0.06);
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.26s var(--ease);
}

.slide.is-active {
  visibility: visible;
  opacity: 1;
}

.slide__body {
  flex: 1 1 auto;
  min-height: 0;
  overflow: hidden;
  padding: 62px 78px;
}

.slide .prose--slide {
  flex: 0 0 auto;
  font-size: calc(28px * var(--slide-scale, 1));
  line-height: 1.55;
  letter-spacing: -0.005em;
}

.slide .prose--slide > *:first-child {
  margin-top: 0;
}

.slide .prose--slide h1 {
  font-size: 1.85em;
  margin: 0 0 0.55em;
  letter-spacing: -0.02em;
  font-weight: 700;
}

.slide .prose--slide h2 {
  font-size: 1.4em;
  margin: 0 0 0.6em;
  padding: 0;
  border: none;
  font-weight: 680;
}

.slide .prose--slide h3 {
  font-size: 1.12em;
  margin: 1.1em 0 0.45em;
  color: var(--slide-dim);
  font-weight: 640;
}

.slide .prose--slide h4 {
  font-size: 1em;
  margin: 1em 0 0.4em;
}

.slide .prose--slide p {
  margin: 0.6em 0;
}

.slide .prose--slide ul,
.slide .prose--slide ol {
  margin: 0.55em 0;
  padding-left: 1.25em;
}

.slide .prose--slide li {
  margin: 0.32em 0;
}

.slide .prose--slide li::marker {
  color: var(--accent);
}

.slide .prose--slide strong {
  color: inherit;
  font-weight: 680;
}

.slide .prose--slide a {
  color: var(--accent);
  text-decoration-color: currentColor;
}

.slide .prose--slide blockquote {
  margin: 0.8em 0;
  padding: 0.35em 0.9em;
  font-size: 1em;
  background: var(--bg-soft);
  background: color-mix(in srgb, var(--slide-fg) 5%, transparent);
  border-left-width: 4px;
}

.slide .prose--slide .table-wrap {
  margin: 0.8em 0;
}

.slide .prose--slide table {
  font-size: 0.8em;
}

.slide .prose--slide th,
.slide .prose--slide td {
  padding: 0.45em 0.7em;
}

.slide .prose--slide .code-block {
  margin: 0.75em 0;
  border-radius: 10px;
}

.slide .prose--slide .code-block pre {
  padding: 0.75em 0.95em;
}

.slide .prose--slide .code-block pre code {
  font-size: 0.68em;
  line-height: 1.55;
}

.slide .prose--slide :not(pre) > code {
  font-size: 0.82em;
  background: var(--bg-soft);
  background: color-mix(in srgb, var(--slide-fg) 7%, transparent);
  border-color: transparent;
  color: inherit;
}

.slide .prose--slide img {
  max-width: 100%;
  max-height: calc(360px * var(--slide-scale, 1));
  width: auto;
  height: auto;
  object-fit: contain;
  border: none;
  border-radius: 8px;
  margin: 0.3em 0;
}

.slide .prose--slide hr {
  margin: 1.4em 0;
}

/* 封面 */
.slide--cover .slide__body {
  display: flex;
  align-items: center;
  padding: 84px 96px;
}

.slide--cover .prose--slide {
  width: 100%;
}

.slide--cover .prose--slide h1 {
  font-size: 2.55em;
  line-height: 1.22;
  margin-bottom: 0.35em;
  background: linear-gradient(120deg, var(--slide-fg) 25%, var(--accent) 110%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 封面页里紧跟大标题的那一段，当作副标题使用 */
.slide--cover .prose--slide > h1 + p {
  font-size: 1.06em;
  color: var(--slide-dim);
}

.slide--cover .slide__body::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(
    80% 120% at 100% 0%,
    color-mix(in srgb, var(--accent) 18%, transparent) 0%,
    transparent 60%
  );
  pointer-events: none;
}

.slide__empty {
  color: var(--slide-dim);
}

/* 进度条 */
.deck__proof {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: rgba(255, 255, 255, 0.08);
  z-index: 6;
}

#deck-progress {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #6366f1, #a855f7);
  transition: width 0.3s var(--ease);
}

/* 底部工具条 */
.deck__chrome {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 7;
  padding: 0 24px 18px;
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

.deck.is-idle:not(.is-overview) .deck__chrome,
.deck.is-idle:not(.is-overview) .deck__nav {
  opacity: 0;
  transform: translateY(6px);
  pointer-events: none;
}

.deck__bar {
  display: flex;
  align-items: center;
  gap: 14px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 8px 10px 8px 16px;
  border-radius: 999px;
  background: rgba(18, 22, 32, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(14px);
  color: #cdd5e2;
  font-size: 12.5px;
}

.deck__title {
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: #e6ebf4;
  font-weight: 560;
}

.deck__counter {
  flex: 0 0 auto;
  font-variant-numeric: tabular-nums;
  color: #8d98ab;
  padding: 0 4px;
}

.deck__buttons {
  display: flex;
  align-items: center;
  gap: 2px;
  flex: 0 0 auto;
}

.deck__btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 30px;
  padding: 0 9px;
  border-radius: 999px;
  color: #cdd5e2;
  transition: background 0.15s var(--ease), color 0.15s var(--ease);
}

.deck__btn svg {
  width: 15px;
  height: 15px;
}

.deck__btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

.deck__btn--exit span {
  font-size: 12px;
}

/* 翻页按钮 */
.deck__nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 6;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: rgba(255, 255, 255, 0.65);
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(8px);
  transition: opacity 0.25s var(--ease), background 0.15s var(--ease), color 0.15s var(--ease);
}

.deck__nav svg {
  width: 18px;
  height: 18px;
}

.deck__nav:hover {
  background: rgba(255, 255, 255, 0.14);
  color: #fff;
}

.deck__nav:disabled {
  opacity: 0;
  pointer-events: none;
}

.deck__nav--prev {
  left: 18px;
}

.deck__nav--next {
  right: 18px;
}

/* 总览 */
.deck__overview {
  position: absolute;
  inset: 0;
  z-index: 8;
  overflow-y: auto;
  padding: 48px 32px 96px;
  background: rgba(8, 10, 15, 0.9);
  backdrop-filter: blur(12px);
}

.deck__overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(248px, 1fr));
  gap: 22px;
  max-width: 1160px;
  margin: 0 auto;
}

.deck__thumb {
  position: relative;
  padding: 0;
  border-radius: 10px;
  border: 2px solid transparent;
  background: none;
  transition: border-color 0.15s var(--ease), transform 0.15s var(--ease);
}

.deck__thumb:hover {
  transform: translateY(-2px);
}

.deck__thumb.is-active {
  border-color: #8b93ff;
}

.deck__thumb-inner {
  position: relative;
  overflow: hidden;
  border-radius: 8px;
  background: var(--slide-bg);
  box-shadow: 0 10px 30px -16px rgba(0, 0, 0, 0.9);
}

.deck__thumb-inner .slide {
  position: absolute;
  top: 0;
  left: 0;
  right: auto;
  bottom: auto;
  width: 1280px;
  height: 720px;
  border-radius: 0;
  box-shadow: none;
  visibility: visible !important;
  opacity: 1 !important;
}

.deck__thumb-num {
  position: absolute;
  left: 6px;
  bottom: -2px;
  font-size: 11px;
  color: #8d98ab;
  font-variant-numeric: tabular-nums;
}

body.is-presenting {
  overflow: hidden;
}

/* ---------------------------------------------------------------- */
/* 11. 浮层                                                          */
/* ---------------------------------------------------------------- */

.lightbox {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: grid;
  place-items: center;
  padding: 40px;
  background: rgba(6, 8, 12, 0.86);
  backdrop-filter: blur(6px);
  cursor: zoom-out;
}

.lightbox img {
  max-width: 100%;
  max-height: 100%;
  border-radius: var(--radius);
  box-shadow: 0 40px 90px -40px #000;
  background: #fff;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  z-index: 400;
  transform: translate(-50%, 12px);
  padding: 8px 16px;
  font-size: 13px;
  color: #fff;
  background: rgba(24, 28, 38, 0.92);
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease);
  box-shadow: 0 14px 40px -18px #000;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ---------------------------------------------------------------- */
/* 12. 响应式 & 打印                                                 */
/* ---------------------------------------------------------------- */

@media (max-width: 1280px) {
  .toc {
    --toc-w: 208px;
  }
}

@media (max-width: 1120px) {
  .toc {
    display: none;
  }
}

@media (max-width: 900px) {
  .app {
    grid-template-columns: minmax(0, 1fr);
  }

  .sidebar {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 50;
    width: min(86vw, 320px);
    transform: translateX(-102%);
    transition: transform 0.26s var(--ease);
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.35);
  }

  .sidebar.is-open {
    transform: translateX(0);
  }

  .sidebar__close {
    display: inline-grid;
  }

  .topbar__menu {
    display: inline-grid;
  }

  .topbar {
    padding-left: 10px;
  }

  .doc {
    padding: 28px 20px 120px;
  }

  .prose {
    font-size: 15.5px;
  }

  .prose h1 {
    font-size: 1.7em;
  }

  .pager {
    grid-template-columns: 1fr;
  }

  .pager__link--next {
    text-align: left;
    align-items: flex-start;
  }

  .deck__stage {
    padding: 0;
  }

  .slide {
    border-radius: 0;
  }

  .deck__nav {
    display: none;
  }
}

@media (max-width: 620px) {
  .topbar__actions .icon-btn:not(#copy-link) {
    display: none;
  }

  .btn--accent span {
    display: none;
  }

  .btn--accent {
    padding: 0 10px;
  }

  .crumbs__item {
    max-width: 130px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

@media print {
  body {
    overflow: visible;
    background: #fff;
    color: #000;
  }

  .app {
    display: block;
    height: auto;
  }

  .sidebar,
  .topbar,
  .toc,
  .to-top,
  .deck,
  .lightbox,
  .toast,
  .code-block__bar,
  .doc-footer__meta {
    display: none !important;
  }

  .reader {
    overflow: visible;
    height: auto;
  }

  .doc {
    max-width: none;
    padding: 0;
  }

  .code-block,
  .table-wrap,
  .prose blockquote,
  .prose img,
  .pager {
    break-inside: avoid;
  }

  .prose h1,
  .prose h2,
  .prose h3 {
    break-after: avoid;
  }

  .prose a {
    color: #000;
    text-decoration: underline;
  }

  .prose img.heading__anchor,
  .prose .heading__anchor {
    display: none;
  }
}