/* 主题：默认浅色，其余通过 html[data-theme] 覆盖同一组变量 */
:root {
  color-scheme: light;
  --fg: #1f2328;
  --muted: #59636e;
  --border: #d1d9e0;
  --bg: #ffffff;
  --soft: #f6f8fa;
  --link: #0969da;
  --accent: #0969da;
  --topbar-bg: rgba(255, 255, 255, .9);
  --ctrl-bg: #ffffff;
  --active-bg: #ddf4ff;
  --ring: rgba(9, 105, 218, .12);
  --b-md-bg: #ddf4ff;  --b-md-fg: #0969da;  --b-md-bd: #b6e3ff;
  --b-dir-bg: #fff8c5; --b-dir-fg: #7d4e00; --b-dir-bd: #f0e17a;
  --b-img-bg: #dafbe1; --b-img-fg: #1a7f37; --b-img-bd: #a7f3ba;
  --footer-h: 41px;   /* 吸底页脚高度，render.js 会按实际高度覆盖 */
  --toc-top: 56px;   /* 悬浮大纲面板顶部位置，刘海屏会另行覆盖 */
  --side-w: 296px;   /* 左侧目录宽度，拖动右边缘可调，双击复位 */
}
/* 宽屏两个开关浮起时，面板下移让出按钮位置 */
body.tools-float { --toc-top: 104px; }

/* 深色 */
html[data-theme="dark"] {
  color-scheme: dark;
  --fg: #e6edf3;
  --muted: #9198a1;
  --border: #3d444d;
  --bg: #0d1117;
  --soft: #151b23;
  --link: #4493f8;
  --accent: #4493f8;
  --topbar-bg: rgba(13, 17, 23, .85);
  --ctrl-bg: #151b23;
  --active-bg: #14385a;
  --ring: rgba(68, 147, 248, .25);
  --b-md-bg: #0c2d4a;  --b-md-fg: #6cb6ff;  --b-md-bd: #1f4b73;
  --b-dir-bg: #3a2d0a; --b-dir-fg: #e3b341; --b-dir-bd: #57430d;
  --b-img-bg: #12261a; --b-img-fg: #3fb950; --b-img-bd: #1e4a2c;
}

/* 护眼（米黄） */
html[data-theme="sepia"] {
  color-scheme: light;
  --fg: #3b3327;
  --muted: #7a6a52;
  --border: #ddcfb4;
  --bg: #f6efe1;
  --soft: #efe6d2;
  --link: #9a5b1f;
  --accent: #b06d1f;
  --topbar-bg: rgba(246, 239, 225, .9);
  --ctrl-bg: #fbf6ea;
  --active-bg: #efdcb9;
  --ring: rgba(176, 109, 31, .18);
  --b-md-bg: #efe1c4;  --b-md-fg: #8a5a12; --b-md-bd: #dcc79a;
  --b-dir-bg: #f6e7b8; --b-dir-fg: #7d4e00; --b-dir-bd: #e2cd8f;
  --b-img-bg: #dfeed3; --b-img-fg: #3f6b2f; --b-img-bd: #bfd9ac;
}

/* 暗蓝（Nord） */
html[data-theme="nord"] {
  color-scheme: dark;
  --fg: #e5e9f0;
  --muted: #9aa5b8;
  --border: #4c566a;
  --bg: #2e3440;
  --soft: #3b4252;
  --link: #88c0d0;
  --accent: #88c0d0;
  --topbar-bg: rgba(46, 52, 64, .9);
  --ctrl-bg: #3b4252;
  --active-bg: #434c5e;
  --ring: rgba(136, 192, 208, .25);
  --b-md-bg: #3a4d5c;  --b-md-fg: #8fbcbb; --b-md-bd: #4f6577;
  --b-dir-bg: #4a4331; --b-dir-fg: #ebcb8b; --b-dir-bd: #6b5f42;
  --b-img-bg: #3a4a3f; --b-img-fg: #a3be8c; --b-img-bd: #52654f;
}

* { box-sizing: border-box; }
html { background: var(--bg); }
body {
  margin: 0;
  color: var(--fg);
  background: var(--bg);
  font: 16px/1.7 -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  transition: background-color .18s ease, color .18s ease;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  overflow-wrap: break-word;
  padding-bottom: var(--footer-h);   /* 给吸底页脚让位，末段内容不被遮住 */
}

/* 顶栏 */
.topbar {
  position: sticky; top: 0; z-index: 20;
  padding: 10px 28px;
  background: var(--topbar-bg);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
  font-size: 14px; color: var(--muted);
  display: flex; align-items: center; gap: 8px;
}
.topbar .crumbs { display: flex; align-items: center; gap: 8px; min-width: 0; overflow: hidden; }
.topbar a { color: var(--link); text-decoration: none; }
.topbar a:hover { text-decoration: underline; }
.topbar i { color: var(--border); font-style: normal; }
.topbar .acts { margin-left: auto; display: flex; align-items: center; gap: 30px; }
.topbar .raw { white-space: nowrap; }

/* 主题选择 */
.theme-pick { display: flex; align-items: center; gap: 6px; white-space: nowrap; }
.theme-pick .theme-label { font-size: 12px; color: var(--muted); }
.theme-pick select {
  font: inherit; font-size: 13px;
  padding: 3px 8px;
  color: var(--fg); background: var(--ctrl-bg);
  border: 1px solid var(--border); border-radius: 6px;
  cursor: pointer; outline: none;
}
.theme-pick select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--ring); }

.search {
  width: 100%; margin-top: 8px;
  padding: 8px 12px;
  color: var(--fg);
  background: var(--ctrl-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 14px; outline: none;
}
.search:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--ring); }

/* 主体：左目录 + 正文 + 右大纲 */
.layout {
  display: flex; gap: 28px;
  max-width: 1360px; margin: 0 auto; padding: 22px 26px 64px;
  align-items: flex-start;
}
.markdown-body { flex: 1 1 auto; min-width: 0; }

/* 宽屏：两个开关浮在内容上方两侧，随滚动吸附在顶栏下方 */
.float-tools {
  position: sticky; top: 56px; z-index: 27;
  height: 30px; margin: 0 auto -30px; max-width: 1360px;
  pointer-events: none;
}
@media (max-width: 820px) {
  .float-tools { display: none; }
}
.float-tools .side-fab,
.float-tools .toc-fab { position: absolute; top: 10px; pointer-events: auto; }
.float-tools .side-fab {
  left: 18px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, .12);
}
.float-tools .toc-fab {
  right: 18px;
  padding: 6px 12px; border-radius: 999px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, .12);
}

/* 悬浮目录展开时，桌面正文右侧留位，避免被面板遮住 */
@media (min-width: 1181px) {
  body.has-toc:not(.toc-hidden) .layout { padding-right: 282px; }
  body.focus-mode.has-toc:not(.toc-hidden) .layout { padding-right: 282px; }
}

/* 左侧目录栏：宽度可拖动调整，右边缘为拖拽条 */
.sidebar {
  flex: 0 0 var(--side-w, 296px);
  width: var(--side-w, 296px);
  min-width: 0;
  position: sticky; top: 56px;
  max-height: calc(100vh - 76px - var(--footer-h));
  max-height: calc(100dvh - 76px - var(--footer-h));
  display: flex;
  padding: 0;
  border-right: 1px solid var(--border);
}
.side-scroll {
  flex: 1 1 auto;
  min-width: 0; min-height: 0;
  overflow: auto;
  overscroll-behavior: contain;
  padding-right: 16px;
}
.side-resizer {
  display: none;
  position: absolute; top: 0; right: -5px; bottom: 0;
  width: 10px; z-index: 2;
  cursor: col-resize; touch-action: none;
  outline: none;
}
body.has-drawer .side-resizer { display: block; }
.side-resizer::before {
  content: "";
  position: absolute; top: 0; bottom: 0; left: 4px; width: 2px;
  border-radius: 2px; background: transparent;
  transition: background-color .15s ease;
}
.side-resizer:hover::before,
.side-resizer:focus-visible::before,
body.side-resizing .side-resizer::before { background: var(--accent); }
body.side-resizing { cursor: col-resize; -webkit-user-select: none; user-select: none; }
body.side-resizing * { cursor: col-resize !important; }
.side-head { position: sticky; top: 0; z-index: 1; background: var(--bg); padding-bottom: 8px; }
.side-title { font-size: 15px; font-weight: 600; }
@media (min-width: 821px) {
  body.has-drawer .side-title { padding-left: 40px; }
}
.side-count { font-size: 12px; color: var(--muted); }
.filelist { list-style: none; margin: 0; padding: 0; }
.filelist .row { border-bottom: 1px solid var(--soft); }
.filelist .row:last-child { border-bottom: none; }
.filelist a {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 10px; border-radius: 8px;
  text-decoration: none; color: var(--fg);
}
.filelist a:hover { background: var(--soft); }
.filelist .active > a { background: var(--active-bg); }
.filelist .ficon {
  flex: 0 0 auto; display: inline-flex;
  width: 17px; height: 17px; color: var(--muted);
}
.filelist .ficon svg { display: block; width: 100%; height: 100%; }
.filelist .f-dir { color: var(--b-dir-fg); }
.filelist .f-md  { color: var(--b-md-fg); }
.filelist .f-img { color: var(--b-img-fg); }
.filelist .rname {
  flex: 1 1 auto; min-width: 0;
  font-size: 14px; line-height: 1.5;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.filelist .rmeta { flex: 0 0 auto; font-size: 11px; color: var(--muted); white-space: nowrap; }

/* 目录翻页 */
.pager {
  display: flex; align-items: center; gap: 6px;
  padding: 10px 0 2px;
}
.pager button {
  padding: 4px 10px; font-size: 13px; cursor: pointer;
  color: var(--fg); background: var(--ctrl-bg);
  border: 1px solid var(--border); border-radius: 6px;
}
.pager button:hover:enabled { border-color: var(--accent); color: var(--link); }
.pager button:disabled { opacity: .45; cursor: default; }
.pager-info { font-size: 12px; color: var(--muted); margin-left: auto; }

/* 右侧标题大纲：悬浮面板，可隐藏 */
.toc {
  display: none;
  position: fixed; top: var(--toc-top);
  right: max(18px, calc((100vw - 1360px) / 2 + 18px));
  z-index: 26;
  width: min(236px, calc(100vw - 36px));
  max-height: calc(100vh - var(--toc-top) - 16px - var(--footer-h));
  max-height: calc(100dvh - var(--toc-top) - 16px - var(--footer-h));
  overflow: auto; overscroll-behavior: contain;
  padding: 10px 14px 14px;
  background: var(--bg);
  border: 1px solid var(--border); border-radius: 10px;
  box-shadow: 0 8px 28px rgba(0, 0, 0, .12);
  font-size: 14px;
}
body.has-toc:not(.toc-hidden) .toc { display: block; }
.toc-head { display: flex; align-items: center; gap: 8px; margin-bottom: 6px; }
.toc-title { flex: 1 1 auto; font-weight: 600; color: var(--muted); }
.toc-close {
  flex: 0 0 auto; width: 24px; height: 24px; padding: 0;
  font: inherit; font-size: 18px; line-height: 1;
  color: var(--muted); background: transparent;
  border: 0; border-radius: 6px; cursor: pointer;
}
.toc-close:hover { color: var(--fg); background: var(--soft); }
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc li { margin: 4px 0; }
.toc .lv2 { padding-left: 12px; }
.toc .lv3 { padding-left: 24px; font-size: 13px; }
.toc a { color: var(--muted); text-decoration: none; }
.toc a:hover { color: var(--link); }

.empty { color: var(--muted); font-size: 14px; padding: 10px 2px; }

/* markdown 正文 */
.markdown-body > *:first-child { margin-top: 0; }
.markdown-body h1, .markdown-body h2 {
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px; margin-top: 32px;
}
.markdown-body h1 { font-size: 28px; }
.markdown-body h2 { font-size: 22px; }
.markdown-body h3 { font-size: 19px; margin-top: 26px; }
.markdown-body h1, .markdown-body h2, .markdown-body h3 { scroll-margin-top: 64px; }
.markdown-body a { color: var(--link); }
.markdown-body code {
  background: var(--soft); border-radius: 6px;
  padding: 2px 6px; font-size: .9em;
  font-family: "SFMono-Regular", Consolas, Menlo, monospace;
}
.markdown-body pre {
  background: var(--soft);
  border: 1px solid var(--border);
  border-radius: 8px; padding: 14px 16px; overflow: auto;
}
.markdown-body pre code { background: none; padding: 0; }
.markdown-body blockquote {
  margin: 16px 0; padding: 0 14px;
  color: var(--muted); border-left: 4px solid var(--border);
}
.markdown-body table {
  border-collapse: collapse; display: block;
  overflow: auto; width: max-content; max-width: 100%;
}
.markdown-body th, .markdown-body td { border: 1px solid var(--border); padding: 6px 12px; }
.markdown-body th { background: var(--soft); }
.markdown-body img { max-width: 100%; }
.markdown-body hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }
.markdown-body kbd {
  border: 1px solid var(--border); border-bottom-width: 2px;
  border-radius: 5px; padding: 1px 5px; font-size: 12px; background: var(--soft);
}

/* 底部备案 */
.site-footer {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 18;
  border-top: 1px solid var(--border);
  background: var(--soft);
}
.footer-inner {
  max-width: 1360px; margin: 0 auto;
  padding: 10px 26px;
  display: flex; align-items: center; justify-content: center; gap: 12px;
  font-size: 13px; color: var(--muted); white-space: nowrap;
}
.footer-slogan { color: var(--fg); opacity: .7; letter-spacing: .5px; }
.footer-inner a { color: var(--muted); text-decoration: none; }
.footer-inner a:hover { color: var(--link); text-decoration: underline; }

/* ===== 多端适配：桌面 / 平板 / 手机 ===== */

/* 平板横屏 / 小笔记本（821–1180）：目录收窄，留白减小 */
@media (max-width: 1180px) and (min-width: 821px) {
  :root { --side-w: 248px; }
  .layout { gap: 22px; padding: 20px 20px 56px; }
  .footer-inner { padding: 16px 20px; }
}

/* 平板竖屏 / 手机（≤820）：改单列，目录移到正文下方 */
@media (max-width: 820px) {
  .layout { flex-direction: column; gap: 16px; padding: 14px 14px 48px; }
  .topbar { padding: 8px 14px; gap: 6px; }
  .topbar .crumbs {
    white-space: nowrap;
    overflow-x: auto; overflow-y: hidden;
    scrollbar-width: none;              /* 面包屑过长时横向滑动，不换行挤压按钮 */
    -webkit-overflow-scrolling: touch;
  }
  .topbar .crumbs::-webkit-scrollbar { display: none; }
  .topbar .crumbs > * { flex: 0 0 auto; }
  .topbar .acts { gap: 10px; }
  .theme-pick .theme-label { display: none; }
  .theme-pick select, .search { font-size: 16px; }   /* 16px 以下 iOS 聚焦会自动放大页面 */
  .sidebar {
    order: 2; flex: none; width: 100%;
    position: static; max-height: none;
    padding: 12px 0 0; border-right: none;
    border-top: 1px solid var(--border);
  }
  .side-scroll { overflow: visible; padding-right: 0; }
  body.has-drawer .side-resizer { display: none; }
  .side-head { position: static; }
  .markdown-body { order: 1; }
  .footer-inner { padding: 10px 14px; font-size: 12.5px; }
  .markdown-body h1 { font-size: clamp(21px, 5.6vw, 28px); }
  .markdown-body h2 { font-size: clamp(18px, 4.8vw, 22px); }
  .markdown-body h3 { font-size: 17px; }
  .markdown-body pre { padding: 12px; font-size: 13px; -webkit-overflow-scrolling: touch; }
  .markdown-body table { font-size: 14px; -webkit-overflow-scrolling: touch; }
  .markdown-body th, .markdown-body td { padding: 6px 10px; }
  .markdown-body blockquote { margin: 14px 0; padding: 0 12px; }
  .markdown-body img { height: auto; }
}

/* 手机（≤560）：再压一档字号与留白 */
@media (max-width: 560px) {
  .topbar { padding: 7px 10px; font-size: 13px; }
  .topbar .acts { gap: 8px; }
  .focus-btn { padding: 3px 8px; }
  .theme-pick select { max-width: 76px; }
  .layout { padding: 12px 12px 40px; }
  .markdown-body { font-size: 15.5px; line-height: 1.75; }
  .markdown-body h1 { font-size: 20px; }
  .markdown-body h2 { font-size: 18px; }
  .markdown-body h3 { font-size: 16.5px; }
  .filelist .rname { font-size: 15px; }
  .filelist .rmeta { font-size: 11.5px; }
  .footer-inner { padding: 8px 12px; font-size: 12px; gap: 8px; }
}

/* 触屏设备：加大点击区域，避免误触 */
@media (pointer: coarse) {
  .filelist a { padding: 11px 10px; }
  .pager button, .focus-btn { min-height: 36px; padding: 6px 12px; }
  .theme-pick select { min-height: 34px; }
  .toc a { display: block; padding: 4px 0; }
  .topbar a { display: inline-block; padding: 4px 0; }
}

/* 顶栏按钮：全屏阅读 */
.focus-btn {
  font: inherit; font-size: 13px;
  padding: 3px 10px;
  color: var(--fg); background: var(--ctrl-bg);
  border: 1px solid var(--border); border-radius: 6px;
  cursor: pointer; white-space: nowrap;
}
.focus-btn:hover { border-color: var(--accent); color: var(--link); }
.focus-btn[aria-pressed="true"] { background: var(--active-bg); border-color: var(--accent); color: var(--link); }

/* 全屏阅读：收起左栏，正文居中；悬浮目录保持用户选择 */
body.focus-mode .sidebar { display: none; }
body.focus-mode .layout { max-width: 1120px; padding: 16px 26px 80px; }
body.focus-mode .markdown-body { max-width: 880px; margin: 0 auto; }
body.focus-mode .footer-inner { max-width: 1120px; }

/* 左栏收起后，正文展示与全屏阅读一致：1120 版心、880 阅读宽度居中 */
@media (min-width: 821px) {
  body.has-drawer:not(.side-open) .layout {
    max-width: 1120px; padding: 16px 26px 80px;
  }
  body.has-drawer:not(.side-open) .markdown-body { max-width: 880px; margin: 0 auto; }
  body.has-drawer:not(.side-open) .footer-inner { max-width: 1120px; }
}
@media (min-width: 1181px) and (max-width: 1389px) {
  body.has-drawer:not(.side-open).has-toc:not(.toc-hidden) .layout {
    padding-right: 282px;
  }
}

/* 顶栏「大纲」开关：与左侧目录按钮同一行，点击展开 / 收起悬浮目录 */
.toc-fab {
  display: none;
  font: inherit; font-size: 13px;
  padding: 3px 10px; border-radius: 6px;
  color: var(--fg); background: var(--ctrl-bg);
  border: 1px solid var(--border); cursor: pointer;
  white-space: nowrap;
}
body.has-toc .toc-fab { display: inline-block; }
body.has-toc:not(.toc-hidden) .toc-fab {
  background: var(--active-bg); border-color: var(--accent); color: var(--link);
}

/* 刘海屏 / 圆角屏安全区（仅移动端生效，桌面不受影响） */
@media (max-width: 820px) {
  @supports (padding: env(safe-area-inset-top)) {
    .topbar {
      padding-top: max(8px, env(safe-area-inset-top));
      padding-left: max(12px, env(safe-area-inset-left));
      padding-right: max(12px, env(safe-area-inset-right));
    }
    .layout {
      padding-left: max(12px, env(safe-area-inset-left));
      padding-right: max(12px, env(safe-area-inset-right));
    }
    .footer-inner { padding-bottom: max(14px, env(safe-area-inset-bottom)); }
    :root {
      --toc-top: max(56px, calc(env(safe-area-inset-top) + 54px));
    }
  }
}

/* 全屏模式在窄屏上的留白：放在最后以覆盖前面的基础规则 */
@media (max-width: 820px) {
  body.focus-mode .layout { padding: 14px 14px 64px; }
}
@media (max-width: 560px) {
  body.focus-mode .layout { padding: 12px 12px 64px; }
}

/* ===== 目录开关：桌面收起左栏，小屏抽屉；JS 加 has-drawer 后启用 ===== */
.side-fab, .side-close { display: none; }
body.has-drawer .side-fab {
  display: inline-flex; align-items: center; justify-content: center;
  flex: 0 0 auto;
  width: 32px; height: 30px; padding: 0;
  font: inherit; font-size: 17px; line-height: 1; text-align: center;
  border-radius: 8px;
  color: var(--fg); background: var(--ctrl-bg);
  border: 1px solid var(--border); cursor: pointer;
  white-space: nowrap;
}
body.has-drawer .side-fab[aria-expanded="true"] {
  background: var(--active-bg); border-color: var(--accent); color: var(--link);
}
body.focus-mode .side-fab { display: none !important; }

body.has-drawer .side-close {
  display: inline-flex; align-items: center; justify-content: center;
  position: absolute; top: 0; right: 0;
  width: 28px; height: 28px; padding: 0;
  font: inherit; font-size: 18px; line-height: 1;
  color: var(--muted); background: var(--ctrl-bg);
  border: 1px solid var(--border); border-radius: 8px;
  cursor: pointer;
}
body.has-drawer .side-close:hover { color: var(--link); border-color: var(--accent); }

/* 桌面：左栏保持在版心内，用顶栏按钮收起 / 展开 */
@media (min-width: 821px) {
  body.has-drawer:not(.side-open) .sidebar { display: none; }
  body.has-drawer .side-head { padding-right: 34px; }
}

.side-mask {
  display: none;
  position: fixed; top: 0; right: 0; bottom: 0; left: 0;
  background: rgba(0, 0, 0, .42);
  z-index: 39;
}

@media (max-width: 820px) {
  /* 小屏：抽屉从左边滑出，按钮在顶栏最左侧 */
  body.has-drawer .sidebar {
    position: fixed; top: 0; bottom: 0; left: 0;
    order: 0; z-index: 40;
    width: min(320px, 86vw);
    max-height: none; margin: 0;
    padding: 0;
    background: var(--bg);
    border-top: none; border-right: 1px solid var(--border);
    overflow: hidden;
    box-shadow: 8px 0 24px rgba(0, 0, 0, .16);
    transform: translateX(-102%);
    visibility: hidden;
    transition: transform .22s ease, visibility .22s ease;
  }
  body.has-drawer .side-scroll {
    padding: 14px 14px 20px;
    padding-top: max(14px, env(safe-area-inset-top));
    overflow: auto; -webkit-overflow-scrolling: touch;
  }
  body.has-drawer.side-open .sidebar { transform: none; visibility: visible; }
  body.has-drawer.side-open .side-mask { display: block; }
  body.side-open { overflow: hidden; }

  body.has-drawer .side-head { position: sticky; top: 0; background: var(--bg); z-index: 1; padding-right: 34px; }
}