@charset "utf-8";
/* ============================================================
   NuoinNav v3.0 · Pintree 风格网址导航
   结构：左侧分类栏 / 顶栏 / 文件夹索引 / 链接网格 6 列
   ============================================================ */

/* ---------- 1. 设计变量 ---------- */
:root {
  --bg: #ffffff;
  --panel: #ffffff;
  --panel-2: #fafbfc;
  --soft: #f3f4f6;
  --hover: #f9fafb;
  --line: #e5e7eb;
  --line-strong: #d7dbe0;
  --text: #111827;
  --title: #0f172a;
  --muted: #6b7280;
  --faint: #9ca3af;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, .05);
  --shadow-md: 0 6px 20px rgba(16, 24, 40, .08);
  --shadow-lg: 0 18px 44px rgba(16, 24, 40, .12);
}

html.dark {
  --bg: #0f1115;
  --panel: #151922;
  --panel-2: #171c25;
  --soft: #1d232e;
  --hover: #1a1f29;
  --line: #262d39;
  --line-strong: #323a48;
  --text: #e5e7eb;
  --title: #f3f4f6;
  --muted: #9ca3af;
  --faint: #6b7280;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, .45);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, .55);
}

/* ---------- 2. 基础 ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body.nk-body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  color: var(--text);
  font: 14px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
img { max-width: 100%; border: 0; }
h1, h2, h3, h4 { margin: 0; font-weight: 700; }
p { margin: 0; }
::selection { background: var(--brand-soft); color: var(--brand); }

.nk-bg-mask {
  position: fixed; inset: 0; z-index: 0;
  background: rgba(255, 255, 255, .72);
  pointer-events: none;
}
html.dark .nk-bg-mask { background: rgba(10, 12, 16, .78); }

/* 通用按钮 */
.nk-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  height: 36px; padding: 0 16px; border-radius: 9px;
  border: 1px solid var(--line); background: var(--panel); color: var(--text);
  font-size: 13px; font-weight: 500; transition: .16s ease;
}
.nk-btn:hover { border-color: var(--line-strong); background: var(--hover); }
.nk-btn-primary { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.nk-btn-primary:hover { filter: brightness(.94); background: var(--brand); border-color: var(--brand); }

.nk-dot { color: var(--faint); margin: 0 6px; }

/* ---------- 3. 左侧栏 ---------- */
.nk-sidebar {
  position: fixed; top: 0; bottom: 0; left: 0; z-index: 40;
  display: flex; flex-direction: column;
  width: var(--side, 240px);
  background: var(--panel);
  border-right: 1px solid var(--line);
}
.nk-side-head {
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
  height: 64px; flex: 0 0 64px; padding: 0 16px;
}
.nk-brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.nk-brand-mark {
  display: flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; flex: 0 0 34px;
  border-radius: 10px; background: var(--brand);
  color: #fff; font-size: 17px; font-weight: 800;
  box-shadow: var(--shadow-sm);
}
.nk-brand-img { width: auto; height: 32px; max-width: 132px; object-fit: contain; }
.nk-brand-text { display: flex; flex-direction: column; line-height: 1.25; min-width: 0; }
.nk-brand-text b {
  font-size: 17px; font-weight: 800; letter-spacing: -.3px; color: var(--title);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-brand-text i { font-style: normal; font-size: 10.5px; color: var(--faint); letter-spacing: .2px; }

.nk-nav { display: flex; flex-direction: column; gap: 2px; flex: 1 1 auto; overflow-y: auto; padding: 4px 12px 12px; }
.nk-nav::-webkit-scrollbar { width: 4px; }
.nk-nav::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 4px; }
.nk-nav-item {
  display: flex; align-items: center; gap: 11px;
  min-height: 42px; padding: 8px 12px; border-radius: 10px;
  color: var(--text); font-size: 15px; font-weight: 500;
  transition: background .14s ease, color .14s ease;
}
.nk-nav-item:hover { background: var(--hover); color: var(--title); }
.nk-nav-item.on { background: var(--brand-soft); color: var(--brand); font-weight: 650; }
.nk-nav-ico { display: flex; flex: 0 0 20px; color: var(--faint); }
.nk-nav-item.on .nk-nav-ico, .nk-nav-item:hover .nk-nav-ico { color: currentColor; }
.nk-nav-text { flex: 1 1 auto; min-width: 0; display: flex; flex-direction: column; gap: 1px; }
.nk-nav-name { font-weight: inherit; font-size: 15px; letter-spacing: .1px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.nk-nav-sub {
  font-style: normal; font-size: 11px; font-weight: 400; line-height: 1.25;
  color: var(--faint); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-nav-item.on .nk-nav-sub { color: var(--brand); opacity: .72; }
.nk-nav-num { flex: 0 0 auto; font-size: 11.5px; color: var(--faint); font-variant-numeric: tabular-nums; }
.nk-nav-item.on .nk-nav-num { color: var(--brand); opacity: .75; }

.nk-side-foot { flex: 0 0 auto; padding: 0 12px 14px; display: flex; flex-direction: column; gap: 10px; }
.nk-side-card { padding: 10px 12px; border-radius: 11px; background: var(--panel-2); border: 1px solid var(--line); }
.nk-side-title {
  display: flex; align-items: center; gap: 6px;
  font-size: 11px; font-weight: 700; letter-spacing: .4px;
  color: var(--faint); text-transform: uppercase; margin-bottom: 6px;
}
.nk-side-link {
  position: relative; display: flex; align-items: center; justify-content: space-between;
  width: 100%; padding: 4px 0; border: 0; background: none;
  font-size: 12.5px; color: var(--muted); text-align: left;
}
.nk-side-link:hover { color: var(--brand); }
.nk-side-link em { font-style: normal; font-size: 10px; color: var(--faint); opacity: 0; transition: .15s; }
.nk-copy:hover em { opacity: 1; }
.nk-wx-pop {
  position: absolute; right: 0; bottom: 26px; z-index: 5;
  display: none; padding: 6px; background: #fff; border-radius: 10px;
  box-shadow: var(--shadow-lg); border: 1px solid var(--line);
}
.nk-wx-pop img { display: block; width: 132px; height: 132px; object-fit: contain; }
.nk-wx:hover .nk-wx-pop { display: block; }

.nk-close { display: none; border: 0; background: none; color: var(--muted); padding: 4px; }
.nk-backdrop { display: none; }

/* ---------- 4. 右侧容器 / 顶栏 ---------- */
.nk-content { position: relative; z-index: 1; display: flex; flex-direction: column; min-height: 100vh; margin-left: var(--side, 240px); }
.nk-topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; gap: 18px;
  height: 64px; flex: 0 0 64px; padding: 0 24px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}
.nk-menu { display: none; align-items: center; justify-content: center; width: 36px; height: 36px; flex: 0 0 36px; border: 1px solid var(--line); border-radius: 9px; background: transparent; color: var(--text); }

.nk-search {
  position: relative; display: flex; align-items: center; gap: 8px;
  flex: 0 1 340px; height: 38px; padding: 0 10px;
  border-radius: 9px; color: var(--faint);
  transition: background .15s, box-shadow .15s;
}
.nk-search:hover { background: var(--hover); }
.nk-search:focus-within { background: var(--hover); box-shadow: 0 0 0 1px var(--line) inset; color: var(--muted); }
.nk-search input {
  flex: 1 1 auto; width: 100%; min-width: 0; height: 100%;
  border: 0; background: transparent; outline: none;
  font: inherit; font-size: 13px; color: var(--text);
}
.nk-search input::-webkit-search-cancel-button { display: none; }
.nk-search-clear { display: none; border: 0; background: none; color: var(--faint); font-size: 17px; line-height: 1; padding: 0 2px; }
.nk-search.has-value .nk-search-clear { display: block; }

/* v3.13 全站搜索结果页：与首页同构（复用 nk-folder / nk-group / nk-link 全套样式） */
#nk-search-results { padding-bottom: 24px; }
#nk-search-results[hidden] { display: none; }
#nk-search-results .nk-folder { margin-bottom: 18px; }
#nk-search-results .nk-folder-head { cursor: pointer; }
#nk-search-results .nk-folder-chev { display: none; }
#nk-search-results .nk-folder-head .nk-folder-ico svg { transition: transform .18s; }
#nk-search-results .nk-folder:not(.is-open) .nk-folder-head .nk-folder-ico svg { transform: rotate(-90deg); }
.nk-rs-head {
  display: flex; align-items: center; gap: 8px;
  margin: 0 0 14px; padding: 10px 14px;
  font-size: 13px; color: var(--muted);
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--nk-radius, 12px);
}
.nk-rs-head b { color: var(--brand); font-weight: 700; }

/* v3.15：只展示自身含关键词的网址；名称命中的分类/分组仅作入口提示 */
.nk-rs-near-tip {
  display: flex; flex-wrap: wrap; align-items: center; gap: 6px;
  margin: -6px 0 16px; padding: 0 2px;
  font-size: 12px; color: var(--faint);
}
.nk-rs-near-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.nk-rs-near-item {
  display: inline-flex; align-items: center;
  padding: 3px 10px; border-radius: 999px;
  font-size: 12px; color: var(--muted); text-decoration: none;
  background: var(--soft); border: 1px solid var(--line);
  transition: color .15s, background .15s, border-color .15s;
}
a.nk-rs-near-item:hover { color: var(--brand); background: var(--brand-soft); border-color: var(--brand-line); }
.nk-rs-near-more { font-size: 12px; color: var(--faint); }

.nk-top-right { display: flex; align-items: center; gap: 16px; margin-left: auto; }
.nk-top-link { font-size: 13px; color: var(--muted); transition: color .15s; }
.nk-top-link:hover { color: var(--title); }
.nk-theme-btn {
  display: flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 50%;
  border: 1px solid var(--line); background: var(--panel); color: var(--muted);
  box-shadow: var(--shadow-sm); transition: .16s;
}
.nk-theme-btn:hover { color: var(--title); border-color: var(--line-strong); }
.nk-theme-btn .nk-moon { display: none; }
html.dark .nk-theme-btn .nk-sun { display: none; }
html.dark .nk-theme-btn .nk-moon { display: block; }

/* ---------- 5. 主容器 ---------- */
.nk-main { flex: 1 0 auto; display: flex; flex-direction: column; }
.nk-wrap { width: 100%; max-width: 1560px; margin: 0 auto; padding: 18px 24px 44px; }
.nk-wrap-narrow { max-width: 1120px; }

/* 面包屑 */
.nk-crumbs {
  display: flex; align-items: center; gap: 6px; flex-wrap: wrap;
  padding: 2px 2px 16px; font-size: 12.5px; color: var(--faint);
}
.nk-crumbs a { display: inline-flex; align-items: center; gap: 5px; color: var(--faint); }
.nk-crumbs a:hover { color: var(--brand); }
.nk-crumbs b { color: var(--muted); font-weight: 600; }
.nk-crumbs .nk-sep { display: inline-flex; color: var(--line-strong); }
.nk-crumb-right { margin-left: auto; }
.nk-crumb-stat { font-size: 11.5px; color: var(--faint); font-variant-numeric: tabular-nums; }

.nk-welcome { margin: 0 0 14px; font-size: 13.5px; color: var(--muted); }

/* ---------- 6. 轮播 ---------- */
.nk-hero {
  position: relative; width: 100%; height: var(--hero-h, 200px);
  margin: 2px 0 18px; border-radius: 16px; overflow: hidden;
  background: var(--soft); box-shadow: var(--shadow-sm);
}
.nk-hero-track { position: absolute; inset: 0; }
.nk-slide {
  position: absolute; inset: 0;
  background-size: cover; background-position: center;
  opacity: 0; transform: scale(1.02);
  transition: opacity .7s ease, transform 6s linear;
  display: flex; align-items: flex-end;
}
.nk-slide.on { opacity: 1; transform: scale(1); }
.nk-slide-mask { position: absolute; inset: 0; background: linear-gradient(180deg, rgba(0,0,0,0) 30%, rgba(0,0,0,.55) 100%); }
.nk-slide-in { position: relative; display: flex; flex-direction: column; gap: 4px; padding: 26px; color: #fff; }
.nk-slide-in b { font-size: 22px; font-weight: 800; letter-spacing: -.4px; text-shadow: 0 2px 16px rgba(0,0,0,.35); }
.nk-slide-in i { font-style: normal; font-size: 13px; opacity: .88; }
.nk-hero-dots { position: absolute; right: 18px; bottom: 16px; display: flex; gap: 6px; }
.nk-hero-dots button {
  width: 7px; height: 7px; padding: 0; border: 0; border-radius: 7px;
  background: rgba(255,255,255,.45); transition: .2s;
}
.nk-hero-dots button.on { width: 20px; background: #fff; }

/* ---------- 7. 文件夹索引条（v3.3：固定在顶部，单行横滚） ---------- */
.nk-strip {
  position: sticky; top: 64px; z-index: 25;
  margin: 0 0 18px; padding: 12px 16px 10px;
  border: 1px solid var(--line); border-radius: 14px;
  background: var(--panel); box-shadow: var(--shadow-sm);
}
.nk-strip.is-stuck { border-radius: 0 0 14px 14px; box-shadow: 0 10px 24px -18px rgba(16, 24, 40, .45); }
.nk-strip-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 0 2px 8px; }
.nk-strip-head-slim { justify-content: flex-end; padding: 0 2px 6px; }
.nk-strip-title { font-size: 12px; font-weight: 700; color: var(--faint); letter-spacing: .5px; text-transform: uppercase; }
.nk-strip-sub {
  display: inline-block; margin-left: 8px; padding: 1px 7px;
  border-radius: 20px; background: var(--brand-soft); color: var(--brand);
  font-size: 10.5px; font-weight: 600; letter-spacing: 0; text-transform: none;
  vertical-align: 1px;
}
.nk-strip-actions { display: flex; gap: 6px; }
.nk-mini {
  display: inline-flex; align-items: center; gap: 4px;
  height: 26px; padding: 0 9px; border-radius: 7px;
  border: 1px solid var(--line); background: transparent;
  font-size: 11.5px; color: var(--faint); transition: .15s;
}
.nk-mini:hover { color: var(--text); border-color: var(--line-strong); background: var(--hover); }

.nk-folders { display: grid; grid-template-columns: repeat(var(--fcols, 8), minmax(0, 1fr)); gap: 6px; }
/* 顶部条内的文件夹改成单行横滚，才不会因为文件夹多把页面顶下去 */
.nk-strip .nk-folders {
  display: flex; flex-wrap: nowrap; gap: 4px;
  overflow-x: auto; overflow-y: hidden;
  padding-bottom: 3px;
  scrollbar-width: thin;
  -webkit-overflow-scrolling: touch;
  scroll-behavior: smooth;
}
.nk-strip .nk-folders::-webkit-scrollbar { height: 5px; }
.nk-strip .nk-folders::-webkit-scrollbar-thumb { background: var(--line-strong); border-radius: 4px; }
.nk-strip .nk-folders::-webkit-scrollbar-track { background: transparent; }
.nk-strip .nk-fcard { flex: 0 0 96px; }
.nk-strip .nk-fcard-ico { width: 60px; }
.nk-fcard {
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  padding: 8px 6px 9px; border-radius: 11px; min-width: 0;
  transition: background .16s ease, transform .16s ease;
}
.nk-fcard:hover { background: var(--hover); transform: translateY(-2px); }
.nk-fcard-ico { display: block; width: 66px; max-width: 100%; }
.nk-fcard-name {
  width: 100%; font-size: 12px; line-height: 1.4; text-align: center; color: var(--muted);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-fcard:hover .nk-fcard-name { color: var(--title); }
.nk-fcard-num { font-size: 10px; color: var(--faint); opacity: .8; font-variant-numeric: tabular-nums; }

/* ---------- 8. Pintree 文件夹图标（原版几何 + 悬浮动画） ---------- */
.folder__svg { display: block; width: 100%; height: auto; overflow: visible; }
.folder__back { fill: #0ba665; rx: 10px; ry: 10px; }
.paper-1, .paper-2 { fill: #e6e6e6; rx: 10px; ry: 10px; transition: all .3s ease-in-out; }
.paper-2 { fill: #efefef; }
.folder__front { fill: var(--brand); rx: 10px; ry: 10px; transform-origin: bottom; transition: all .3s ease-in-out; }
html.dark .paper-1 { fill: #d5d9e0; }
html.dark .paper-2 { fill: #e6e9ee; }

.nk-fcard:hover .paper-1,
.nk-folder-head:hover .paper-1 { y: 12px; }
.nk-fcard:hover .paper-2,
.nk-folder-head:hover .paper-2 { y: 22px; }
.nk-fcard:hover .folder__front,
.nk-folder-head:hover .folder__front { rx: 13px; ry: 13px; y: 10px; height: 80px; transform: scaleY(.6); }

/* ---------- 9. 文件夹（文章）区块 ---------- */
.nk-sections { display: flex; flex-direction: column; }
.nk-folder {
  margin-bottom: 14px; border: 1px solid var(--line); border-radius: 14px;
  background: var(--panel); box-shadow: var(--shadow-sm);
  transition: border-color .18s ease, box-shadow .18s ease;
}
.nk-folder:hover { border-color: var(--line-strong); }
.nk-folder.is-flash { box-shadow: 0 0 0 3px var(--brand-soft); border-color: var(--brand-line); }
.nk-folder-head {
  display: flex; align-items: center; gap: 14px; width: 100%;
  padding: 14px 18px; border: 0; background: none; text-align: left;
  border-radius: 14px;
}
.nk-folder-ico { display: block; width: 54px; flex: 0 0 54px; }
.nk-folder-info { display: flex; flex-direction: column; gap: 3px; flex: 1 1 auto; min-width: 0; }
.nk-folder-name {
  font-size: 15px; font-weight: 700; color: var(--title); letter-spacing: -.2px;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-folder-sub { font-size: 11.5px; color: var(--faint); font-weight: 400; }
.nk-folder-count {
  flex: 0 0 auto; padding: 2px 9px; border-radius: 20px;
  background: var(--soft); color: var(--muted);
  font-size: 11px; font-weight: 600; font-variant-numeric: tabular-nums;
}
.nk-folder-chev { display: flex; flex: 0 0 auto; color: var(--faint); transition: transform .2s ease; }
.nk-folder.is-open .nk-folder-chev { transform: rotate(90deg); }
.nk-folder:not(.is-open) .nk-folder-body { display: none; }
.nk-folder-body { padding: 0 18px 14px; animation: nkFade .2s ease; }
@keyframes nkFade { from { opacity: 0; transform: translateY(-3px); } to { opacity: 1; transform: none; } }

/* ---------- 9.2 三级分类条（v3.5 起；v3.7 搬到二级文件夹条下方，同为顶部固定区） ---------- */
.nk-substrip {
  display: none;
  align-items: center; gap: 6px;
  margin: 8px -2px 0; padding: 8px 2px 1px;
  border-top: 1px dashed var(--line);
  overflow-x: auto; overflow-y: hidden;
  scrollbar-width: none; -webkit-overflow-scrolling: touch;
}
.nk-substrip.is-on { display: flex; }
.nk-substrip::-webkit-scrollbar { display: none; }
.nk-sub {
  display: inline-flex; align-items: center; gap: 5px; flex: 0 0 auto;
  height: 27px; padding: 0 9px; border-radius: 8px;
  border: 1px solid var(--line); background: var(--panel);
  color: var(--muted); font-size: 12px; line-height: 1; white-space: nowrap;
  transition: color .15s, border-color .15s, background .15s;
}
.nk-sub svg { opacity: .5; }
.nk-sub i { font-style: normal; font-size: 10.5px; color: var(--faint); font-variant-numeric: tabular-nums; }
.nk-sub:hover { color: var(--title); border-color: var(--line-strong); background: var(--hover); }
.nk-sub.on { color: var(--brand); border-color: var(--brand-line); background: var(--brand-soft); font-weight: 600; }
.nk-sub.on svg { opacity: 1; }
.nk-sub.on i { color: var(--brand); opacity: .75; }

/* 三级分类区块 */
.nk-group + .nk-group { margin-top: 18px; }
.nk-group-name {
  display: flex; align-items: baseline; gap: 8px;
  margin: 0 0 9px; font-size: 12.5px; font-weight: 650; color: var(--muted);
  letter-spacing: .2px;
}
.nk-group-name i { font-style: normal; font-size: 10.5px; font-weight: 400; color: var(--faint); }

/* ---------- 9.1 互斥切换模式：同一时间只显示一个文件夹 ---------- */
.nk-mode-one .nk-folder { display: none; }
.nk-mode-one .nk-folder.is-active { display: block; }
/* 单选模式没有头卡，正文直接顶到区块上沿 */
.nk-mode-one .nk-folder-body { padding-top: 14px; }
.nk-mode-one .nk-folder-head { cursor: default; }
.nk-mode-one .nk-folder-head:hover .paper-1 { y: 0; }
.nk-mode-one .nk-folder-head:hover .paper-2 { y: 8px; }
/* 搜索时临时放开，让命中的文件夹全部可见 */
.nk-mode-one.nk-search-on .nk-folder { display: block; }
.nk-mode-one.nk-search-on .nk-folder:not(.is-active) .nk-folder-body { display: none; }
.nk-mode-one.nk-search-on .nk-folder.is-filtered { display: none; }

/* 顶部文件夹卡片：当前选中态 */
.nk-fcard.is-on { background: var(--brand-soft); }
.nk-fcard.is-on .nk-fcard-name { color: var(--brand); font-weight: 650; }
.nk-fcard.is-on .nk-fcard-num { color: var(--brand); opacity: 1; }

.nk-folder-foot {
  display: flex; align-items: center; justify-content: flex-end; gap: 12px;
  margin-top: 12px; padding-top: 10px; border-top: 1px dashed var(--line);
  font-size: 11.5px; color: var(--faint);
}
.nk-folder-foot a { display: inline-flex; align-items: center; gap: 4px; }
.nk-folder-foot a:hover { color: var(--brand); }
/* v3.9：仅管理员可见的后台编辑入口 */
.nk-folder-edit {
  padding: 2px 9px; border: 1px solid var(--line); border-radius: 20px;
  color: var(--faint); transition: color .14s ease, border-color .14s ease, background .14s ease;
}
.nk-folder-edit:hover { color: var(--brand); border-color: var(--brand-line); background: var(--brand-soft); }
.nk-folder-toggle { border: 0; background: none; color: var(--faint); font-size: 11.5px; padding: 0; }
.nk-folder-toggle:hover { color: var(--text); }

/* ---------- 10. 链接网格 ---------- */
.nk-links { display: grid; grid-template-columns: repeat(var(--cols, 6), minmax(0, 1fr)); gap: 12px; }
.nk-link {
  display: flex; align-items: center; gap: 11px;
  min-width: 0; padding: 11px 12px;
  border: 1px solid var(--line); border-radius: var(--nk-radius, 12px);
  background: var(--panel);
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease, background .16s ease;
}
.nk-link:hover {
  transform: translateY(-2px);
  border-color: var(--brand-line);
  box-shadow: var(--shadow-md);
}
.nk-links-plain .nk-link { border-color: transparent; background: transparent; padding: 9px 8px; }
.nk-links-plain .nk-link:hover { background: var(--hover); box-shadow: none; transform: none; border-color: transparent; }

.nk-ico {
  position: relative; display: flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; flex: 0 0 36px;
  border-radius: 9px; overflow: hidden;
  color: #fff; font-size: 15px; font-weight: 700;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.12);
}
.nk-ico::after { content: attr(data-letter); }
.nk-ico.has-img { background: #fff !important; box-shadow: inset 0 0 0 1px var(--line); }
.nk-ico.has-img::after { display: none; }
.nk-ico img { width: 100%; height: 100%; object-fit: contain; padding: 5px; display: block; }

.nk-link-body { display: flex; flex-direction: column; gap: 1px; min-width: 0; flex: 1 1 auto; }
.nk-link-title {
  font-size: 13.5px; font-weight: 600; color: var(--title); line-height: 1.35;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-link-desc {
  font-size: 11.5px; color: var(--faint); line-height: 1.45;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.nk-link:hover .nk-link-title { color: var(--brand); }
.is-hidden { display: none !important; }

/* ---------- 11. 广告位 ---------- */
.nk-ad { position: relative; margin: 18px 0; text-align: center; line-height: 0; }
.nk-ad img, .nk-ad iframe { max-width: 100%; height: auto; }
.nk-ad-flag {
  position: absolute; top: 0; right: 0; z-index: 1;
  padding: 1px 6px; border-radius: 0 8px 0 6px;
  background: var(--soft); color: var(--faint);
  font-size: 9.5px; line-height: 1.6; letter-spacing: 1px;
}
.nk-ad-mb { display: none; }
.nk-ad-cell { grid-column: span 2; min-width: 0; padding: 10px; border: 1px dashed var(--line); border-radius: 10px; }
.nk-ad-cell .nk-ad { margin: 0; }
.nk-ad-cell .nk-ad-flag { display: none; }

/* ---------- 12. 空状态 ---------- */
.nk-empty {
  padding: 20px; border: 1px dashed var(--line); border-radius: 12px;
  background: var(--panel-2); color: var(--faint); font-size: 12.5px; line-height: 1.8;
}
.nk-empty code { background: var(--soft); padding: 1px 5px; border-radius: 4px; font-size: 11.5px; }
.nk-empty-lg { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; padding: 40px 32px; }
.nk-empty-lg b { font-size: 15px; color: var(--text); }
.nk-empty-lg .nk-btn { margin-top: 8px; }

/* ---------- 13. 页脚 ---------- */
.nk-footer { flex: 0 0 auto; border-top: 1px solid var(--line); background: var(--panel); }
.nk-footer-inner { max-width: 1560px; margin: 0 auto; padding: 26px 24px 28px; text-align: center; }
.nk-footer-about { color: var(--muted); font-size: 12.5px; line-height: 1.8; }
.nk-footer-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 16px; margin-top: 8px; font-size: 12px; }
.nk-footer-links a { color: var(--muted); }
.nk-footer-links a:hover { color: var(--brand); }
.nk-footer-copy { margin-top: 10px; font-size: 11.5px; color: var(--faint); }
.nk-footer-copy a { color: var(--faint); }
.nk-footer-copy a:hover { color: var(--brand); }

.nk-backtop {
  position: fixed; right: 22px; bottom: 22px; z-index: 35;
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid var(--line); background: var(--panel); color: var(--muted);
  box-shadow: var(--shadow-md);
  opacity: 0; visibility: hidden; transform: translateY(8px);
  transition: .2s ease;
}
.nk-backtop.on { opacity: 1; visibility: visible; transform: none; }
.nk-backtop:hover { color: var(--brand); border-color: var(--brand-line); }

/* ---------- 14. 文章详情 ---------- */
.nk-article { border: 1px solid var(--line); border-radius: 16px; background: var(--panel); padding: 22px 26px 26px; box-shadow: var(--shadow-sm); }
.nk-article-head { display: flex; align-items: center; gap: 16px; padding-bottom: 16px; border-bottom: 1px solid var(--line); }
.nk-article-ico { display: block; width: 60px; flex: 0 0 60px; }
.nk-article-info { min-width: 0; }
.nk-article-title { font-size: 23px; line-height: 1.35; letter-spacing: -.4px; color: var(--title); }
.nk-article-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 2px; margin-top: 5px; font-size: 12px; color: var(--faint); }
.nk-article-meta a { color: var(--muted); }
.nk-article-meta a:hover { color: var(--brand); }
.nk-article-links { padding: 18px 0 4px; }
.nk-article-content { padding: 18px 0 4px; font-size: 14.5px; line-height: 1.9; color: var(--text); }
.nk-article-content p { margin: 0 0 12px; }
.nk-article-content a { color: var(--brand); text-decoration: underline; text-underline-offset: 3px; }
.nk-article-content img { border-radius: 10px; height: auto; }
.nk-article-content h2, .nk-article-content h3 { margin: 22px 0 10px; font-size: 18px; }
.nk-article-content ul, .nk-article-content ol { padding-left: 22px; margin: 0 0 12px; }
.nk-article-content blockquote {
  margin: 14px 0; padding: 10px 16px; border-left: 3px solid var(--brand);
  background: var(--panel-2); border-radius: 0 8px 8px 0; color: var(--muted);
}
.nk-article-content pre, .nk-article-content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 12.5px; background: var(--soft); border-radius: 6px;
}
.nk-article-content pre { padding: 12px 14px; overflow: auto; }
.nk-article-content code { padding: 1px 5px; }
.nk-copyright { margin: 20px 0 0; padding: 10px 14px; border-radius: 9px; background: var(--panel-2); color: var(--faint); font-size: 12px; }

.nk-pager { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin: 16px 0; }
.nk-pager-item {
  display: flex; flex-direction: column; gap: 2px; padding: 12px 16px;
  border: 1px solid var(--line); border-radius: 12px; background: var(--panel);
  transition: .16s;
}
.nk-pager-item:hover { border-color: var(--brand-line); box-shadow: var(--shadow-sm); }
.nk-pager-item em { font-style: normal; font-size: 11px; color: var(--faint); }
.nk-pager-item b { font-size: 13px; font-weight: 600; color: var(--title); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.nk-pager-next { text-align: right; }
.nk-pager-next:only-child { grid-column: 2; }

.nk-sec-title { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--title); margin: 0 0 12px; }
.nk-count { padding: 1px 8px; border-radius: 20px; background: var(--soft); color: var(--muted); font-size: 11px; font-weight: 600; }

.nk-related { margin: 22px 0 8px; }
.nk-related-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; }
.nk-related-item {
  display: flex; align-items: center; gap: 10px; padding: 12px;
  border: 1px solid var(--line); border-radius: 12px; background: var(--panel); transition: .16s;
}
.nk-related-item:hover { border-color: var(--brand-line); box-shadow: var(--shadow-sm); }
.nk-related-ico { display: block; width: 40px; flex: 0 0 40px; }
.nk-related-body { display: flex; flex-direction: column; min-width: 0; }
.nk-related-body b { font-size: 13px; font-weight: 600; color: var(--title); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.nk-related-body i { font-style: normal; font-size: 11px; color: var(--faint); }

/* ---------- 15. 评论 ---------- */
.nk-comments-wrap { margin-top: 20px; }
.nk-comments { padding: 20px 22px; border: 1px solid var(--line); border-radius: 14px; background: var(--panel); }
.nk-comment-list { list-style: none; margin: 0 0 18px; padding: 0; display: flex; flex-direction: column; gap: 14px; }
.nk-comment { display: flex; gap: 10px; }
.nk-avatar {
  display: flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; flex: 0 0 34px; border-radius: 50%;
  background: var(--soft); color: transparent; overflow: hidden;
  font-size: 1px;
}
.nk-comment-main { flex: 1 1 auto; min-width: 0; }
.nk-comment-meta { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--faint); }
.nk-comment-meta b { color: var(--text); font-weight: 600; }
.nk-comment-text { margin-top: 3px; font-size: 13px; line-height: 1.75; color: var(--muted); }
.nk-comment-empty { color: var(--faint); font-size: 12.5px; margin-bottom: 14px; }
.nk-reply { display: flex; flex-direction: column; gap: 10px; }
.nk-reply-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.nk-reply input, .nk-reply textarea {
  width: 100%; padding: 9px 12px; border: 1px solid var(--line); border-radius: 9px;
  background: var(--panel); color: var(--text); font: inherit; font-size: 13px; outline: none;
}
.nk-reply input:focus, .nk-reply textarea:focus { border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft); }
.nk-reply textarea { resize: vertical; line-height: 1.7; }
.nk-reply-foot { display: flex; justify-content: flex-end; }

/* ---------- 16. 404 ---------- */
.nk-404 { padding: 70px 24px 90px; text-align: center; }
.nk-404-num { font-size: 84px; font-weight: 800; line-height: 1; letter-spacing: -4px; color: var(--line-strong); }
.nk-404 h1 { margin: 10px 0 6px; font-size: 20px; color: var(--title); }
.nk-404 p { color: var(--muted); font-size: 13px; }
.nk-404-actions { display: flex; justify-content: center; gap: 10px; margin-top: 22px; }

/* ---------- 17. 搜索过滤态 ---------- */
.nk-filter-empty {
  display: none; padding: 24px; border: 1px dashed var(--line); border-radius: 12px;
  color: var(--faint); font-size: 13px; text-align: center; background: var(--panel-2);
}
.nk-filter-empty.on { display: block; }
.nk-folder.is-filtered { display: none; }

/* ---------- 18. 响应式 ---------- */
@media (max-width: 1440px) {
  .nk-links { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .nk-folders { grid-template-columns: repeat(7, minmax(0, 1fr)); }
}
@media (max-width: 1240px) {
  .nk-links { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .nk-folders { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .nk-related-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 1080px) {
  .nk-folders { grid-template-columns: repeat(5, minmax(0, 1fr)); }
  .nk-fcard-ico { width: 58px; }
}
@media (max-width: 960px) {
  .nk-sidebar { transform: translateX(-100%); transition: transform .22s ease; box-shadow: var(--shadow-lg); }
  .nk-sidebar .nk-close { display: flex; }
  .nk-open .nk-sidebar { transform: none; }
  .nk-content { margin-left: 0; }
  .nk-menu { display: flex; }
  .nk-open .nk-backdrop {
    display: block; position: fixed; inset: 0; z-index: 35;
    background: rgba(15, 23, 42, .4);
  }
  .nk-topbar { padding: 0 14px; gap: 10px; }
  .nk-wrap { padding: 12px 16px 32px; }
  .nk-links { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .nk-folders { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .nk-related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .nk-top-link { display: none; }
}
@media (max-width: 720px) {
  .nk-wrap { padding: 8px 10px 28px; }
  .nk-links { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; }
  .nk-folders { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .nk-link { padding: 8px 6px; gap: 7px; border-radius: 9px; }
  .nk-ico { width: 28px; height: 28px; flex: 0 0 28px; font-size: 12px; border-radius: 7px; }
  .nk-link-title { font-size: 11.5px; }
  .nk-link-desc { display: none; }
  .nk-folder { border-radius: 12px; margin-bottom: 10px; }
  .nk-folder-head { padding: 12px 14px; gap: 10px; }
  .nk-folder-ico { width: 42px; flex: 0 0 42px; }
  .nk-folder-name { font-size: 14px; }
  .nk-folder-body { padding: 0 14px 12px; }
  .nk-folder-count { display: none; }
  .nk-strip { padding: 12px 12px 8px; }
  .nk-strip .nk-fcard { flex: 0 0 82px; }
  .nk-strip .nk-fcard-ico { width: 52px; }
  .nk-strip-sub { display: none; }
  .nk-folder-foot { font-size: 11px; }
  .nk-article { padding: 16px 16px 20px; border-radius: 13px; }
  .nk-article-title { font-size: 19px; }
  .nk-article-ico { width: 46px; flex: 0 0 46px; }
  .nk-pager { grid-template-columns: 1fr; }
  .nk-pager-next { text-align: left; }
  .nk-reply-row { grid-template-columns: 1fr; }
  .nk-related-grid { grid-template-columns: 1fr; }
  .nk-slide-in { padding: 18px; }
  .nk-slide-in b { font-size: 18px; }
  .nk-hero { height: calc(var(--hero-h, 200px) * .72); border-radius: 13px; }
  .nk-ad-pc { display: none; }
  .nk-ad-mb { display: block; }
  .nk-crumb-stat { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

/* 宽屏（视口 ≥ 1800px，即 主区 1560 + 侧栏 240 放得下且开始出现空隙时）：
   侧栏不再钉在屏幕左缘，而是与主区作为整体居中 */
@media (min-width: 1800px) {
  .nk-sidebar { left: calc(50% - 900px); }
  .nk-content { margin-left: calc(50% - 660px); margin-right: calc(50% - 900px); }
}