/* ============================================================
   列宁文库 · 复古档案风
   旧报纸 / 档案馆排版 · 泛黄纸 · 红字刊头
   ============================================================ */

:root, [data-theme="sepia"] {
  --paper: #f2e8d0;
  --paper-deep: #e7d8b3;
  --paper-card: #efe4c6;
  --ink: #2e2618;
  --muted: #6f5e40;
  --rule: #9a1f1f;
  --accent: #9a1f1f;
  --link: #7a2b12;
  --border: #c9b98f;
  --footnote-bg: #ece0bf;
  --shadow: rgba(60, 40, 10, 0.28);
  --mark: #d9b84a;
}
[data-theme="dark"] {
  --paper: #201b13;
  --paper-deep: #2b2417;
  --paper-card: #282114;
  --ink: #e6d7b3;
  --muted: #9a8a66;
  --rule: #c03a3a;
  --accent: #d05050;
  --link: #d8a06a;
  --border: #4c4230;
  --footnote-bg: #241d12;
  --shadow: rgba(0, 0, 0, 0.55);
  --mark: #8a6d2a;
}

* { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  padding: 0 16px 48px;
  font-family: "Songti SC", "SimSun", "STSong", "Noto Serif CJK SC", "AR PL UMing CN", serif;
  color: var(--ink);
  background-color: var(--paper);
  background-image: radial-gradient(ellipse at 50% 0%, var(--paper) 0%, var(--paper-deep) 130%);
  background-attachment: fixed;
  line-height: 1.9;
  -webkit-font-smoothing: antialiased;
  transition: background-color .3s, color .3s;
}

/* 纸张噪点 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='220' height='220'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.045'/%3E%3C/svg%3E");
  opacity: 1;
}

/* ============ 刊头 ============ */
.masthead {
  position: relative;
  z-index: 1;
  max-width: 980px;
  margin: 18px auto 0;
  padding: 18px 26px 14px;
  background: var(--paper-card);
  border-top: 4px double var(--rule);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 3px 14px var(--shadow);
}
.masthead-inner { display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 18px; }
/* 标题栏苏联国旗 */
.masthead-flag {
  width: 50px;
  height: 28px;
  flex: none;
  align-self: center;
  border: 1px solid var(--border);
  box-shadow: 0 1px 3px var(--shadow);
}
/* 标题后的苏俄（РСФСР）国旗 */
.brand-flag {
  flex: none;
  align-self: center;
  border: 1px solid var(--border);
  box-shadow: 0 1px 3px var(--shadow);
}
.brand {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", "SimSun", serif;
  font-size: 2.1rem;
  font-weight: 700;
  letter-spacing: 6px;
  color: var(--rule);
  text-decoration: none;
  text-shadow: 1px 1px 0 rgba(0,0,0,.06);
}
.brand:hover { color: var(--accent); }
.masthead-sub {
  font-family: "Times New Roman", Georgia, serif;
  font-size: .72rem;
  letter-spacing: 2px;
  color: var(--muted);
  text-transform: uppercase;
  white-space: nowrap;
}
.masthead-years {
  margin-left: auto;
  font-family: "Times New Roman", serif;
  font-size: .8rem;
  color: var(--muted);
  letter-spacing: 1px;
}
.topnav {
  display: flex;
  flex-wrap: wrap;
  gap: 2px 22px;
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px solid var(--border);
}
.topnav a {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", "SimSun", serif;
  font-size: .98rem;
  letter-spacing: 2px;
  color: var(--ink);
  text-decoration: none;
}
.topnav a:hover { color: var(--rule); text-decoration: underline; text-decoration-style: wavy; }
.topnav a.active { color: var(--rule); }

.reader-controls {
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px dashed var(--border);
  display: flex;
  gap: 6px;
  align-items: center;
}
.reader-controls button {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .9rem;
  padding: 2px 11px;
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--border);
  border-radius: 3px;
  cursor: pointer;
}
.reader-controls button:hover { border-color: var(--rule); color: var(--rule); }
.reader-controls .wc {
  margin-left: auto;
  font-size: .72rem;
  color: var(--muted);
}

/* ============ 主体容器 ============ */
.page {
  position: relative;
  z-index: 1;
  max-width: 980px;
  margin: 20px auto 0;
  padding: 30px 38px 36px;
  background: var(--paper-card);
  border: 1px solid var(--border);
  outline: 3px double var(--border);
  outline-offset: 5px;
  box-shadow: 0 5px 22px var(--shadow);
}
/* 四角装饰 */
.page::before, .page::after {
  content: "";
  position: absolute;
  width: 22px; height: 22px;
  border-color: var(--rule);
  border-style: solid;
  border-width: 0;
}
.page::before {
  top: 8px; left: 8px;
  border-top-width: 2px; border-left-width: 2px;
}
.page::after {
  bottom: 8px; right: 8px;
  border-bottom-width: 2px; border-right-width: 2px;
}

.breadcrumb {
  font-size: .82rem;
  color: var(--muted);
  margin: 0 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
.breadcrumb a { color: var(--link); text-decoration: none; }
.breadcrumb a:hover { color: var(--rule); text-decoration: underline; }
.breadcrumb .sep { margin: 0 6px; color: var(--muted); }

/* ============ 文章页 ============ */
.article { max-width: 880px; }
.article-head { text-align: center; margin: 8px 0 24px; }
.article-head h1 {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", "SimSun", serif;
  font-size: 1.7rem;
  line-height: 1.5;
  margin: 0 0 10px;
  color: var(--ink);
  letter-spacing: 1px;
}
.article-head .byline {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  color: var(--muted);
  font-size: .9rem;
  margin: 0;
}
.article-head .byline .date { margin-left: 10px; }
/* 首页肖像照 */
.portrait {
  margin: 26px auto 4px;
  text-align: center;
}
.portrait img {
  max-width: 430px;
  width: 100%;
  height: auto;
  display: block;
  margin-inline: auto;
  border: 1px solid var(--border);
  outline: 2px double var(--border);
  outline-offset: 5px;
  box-shadow: 0 4px 18px var(--shadow);
  filter: sepia(.24) contrast(1.03);
}
.portrait figcaption {
  margin-top: 16px;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .82rem;
  color: var(--muted);
  letter-spacing: 1px;
  line-height: 1.7;
}
/* 纪念列宁 · 苏俄元素横幅 */
.memorial {
  margin: 30px auto 4px;
  max-width: 460px;
  padding: 20px 24px 18px;
  text-align: center;
  border: 2px solid var(--rule);
  outline: 1px solid var(--rule);
  outline-offset: 3px;
  background: var(--paper);
}
.memorial__star {
  display: block;
  width: 30px;
  height: 30px;
  margin: 0 auto 8px;
  color: var(--rule);
}
.memorial__year {
  margin: 0;
  font-family: "Times New Roman", Georgia, serif;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: .35em;
  text-indent: .35em;
  color: var(--rule);
}
.memorial__name {
  margin: 6px 0 0;
  font-family: "Times New Roman", Georgia, "KaiTi", "STKaiti", "楷体", serif;
  font-size: 1rem;
  letter-spacing: .18em;
  color: var(--ink);
}
.memorial__note {
  margin: 10px 0 0;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .84rem;
  line-height: 1.8;
  color: var(--muted);
  text-align: justify;
}
.rule-hr {
  border: none;
  border-top: 1px solid var(--rule);
  margin: 4px auto 22px;
  width: 58%;
}

.article-body {
  font-size: 1.02rem;
  text-align: justify;
}
.article-body p, .article-body div {
  margin: 0.65em 0;
}
.article-body br { content: ""; display: block; margin: 0.55em 0; }
.article-body a { color: var(--link); }
.article-body a:hover { color: var(--rule); text-decoration-style: wavy; }
.article-body h3, .article-body h4 {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  text-align: center;
  margin: 1.4em 0 0.8em;
  color: var(--ink);
}
.article-body table { margin: 1em auto; border-collapse: collapse; }
.article-body td { padding: 2px 12px; }
.article-body .editor-note {
  display: block;
  font-size: .9em;
  color: var(--muted);
  border-left: 3px solid var(--border);
  padding-left: 14px;
  margin: 1em 0;
}
.article-body .quote-block {
  display: block;
  border-left: 3px solid var(--border);
  padding-left: 16px;
  margin: 1em 1.5em;
  color: var(--muted);
}
.article-body .page-marker {
  display: block;
  text-align: center;
  font-size: .78em;
  color: var(--muted);
  margin: 1.2em 0;
  letter-spacing: 2px;
}
.article-body .img-missing, .article-body .dead-link {
  font-style: italic;
  color: var(--muted);
}
.article-body .ext-missing {
  color: var(--muted);
  border-bottom: 1px dotted var(--border);
  cursor: help;
}
.article-body .footnote-as-sidebar {
  display: block;
  font-size: .86em;
  color: var(--muted);
  margin: 0.6em 0;
}
sup.fn-ref, .article-body sup { font-size: .72em; }

/* 脚注区 */
.footnotes {
  margin-top: 26px;
  padding-top: 14px;
  border-top: 2px solid var(--rule);
  background: var(--footnote-bg);
  padding: 12px 18px;
  font-size: .84rem;
  color: var(--muted);
}
.footnotes .fn-head {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  color: var(--rule);
  letter-spacing: 4px;
  margin: 0 0 8px;
}
.footnotes a { color: var(--link); }
.footnotes a:hover { color: var(--rule); }

/* ============ 主页：时期章节 ============ */
.period-section { margin: 26px 0; }
.period-title {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 12px;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: 1.25rem;
  color: var(--rule);
  letter-spacing: 3px;
}
.period-title::after {
  content: "";
  flex: 1;
  border-top: 1px solid var(--border);
}
.entry-list { list-style: none; margin: 0; padding: 0; }
.entry-list li {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 4px 0;
  border-bottom: 1px dotted var(--border);
}
.entry-list li::before { content: "◆"; color: var(--rule); font-size: .55rem; align-self: center; }
.entry-list .entry-title { color: var(--link); text-decoration: none; }
.entry-list .entry-title:hover { color: var(--rule); text-decoration: underline; text-decoration-style: wavy; }
.entry-list .entry-date { color: var(--muted); font-size: .8rem; margin-left: auto; white-space: nowrap; }
.entry-list li.star .entry-title::after { content: " ★"; color: var(--rule); font-size: .75em; }

/* ============ 分类页 ============ */
.catalog-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }
.catalog-card {
  border: 1px solid var(--border);
  background: var(--paper);
  padding: 14px 18px 16px;
  box-shadow: 0 2px 8px var(--shadow);
}
.catalog-card h3 {
  margin: 0 0 10px;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  color: var(--rule);
  letter-spacing: 2px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 6px;
}
.catalog-card ul { list-style: none; margin: 0; padding: 0; font-size: .92rem; }
.catalog-card li { padding: 2px 0; }
.catalog-card a { color: var(--link); text-decoration: none; }
.catalog-card a:hover { color: var(--rule); text-decoration: underline; }
.catalog-card .count { float: right; color: var(--muted); font-size: .75rem; }

/* ============ 搜索 ============ */
.search-box {
  max-width: 680px;
  margin: 10px auto 24px;
  display: flex;
  gap: 10px;
}
.search-box input {
  flex: 1;
  font-family: inherit;
  font-size: 1.02rem;
  padding: 10px 14px;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 3px;
  outline: none;
}
.search-box input:focus { border-color: var(--rule); }
.search-loading { text-align: center; color: var(--muted); font-family: "KaiTi", serif; letter-spacing: 2px; }
.search-meta { text-align: center; color: var(--muted); font-size: .82rem; margin-bottom: 16px; }
.search-results { max-width: 860px; margin: 0 auto; }
.search-result {
  padding: 12px 16px;
  margin: 0 0 14px;
  border: 1px solid var(--border);
  background: var(--paper);
}
.search-result .sr-title a { font-family: "KaiTi", serif; font-size: 1.05rem; color: var(--rule); text-decoration: none; }
.search-result .sr-title a:hover { text-decoration: underline; }
.search-result .sr-meta { font-size: .76rem; color: var(--muted); margin-top: 2px; }
.search-result .sr-snippet { font-size: .9rem; color: var(--ink); margin-top: 6px; }
.search-result mark { background: var(--mark); color: inherit; padding: 0 2px; border-radius: 2px; }
.no-result { text-align: center; color: var(--muted); padding: 40px 0; font-family: "KaiTi", serif; letter-spacing: 3px; }

/* ============ 统计页 ============ */
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 16px; margin: 22px 0; }
.stat-tile {
  text-align: center;
  border: 1px solid var(--border);
  background: var(--paper);
  padding: 18px 10px;
}
.stat-tile .stat-num { font-family: "Times New Roman", serif; font-size: 2rem; color: var(--rule); }
.stat-tile .stat-label { font-family: "KaiTi", serif; font-size: .8rem; color: var(--muted); letter-spacing: 2px; }
.bar-chart { margin: 10px 0 26px; }
.bar-row { display: flex; align-items: center; gap: 12px; margin: 6px 0; }
.bar-label { width: 120px; text-align: right; font-family: "KaiTi", serif; font-size: .86rem; color: var(--muted); }
.bar-track { flex: 1; background: var(--border); height: 14px; border: 1px solid var(--border); position: relative; }
.bar-fill { height: 100%; background: var(--rule); }
.bar-num { width: 56px; font-family: "Times New Roman", serif; color: var(--muted); font-size: .8rem; }
.classic-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; margin-top: 14px; }
.classic-card {
  border: 1px solid var(--border);
  border-top: 3px solid var(--rule);
  background: var(--paper);
  padding: 14px 16px;
}
.classic-card h4 { margin: 0 0 4px; font-family: "KaiTi", serif; color: var(--ink); }
.classic-card h4 a { color: var(--link); text-decoration: none; }
.classic-card h4 a:hover { color: var(--rule); }
.classic-card .cc-meta { font-size: .76rem; color: var(--muted); }
.missing-note {
  margin-top: 26px;
  padding: 14px 18px;
  border: 1px dashed var(--border);
  background: var(--footnote-bg);
  font-size: .86rem;
  color: var(--muted);
}
.missing-note h3 { font-family: "KaiTi", serif; color: var(--rule); letter-spacing: 2px; margin: 0 0 8px; }

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  z-index: 1;
  max-width: 980px;
  margin: 30px auto 0;
  padding: 12px 20px;
  text-align: center;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  font-size: .74rem;
  color: var(--muted);
  font-family: "KaiTi", "STKaiti", "Kai", serif;
  letter-spacing: 1px;
}
.site-footer a { color: var(--link); text-decoration: none; }
.site-footer a:hover { color: var(--rule); }

/* ============ 1917–1924 苏俄年代装饰 ============ */
/* 左右两侧固定旧照片条（宽屏显示，窄屏隐藏） */
.era-frame__panel {
  position: fixed;
  top: 50%;
  transform: translateY(-50%);
  width: 168px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  z-index: 0;
  pointer-events: none;
}
.era-frame__panel--left { left: 16px; }
.era-frame__panel--right { right: 16px; }
.era-photo {
  padding: 6px 6px 4px;
  background: var(--paper-card);
  border: 1px solid var(--border);
  outline: 1px solid var(--border);
  outline-offset: 3px;
  box-shadow: 0 3px 12px var(--shadow);
}
/* 轮换画廊：多张不同年代图交叉淡入 */
.era-rotator { display: grid; }
.era-slide {
  grid-area: 1 / 1;
  margin: 0;
  opacity: 0;
  transition: opacity .8s ease;
}
.era-slide.is-active { opacity: 1; }
.era-slide img {
  display: block;
  width: 100%;
  height: 200px;
  object-fit: cover;
  filter: sepia(.55) saturate(.65) contrast(.95);
}
.era-slide figcaption {
  margin: 6px 0 2px;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .64rem;
  text-align: center;
  color: var(--muted);
  letter-spacing: 1px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 锤镰水印（页面中央淡印） */
.hs-watermark {
  position: fixed;
  left: 50%;
  top: 50%;
  width: 460px;
  height: 460px;
  transform: translate(-50%, -50%);
  z-index: 0;
  opacity: .05;
  pointer-events: none;
  object-fit: contain;
}

/* 浮动标语徽标 */
.float-slogan {
  position: fixed;
  right: 14px;
  bottom: 16px;
  z-index: 6;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 7px 15px 7px 8px;
  background: var(--rule);
  color: #f6e9c8;
  border: 1px solid var(--border);
  outline: 1px solid var(--border);
  outline-offset: 2px;
  box-shadow: 0 3px 14px var(--shadow);
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .84rem;
  letter-spacing: 2px;
  white-space: nowrap;
}
.float-slogan__hs { width: 24px; height: 24px; flex: none; }
.float-slogan[hidden] { display: none; }
.float-quote[hidden] { display: none; }
.era-frame[hidden], .hs-watermark[hidden] { display: none; }

/* 列宁名言卡（左下角固定，点击换句） */
.float-quote {
  position: fixed;
  left: 14px;
  bottom: 16px;
  z-index: 6;
  max-width: 300px;
  padding: 10px 14px;
  background: var(--paper-card);
  border: 1px solid var(--border);
  outline: 1px solid var(--border);
  outline-offset: 2px;
  box-shadow: 0 3px 14px var(--shadow);
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .8rem;
  line-height: 1.75;
  color: var(--ink);
  text-align: justify;
  cursor: pointer;
}
.float-quote__text { margin: 0; }
.float-quote__text::before { content: "「"; color: var(--rule); }
.float-quote__text::after { content: "」"; color: var(--rule); }
.float-quote__src {
  display: block;
  margin-top: 5px;
  text-align: right;
  color: var(--rule);
  font-size: .68rem;
  letter-spacing: 1px;
}

/* 开关按钮的隐藏态 */
#slogan-toggle.off, #images-toggle.off { opacity: .45; text-decoration: line-through; }

/* ============ 响应式 ============ */
@media (max-width: 1390px) {
  .era-frame__panel { display: none; }
}
@media (max-width: 700px) {
  .float-slogan { right: 8px; bottom: 10px; font-size: .72rem; padding: 5px 10px 5px 6px; }
  .float-slogan__hs { width: 18px; height: 18px; }
  .float-quote { display: none; }
  .hs-watermark { display: none; }
}
@media (max-width: 700px) {
  body { padding: 0 8px 30px; }
  .page { padding: 20px 16px; }
  .article-body { font-size: .98rem; }
  .masthead { padding: 14px 16px; }
  .entry-list .entry-date { white-space: normal; margin-left: 0; }
}

/* 返回主站链接 */
.goto-gpa {
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: .78rem;
  letter-spacing: 1px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px dashed var(--border);
  white-space: nowrap;
}
.goto-gpa:hover { color: var(--rule); border-bottom-style: solid; }
.site-footer .goto-gpa { font-size: inherit; }
@media (max-width: 700px) {
  .masthead-inner .goto-gpa { display: none; }
}

/* ============================================================
   长页目录抽屉（由 app.js 在长文页注入）
   ============================================================ */
.toc-drawer {
  position: fixed;
  z-index: 60;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: min(640px, calc(100vw - 32px));
  max-height: min(78vh, 760px);
  display: flex;
  flex-direction: column;
  background: var(--paper-card);
  border: 1px solid var(--border);
  outline: 2px double var(--border);
  outline-offset: 4px;
  box-shadow: 0 10px 40px var(--shadow);
}
.toc-drawer[hidden] { display: none; }
.toc-drawer__head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.toc-drawer__title {
  margin: 0;
  font-family: "KaiTi", "STKaiti", "Kai", "楷体", serif;
  font-size: 1.05rem;
  letter-spacing: 4px;
  color: var(--rule);
}
.toc-drawer__close {
  margin-left: auto;
  min-width: 44px;
  min-height: 32px;
  font-family: inherit;
  font-size: .9rem;
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--border);
  border-radius: 3px;
  cursor: pointer;
}
.toc-drawer__close:hover { border-color: var(--rule); color: var(--rule); }
.toc-drawer__list {
  flex: 1;
  list-style: none;
  margin: 0;
  padding: 6px 6px 12px;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}
.toc-drawer__list a {
  display: block;
  padding: 9px 12px;
  font-size: .95rem;
  line-height: 1.6;
  color: var(--link);
  text-decoration: none;
  border-bottom: 1px dotted var(--border);
}
.toc-drawer__list a:hover { color: var(--rule); }
.toc-drawer__list li.is-current > a { color: var(--rule); background: var(--footnote-bg); }

.toc-backdrop {
  position: fixed;
  inset: 0;
  z-index: 55;
  background: rgba(30, 20, 5, .45);
}
.toc-backdrop[hidden] { display: none; }

/* 抽屉打开时锁住背景滚动 */
body.toc-open { overflow: hidden; }

/* 锚点跳转时给固定工具条留出余量 */
.article-body h2[id], .article-body h3[id], .article-body h4[id] { scroll-margin-top: 14px; }

/* 返回顶部（仅手机出现，见下方媒体查询；JS 滚动后加 .is-on） */
#back-top {
  position: fixed;
  right: 14px;
  bottom: calc(66px + env(safe-area-inset-bottom));
  z-index: 40;
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  font-size: 1.1rem;
  background: var(--paper-card);
  color: var(--ink);
  border: 1px solid var(--border);
  border-radius: 3px;
  box-shadow: 0 3px 14px var(--shadow);
  cursor: pointer;
}
#back-top.is-on { display: flex; }
@media (min-width: 701px) { #back-top { display: none !important; } }

/* ============================================================
   移动端适配层（2026-09-13 追加）
   只覆盖，不改写上方任何原规则；字号一律 rem，跟随 A+/A− 根字号
   ============================================================ */

/* ---------- ≤1024px：解除固定栏宽，版面跟随屏幕 ---------- */
@media (max-width: 1024px) {
  .masthead, .page, .site-footer { max-width: none; }
  .article, .search-results, .search-box { max-width: none; }
}

/* ---------- ≤700px：手机 ---------- */
@media (max-width: 700px) {
  /* 页面留出吸底工具条的高度 */
  body { padding: 0 12px calc(58px + env(safe-area-inset-bottom)); }

  /* 版面收边（原 padding 8px 会让四角装饰描边贴到屏幕外） */
  .page { padding: 20px 16px 24px; outline-width: 2px; outline-offset: 3px; }
  /* 抬高刊头层级：吸底工具条是它的子元素，不抬高会被 .page 的同级 z-index:1 盖住 */
  .masthead { padding: 14px 16px 12px; z-index: 50; }

  /* 装饰全部收起：标语徽标 / 锤镰水印 / 名言卡 / 侧栏画廊 */
  .era-frame, .era-frame__panel, .hs-watermark,
  .float-slogan, .float-quote { display: none !important; }
  #slogan-toggle, #images-toggle { display: none; }  /* 装饰已隐藏，开关无意义 */
  body::before { display: none; }                    /* 纸张噪点：手机省渲染 */

  /* 正文可读性 */
  .article-body { font-size: 1.08rem; line-height: 1.9; overflow-wrap: break-word; }
  .article-body p, .article-body div { margin: 0.8em 0; }
  .article-body img { max-width: 100%; height: auto; }
  .article-head h1 { font-size: 1.5rem; letter-spacing: 0; }
  .breadcrumb { overflow-wrap: break-word; }

  /* 表格横向滚动（原站布局表/数据表，列宁站 3192 个页面含表） */
  .article-body table { display: block; max-width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .article-body td, .article-body th { padding: 2px 8px; }

  /* 导航可横滑，不换行挤压 */
  .topnav { flex-wrap: nowrap; overflow-x: auto; gap: 0 20px; scrollbar-width: none; }
  .topnav::-webkit-scrollbar { display: none; }

  /* 统计页条形图：标签列收窄，给条形留出宽度 */
  .bar-row { gap: 8px; }
  .bar-label { width: 86px; font-size: .78rem; }
  .bar-num { width: 46px; font-size: .74rem; }

  /* 分类卡：点标题折叠（app.js 切换 .collapsed） */
  .catalog-card h3 { cursor: pointer; display: flex; align-items: center; gap: 8px; }
  .catalog-card h3::after { content: "▾"; margin-left: auto; color: var(--muted); font-size: .8em; }
  .catalog-card.collapsed h3::after { content: "▸"; }
  .catalog-card.collapsed > *:not(h3) { display: none; }
  .catalog-card .count { float: none; }

  /* 阅读工具条吸底：拇指可达，按钮 ≥44×36 */
  .reader-controls {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 50;
    margin: 0;
    padding: 6px 10px calc(6px + env(safe-area-inset-bottom));
    gap: 8px;
    background: var(--paper-card);
    border-top: 1px solid var(--border);
    box-shadow: 0 -3px 14px var(--shadow);
  }
  .reader-controls button { min-width: 44px; min-height: 36px; font-size: 1rem; padding: 2px 8px; }
  .reader-controls .wc { display: none; }   /* 窄屏放不下 */

  /* 目录抽屉占满窄屏 */
  .toc-drawer {
    left: 0; right: 0; top: 0; bottom: 0;
    width: auto; max-width: none; max-height: none;
    transform: none;
    border: none; outline: none;
  }
}

/* ---------- ≤480px：小屏进一步压缩 ---------- */
@media (max-width: 480px) {
  .brand { font-size: 1.7rem; letter-spacing: 4px; }
  .masthead-sub, .masthead-years { display: none; }
  .article-head h1 { font-size: 1.32rem; }
  .page { padding: 18px 13px 22px; }
  .topnav a { font-size: .92rem; letter-spacing: 1px; }
}

/* ---------- 触屏：去掉只在 hover 成立的反馈，补 :active ---------- */
@media (hover: none) {
  .topnav a:hover, .entry-list .entry-title:hover, .catalog-card a:hover,
  .article-body a:hover, .site-footer a:hover, .goto-gpa:hover { text-decoration: none; }
  .reader-controls button:hover { border-color: var(--border); color: var(--ink); }
  .topnav a:active, .entry-list .entry-title:active, .catalog-card a:active { color: var(--rule); }
  .reader-controls button:active { border-color: var(--rule); color: var(--rule); }
}