/* ══════════════════════════════════════════════════════════
   知识观测站 — 深色知识档案馆风格
   ══════════════════════════════════════════════════════════ */

/* ── 设计令牌 ──────────────────────────────────────────── */
:root {
  --bg:           #0e1520;
  --bg-panel:     #121b2d;
  --bg-card:      #172030;
  --bg-hover:     #1c2840;
  --border:       #243044;
  --border-faint: #1b2636;
  --accent:       #4b8fc8;
  --accent-dim:   #2b5a8c;
  --accent-tint:  rgba(75, 143, 200, 0.09);
  --text:         #e2ddd4;
  --text-dim:     #7c8fa8;
  --text-muted:   #415060;
  --green:        #4d9c72;
  --radius:       4px;
  --header-h:     58px;
  --max-w:        1440px;
  --sidebar-w:    220px;
  --trans:        140ms ease;
}

/* ── 重置 ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
button { font-family: inherit; cursor: pointer; }

/* ── 滚动条 ────────────────────────────────────────────── */
::-webkit-scrollbar       { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ── 顶部导航 ──────────────────────────────────────────── */
#header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--header-h);
  background: rgba(14, 21, 32, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.75rem;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 2.5rem;
}
.site-logo {
  cursor: pointer;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
  user-select: none;
}
.logo-name {
  font-size: 0.98rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--text-dim);
  line-height: 1.2;
}
.logo-name em { color: var(--accent); font-style: normal; }
.logo-sub {
  font-size: 0.63rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  line-height: 1;
}
.main-nav {
  display: flex;
  gap: 0;
  flex: 1;
}
.nav-btn {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  font-size: 0.84rem;
  padding: 0.375rem 1rem;
  border-radius: 0;
  letter-spacing: 0.02em;
  transition: color var(--trans), border-color var(--trans);
}
.nav-btn:hover  { color: var(--text-dim); }
.nav-btn.active { color: var(--accent); border-bottom-color: var(--accent); background: none; }

/* ── 视图容器 ──────────────────────────────────────────── */
.view { min-height: calc(100vh - var(--header-h)); }
#view-reading {
  min-height: unset;
  height: calc(100vh - var(--header-h));
  overflow: hidden;
}

/* ── 通用：统计卡片 ────────────────────────────────────── */
.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.125rem 1.375rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.stat-label {
  font-size: 0.65rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.stat-value {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}
.stat-note { font-size: 0.7rem; color: var(--text-dim); }

/* ── 通用：分组标签 ────────────────────────────────────── */
.group-tag {
  font-size: 0.59rem;
  padding: 0.09rem 0.42rem;
  border-radius: 2px;
  font-weight: 500;
  white-space: nowrap;
  flex-shrink: 0;
  letter-spacing: 0.02em;
}
.group-tag.qian {
  background: rgba(40, 74, 112, 0.38);
  color: #7aaedd;
  border: 1px solid rgba(40, 74, 112, 0.58);
}
.group-tag.zhou {
  background: rgba(36, 68, 52, 0.38);
  color: #6ab88e;
  border: 1px solid rgba(36, 68, 52, 0.58);
}

/* ── 通用：搜索高亮 ────────────────────────────────────── */
mark {
  background: rgba(75, 143, 200, 0.22);
  color: var(--text);
  border-radius: 2px;
  padding: 0 1px;
}

/* ── 通用：内容区块 ────────────────────────────────────── */
.ov-section {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.375rem 1.5rem;
}
.ov-section-title {
  font-size: 0.63rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.09em;
  margin-bottom: 1rem;
  padding-bottom: 0.625rem;
  border-bottom: 1px solid var(--border-faint);
}

/* ════════════════════════════════════════════════════════
   总览
   ════════════════════════════════════════════════════════ */
.overview-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2rem 1.75rem 3rem;
}
.ov-stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.875rem;
  margin-bottom: 1.375rem;
}
.ov-two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}

/* 最近新增 */
.recent-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border-faint);
  cursor: pointer;
  transition: opacity var(--trans);
}
.recent-item:last-child { border-bottom: none; }
.recent-item:hover .recent-title { color: var(--accent); }
.recent-date  { font-size: 0.66rem; color: var(--text-muted); white-space: nowrap; }
.recent-title {
  font-size: 0.85rem;
  flex: 1;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  transition: color var(--trans);
}

/* 时间分布 */
.time-dist-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.42rem 0;
  border-bottom: 1px solid var(--border-faint);
  font-size: 0.845rem;
}
.time-dist-item:last-child { border-bottom: none; }
.time-dist-year  { color: var(--text-dim); width: 3.75rem; flex-shrink: 0; font-size: 0.82rem; }
.time-dist-bar-wrap { flex: 1; height: 3px; background: var(--border); border-radius: 2px; overflow: hidden; }
.time-dist-bar { height: 100%; background: var(--accent-dim); border-radius: 2px; transition: width 0.35s ease; }
.time-dist-count { font-size: 0.72rem; color: var(--text-muted); width: 3.25rem; text-align: right; flex-shrink: 0; }

/* 操作区 */
.ov-actions { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.action-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--text-muted);
  border-radius: var(--radius);
  padding: 0.35rem 0.875rem;
  font-size: 0.77rem;
  transition: border-color var(--trans), color var(--trans);
}
.action-btn:hover { border-color: var(--accent-dim); color: var(--text-dim); }

/* ════════════════════════════════════════════════════════
   阅读库
   ════════════════════════════════════════════════════════ */
.reading-layout {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(300px, 460px) 1fr;
  height: 100%;
  overflow: hidden;
}

/* 左侧筛选栏 */
.reading-sidebar {
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 1.25rem 0 1.25rem;
  background: var(--bg-panel);
}
.sidebar-section { margin-bottom: 1.625rem; }
.sidebar-label {
  display: block;
  font-size: 0.6rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0 1rem 0.5rem;
}
.sidebar-pill-group { display: flex; flex-direction: column; }
.sidebar-pill {
  background: none;
  border: none;
  border-left: 2px solid transparent;
  color: var(--text-dim);
  font-size: 0.8rem;
  text-align: left;
  padding: 0.32rem 1rem 0.32rem 0.875rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
  transition: color var(--trans), background var(--trans), border-color var(--trans);
}
.sidebar-pill:hover {
  color: var(--text);
  background: var(--bg-hover);
}
.sidebar-pill.active {
  border-left-color: var(--accent);
  color: var(--accent);
  background: var(--accent-tint);
}
.pill-count {
  font-size: 0.61rem;
  color: var(--text-muted);
  background: var(--bg);
  padding: 0.05rem 0.35rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  flex-shrink: 0;
  min-width: 1.5rem;
  text-align: center;
}
.sidebar-pill.active .pill-count {
  color: rgba(75, 143, 200, 0.72);
  border-color: rgba(75, 143, 200, 0.28);
  background: rgba(75, 143, 200, 0.06);
}

/* 移动端筛选折叠按钮 */
.sidebar-toggle-btn {
  display: none;
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-dim);
  font-size: 0.82rem;
  padding: 0.5rem 0.875rem;
  text-align: left;
  margin-bottom: 0.5rem;
  transition: border-color var(--trans), color var(--trans);
}
.sidebar-toggle-btn:hover { border-color: var(--accent-dim); color: var(--text); }

/* 中间文章列表 */
.reading-list-panel {
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg);
}
.list-header {
  flex-shrink: 0;
  border-bottom: 1px solid var(--border);
  padding: 0.875rem 0.875rem;
  background: var(--bg-panel);
}
.list-search {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-size: 0.82rem;
  padding: 0.5rem 0.875rem;
  outline: none;
  transition: border-color var(--trans), box-shadow var(--trans);
}
.list-search::placeholder { color: var(--text-muted); }
.list-search:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(75, 143, 200, 0.1);
}
.list-count { font-size: 0.66rem; color: var(--text-muted); margin-top: 0.375rem; }
.reading-list-scroll { flex: 1; overflow-y: auto; padding: 0.5rem; }

.reading-article-item {
  padding: 0.875rem 0.875rem;
  margin-bottom: 0.25rem;
  border: 1px solid var(--border);
  border-left: 2px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--trans), border-color var(--trans);
}
.reading-article-item:hover { background: var(--bg-hover); }
.reading-article-item.active {
  background: var(--accent-tint);
  border-left-color: var(--accent);
}
.rai-title {
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.3rem;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  line-height: 1.45;
}
.rai-meta {
  font-size: 0.7rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin-bottom: 0.25rem;
  flex-wrap: wrap;
}
.rai-summary {
  font-size: 0.77rem;
  color: var(--text-muted);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  line-height: 1.5;
}

/* 右侧正文阅读区 */
.reading-reader {
  overflow-y: auto;
  background: var(--bg);
}
.reader-inner {
  max-width: 680px;
  margin: 0 auto;
  padding: 2.5rem 2.25rem 4.5rem;
}
.reader-placeholder {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.84rem;
  text-align: center;
  padding: 2rem;
  gap: 0.4rem;
}
.reader-placeholder-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  opacity: 0.65;
}
.mobile-back-btn {
  display: none;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.82rem;
  color: var(--accent);
  background: none;
  border: none;
  padding: 0;
  margin-bottom: 2rem;
  transition: opacity var(--trans);
}
.mobile-back-btn:hover { opacity: 0.72; }
.reader-article-title {
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.38;
  margin-bottom: 0.875rem;
  color: var(--text);
  letter-spacing: -0.015em;
}
.reader-article-meta {
  font-size: 0.77rem;
  color: var(--text-dim);
  display: flex;
  align-items: center;
  gap: 0.625rem;
  flex-wrap: wrap;
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}
.reader-topic-tag { font-size: 0.65rem; color: var(--text-muted); }
.reader-body {
  font-size: 0.96rem;
  line-height: 1.88;
  color: var(--text);
}
.reader-body p { margin-bottom: 1.1rem; }
.reader-body p.spacer { margin-bottom: 0.4rem; }
.reader-pager {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}
.reader-pager-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-size: 0.78rem;
  transition: border-color var(--trans), color var(--trans);
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  text-align: left;
}
.reader-pager-btn:last-child { text-align: right; }
.reader-pager-btn:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.reader-pager-btn:disabled { opacity: 0.3; cursor: not-allowed; }

/* ════════════════════════════════════════════════════════
   时间轴
   ════════════════════════════════════════════════════════ */
.timeline-wrap {
  max-width: 680px;
  margin: 0 auto;
  padding: 2.5rem 1.75rem 5rem;
}
.timeline-intro {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 2.75rem;
  letter-spacing: 0.02em;
}

.timeline-year { margin-bottom: 3rem; }
.timeline-year-label {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  border-left: 2px solid var(--accent);
  padding-left: 0.875rem;
  margin-bottom: 1.25rem;
  letter-spacing: -0.01em;
}

/* 月份条目区域带左竖线 */
.timeline-months-area {
  padding-left: 1.375rem;
  border-left: 1px solid var(--border-faint);
  margin-left: 0.25rem;
}

.timeline-month { margin-bottom: 0.375rem; position: relative; }
.timeline-month::before {
  content: '';
  position: absolute;
  left: -1.375rem;
  top: 0.72rem;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--bg);
  border: 1px solid var(--border);
  transform: translateX(-50%);
  transition: background var(--trans), border-color var(--trans);
}
.timeline-month:hover::before {
  background: var(--accent-dim);
  border-color: var(--accent);
}

.timeline-month-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.42rem 0.625rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--trans);
  user-select: none;
}
.timeline-month-header:hover { background: var(--bg-hover); }
.timeline-month-name  { font-size: 0.88rem; color: var(--text-dim); min-width: 3rem; }
.timeline-month-count {
  font-size: 0.65rem;
  color: var(--text-muted);
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 0.08rem 0.42rem;
  border-radius: 10px;
}
.timeline-chevron {
  margin-left: auto;
  font-size: 0.52rem;
  color: var(--text-muted);
  transition: transform 160ms ease;
}
.timeline-chevron.open { transform: rotate(90deg); }

.timeline-articles {
  display: none;
  margin-left: 0;
  padding-left: 1rem;
  border-left: 1px solid var(--border-faint);
  margin-top: 0.15rem;
  margin-bottom: 0.25rem;
  padding-top: 0.1rem;
  padding-bottom: 0.1rem;
}
.timeline-articles.open { display: block; }

.timeline-article-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.35rem 0.5rem;
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--text-dim);
  font-size: 0.845rem;
  transition: color var(--trans), background var(--trans);
}
.timeline-article-item:hover { color: var(--accent); background: var(--bg-hover); }
.tai-date  { font-size: 0.65rem; color: var(--text-muted); white-space: nowrap; }
.tai-title { flex: 1; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }

/* ════════════════════════════════════════════════════════
   主题探索
   ════════════════════════════════════════════════════════ */
.topics-wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 2.5rem 1.75rem 5rem;
}
.topics-header { margin-bottom: 2rem; }
.topics-title    { font-size: 1.1rem; font-weight: 600; margin-bottom: 0.3rem; }
.topics-subtitle { font-size: 0.8rem; color: var(--text-muted); }

.topics-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 1rem;
  margin-bottom: 2.5rem;
}
.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  cursor: pointer;
  transition: border-color var(--trans), background var(--trans);
  position: relative;
  overflow: hidden;
}
.topic-card:hover  { border-color: #3a4e68; background: var(--bg-hover); }
.topic-card.active { border-color: var(--accent); background: var(--accent-tint); }

.topic-card-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 1rem;
}
.topic-card-icon   { font-size: 1.35rem; line-height: 1; flex-shrink: 0; margin-top: 0.05rem; }
.topic-card-info   { flex: 1; min-width: 0; }
.topic-card-name   { font-size: 0.92rem; font-weight: 600; line-height: 1.3; margin-bottom: 0.15rem; }
.topic-card-count  { font-size: 0.7rem; color: var(--text-muted); }

.topic-card-samples {
  border-top: 1px solid var(--border-faint);
  padding-top: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.topic-card-sample {
  font-size: 0.72rem;
  color: var(--text-dim);
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  line-height: 1.45;
  padding: 0.08rem 0;
}
.topic-card-sample::before {
  content: '·';
  color: var(--text-muted);
  margin-right: 0.35rem;
}

.topic-bar { position: absolute; bottom: 0; left: 0; height: 2px; }

.topics-results { border-top: 1px solid var(--border); padding-top: 1.75rem; }
.topics-results-header {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1.25rem;
}
.topic-article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.75rem;
}
.topic-article-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.875rem 1rem;
  cursor: pointer;
  transition: border-color var(--trans), background var(--trans);
}
.topic-article-item:hover { border-color: var(--accent-dim); background: var(--bg-hover); }
.toi-title {
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.3rem;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}
.toi-meta { font-size: 0.7rem; color: var(--text-dim); display: flex; align-items: center; gap: 0.5rem; }

/* ── 加载错误 ──────────────────────────────────────────── */
.load-error {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--text-dim);
  gap: 0.75rem;
  padding: 2rem;
  font-size: 0.9rem;
}
.load-error code {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.45rem 1.25rem;
  font-family: monospace;
  font-size: 0.875rem;
  color: var(--accent);
}

/* ════════════════════════════════════════════════════════
   响应式
   ════════════════════════════════════════════════════════ */
@media (max-width: 1200px) {
  .reading-layout {
    grid-template-columns: var(--sidebar-w) minmax(280px, 380px) 1fr;
  }
}

@media (max-width: 900px) {
  .reading-layout {
    grid-template-columns: var(--sidebar-w) 1fr;
  }
  .reading-reader { display: none; }
  .reading-reader.mobile-open {
    display: block;
    position: fixed;
    inset: var(--header-h) 0 0 0;
    z-index: 100;
    background: var(--bg);
    overflow-y: auto;
  }
  .mobile-back-btn { display: flex; }
}

@media (max-width: 768px) {
  :root { --header-h: 52px; }

  .logo-sub { display: none; }
  .header-inner { padding: 0 1rem; gap: 1rem; }
  .main-nav { overflow-x: auto; scrollbar-width: none; -webkit-overflow-scrolling: touch; }
  .main-nav::-webkit-scrollbar { display: none; }
  .nav-btn { font-size: 0.79rem; padding: 0.32rem 0.7rem; white-space: nowrap; }

  #view-reading { height: auto; overflow: visible; }
  .reading-layout {
    grid-template-columns: 1fr;
    height: auto;
    overflow: visible;
  }

  .reading-sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1rem;
    overflow: visible;
    display: none;
  }
  .reading-sidebar.mobile-open { display: block; }
  .sidebar-pill-group { flex-direction: row; flex-wrap: wrap; gap: 0.3rem; }
  .sidebar-pill {
    border-left: none;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.76rem;
    padding: 0.22rem 0.6rem;
  }
  .sidebar-pill.active {
    border-color: var(--accent);
    background: var(--accent-tint);
  }
  .sidebar-toggle-btn { display: block; }

  .reading-list-panel { border-right: none; overflow: visible; height: auto; }
  .reading-list-scroll { overflow: visible; height: auto; }

  .reading-reader.mobile-open .reader-inner {
    padding: 1.5rem 1.25rem 3.5rem;
  }

  .ov-stats-row { grid-template-columns: repeat(2, 1fr); }
  .ov-two-col   { grid-template-columns: 1fr; }
  .topics-grid  { grid-template-columns: repeat(auto-fill, minmax(165px, 1fr)); }
  .topic-card-samples { display: none; }
  .overview-wrap { padding: 1.5rem 1rem 2.5rem; }
}

@media (max-width: 480px) {
  .topic-article-grid { grid-template-columns: 1fr; }
  .nav-btn { font-size: 0.73rem; padding: 0.28rem 0.55rem; }
  .reader-article-title { font-size: 1.3rem; }
}