@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@300;400;500;600;700&display=swap');

/* ===== CSS 自定义属性 ===== */
:root {
  --c-base: #1A1A2E;
  --c-accent: #C0392B;
  --c-light: #F5F5F0;
  --c-base-80: rgba(26,26,46,0.80);
  --c-base-60: rgba(26,26,46,0.60);
  --c-base-20: rgba(26,26,46,0.20);
  --c-accent-dark: #9b2e22;
  --c-accent-light: #e04535;
  --c-muted: #8a8a9a;
  --c-border: rgba(245,245,240,0.12);
  --c-surface: #22223a;
  --c-surface-2: #2d2d4a;
  --radius-card: 18px;
  --font-main: 'IBM Plex Sans', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --header-h: 110px;
  --transition-base: 0.25s cubic-bezier(0.4,0,0.2,1);
  --max-prose: 760px;
  --max-wide: 1200px;
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-main);
  background: var(--c-base);
  color: var(--c-light);
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button, input { font-family: inherit; }

/* ===== 站点框架 ===== */
.site-frame { display: flex; flex-direction: column; min-height: 100vh; }
.main-content { flex: 1; }

/* ===== 页眉 ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-base);
  border-bottom: 1px solid var(--c-border);
  box-shadow: 0 2px 24px rgba(0,0,0,0.4);
  will-change: transform;
}

.header-brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px 10px;
  gap: 16px;
  border-bottom: 1px solid var(--c-border);
}

.header-brand-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  justify-content: center;
}

.brand-logo { width: 36px; height: 36px; object-fit: contain; flex-shrink: 0; }

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--c-light);
  letter-spacing: 0.04em;
  white-space: nowrap;
  transition: color var(--transition-base);
}
.brand-name:hover { color: var(--c-accent); }

.brand-sub {
  font-size: 0.72rem;
  color: var(--c-muted);
  font-weight: 300;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 280px;
}

.header-search { flex-shrink: 0; }

.search-form {
  display: flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--c-border);
  border-radius: 6px;
  overflow: hidden;
  transition: border-color var(--transition-base);
}
.search-form:focus-within { border-color: var(--c-accent); }

.search-input {
  background: var(--c-surface);
  color: var(--c-light);
  border: none;
  padding: 8px 12px;
  font-size: 0.85rem;
  width: 200px;
  outline: none;
}
.search-input::placeholder { color: var(--c-muted); }

.search-btn {
  background: var(--c-accent);
  color: #fff;
  border: none;
  padding: 8px 12px;
  cursor: pointer;
  font-size: 0.9rem;
  min-width: 40px;
  min-height: 40px;
  transition: background var(--transition-base);
  display: flex;
  align-items: center;
  justify-content: center;
}
.search-btn:hover { background: var(--c-accent-dark); }

/* ===== 导航行 ===== */
.header-nav-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  gap: 8px;
  min-height: 44px;
}

.nav-left, .nav-right {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: 10px 12px;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--c-muted);
  letter-spacing: 0.02em;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-base), border-color var(--transition-base);
  min-height: 44px;
}
.nav-link:hover { color: var(--c-light); border-bottom-color: var(--c-accent); }
.nav-link--active { color: var(--c-light); border-bottom-color: var(--c-accent); }

/* ===== 首页 Hero ===== */
.hero-section {
  position: relative;
  height: 70vh;
  min-height: 480px;
  max-height: 800px;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: translateY(0);
  will-change: transform;
}

.hero-dot-overlay {
  position: absolute;
  inset: 0;
  background-color: var(--c-base-80);
  background-image: radial-gradient(var(--c-border) 1px, transparent 1px);
  background-size: 28px 28px;
  z-index: 1;
}

.hero-crimson-bar {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 4px;
  background: var(--c-accent);
  z-index: 3;
}

.hero-content {
  position: relative;
  z-index: 4;
  padding: 40px 48px 56px;
  max-width: 760px;
}

.hero-eyebrow {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-accent);
  border: 1px solid var(--c-accent);
  padding: 3px 10px;
  margin-bottom: 16px;
}

.hero-h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--c-light);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.hero-lead {
  font-size: 1rem;
  color: rgba(245,245,240,0.8);
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 540px;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--c-accent);
  color: #fff;
  padding: 12px 28px;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 4px;
  transition: background var(--transition-base), transform var(--transition-base);
  min-height: 44px;
}
.hero-cta:hover { background: var(--c-accent-dark); transform: translateY(-2px); }

.hero-scroll-hint {
  position: absolute;
  bottom: 24px;
  right: 32px;
  z-index: 4;
  opacity: 0.5;
}
.scroll-arrow {
  display: block;
  width: 24px;
  height: 24px;
  border-right: 2px solid var(--c-light);
  border-bottom: 2px solid var(--c-light);
  transform: rotate(45deg);
  animation: arrowBounce 1.6s ease-in-out infinite;
}
@keyframes arrowBounce {
  0%, 100% { transform: rotate(45deg) translateY(0); }
  50% { transform: rotate(45deg) translateY(6px); }
}

/* ===== 视差层 ===== */
.parallax-layer {
  pointer-events: none;
  overflow: hidden;
  position: relative;
  height: 80px;
  display: flex;
  align-items: center;
}
.layer-1 { background: var(--c-surface); }
.layer-bg-text {
  font-size: 5rem;
  font-weight: 700;
  color: var(--c-border);
  letter-spacing: 0.3em;
  white-space: nowrap;
  padding: 0 32px;
  user-select: none;
}

/* ===== 内容章节 ===== */
.content-section { padding: 56px 24px; }

.content-prose {
  max-width: var(--max-prose);
  margin: 0 auto;
}
.prose-inner { width: 100%; }

/* ===== 卡片网格 ===== */
.cards-section {
  background: var(--c-surface);
  padding: 56px 24px;
}

.cards-header {
  display: flex;
  align-items: center;
  gap: 20px;
  max-width: var(--max-wide);
  margin: 0 auto 36px;
}

.cards-heading {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--c-light);
  white-space: nowrap;
}

.cards-rule-line {
  flex: 1;
  height: 1px;
  background: var(--c-border);
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  max-width: var(--max-wide);
  margin: 0 auto;
}

/* ===== 卡片通用 ===== */
.card, .topic-card, .sib-card {
  background: var(--c-surface-2);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  position: relative;
}
.card:hover, .topic-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0,0,0,0.5);
}

.card-inner, .topic-card-body {
  padding: 24px 24px 16px;
}

.card-eyebrow {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-accent);
  display: block;
  margin-bottom: 8px;
}

.card-title a, .topic-card-title a {
  color: var(--c-light);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  transition: color var(--transition-base);
}
.card-title a:hover, .topic-card-title a:hover { color: var(--c-accent); }

.card-title { margin-bottom: 8px; font-size: 1rem; }
.topic-card-title { margin-bottom: 8px; font-size: 1rem; }

.card-desc, .topic-card-desc {
  font-size: 0.85rem;
  color: var(--c-muted);
  line-height: 1.6;
  margin-bottom: 12px;
}

.card-date {
  font-size: 0.75rem;
  color: var(--c-muted);
  display: block;
  margin-bottom: 16px;
}

.card-rule {
  height: 3px;
  background: linear-gradient(90deg, var(--c-accent) 0%, var(--c-accent-dark) 100%);
  border-radius: 0 0 var(--radius-card) var(--radius-card);
  margin-top: auto;
}

.card-thumb-wrap {
  overflow: hidden;
  border-radius: var(--radius-card) var(--radius-card) 0 0;
  aspect-ratio: 16/9;
}
.card-thumb {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.topic-card:hover .card-thumb { transform: scale(1.04); }

/* ===== reveal 动画 ===== */
[data-reveal] {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}
[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  font-size: 0.78rem;
  color: var(--c-muted);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
}
.breadcrumb a { color: var(--c-muted); transition: color var(--transition-base); }
.breadcrumb a:hover { color: var(--c-accent); }

/* ===== 栏目页 Hero ===== */
.topic-hero {
  position: relative;
  overflow: hidden;
}
.topic-hero--img { height: 340px; }
.topic-hero--plain { background: var(--c-surface); border-bottom: 4px solid var(--c-accent); }

.topic-hero-bg {
  position: absolute;
  inset: 0;
}
.topic-hero-img { width: 100%; height: 100%; object-fit: cover; }
.topic-hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--c-base-80) 60%, var(--c-base-60) 100%);
}
.topic-hero-stripe {
  height: 6px;
  background: var(--c-accent);
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
}

.topic-hero-content {
  position: relative;
  z-index: 2;
  padding: 40px 48px;
  max-width: var(--max-wide);
  margin: 0 auto;
}
.topic-hero--plain .topic-hero-content { padding: 32px 48px 28px; }

.topic-h1 {
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--c-light);
  margin-bottom: 12px;
  line-height: 1.25;
}

.topic-lead {
  font-size: 1rem;
  color: rgba(245,245,240,0.8);
  max-width: 620px;
  line-height: 1.7;
}

.topic-date {
  display: block;
  font-size: 0.78rem;
  color: var(--c-muted);
  margin-top: 10px;
}

/* ===== 栏目页主体 ===== */
.topic-body-wrap {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 48px 24px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

.topic-article { width: 100%; }

.topic-children-header {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--c-border);
  padding-bottom: 12px;
}
.topic-children-title { font-size: 1.2rem; font-weight: 700; }
.topic-children-count { font-size: 0.78rem; color: var(--c-muted); }

.topic-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}

/* ===== 文章页 ===== */
.article-header-band {
  background: linear-gradient(180deg, var(--c-surface) 0%, var(--c-base) 100%);
  border-bottom: 3px solid var(--c-accent);
  padding: 40px 24px;
}
.article-header-inner {
  max-width: var(--max-wide);
  margin: 0 auto;
}

.article-h1 {
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--c-light);
  margin-bottom: 16px;
  line-height: 1.25;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  margin-bottom: 20px;
}

.article-date {
  font-size: 0.78rem;
  color: var(--c-muted);
  border-left: 2px solid var(--c-accent);
  padding-left: 8px;
}
.article-date--mod { border-left-color: var(--c-muted); }

.article-cat-link {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--c-accent);
  border: 1px solid var(--c-accent);
  padding: 2px 8px;
  border-radius: 3px;
  transition: background var(--transition-base), color var(--transition-base);
}
.article-cat-link:hover { background: var(--c-accent); color: #fff; }

.article-hero-wrap { margin-top: 20px; border-radius: 8px; overflow: hidden; }
.article-hero-img { width: 100%; height: auto; }

.article-layout-wrap {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 48px 24px;
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  align-items: start;
}

.article-body { min-width: 0; }

/* ===== 侧边栏 ===== */
.article-sidebar, .about-sidebar, .privacy-toc-aside {
  position: sticky;
  top: calc(var(--header-h) + 16px);
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar-block {
  background: var(--c-surface);
  border-radius: 12px;
  padding: 20px;
  border-left: 3px solid var(--c-accent);
}

.sidebar-block-title {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 14px;
}

.sidebar-parent-link {
  font-size: 0.9rem;
  color: var(--c-light);
  font-weight: 500;
  transition: color var(--transition-base);
}
.sidebar-parent-link:hover { color: var(--c-accent); }

.sidebar-nav-dl { display: flex; flex-direction: column; gap: 4px; }
.sidebar-nav-dl dt, .sidebar-nav-dl dd { margin: 0; padding: 0; }
.sidebar-nav-link {
  display: block;
  font-size: 0.85rem;
  color: var(--c-muted);
  padding: 6px 0;
  border-bottom: 1px solid var(--c-border);
  transition: color var(--transition-base), padding-left var(--transition-base);
  min-height: 40px;
  display: flex;
  align-items: center;
}
.sidebar-nav-link:hover { color: var(--c-accent); padding-left: 6px; }

.sib-cards { display: flex; flex-direction: column; gap: 12px; }
.sib-card {
  background: var(--c-base);
  border-radius: 8px;
  padding: 12px 14px 0;
}
.sib-card-title { font-size: 0.85rem; margin-bottom: 4px; }
.sib-card-title a { color: var(--c-light); font-weight: 500; line-height: 1.4; }
.sib-card-title a:hover { color: var(--c-accent); }
.sib-card-desc { font-size: 0.75rem; color: var(--c-muted); margin-bottom: 10px; }
.sib-card .card-rule { margin: 0 -14px; border-radius: 0 0 8px 8px; }

/* ===== About 页 ===== */
.about-banner {
  position: relative;
  background: var(--c-surface);
  padding: 60px 48px 40px;
  overflow: hidden;
  border-bottom: 4px solid var(--c-accent);
}
.about-banner-accent {
  position: absolute;
  top: 0;
  left: 0;
  width: 6px;
  height: 100%;
  background: var(--c-accent);
}
.about-banner-content { max-width: var(--max-wide); margin: 0 auto; padding-left: 20px; }
.about-eyebrow {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 10px;
}
.about-h1 {
  font-size: clamp(1.6rem, 3.5vw, 2.8rem);
  font-weight: 700;
  color: var(--c-light);
  line-height: 1.2;
}
.about-date { font-size: 0.78rem; color: var(--c-muted); display: block; margin-top: 10px; }

.about-body-wrap, .privacy-body-wrap {
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 48px 24px;
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 40px;
  align-items: start;
}

.about-article, .privacy-article { min-width: 0; }

.about-sidebar-text {
  font-size: 0.85rem;
  color: var(--c-muted);
  line-height: 1.6;
}

/* ===== Privacy 页 ===== */
.privacy-banner {
  position: relative;
  background: var(--c-surface);
  padding: 48px 48px 36px;
  border-bottom: 4px solid var(--c-accent);
  overflow: hidden;
}
.privacy-banner-line {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: repeating-linear-gradient(90deg, var(--c-accent) 0, var(--c-accent) 20px, transparent 20px, transparent 28px);
}
.privacy-banner-content { max-width: var(--max-wide); margin: 0 auto; }
.privacy-h1 {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--c-light);
  margin-bottom: 10px;
  line-height: 1.25;
}
.privacy-updated { font-size: 0.78rem; color: var(--c-muted); }

/* ===== 正文排版 ===== */
.prose-inner h1,
.prose-inner h2,
.prose-inner h3,
.prose-inner h4 {
  color: var(--c-light);
  font-weight: 700;
  line-height: 1.3;
  margin-top: 2em;
  margin-bottom: 0.6em;
}
.prose-inner h2 {
  font-size: 1.3rem;
  border-left: 4px solid var(--c-accent);
  padding-left: 14px;
  margin-left: -18px;
}
.prose-inner h3 { font-size: 1.1rem; }
.prose-inner h4 { font-size: 1rem; color: var(--c-muted); }
.prose-inner p { margin-bottom: 1.2em; color: rgba(245,245,240,0.88); }
.prose-inner a { color: var(--c-accent-light); text-decoration: underline; text-underline-offset: 3px; transition: color var(--transition-base); }
.prose-inner a:hover { color: var(--c-light); }
.prose-inner ul, .prose-inner ol { padding-left: 1.5em; margin-bottom: 1.2em; }
.prose-inner li { margin-bottom: 0.4em; color: rgba(245,245,240,0.88); }
.prose-inner blockquote {
  border-left: 3px solid var(--c-accent);
  padding: 12px 20px;
  margin: 1.5em 0;
  background: var(--c-surface);
  border-radius: 0 8px 8px 0;
  color: var(--c-muted);
  font-style: italic;
}
.prose-inner code {
  background: var(--c-surface-2);
  color: var(--c-accent-light);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.88em;
}
.prose-inner pre {
  background: var(--c-surface-2);
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: 1.2em;
}
.prose-inner pre code { background: none; padding: 0; }
.prose-inner table { width: 100%; border-collapse: collapse; margin-bottom: 1.2em; font-size: 0.9rem; }
.prose-inner th, .prose-inner td { padding: 10px 14px; border: 1px solid var(--c-border); text-align: left; }
.prose-inner th { background: var(--c-surface); font-weight: 600; }
.prose-inner img { border-radius: 8px; margin: 1em 0; }
.prose-inner time { color: var(--c-muted); font-size: 0.85em; }
.prose-inner hr { border: none; border-top: 1px solid var(--c-border); margin: 2em 0; }

/* ===== 页脚 ===== */
.site-footer {
  background: var(--c-surface);
  border-top: 3px solid var(--c-accent);
  padding: 48px 24px 0;
  margin-top: auto;
}

.footer-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  max-width: var(--max-wide);
  margin: 0 auto 36px;
}

.footer-col-title {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 14px;
}

.footer-col-text { font-size: 0.85rem; color: var(--c-muted); line-height: 1.6; margin-bottom: 10px; }
.footer-col-link { font-size: 0.82rem; color: var(--c-accent-light); text-decoration: underline; text-underline-offset: 2px; }
.footer-col-link:hover { color: var(--c-light); }

.footer-nav-dl {
  display: flex;
  flex-direction: column;
  gap: 2px;
  list-style: none;
}
.footer-nav-dt { margin: 0; }
.footer-nav-dd { margin: 0; }
.footer-nav-dd a {
  display: flex;
  align-items: center;
  min-height: 40px;
  font-size: 0.84rem;
  color: var(--c-muted);
  padding: 4px 0;
  border-bottom: 1px solid var(--c-border);
  transition: color var(--transition-base), padding-left var(--transition-base);
}
.footer-nav-dd a:hover { color: var(--c-accent); padding-left: 6px; }

.footer-bottom {
  border-top: 1px solid var(--c-border);
  padding: 20px 0;
  text-align: center;
  max-width: var(--max-wide);
  margin: 0 auto;
}
.footer-copy { font-size: 0.78rem; color: var(--c-muted); margin-bottom: 4px; }
.footer-icp { font-size: 0.72rem; color: rgba(138,138,154,0.6); }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .article-layout-wrap { grid-template-columns: 1fr; }
  .article-sidebar { position: static; }
  .about-body-wrap, .privacy-body-wrap { grid-template-columns: 1fr; }
  .about-sidebar, .privacy-toc-aside { position: static; }
  .footer-columns { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  .header-brand-row { flex-wrap: wrap; padding: 10px 16px; }
  .header-brand-inner { justify-content: flex-start; }
  .brand-sub { display: none; }
  .header-search { width: 100%; }
  .search-input { width: 100%; flex: 1; }
  .search-form { width: 100%; }

  .header-nav-row { padding: 0 12px; overflow-x: auto; scrollbar-width: none; gap: 0; }
  .header-nav-row::-webkit-scrollbar { display: none; }
  .nav-left, .nav-right { gap: 0; flex-wrap: nowrap; }
  .nav-link { padding: 10px 8px; font-size: 0.78rem; }

  .hero-section { height: 60vh; min-height: 360px; }
  .hero-content { padding: 24px 20px 44px; }
  .hero-h1 { font-size: 1.5rem; }
  .hero-lead { font-size: 0.9rem; }

  .topic-hero-content { padding: 24px 20px; }
  .topic-h1 { font-size: 1.3rem; }

  .article-header-band { padding: 28px 16px; }
  .article-h1 { font-size: 1.3rem; }
  .article-layout-wrap { padding: 28px 16px; gap: 28px; }

  .about-banner { padding: 36px 20px 28px; }
  .about-banner-content { padding-left: 12px; }
  .about-h1 { font-size: 1.4rem; }
  .about-body-wrap, .privacy-body-wrap { padding: 28px 16px; gap: 24px; }

  .privacy-banner { padding: 32px 20px 24px; }

  .cards-section { padding: 36px 16px; }
  .cards-grid { grid-template-columns: 1fr; }
  .topic-cards-grid { grid-template-columns: 1fr; }

  .footer-columns { grid-template-columns: 1fr; gap: 24px; }
  .site-footer { padding: 32px 16px 0; }

  .content-section { padding: 36px 16px; }
  .topic-body-wrap { padding: 28px 16px; }
}

/* ===== 可访问性：减少动效 ===== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .scroll-arrow { animation: none; }
}