@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:ital,wght@0,400;0,600;0,700;0,800;1,400&display=swap');

/* ===== 变量 ===== */
:root {
  --c-primary: #3730A3;
  --c-primary-dark: #1E1B4B;
  --c-accent: #F59E0B;
  --c-bg: #F8F7FF;
  --c-surface: #FFFFFF;
  --c-border: #3730A3;
  --c-text: #1E1B4B;
  --c-text-muted: #6B7280;
  --c-text-light: #9CA3AF;
  --c-link: #3730A3;
  --c-link-hover: #F59E0B;
  --radius: 4px;
  --bottom-nav-h: 56px;
  --topbar-h: 48px;
  --font: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  padding-bottom: var(--bottom-nav-h);
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--c-link); text-decoration: none; transition: color 150ms ease; }
a:hover { color: var(--c-link-hover); }
ul { list-style: none; }

/* ===== 顶部条 ===== */
.topbar {
  background: var(--c-primary-dark);
  color: #fff;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 20px;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 3px solid var(--c-accent);
}
.topbar-brand {
  color: #fff;
  font-weight: 800;
  font-size: 1rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar-brand:hover { color: var(--c-accent); }
.topbar-sep { color: var(--c-accent); font-weight: 700; }
.topbar-current {
  color: rgba(255,255,255,0.7);
  font-size: 0.875rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ===== 面包屑 ===== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.6);
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.breadcrumb a { color: rgba(255,255,255,0.8); }
.breadcrumb a:hover { color: var(--c-accent); }
.breadcrumb span { color: rgba(255,255,255,0.5); }

/* ===== Hero（首页） ===== */
.hero-wrap {
  position: relative;
  min-height: 70vh;
  background: var(--c-primary-dark);
  overflow: hidden;
  display: flex;
  align-items: center;
}
.hero-band {
  position: absolute;
  right: -60px;
  top: -40px;
  width: 55%;
  height: 130%;
  background: var(--c-primary);
  transform: skewX(-8deg);
  z-index: 0;
}
.hero-inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 64px 20px 48px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}
.hero-text { max-width: 520px; }
.hero-eyebrow {
  display: inline-block;
  background: var(--c-accent);
  color: var(--c-primary-dark);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 12px;
  border-radius: var(--radius);
  margin-bottom: 16px;
  text-transform: uppercase;
}
.hero-h1 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.2;
  margin-bottom: 16px;
}
.hero-lead {
  color: rgba(255,255,255,0.75);
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 28px;
}
.hero-images {
  position: relative;
  height: 340px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero-img {
  position: absolute;
  border-radius: var(--radius);
  border: 3px solid var(--c-accent);
  object-fit: cover;
  width: 200px;
  height: 260px;
}
.hero-img-1 {
  top: 0;
  left: 10%;
  transform: rotate(-3deg);
  z-index: 2;
}
.hero-img-2 {
  bottom: 0;
  right: 5%;
  transform: rotate(3deg);
  z-index: 1;
  border-color: var(--c-primary);
}

/* ===== 按钮 ===== */
.btn-primary {
  display: inline-block;
  background: var(--c-accent);
  color: var(--c-primary-dark);
  font-weight: 700;
  font-size: 0.9rem;
  padding: 12px 24px;
  border-radius: var(--radius);
  border: 2px solid var(--c-accent);
  transition: background 150ms ease, color 150ms ease;
  min-height: 44px;
}
.btn-primary:hover { background: transparent; color: var(--c-accent); }
.btn-secondary {
  display: inline-block;
  background: transparent;
  color: var(--c-primary);
  font-weight: 600;
  font-size: 0.875rem;
  padding: 10px 20px;
  border-radius: var(--radius);
  border: 2px solid var(--c-primary);
  transition: background 150ms ease, color 150ms ease;
  min-height: 40px;
}
.btn-secondary:hover { background: var(--c-primary); color: #fff; }

/* ===== 主题区块 ===== */
.topics-section,
.articles-section,
.children-section {
  padding: 48px 0;
}
.topics-section { background: var(--c-surface); border-top: 3px solid var(--c-primary); }
.articles-section { background: var(--c-bg); }
.children-section { background: var(--c-surface); border-top: 3px solid var(--c-accent); }
.section-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.section-inner > h2 {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--c-primary-dark);
  margin-bottom: 4px;
}

/* ===== 卡片网格 ===== */
.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
  margin-top: 20px;
}
.topic-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--c-surface);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  transition: border-color 150ms ease, background 150ms ease;
}
.topic-card:hover { background: var(--c-primary); border-color: var(--c-primary); }
.topic-card:hover strong,
.topic-card:hover span { color: #fff; }
.topic-card strong {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--c-primary-dark);
  line-height: 1.3;
}
.topic-card span {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  line-height: 1.5;
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin-top: 20px;
}
.article-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px;
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  border-radius: var(--radius);
  transition: border-color 150ms ease;
}
.article-card:hover { border-color: var(--c-accent); }
.article-card strong {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--c-primary-dark);
  line-height: 1.4;
}
.article-card .article-meta { font-size: 0.75rem; color: var(--c-text-light); }
.article-card .article-desc { font-size: 0.82rem; color: var(--c-text-muted); line-height: 1.5; }

.child-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
  margin-top: 20px;
}
.child-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background: var(--c-bg);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  transition: border-color 150ms ease, transform 150ms ease;
}
.child-card:hover { border-color: var(--c-accent); transform: translateY(-2px); }
.child-card strong {
  display: block;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--c-primary-dark);
  line-height: 1.4;
}
.child-card .child-date { font-size: 0.75rem; color: var(--c-text-light); }
.child-card .child-desc { font-size: 0.82rem; color: var(--c-text-muted); line-height: 1.5; }

/* ===== 内容布局（含侧边栏） ===== */
.content-layout {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 32px;
  align-items: start;
  padding-top: 32px;
  padding-bottom: 48px;
}

/* ===== 正文容器结构约束 ===== */
main > .wrap {
  width: 100%;
}
main > .wrap > article {
  width: 100%;
}
main > .wrap > article > div {
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  border-radius: var(--radius);
  padding: 32px;
}

/* ===== 侧边栏 ===== */
.content-aside {
  position: sticky;
  top: calc(var(--topbar-h) + 16px);
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.aside-block {
  background: var(--c-surface);
  border: 2px solid var(--c-primary);
  border-radius: var(--radius);
  padding: 20px;
}
.aside-block > h2 {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--c-primary-dark);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
}
.aside-links {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.aside-links li a {
  display: block;
  font-size: 0.85rem;
  color: var(--c-text);
  padding: 6px 10px;
  border-radius: var(--radius);
  border-left: 3px solid transparent;
  transition: border-color 150ms ease, background 150ms ease;
}
.aside-links li a:hover {
  border-left-color: var(--c-accent);
  background: var(--c-bg);
  color: var(--c-primary);
}

/* 首页侧边栏横排 */
.home-aside {
  background: var(--c-primary-dark);
  padding: 32px 20px;
}
.home-aside .aside-inner {
  max-width: 1200px;
  margin: 0 auto;
}
.home-aside h2 {
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 4px;
}
.home-aside .aside-links {
  flex-direction: row;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}
.home-aside .aside-links li a {
  color: rgba(255,255,255,0.8);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.2);
  border-left: 3px solid var(--c-accent);
  padding: 8px 16px;
  font-size: 0.85rem;
  border-radius: var(--radius);
}
.home-aside .aside-links li a:hover {
  background: var(--c-accent);
  color: var(--c-primary-dark);
  border-color: var(--c-accent);
}

/* ===== 正文区 ===== */
.prose {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-text);
}
.prose h2 { font-size: 1.3rem; font-weight: 700; color: var(--c-primary-dark); margin: 2em 0 0.5em; }
.prose h3 { font-size: 1.1rem; font-weight: 700; color: var(--c-primary); margin: 1.5em 0 0.4em; }
.prose p { margin-bottom: 1em; }
.prose ul, .prose ol { padding-left: 1.5em; margin-bottom: 1em; }
.prose li { margin-bottom: 0.4em; }
.prose a { color: var(--c-primary); text-decoration: underline; text-underline-offset: 3px; }
.prose a:hover { color: var(--c-accent); }
.prose strong { font-weight: 700; color: var(--c-primary-dark); }
.prose table { width: 100%; border-collapse: collapse; margin-bottom: 1em; font-size: 0.9rem; }
.prose th { background: var(--c-primary); color: #fff; padding: 10px 12px; text-align: left; font-weight: 700; }
.prose td { border: 1px solid #e5e7eb; padding: 8px 12px; }
.prose tr:nth-child(even) td { background: var(--c-bg); }
.prose blockquote { border-left: 4px solid var(--c-accent); padding: 12px 16px; background: var(--c-bg); margin-bottom: 1em; }
.prose code { background: var(--c-bg); border: 1px solid #e5e7eb; padding: 2px 6px; border-radius: 3px; font-size: 0.875em; }
.prose pre { background: var(--c-primary-dark); color: #e5e7eb; padding: 16px; border-radius: var(--radius); overflow-x: auto; margin-bottom: 1em; }
.prose pre code { background: none; border: none; padding: 0; color: inherit; }

/* ===== 副标题 ===== */
h2 + .subtitle,
h2 + p.subtitle,
h2 + p.subhead,
h2 + p.desc,
h2 + p.lead {
  font-size: 0.875rem;
  color: var(--c-text-muted);
  margin-top: 4px;
  margin-bottom: 20px;
  line-height: 1.5;
}

/* ===== Topic Hero ===== */
.topic-hero {
  position: relative;
  background: var(--c-primary-dark);
  overflow: hidden;
  padding: 48px 0 40px;
}
.topic-hero-band {
  position: absolute;
  left: -40px;
  top: -30px;
  width: 45%;
  height: 160%;
  background: var(--c-primary);
  transform: skewX(8deg);
  z-index: 0;
}
.topic-hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.topic-hero-inner h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 12px;
}
.topic-hero-desc {
  color: rgba(255,255,255,0.75);
  font-size: 0.95rem;
  max-width: 680px;
  line-height: 1.65;
}

/* ===== About Hero ===== */
.about-hero {
  position: relative;
  background: var(--c-primary-dark);
  overflow: hidden;
  padding: 48px 0 40px;
}
.about-hero-band {
  position: absolute;
  right: -60px;
  bottom: -40px;
  width: 50%;
  height: 140%;
  background: var(--c-primary);
  transform: skewX(-6deg);
  z-index: 0;
}
.about-hero-inner {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.about-hero-inner h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 12px;
}
.about-hero-desc {
  color: rgba(255,255,255,0.75);
  font-size: 0.95rem;
  max-width: 680px;
  line-height: 1.65;
}

/* ===== Privacy Header ===== */
.privacy-header {
  background: var(--c-primary-dark);
  padding: 40px 0 32px;
  border-bottom: 4px solid var(--c-accent);
}
.privacy-header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.privacy-header-inner h1 {
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  font-weight: 800;
  color: #fff;
  margin-bottom: 10px;
}
.privacy-lead {
  color: rgba(255,255,255,0.75);
  font-size: 0.95rem;
  max-width: 640px;
  line-height: 1.65;
}
.privacy-date {
  font-size: 0.8rem;
  color: var(--c-accent);
  margin-top: 8px;
}

/* ===== 文章页 ===== */
.article-header { margin-bottom: 24px; }
.article-hero-img-wrap {
  margin-bottom: 20px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 2px solid var(--c-primary);
}
.article-hero-img { width: 100%; max-height: 320px; object-fit: cover; }
.article-header h1 {
  font-size: clamp(1.3rem, 2.5vw, 1.85rem);
  font-weight: 800;
  color: var(--c-primary-dark);
  line-height: 1.25;
  margin-bottom: 12px;
}
.article-meta-row {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.article-pub-date,
.article-mod-date {
  font-size: 0.8rem;
  color: var(--c-text-muted);
  background: var(--c-bg);
  border: 1px solid #e5e7eb;
  border-radius: var(--radius);
  padding: 4px 10px;
}
.article-lead {
  font-size: 0.95rem;
  color: var(--c-text-muted);
  line-height: 1.65;
  margin-bottom: 24px;
  padding-left: 12px;
  border-left: 3px solid var(--c-accent);
}
.article-footer-links,
.about-links,
.privacy-footer-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 2px solid var(--c-bg);
}

/* ===== 页脚 ===== */
footer {
  background: var(--c-primary-dark);
  color: rgba(255,255,255,0.75);
  margin-bottom: var(--bottom-nav-h);
  padding-top: 0;
}
footer > article {
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-brand-section { padding: 32px 20px 24px; max-width: 1200px; margin: 0 auto; }
.footer-brand-name {
  font-size: 1.1rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 8px;
}
.footer-desc { font-size: 0.82rem; line-height: 1.6; max-width: 480px; }
.footer-nav-section,
.footer-info-section,
.footer-legal-section { padding: 24px 20px; max-width: 1200px; margin: 0 auto; }
.footer-nav-title {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--c-accent);
  margin-bottom: 10px;
  display: block;
}
footer dl dd {
  margin-bottom: 6px;
}
footer dl dd a {
  color: rgba(255,255,255,0.7);
  font-size: 0.85rem;
  transition: color 150ms ease;
  padding: 4px 0;
  display: inline-block;
  min-height: 40px;
  line-height: 40px;
}
footer dl dd a:hover { color: var(--c-accent); }
.footer-legal-text { font-size: 0.8rem; color: rgba(255,255,255,0.5); line-height: 1.5; }
.footer-copyright {
  background: rgba(0,0,0,0.3);
  text-align: center;
  padding: 16px 20px;
  font-size: 0.78rem;
  color: rgba(255,255,255,0.4);
  line-height: 1.7;
}

/* ===== 底部固定导航 ===== */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 200;
  background: var(--c-primary-dark);
  border-top: 3px solid var(--c-accent);
  height: var(--bottom-nav-h);
  display: flex;
  flex-direction: column;
  box-shadow: none;
}
.bottom-nav-brand {
  display: none;
  background: var(--c-primary);
  padding: 4px 16px;
}
.bottom-nav-brand a {
  color: #fff;
  font-weight: 800;
  font-size: 0.8rem;
}
.bottom-nav-links {
  display: flex;
  align-items: center;
  justify-content: space-around;
  flex: 1;
  padding: 0 4px;
}
.bottom-nav-links a {
  color: rgba(255,255,255,0.75);
  font-size: 0.75rem;
  font-weight: 600;
  text-align: center;
  padding: 8px 6px;
  border-radius: var(--radius);
  transition: color 150ms ease, background 150ms ease;
  min-height: 40px;
  display: flex;
  align-items: center;
  white-space: nowrap;
}
.bottom-nav-links a:hover,
.bottom-nav-links a:focus {
  color: var(--c-accent);
  background: rgba(255,255,255,0.08);
}

/* ===== 首页布局 ===== */
.page-home main {
  background: var(--c-bg);
  padding: 32px 0;
}
.page-home main .wrap {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.home-content h2 {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--c-primary-dark);
  margin-bottom: 4px;
}
.home-content {
  background: var(--c-surface);
  border: 2px solid var(--c-border);
  border-radius: var(--radius);
  padding: 28px;
}

/* ===== 通用 wrapper ===== */
.site-wrapper { min-height: 100vh; }

/* ===== 动效 ===== */
@media (prefers-reduced-motion: no-preference) {
  .topic-card,
  .article-card,
  .child-card {
    transition: border-color 150ms ease, background 150ms ease, transform 150ms ease;
  }
  .topic-card:hover { transform: translateY(-2px); }
  .article-card:hover { transform: translateY(-2px); }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

/* ===== 响应式 ===== */
@media (min-width: 768px) {
  .bottom-nav {
    height: auto;
    flex-direction: column;
  }
  .bottom-nav-brand {
    display: block;
    text-align: center;
    padding: 6px 20px;
  }
  .bottom-nav-links {
    padding: 0 20px;
    justify-content: center;
    gap: 4px;
  }
  .bottom-nav-links a { font-size: 0.85rem; padding: 10px 14px; min-height: 44px; }
  body { padding-bottom: 80px; }
  footer { margin-bottom: 80px; }

  .footer-nav-section,
  .footer-info-section,
  .footer-legal-section {
    max-width: 1200px;
  }
}

@media (min-width: 1024px) {
  .hero-inner { padding: 80px 40px 64px; }
  .section-inner { padding: 0 40px; }
  .content-layout { padding-left: 40px; padding-right: 40px; }
  footer > article { padding-left: 40px; padding-right: 40px; }
  .bottom-nav-links { gap: 8px; }
  .bottom-nav-links a { font-size: 0.9rem; padding: 10px 20px; }
}

@media (max-width: 900px) {
  .content-layout {
    grid-template-columns: 1fr;
  }
  .content-aside {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 16px;
  }
  .aside-block { flex: 1 1 240px; }
}

@media (max-width: 700px) {
  .hero-inner {
    grid-template-columns: 1fr;
    padding: 40px 16px 32px;
  }
  .hero-images { display: none; }
  .hero-h1 { font-size: 1.5rem; }
  .content-layout { padding-left: 16px; padding-right: 16px; padding-top: 20px; }
  main > .wrap > article > div { padding: 20px 16px; }
  .section-inner { padding: 0 16px; }
  .topic-grid,
  .article-grid,
  .child-grid { grid-template-columns: 1fr; }
  .footer-brand-section,
  .footer-nav-section,
  .footer-info-section,
  .footer-legal-section { padding-left: 16px; padding-right: 16px; }
  .article-header h1 { font-size: 1.25rem; }
  .article-meta-row { gap: 8px; }
  .home-aside .aside-links { flex-direction: column; }
  .topbar { padding: 0 12px; }
  .bottom-nav-links a { font-size: 0.7rem; padding: 6px 4px; }
}

@media (max-width: 400px) {
  html { font-size: 15px; }
  .hero-h1 { font-size: 1.3rem; }
  .bottom-nav-links { gap: 0; }
  .bottom-nav-links a { font-size: 0.68rem; padding: 6px 3px; }
}