/* === 字体引入 === */
@import url('https://fonts.googleapis.com/css2?family=Baloo+2:wght@400;500;600;700&family=Comic+Neue:wght@300;400;700&display=swap');

/* === CSS 自定义属性 === */
:root {
  --c-black: #000000;
  --c-white: #ffffff;
  --c-accent: #000000;
  --c-gray-100: #f5f5f5;
  --c-gray-200: #e8e8e8;
  --c-gray-400: #999999;
  --c-gray-600: #555555;
  --c-border: #000000;

  --font-main: 'Baloo 2', 'Comic Neue', system-ui, -apple-system, sans-serif;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 64px;
  --space-7: 96px;

  --grid-cols: 12;
  --grid-gap: 1rem;
  --max-width: 1200px;
  --aside-width: 220px;

  --radius: 0;
  --header-h: 60px;
}

/* === 重置 === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  font-size: 1rem;
  line-height: 1.7;
  color: var(--c-black);
  background: var(--c-white);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--c-black);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  text-decoration: none;
  opacity: 0.7;
}

ul, menu {
  list-style: none;
}

hr {
  border: none;
  border-top: 2px solid var(--c-black);
  margin: var(--space-2) 0;
}

/* === 整体包裹 === */
.site-wrap {
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  min-height: 100vh;
}

/* === 顶部导航 === */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-black);
  color: var(--c-white);
  border-bottom: 2px solid var(--c-black);
  height: var(--header-h);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  height: 100%;
}

.brand {
  font-family: var(--font-main);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--c-white);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  letter-spacing: 0.02em;
}

.brand:hover {
  opacity: 0.85;
}

.main-nav {
  flex: 1;
}

/* details/summary 导航 */
.nav-details {
  position: relative;
}

.nav-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--c-white);
  padding: var(--space-1) var(--space-2);
  min-height: 40px;
  list-style: none;
  border: 1px solid rgba(255,255,255,0.3);
  transition: background 0.2s;
}

.nav-toggle::-webkit-details-marker { display: none; }

.nav-toggle::after {
  content: '▾';
  font-size: 0.75rem;
}

.nav-details[open] .nav-toggle::after {
  content: '▴';
}

.nav-toggle:hover {
  background: rgba(255,255,255,0.1);
}

.nav-menu {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  background: var(--c-white);
  border: 2px solid var(--c-black);
  min-width: 280px;
  z-index: 200;
}

.nav-menu li a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--c-black);
  text-decoration: none;
  border-bottom: 1px solid var(--c-gray-200);
  transition: background 0.15s;
  min-height: 44px;
  display: flex;
  align-items: center;
}

.nav-menu li:last-child a {
  border-bottom: none;
}

.nav-menu li a:hover {
  background: var(--c-gray-100);
  opacity: 1;
}

.nav-contact {
  color: var(--c-white);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--c-white);
  padding: var(--space-1) var(--space-2);
  min-height: 40px;
  display: flex;
  align-items: center;
  white-space: nowrap;
  flex-shrink: 0;
  transition: background 0.2s, color 0.2s;
}

.nav-contact:hover {
  background: var(--c-white);
  color: var(--c-black);
  opacity: 1;
}

/* === 二级粘性锚点条 === */
.subnav-bar {
  background: var(--c-gray-100);
  border-bottom: 1px solid var(--c-gray-200);
  position: sticky;
  top: var(--header-h);
  z-index: 90;
  display: flex;
  align-items: center;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
}

.subnav-bar::-webkit-scrollbar { display: none; }

.subnav-bar a {
  display: flex;
  align-items: center;
  padding: var(--space-1) var(--space-2);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--c-black);
  text-decoration: none;
  white-space: nowrap;
  border-right: 1px solid var(--c-gray-200);
  min-height: 40px;
  transition: background 0.15s;
  letter-spacing: 0.01em;
}

.subnav-bar a:hover {
  background: var(--c-gray-200);
  opacity: 1;
}

/* === Grid 工具 === */
.grid-wrap {
  display: grid;
  grid-template-columns: var(--aside-width) 1fr;
  gap: var(--space-4);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-3);
  align-items: start;
}

/* === 侧边栏（左侧） === */
.left-aside {
  position: sticky;
  top: calc(var(--header-h) + 40px + var(--space-3));
  border: 2px solid var(--c-black);
  padding: var(--space-3);
  background: var(--c-white);
}

.left-aside h2 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-1);
}

.left-aside h3 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin: var(--space-3) 0 var(--space-1);
}

.aside-nav li {
  border-bottom: 1px solid var(--c-gray-200);
}

.aside-nav li:last-child {
  border-bottom: none;
}

.aside-nav li a {
  display: flex;
  align-items: center;
  padding: 6px 0;
  font-size: 0.82rem;
  font-weight: 500;
  text-decoration: none;
  transition: opacity 0.15s;
  min-height: 36px;
}

.aside-nav li a:hover {
  opacity: 0.65;
}

.aside-related {
  margin-top: var(--space-3);
}

.aside-related ul li a {
  display: block;
  padding: 5px 0;
  font-size: 0.8rem;
  text-decoration: none;
  border-bottom: 1px dashed var(--c-gray-200);
  min-height: 34px;
  display: flex;
  align-items: center;
}

.aside-related ul li a:hover {
  opacity: 0.6;
}

.aside-back {
  margin-top: var(--space-2);
}

.aside-back a {
  font-size: 0.8rem;
  font-weight: 600;
  text-decoration: none;
}

.aside-info {
  margin-top: var(--space-3);
  font-size: 0.78rem;
  color: var(--c-gray-600);
  line-height: 1.5;
}

.aside-info h3 {
  color: var(--c-black);
  margin-bottom: 4px;
}

/* === 正文容器 === */
.main-content {
  min-width: 0;
}

/* === main > section > div 三层结构 === */
main {
  flex: 1;
}

/* === Hero 区块（首页） === */
.hero-section {
  background: var(--c-black);
  color: var(--c-white);
  position: relative;
  min-height: 45vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding: var(--space-6) var(--space-3);
  clip-path: polygon(0 0, 100% 0, 100% 88%, 0 100%);
  margin-bottom: var(--space-5);
}

.hero-content {
  max-width: 600px;
  margin-left: calc((100% - var(--max-width)) / 2 + var(--space-3));
  position: relative;
  z-index: 2;
}

@media (max-width: 900px) {
  .hero-content {
    margin-left: var(--space-3);
  }
}

.hero-content h1 {
  font-size: clamp(1.6rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-2);
  letter-spacing: -0.01em;
}

.hero-desc {
  font-size: 1rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.85);
  margin-bottom: var(--space-3);
  max-width: 480px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  background: var(--c-white);
  color: var(--c-black);
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
  border: 2px solid var(--c-white);
  letter-spacing: 0.03em;
  transition: background 0.2s, color 0.2s;
  min-height: 44px;
}

.btn-primary:hover {
  background: transparent;
  color: var(--c-white);
  opacity: 1;
}

.hero-media {
  position: absolute;
  right: 0;
  top: 0;
  bottom: 0;
  width: 45%;
  overflow: hidden;
  opacity: 0.3;
}

.hero-media .hero-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* === 分类网格（首页） === */
.cat-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-3);
}

.cat-section h2 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-1);
}

.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.cat-item {
  border: 2px solid var(--c-black);
  transition: background 0.2s;
}

.cat-item a {
  display: flex;
  flex-direction: column;
  padding: var(--space-3);
  text-decoration: none;
  min-height: 90px;
}

.cat-item a:hover {
  background: var(--c-black);
  opacity: 1;
}

.cat-item a:hover .cat-title,
.cat-item a:hover .cat-desc {
  color: var(--c-white);
}

.cat-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--c-black);
  margin-bottom: 4px;
  transition: color 0.2s;
}

.cat-desc {
  font-size: 0.78rem;
  color: var(--c-gray-600);
  line-height: 1.4;
  transition: color 0.2s;
}

/* === 子页卡片 === */
.child-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.child-cards .card {
  border: 1px solid var(--c-gray-200);
  padding: var(--space-3);
  transition: border-color 0.2s;
}

.child-cards .card:hover {
  border-color: var(--c-black);
}

.child-cards .card h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: var(--space-1);
}

.child-cards .card h3 a {
  text-decoration: none;
}

.child-cards .card h3 a:hover {
  text-decoration: underline;
  opacity: 1;
}

.child-cards .card p {
  font-size: 0.82rem;
  color: var(--c-gray-600);
  line-height: 1.5;
  margin-bottom: 6px;
}

.child-cards .card time {
  font-size: 0.75rem;
  color: var(--c-gray-400);
  font-weight: 500;
}

/* === 面包屑 === */
.breadcrumb {
  font-size: 0.8rem;
  color: var(--c-gray-600);
  margin-bottom: var(--space-2);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px;
}

.breadcrumb a {
  color: var(--c-gray-600);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
  opacity: 1;
}

.breadcrumb span {
  color: var(--c-gray-400);
}

/* === 页面 Banner（栏目页） === */
.page-banner {
  background: var(--c-gray-100);
  border-bottom: 2px solid var(--c-black);
  padding: var(--space-4) var(--space-3);
}

.cat-banner {
  max-width: 100%;
  padding-left: calc((100% - var(--max-width)) / 2 + var(--space-3));
  padding-right: var(--space-3);
}

@media (max-width: 1240px) {
  .cat-banner {
    padding-left: var(--space-3);
  }
}

.page-banner h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  margin-top: var(--space-1);
  letter-spacing: -0.01em;
}

/* === 栏目子页列表 (div > section×n) === */
.child-list {
  margin-top: var(--space-4);
}

.child-list h2 {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-1);
}

.list-item {
  border-top: 1px solid var(--c-gray-200);
  padding: var(--space-2) 0;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  transition: background 0.15s;
}

.list-item:hover {
  background: var(--c-gray-100);
  padding-left: var(--space-1);
}

.list-item-main {
  flex: 1;
  min-width: 0;
}

.list-item h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.list-item h3 a {
  text-decoration: none;
}

.list-item h3 a:hover {
  text-decoration: underline;
  opacity: 1;
}

.list-item p {
  font-size: 0.82rem;
  color: var(--c-gray-600);
  line-height: 1.4;
}

.list-item time {
  font-size: 0.75rem;
  color: var(--c-gray-400);
  white-space: nowrap;
  font-weight: 500;
  flex-shrink: 0;
  margin-top: 2px;
}

/* === 文章页 === */
.article-header-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-3) var(--space-2);
}

.article-header-section h1 {
  font-size: clamp(1.4rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-2);
}

.article-meta {
  display: flex;
  gap: var(--space-3);
  font-size: 0.8rem;
  color: var(--c-gray-400);
  margin-bottom: var(--space-2);
  flex-wrap: wrap;
}

.article-meta time {
  font-weight: 600;
}

.article-hero-img {
  width: 100%;
  max-height: 380px;
  object-fit: cover;
  margin-top: var(--space-2);
  border: 1px solid var(--c-gray-200);
}

.article-footer-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-3);
  border-top: 2px solid var(--c-black);
}

.article-footer-section h2 {
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-1);
}

/* === 正文内容（prose） === */
.prose {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-black);
}

.prose h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: var(--space-4) 0 var(--space-1);
  letter-spacing: -0.01em;
}

.prose h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin: var(--space-3) 0 var(--space-1);
}

.prose p {
  margin-bottom: var(--space-2);
}

.prose ul, .prose ol {
  padding-left: var(--space-3);
  margin-bottom: var(--space-2);
}

.prose li {
  margin-bottom: 4px;
  list-style: disc;
}

.prose ol li {
  list-style: decimal;
}

.prose a {
  color: var(--c-black);
  font-weight: 600;
}

.prose blockquote {
  border-left: 4px solid var(--c-black);
  padding-left: var(--space-2);
  margin: var(--space-2) 0;
  color: var(--c-gray-600);
  font-style: italic;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-3) 0;
  font-size: 0.9rem;
}

.prose th, .prose td {
  border: 1px solid var(--c-gray-200);
  padding: 8px 12px;
  text-align: left;
}

.prose th {
  background: var(--c-gray-100);
  font-weight: 700;
}

/* === 关于/隐私/默认页 === */
.about-header-section,
.privacy-header-section,
.default-header-section {
  background: var(--c-black);
  color: var(--c-white);
  padding: var(--space-5) var(--space-3) var(--space-4);
}

.about-header-section h1,
.privacy-header-section h1,
.default-header-section h1 {
  max-width: var(--max-width);
  margin: 0 auto;
  font-size: clamp(1.4rem, 3vw, 2.2rem);
  font-weight: 700;
  line-height: 1.2;
}

.about-lead {
  max-width: var(--max-width);
  margin: var(--space-2) auto 0;
  font-size: 1rem;
  color: rgba(255,255,255,0.8);
  line-height: 1.6;
}

.privacy-date {
  max-width: var(--max-width);
  margin: var(--space-1) auto 0;
  font-size: 0.8rem;
  color: rgba(255,255,255,0.6);
}

.about-links-section,
.privacy-footer-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4) var(--space-3);
  border-top: 2px solid var(--c-black);
}

.about-links-section h2,
.privacy-footer-section h2 {
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-1);
}

.about-link-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  margin-top: var(--space-2);
}

.about-link-item {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  border: 2px solid var(--c-black);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  min-height: 40px;
  transition: background 0.2s, color 0.2s;
}

.about-link-item:hover {
  background: var(--c-black);
  color: var(--c-white);
  opacity: 1;
}

.page-date {
  font-size: 0.8rem;
  color: var(--c-gray-400);
  margin-top: var(--space-3);
}

/* === 按钮 === */
.btn-outline {
  display: inline-flex;
  align-items: center;
  padding: 10px 24px;
  border: 2px solid var(--c-black);
  font-size: 0.85rem;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 0.03em;
  min-height: 44px;
  transition: background 0.2s, color 0.2s;
}

.btn-outline:hover {
  background: var(--c-black);
  color: var(--c-white);
  opacity: 1;
}

.continue-nav {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-top: var(--space-2);
}

/* === 页脚 === */
.site-footer {
  background: var(--c-black);
  color: var(--c-white);
  border-top: 2px solid var(--c-black);
  display: grid;
  grid-template-columns: 1fr 1fr;
  max-width: 100%;
}

.footer-brand {
  padding: var(--space-5) var(--space-4);
  border-right: 1px solid rgba(255,255,255,0.1);
}

.footer-brand strong {
  font-size: 1.05rem;
  font-weight: 700;
  display: block;
  margin-bottom: var(--space-1);
  letter-spacing: 0.02em;
}

.footer-brand p {
  font-size: 0.82rem;
  color: rgba(255,255,255,0.6);
  line-height: 1.5;
  max-width: 320px;
}

.footer-links {
  padding: var(--space-5) var(--space-4);
}

.footer-links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 4px var(--space-3);
  margin-bottom: var(--space-3);
}

.footer-links ul li a {
  color: rgba(255,255,255,0.75);
  font-size: 0.82rem;
  text-decoration: none;
  min-height: 36px;
  display: flex;
  align-items: center;
  transition: color 0.15s;
}

.footer-links ul li a:hover {
  color: var(--c-white);
  opacity: 1;
}

.footer-copy {
  font-size: 0.75rem;
  color: rgba(255,255,255,0.4);
  display: flex;
  gap: var(--space-2);
  align-items: center;
  flex-wrap: wrap;
}

.footer-copy a {
  color: rgba(255,255,255,0.5);
  text-decoration: none;
}

.footer-copy a:hover {
  color: var(--c-white);
  opacity: 1;
}

/* === 内容区域（page-content 非 prose） === */
.page-content {
  font-size: 1rem;
  line-height: 1.75;
}

.page-content h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: var(--space-4) 0 var(--space-1);
}

.page-content h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: var(--space-3) 0 var(--space-1);
}

.page-content p {
  margin-bottom: var(--space-2);
}

.page-content ul, .page-content ol {
  padding-left: var(--space-3);
  margin-bottom: var(--space-2);
}

.page-content li {
  list-style: disc;
  margin-bottom: 4px;
}

.page-content a {
  color: var(--c-black);
  font-weight: 600;
}

/* === 动效（prefers-reduced-motion 兼容） === */
@media (prefers-reduced-motion: no-preference) {
  .card,
  .list-item,
  .cat-item,
  .child-cards .card {
    transition: transform 0.18s ease, border-color 0.18s ease, background 0.18s ease;
  }

  .card:hover,
  .child-cards .card:hover {
    transform: translateY(-2px);
  }

  .reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.4s ease, transform 0.4s ease;
  }

  .reveal.visible {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}

/* === 响应式断点 === */
@media (max-width: 900px) {
  .grid-wrap {
    grid-template-columns: 1fr;
    padding: var(--space-3) var(--space-2);
  }

  .left-aside {
    position: static;
    order: -1;
  }

  .site-footer {
    grid-template-columns: 1fr;
  }

  .footer-brand {
    border-right: none;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: var(--space-4) var(--space-3);
  }

  .footer-links {
    padding: var(--space-4) var(--space-3);
  }

  .hero-section {
    clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
    min-height: 40vh;
  }

  .hero-media {
    opacity: 0.15;
  }

  .cat-grid {
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  }
}

@media (max-width: 600px) {
  :root {
    --header-h: 56px;
    --space-5: 36px;
    --space-6: 48px;
  }

  .brand {
    font-size: 0.95rem;
  }

  .hero-content h1 {
    font-size: 1.45rem;
  }

  .hero-desc {
    font-size: 0.9rem;
  }

  .subnav-bar a {
    font-size: 0.75rem;
    padding: var(--space-1) 10px;
  }

  .nav-menu {
    min-width: 240px;
  }

  .cat-banner {
    padding-left: var(--space-2);
    padding-right: var(--space-2);
  }

  .about-header-section,
  .privacy-header-section {
    padding: var(--space-4) var(--space-2) var(--space-3);
  }

  .article-header-section {
    padding: var(--space-3) var(--space-2) var(--space-2);
  }

  .child-cards {
    grid-template-columns: 1fr;
  }

  .continue-nav {
    flex-direction: column;
  }

  .cat-section {
    padding: var(--space-3) var(--space-2);
  }
}

@media (max-width: 375px) {
  .header-inner {
    padding: 0 var(--space-2);
    gap: var(--space-2);
  }

  .nav-contact {
    font-size: 0.75rem;
    padding: var(--space-1) 10px;
  }
}