@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500&family=Playfair+Display:ital,wght@0,400;0,700;0,900;1,400&family=Source+Serif+4:ital,wght@0,300;0,400;0,600;1,300&display=swap');

/* =====================
   CSS 自定义属性
   ===================== */
:root {
  --color-black: #000000;
  --color-white: #ffffff;
  --color-gray-100: #f5f5f5;
  --color-gray-200: #e8e8e8;
  --color-gray-400: #999999;
  --color-gray-600: #555555;
  --color-gray-800: #222222;
  --font-display: 'Playfair Display', 'Source Serif 4', Georgia, serif;
  --font-body: 'Source Serif 4', Georgia, 'Noto Serif SC', serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
  --max-width: 1200px;
  --gap: 2rem;
  --radius: 10px;
  --header-height: 110px;
  --transition: 220ms ease;
}

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

html {
  font-size: 17px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-black);
  background: var(--color-white);
  overflow-x: hidden;
}

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

a {
  color: var(--color-black);
  text-decoration: none;
  transition: opacity var(--transition);
}

a:hover {
  opacity: 0.65;
}

a:focus-visible {
  outline: 2px solid var(--color-black);
  outline-offset: 2px;
}

ul, ol {
  list-style: none;
}

/* =====================
   全局布局容器
   ===================== */
.site-wrapper {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gap);
  width: 100%;
}

/* =====================
   顶部导航（两行）
   ===================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-black);
  color: var(--color-white);
  border-bottom: 2px solid var(--color-black);
}

.header-brand-row {
  border-bottom: 1px solid rgba(255,255,255,0.15);
}

.header-brand-row .header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.75rem;
  padding-bottom: 0.75rem;
  gap: 1rem;
}

.brand-link {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1rem, 2vw, 1.35rem);
  color: var(--color-white);
  letter-spacing: -0.02em;
  line-height: 1.2;
  white-space: nowrap;
}

.brand-link:hover {
  opacity: 0.8;
}

.header-contact {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: rgba(255,255,255,0.55);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.header-nav-row .header-inner {
  padding-top: 0;
  padding-bottom: 0;
}

.main-nav {
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.main-nav::-webkit-scrollbar {
  display: none;
}

.nav-link {
  display: flex;
  align-items: center;
  padding: 0.7rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  color: rgba(255,255,255,0.8);
  letter-spacing: 0.03em;
  border-right: 1px solid rgba(255,255,255,0.1);
  white-space: nowrap;
  min-height: 44px;
  transition: background var(--transition), color var(--transition);
}

.nav-link:first-child {
  border-left: 1px solid rgba(255,255,255,0.1);
}

.nav-link:hover,
.nav-link.active {
  background: var(--color-white);
  color: var(--color-black);
  opacity: 1;
}

/* =====================
   面包屑
   ===================== */
.page-eyebrow {
  background: var(--color-gray-100);
  border-bottom: 1px solid var(--color-gray-200);
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.4rem;
  padding: 0.6rem 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-600);
}

.breadcrumb a {
  color: var(--color-gray-600);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.breadcrumb span[aria-hidden] {
  color: var(--color-gray-400);
}

/* =====================
   Hero（首页）
   ===================== */
.hero {
  position: relative;
  min-height: 70vh;
  background: var(--color-black);
  color: var(--color-white);
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-dot-bg {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle, rgba(255,255,255,0.08) 1px, transparent 1px);
  background-size: 28px 28px;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 5rem var(--gap) 4rem;
  width: 100%;
}

.hero-content {
  max-width: 760px;
}

.hero-h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.4rem, 6vw, 5.5rem);
  line-height: 1.08;
  letter-spacing: -0.03em;
  color: var(--color-white);
  margin-bottom: 1.25rem;
}

.hero-sub {
  font-family: var(--font-body);
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  font-weight: 300;
  color: rgba(255,255,255,0.72);
  line-height: 1.65;
  margin-bottom: 2rem;
  max-width: 540px;
}

.hero-stats {
  display: flex;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.stat-num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 2.4rem;
  line-height: 1;
  color: var(--color-white);
}

.stat-unit {
  font-size: 1.2rem;
}

.stat-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: rgba(255,255,255,0.5);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  padding: 0.85rem 2rem;
  background: var(--color-white);
  color: var(--color-black);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  border-radius: var(--radius);
  min-height: 48px;
  transition: background var(--transition), color var(--transition);
}

.hero-cta:hover {
  background: var(--color-gray-200);
  opacity: 1;
}

/* =====================
   主内容区布局
   ===================== */
.main-content {
  flex: 1;
  padding: 3rem 0 4rem;
}

.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gap);
}

.layout-with-aside {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 3rem;
  align-items: start;
}

.main-col {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

/* =====================
   正文文章容器
   ===================== */
.page-article {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-gray-800);
}

.page-article h2,
.page-article h3 {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-black);
  margin-top: 1.8rem;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.page-article h2 { font-size: 1.5rem; }
.page-article h3 { font-size: 1.2rem; }

.page-article p {
  margin-bottom: 1rem;
}

.page-article ul,
.page-article ol {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.page-article ol { list-style: decimal; }

.page-article a {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-article strong { font-weight: 600; }
.page-article em { font-style: italic; }

.page-article time {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-gray-600);
}

/* =====================
   章节标题
   ===================== */
.section-title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.3rem, 2.5vw, 1.9rem);
  letter-spacing: -0.02em;
  color: var(--color-black);
  margin-bottom: 1.5rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--color-black);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title span {
  display: block;
}

/* =====================
   分类卡片网格
   ===================== */
.cats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
}

.cat-card {
  display: block;
  background: var(--color-gray-100);
  border-radius: var(--radius);
  transition: background var(--transition), transform var(--transition);
  text-decoration: none;
}

.cat-card:hover {
  background: var(--color-black);
  opacity: 1;
  transform: translateY(-2px);
}

.cat-card:hover .cat-card-title,
.cat-card:hover .cat-card-desc,
.cat-card:hover .cat-card-arrow {
  color: var(--color-white);
}

.cat-card-inner {
  padding: 1.4rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.cat-card-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-black);
  line-height: 1.3;
  transition: color var(--transition);
}

.cat-card-desc {
  font-size: 0.85rem;
  color: var(--color-gray-600);
  line-height: 1.5;
  transition: color var(--transition);
}

.cat-card-arrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-gray-400);
  margin-top: 0.5rem;
  transition: color var(--transition);
}

/* =====================
   条目列表 dl
   ===================== */
.child-list,
.entry-list,
.related-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.child-list dt,
.entry-list dt,
.related-list dt {
  padding: 0.9rem 0;
  border-top: 1px solid var(--color-gray-200);
}

.child-list dt:first-child,
.entry-list dt:first-child,
.related-list dt:first-child {
  border-top: none;
}

.child-list dt a,
.entry-list dt a,
.related-list dt a {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-black);
  text-decoration: none;
  transition: color var(--transition);
}

.child-list dt a:hover,
.entry-list dt a:hover,
.related-list dt a:hover {
  color: var(--color-gray-600);
  opacity: 1;
}

.child-desc {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.5rem 1rem;
  padding-bottom: 0.9rem;
  border-bottom: none;
  font-size: 0.88rem;
  color: var(--color-gray-600);
  line-height: 1.55;
}

.entry-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-gray-400);
  letter-spacing: 0.04em;
  flex-shrink: 0;
}

.read-more {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-black);
  text-decoration: underline;
  text-underline-offset: 2px;
  margin-left: auto;
  flex-shrink: 0;
}

/* =====================
   栏目页 Hero
   ===================== */
.cat-hero {
  padding: 2.5rem 0 0;
}

.cat-h1,
.entry-h1,
.tag-h1,
.about-h1,
.privacy-h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  letter-spacing: -0.025em;
  line-height: 1.12;
  color: var(--color-black);
  margin-bottom: 0.75rem;
}

.cat-desc {
  font-size: 1rem;
  color: var(--color-gray-600);
  line-height: 1.7;
  max-width: 620px;
}

/* =====================
   入口页面元信息
   ===================== */
.entry-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 0.75rem;
}

.meta-item {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-gray-600);
}

.meta-item a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* =====================
   标签页
   ===================== */
.tag-h1 {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.tag-label-prefix {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  background: var(--color-black);
  color: var(--color-white);
  padding: 0.2em 0.5em;
  border-radius: 4px;
  flex-shrink: 0;
  align-self: center;
}

.tags-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.tag-pill {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.85rem;
  background: var(--color-gray-100);
  color: var(--color-black);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  border-radius: 99px;
  border: 1px solid var(--color-gray-200);
  min-height: 36px;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.tag-pill:hover,
.tag-pill.active {
  background: var(--color-black);
  color: var(--color-white);
  border-color: var(--color-black);
  opacity: 1;
}

/* =====================
   侧边栏
   ===================== */
.page-aside,
.home-aside {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: sticky;
  top: calc(var(--header-height) + 1rem);
}

.aside-block {
  background: var(--color-gray-100);
  border-radius: var(--radius);
  padding: 1.25rem 1.3rem;
}

.aside-title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--color-black);
  margin-bottom: 0.9rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-gray-200);
  letter-spacing: 0.01em;
}

.aside-title span {
  display: block;
}

.aside-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}

.aside-nav-list li a {
  display: block;
  padding: 0.4rem 0;
  font-size: 0.88rem;
  color: var(--color-gray-800);
  border-bottom: 1px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.aside-nav-list li a:hover {
  color: var(--color-black);
  border-bottom-color: var(--color-gray-200);
  opacity: 1;
}

.aside-nav-list li a[aria-current="page"] {
  font-weight: 600;
  color: var(--color-black);
}

.aside-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-black);
  text-decoration: underline;
  text-underline-offset: 2px;
  margin-top: 0.5rem;
}

.aside-block > p {
  font-size: 0.85rem;
  color: var(--color-gray-600);
  line-height: 1.6;
  margin-bottom: 0.5rem;
}

/* =====================
   关于 / 隐私页
   ===================== */
.about-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-gray-600);
  margin-top: 0.5rem;
}

.privacy-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.privacy-link-item {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1.2rem;
  background: var(--color-gray-100);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  min-height: 40px;
  transition: background var(--transition), color var(--transition);
}

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

/* =====================
   空内容提示
   ===================== */
.no-content {
  color: var(--color-gray-400);
  font-style: italic;
  padding: 1.5rem 0;
}

/* =====================
   页脚
   ===================== */
.site-footer {
  background: var(--color-black);
  color: var(--color-white);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 2px solid var(--color-black);
}

.footer-col {
  padding: 2.5rem 2rem;
  border-right: 1px solid rgba(255,255,255,0.1);
}

.footer-col:last-child {
  border-right: none;
}

.footer-col h3 {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  color: rgba(255,255,255,0.45);
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.footer-col nav dl {
  display: flex;
  flex-direction: column;
  gap: 0.1rem;
}

.footer-col nav dl dt a,
.footer-col nav dl dd a {
  display: block;
  padding: 0.35rem 0;
  font-size: 0.88rem;
  color: rgba(255,255,255,0.7);
  min-height: 40px;
  display: flex;
  align-items: center;
  transition: color var(--transition);
}

.footer-col nav dl dt a:hover,
.footer-col nav dl dd a:hover {
  color: var(--color-white);
  opacity: 1;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 0.5rem;
}

.footer-brand-big {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.1rem, 2.2vw, 1.6rem);
  color: var(--color-white);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.footer-slogan {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.4);
  line-height: 1.5;
}

.footer-bottom {
  grid-column: 1 / -1;
  border-top: 1px solid rgba(255,255,255,0.12);
  padding: 1.25rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: rgba(255,255,255,0.4);
  letter-spacing: 0.04em;
}

.footer-bottom nav dl {
  display: flex;
  flex-direction: row;
  gap: 0;
}

.footer-bottom nav dl dt a,
.footer-bottom nav dl dd a {
  padding: 0.5rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: rgba(255,255,255,0.5);
  min-height: 40px;
  display: flex;
  align-items: center;
  transition: color var(--transition);
}

.footer-bottom nav dl dt a:hover,
.footer-bottom nav dl dd a:hover {
  color: var(--color-white);
  opacity: 1;
}

/* =====================
   交错动画 (stagger)
   ===================== */
@media (prefers-reduced-motion: no-preference) {
  .stagger-item {
    opacity: 0;
    transform: translateY(16px);
    animation: fadeUp 420ms ease forwards;
    animation-delay: calc(var(--stagger-i, 0) * 60ms);
  }

  @keyframes fadeUp {
    to {
      opacity: 1;
      transform: none;
    }
  }

  .cat-card {
    transition: background var(--transition), transform var(--transition), color var(--transition);
  }
}

@media (prefers-reduced-motion: reduce) {
  .stagger-item {
    opacity: 1;
    transform: none;
    animation: none;
  }
}

/* =====================
   首页特有区块
   ===================== */
.home-content-section,
.home-cats,
.home-entries,
.home-tags {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.home-cats .section-title,
.home-entries .section-title,
.home-tags .section-title {
  margin-bottom: 1.25rem;
}

/* =====================
   响应式：平板
   ===================== */
@media (max-width: 960px) {
  .layout-with-aside {
    grid-template-columns: 1fr;
  }

  .page-aside,
  .home-aside {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
  }

  .aside-block {
    flex: 1 1 220px;
  }

  .site-footer {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer-bottom {
    grid-column: 1 / -1;
  }
}

/* =====================
   响应式：手机 (375px)
   ===================== */
@media (max-width: 640px) {
  :root {
    --gap: 1.1rem;
  }

  html {
    font-size: 16px;
  }

  .hero {
    min-height: 70vh;
  }

  .hero-inner {
    padding: 3rem var(--gap) 2.5rem;
  }

  .hero-h1 {
    font-size: clamp(2rem, 10vw, 3rem);
  }

  .hero-stats {
    gap: 1.5rem;
  }

  .stat-num {
    font-size: 1.9rem;
  }

  .cats-grid {
    grid-template-columns: 1fr 1fr;
    gap: 0.8rem;
  }

  .cat-card-inner {
    padding: 1rem 1.1rem;
  }

  .main-nav {
    gap: 0;
  }

  .nav-link {
    padding: 0.65rem 0.7rem;
    font-size: 0.7rem;
    min-height: 44px;
  }

  .brand-link {
    font-size: 0.9rem;
  }

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

  .footer-col {
    padding: 1.5rem 1.1rem;
  }

  .footer-brand-col {
    grid-column: 1 / -1;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    padding: 1rem 1.1rem;
  }

  .footer-bottom nav dl {
    flex-wrap: wrap;
  }

  .layout-with-aside {
    gap: 2rem;
  }

  .page-aside,
  .home-aside {
    flex-direction: column;
  }

  .aside-block {
    flex: none;
  }

  .main-col {
    gap: 2rem;
  }

  .section-title {
    font-size: 1.2rem;
  }

  .cat-h1,
  .entry-h1,
  .tag-h1,
  .about-h1,
  .privacy-h1 {
    font-size: clamp(1.5rem, 7vw, 2rem);
  }

  .privacy-links {
    flex-direction: column;
  }

  .privacy-link-item {
    justify-content: center;
  }
}

/* =====================
   打印
   ===================== */
@media print {
  .site-header,
  .page-aside,
  .home-aside,
  .site-footer,
  .hero-cta {
    display: none;
  }

  body {
    font-size: 12pt;
    color: #000;
  }
}