:root {
  --white: #ffffff;
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --bg-dark: #0a0a0a;
  --text-primary: #0a0a0a;
  --text-secondary: #555555;
  --text-muted: #999999;
  --text-light: #cccccc;
  --border: #e5e5e5;
  --border-light: #dddddd;
  --accent: #2a2a2a;
  --font-en: 'Space Grotesk', sans-serif;
  --font-cn: 'Noto Sans SC', sans-serif;
  --container: 1200px;
  --nav-height: 72px;
  --radius: 3px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
  --transition: 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-cn); color: var(--text-primary); background: var(--bg);
  line-height: 1.7; font-weight: 400;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { border: none; background: none; cursor: pointer; font-family: inherit; }

body::before {
  content: ''; position: fixed; inset: 0; pointer-events: none; z-index: 9999;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  opacity: 0.025;
}

.container { max-width: var(--container); margin: 0 auto; padding: 0 32px; }

.overline {
  font-family: var(--font-en); font-size: 11px; font-weight: 600;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--text-muted);
}

/* Navigation */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-height); z-index: 1000;
  transition: all var(--transition); background: transparent;
}
.nav.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}
.nav.menu-open {
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}
.nav.menu-open .nav-logo { color: var(--text-primary); }
.nav.menu-open .nav-logo .logo-mark { background: var(--text-primary); color: var(--white); }
.nav.menu-open .nav-menu-btn { color: var(--text-primary); }

.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; max-width: var(--container); margin: 0 auto; padding: 0 32px;
}
.nav-logo {
  font-family: var(--font-en); font-size: 20px; font-weight: 700;
  letter-spacing: -0.02em; color: var(--white);
  transition: color var(--transition); display: flex; align-items: center; gap: 10px;
}
.nav-logo .logo-mark {
  width: 32px; height: 32px; background: var(--white); border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700; color: var(--bg-dark);
  transition: background var(--transition), color var(--transition);
}
.nav.scrolled .nav-logo { color: var(--text-primary); }
.nav.scrolled .nav-logo .logo-mark { background: var(--text-primary); color: var(--white); }

.nav-links { display: flex; align-items: center; gap: 36px; }
.nav-links a {
  font-size: 14px; font-weight: 400; color: rgba(255,255,255,0.8);
  transition: color var(--transition); position: relative;
}
.nav-links a::after {
  content: ''; position: absolute; bottom: -4px; left: 0;
  width: 0; height: 1.5px; background: var(--white);
  transition: width var(--transition), background var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--white); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav.scrolled .nav-links a { color: var(--text-secondary); }
.nav.scrolled .nav-links a:hover, .nav.scrolled .nav-links a.active { color: var(--text-primary); }
.nav.scrolled .nav-links a::after { background: var(--text-primary); }

.nav-cta .btn { padding: 10px 24px; font-size: 13px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 24px;
  font-size: 13px; font-weight: 500; letter-spacing: 0.02em;
  border-radius: var(--radius); transition: all var(--transition); cursor: pointer;
}
.btn-primary { background: var(--white); color: var(--text-primary); }
.btn-primary:hover { background: rgba(255,255,255,0.9); }
.nav.scrolled .nav-cta .btn-primary { background: var(--text-primary); color: var(--white); }
.nav.scrolled .nav-cta .btn-primary:hover { background: var(--accent); }

.nav-menu-btn { display: none; color: var(--white); transition: color var(--transition); }
.nav.scrolled .nav-menu-btn { color: var(--text-primary); }

/* Mobile Menu */
.mobile-menu {
  display: none; position: fixed; inset: 0; background: var(--white);
  z-index: 1100; flex-direction: column; align-items: center; justify-content: center; gap: 32px;
  opacity: 0; pointer-events: none; transition: opacity 0.4s ease;
}
.mobile-menu.open { opacity: 1; pointer-events: all; }
.mobile-menu a { font-size: 28px; font-weight: 500; color: var(--text-primary); }
.mobile-menu-close { position: absolute; top: 24px; right: 32px; color: var(--text-primary); z-index: 2; }

/* ===== Article Detail Header ===== */
.detail-header { margin: 40px 0 32px; }
.breadcrumb a { color: #999; }
.breadcrumb a:hover { color: #0a0a0a; }
.breadcrumb .current { color: #666; }
.detail-meta { display: flex; align-items: center; gap: 16px; margin-bottom: 20px; }
.detail-tag {
  font-size: 12px; padding: 4px 14px; border-radius: 20px;
  background: #f5f5f5; color: #666;
}
.detail-date { font-size: 14px; color: #999; }
.detail-title {
  font-size: clamp(28px, 4vw, 42px); font-weight: 700; color: #0a0a0a;
  line-height: 1.25; letter-spacing: -0.02em; margin-bottom: 20px;
}
.detail-desc { font-size: 16px; color: #666; line-height: 1.8; max-width: 720px; }

/* Hero Cover */
.hero-cover {
  position: relative; height: 360px; overflow: hidden;
}
.hero-cover-deco {
  position: absolute; inset: 0; z-index: 2;
  display: flex; align-items: center; justify-content: center;
  pointer-events: none;
}
.hero-cover-deco-text {
  font-family: var(--font-en);
  font-size: clamp(40px, 8vw, 96px);
  font-weight: 700;
  color: rgba(255,255,255,0.08);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  white-space: nowrap;
}
.hero-cover-bg {
  position: absolute; inset: 0; background-size: cover; background-position: center;
  transform: scale(1.05); transition: transform 10s ease;
}
.hero-cover-bg.loaded { transform: scale(1); }
.hero-cover-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0.35) 100%);
}
.hero-cover-content {
  position: relative; z-index: 2; height: 100%;
  display: flex; flex-direction: column; justify-content: flex-end;
  padding-bottom: 72px;
}
.hero-meta {
  display: flex; align-items: center; gap: 12px; margin-bottom: 28px;
}
.hero-meta .date {
  font-family: var(--font-en); font-size: 12px; font-weight: 500;
  letter-spacing: 0.15em; text-transform: uppercase; color: rgba(255,255,255,0.5);
}
.hero-meta .divider { width: 1px; height: 12px; background: rgba(255,255,255,0.3); }
.hero-meta .tag {
  font-size: 12px; padding: 3px 12px; border: 1px solid rgba(255,255,255,0.25);
  border-radius: 20px; color: rgba(255,255,255,0.6);
}
.hero-cover-content h1 {
  font-size: clamp(30px, 5vw, 52px); font-weight: 700; color: var(--white);
  line-height: 1.2; letter-spacing: -0.02em; max-width: 780px; margin-bottom: 24px;
}
.hero-cover-content .hero-desc {
  font-size: clamp(15px, 2vw, 17px); color: rgba(255,255,255,0.7);
  max-width: 620px; line-height: 1.8;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate-fadeIn { animation: fadeIn 0.6s ease forwards; }
.animate-fadeIn-d1 { animation: fadeIn 0.6s ease 0.15s forwards; opacity: 0; }
.animate-fadeIn-d2 { animation: fadeIn 0.6s ease 0.3s forwards; opacity: 0; }

/* Article Layout */
.article-layout {
  display: grid; grid-template-columns: 1fr 300px;
  gap: 80px; align-items: start;
  padding: 64px 0 100px;
}

/* Breadcrumb */
.breadcrumb {
  display: flex; align-items: center; gap: 0;
  font-size: 13px; color: var(--text-muted); margin-bottom: 32px;
}
.breadcrumb a { transition: color var(--transition); }
.breadcrumb a:hover { color: var(--text-primary); }
.breadcrumb .sep { margin: 0 8px; }
.breadcrumb .current { color: var(--text-secondary); }

/* Author Bar */
.author-bar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 20px;
  margin-bottom: 40px; padding-bottom: 32px;
  border-bottom: 1px solid var(--border);
}
.author-info { display: flex; align-items: center; gap: 12px; }
.author-avatar {
  width: 40px; height: 40px; border-radius: 50%; background: var(--bg-alt);
  display: flex; align-items: center; justify-content: center; color: var(--text-primary);
}
.author-name { font-size: 13px; font-weight: 500; color: var(--text-primary); }
.author-role { font-size: 11px; color: var(--text-muted); }
.author-meta {
  display: flex; align-items: center; gap: 16px;
  font-size: 13px; color: var(--text-muted);
}
.author-meta span { display: flex; align-items: center; gap: 6px; }
.author-meta .meta-divider { width: 1px; height: 12px; background: var(--border); }

/* Article Body */
.article-body h2 {
  font-size: 22px; font-weight: 700; margin: 48px 0 16px;
  color: var(--text-primary); letter-spacing: -0.01em; line-height: 1.35;
}
.article-body h2:first-child { margin-top: 0; }
.article-body h3 {
  font-size: 18px; font-weight: 600; margin: 36px 0 12px;
  color: var(--text-primary); line-height: 1.4;
}
.article-body p {
  font-size: 16px; line-height: 1.95; color: var(--text-secondary); margin-bottom: 22px;
}
.article-body blockquote {
  border-left: 3px solid var(--text-primary); padding: 22px 28px; margin: 32px 0;
  background: var(--bg-alt); font-size: 15px; color: var(--text-secondary);
  line-height: 1.85; border-radius: 0 var(--radius) var(--radius) 0;
}
.article-body ul {
  padding-left: 22px; margin-bottom: 22px;
}
.article-body li {
  font-size: 16px; line-height: 1.95; color: var(--text-secondary);
  margin-bottom: 10px; list-style: disc;
}
.article-body .highlight-box {
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px 32px; margin: 32px 0;
  font-size: 15px; line-height: 1.85; color: var(--text-secondary);
}
.article-body .highlight-box strong { color: var(--text-primary); }

/* Tags */
.article-tags {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  margin-top: 40px; padding-top: 32px; border-top: 1px solid var(--border);
}
.article-tags .tags-label { font-size: 13px; color: var(--text-muted); margin-right: 4px; }
.article-tags .tag {
  font-size: 12px; padding: 4px 12px; border: 1px solid var(--border);
  border-radius: 100px; color: var(--text-muted); transition: all var(--transition);
  cursor: pointer;
}
.article-tags .tag:hover {
  background: var(--text-primary); color: var(--white); border-color: var(--text-primary);
}

/* Prev / Next */
.prev-next {
  display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 40px;
}
.prev-next a {
  display: flex; align-items: center; gap: 12px; padding: 20px;
  border: 1px solid var(--border); border-radius: var(--radius);
  transition: all var(--transition);
}
.prev-next a:hover {
  transform: translateY(-2px); box-shadow: var(--shadow-sm);
  border-color: var(--text-primary);
}
.prev-next .next-link { justify-content: flex-end; text-align: right; }
.prev-next .pn-label { font-size: 11px; color: var(--text-muted); margin-bottom: 4px; }
.prev-next .pn-title {
  font-size: 13px; font-weight: 500; color: var(--text-primary);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.prev-next .pn-icon {
  flex-shrink: 0; color: var(--text-muted); width: 16px; height: 16px;
}

/* Sidebar */
.sidebar { position: sticky; top: 96px; }
.sidebar-block { margin-bottom: 40px; }
.sidebar-title {
  font-size: 13px; font-weight: 600; margin-bottom: 20px;
  padding-bottom: 12px; border-bottom: 1px solid var(--border);
  letter-spacing: 0.02em;
}
.sidebar-article {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 12px; margin: 0 -12px; border-radius: var(--radius);
  transition: all var(--transition); cursor: pointer;
}
.sidebar-article:hover {
  transform: translateY(-2px); box-shadow: var(--shadow-md);
}
.sidebar-article-num {
  font-family: var(--font-en); font-size: 20px; font-weight: 700;
  color: var(--border-light); line-height: 1; flex-shrink: 0; margin-top: 2px;
}
.sidebar-article:nth-child(-n+3) .sidebar-article-num { color: var(--text-primary); }
.sidebar-article h5 {
  font-size: 13px; font-weight: 500; line-height: 1.5; margin-bottom: 4px;
  color: var(--text-primary);
}
.sidebar-article .sa-date { font-size: 11px; color: var(--text-muted); }

/* Sidebar CTA */
.sidebar-cta {
  background: var(--bg-dark); color: var(--white); padding: 32px;
  border-radius: var(--radius);
}
.sidebar-cta h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.sidebar-cta p {
  font-size: 13px; color: rgba(255,255,255,0.6); line-height: 1.7; margin-bottom: 24px;
}
.sidebar-cta .btn-cta {
  width: 100%; display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 24px; font-size: 13px; font-weight: 500;
  background: var(--white); color: var(--text-primary); border-radius: var(--radius);
  transition: all var(--transition);
}
.sidebar-cta .btn-cta:hover { background: rgba(255,255,255,0.9); }

/* Related Articles */
.related-section { padding: 100px 0; background: var(--bg-alt); }
.related-header {
  display: flex; justify-content: space-between; align-items: flex-end;
  gap: 16px; margin-bottom: 56px;
}
.related-header .section-label {
  font-family: var(--font-en); font-size: 13px; font-weight: 500;
  letter-spacing: 0.15em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 12px;
}
.related-header h2 {
  font-size: clamp(28px, 4vw, 32px); font-weight: 700;
  letter-spacing: -0.02em; line-height: 1.2;
}
.btn-outline-sm {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 24px;
  font-size: 13px; font-weight: 500; letter-spacing: 0.02em;
  border: 1.5px solid var(--text-primary); color: var(--text-primary);
  border-radius: var(--radius); background: transparent; transition: all var(--transition);
}
.btn-outline-sm:hover { background: var(--text-primary); color: var(--white); }

.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.related-card {
  border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border);
  background: var(--white); transition: all var(--transition); cursor: pointer;
}
.related-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.related-card-img {
  width: 100%; height: 200px; background-size: cover; background-position: center;
  position: relative; transition: transform 0.6s ease;
}
.related-card:hover .related-card-img { transform: scale(1.02); }
.related-card-img::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.45) 0%, transparent 55%);
  opacity: 0; transition: opacity 0.35s ease;
}
.related-card:hover .related-card-img::after { opacity: 1; }
.related-card-body { padding: 24px; }
.related-card-meta { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.related-card-meta .rc-date { font-family: var(--font-en); font-size: 12px; color: var(--text-muted); }
.related-card-meta .rc-tag {
  font-size: 11px; padding: 2px 10px; border: 1px solid var(--border);
  border-radius: 20px; color: var(--text-muted);
}
.related-card-body h3 {
  font-size: 16px; font-weight: 600; line-height: 1.45; margin-bottom: 8px;
}
.related-card-body p {
  font-size: 13px; color: var(--text-secondary); line-height: 1.7;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}

/* Footer */
.footer { background: var(--bg-dark); color: var(--white); padding: 80px 0 0; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 64px; margin-bottom: 64px; }
.footer-brand h3 { font-family: var(--font-en); font-size: 22px; font-weight: 700; margin-bottom: 16px; letter-spacing: -0.02em; }
.footer-brand p { font-size: 14px; color: rgba(255,255,255,0.5); line-height: 1.7; max-width: 320px; }
.footer-col h4 { font-size: 14px; font-weight: 600; margin-bottom: 24px; letter-spacing: 0.02em; }
.footer-col ul li { margin-bottom: 14px; }
.footer-col ul li a { font-size: 14px; color: rgba(255,255,255,0.5); transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--white); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1); padding: 24px 0;
  display: flex; justify-content: space-between; align-items: center;
}
.footer-bottom p { font-size: 13px; color: rgba(255,255,255,0.35); }
.footer-bottom-links { display: flex; gap: 24px; }
.footer-bottom-links a { font-size: 13px; color: rgba(255,255,255,0.35); transition: color var(--transition); }
.footer-bottom-links a:hover { color: rgba(255,255,255,0.7); }

/* Side Tools */
.side-tools {
  position: fixed; right: 28px; top: 50%; transform: translateY(-50%);
  z-index: 950; display: flex; flex-direction: column; gap: 6px;
}
.side-tool-btn {
  width: 52px; height: 52px; background: var(--white); border: 1px solid var(--border);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: all var(--transition); color: var(--text-primary);
  position: relative; box-shadow: var(--shadow-sm); padding: 0;
}
.side-tool-btn:hover {
  background: var(--text-primary); color: var(--white); border-color: var(--text-primary);
  transform: scale(1.08); box-shadow: var(--shadow-md);
}
.side-tool-label {
  position: absolute; right: 62px; white-space: nowrap;
  background: var(--text-primary); color: var(--white);
  padding: 6px 14px; border-radius: var(--radius);
  font-size: 13px; font-weight: 500; opacity: 0; pointer-events: none;
  transform: translateX(8px); transition: all var(--transition); box-shadow: var(--shadow-sm);
}
.side-tool-label::after {
  content: ''; position: absolute; right: -6px; top: 50%; transform: translateY(-50%);
  border-top: 6px solid transparent; border-bottom: 6px solid transparent;
  border-left: 6px solid var(--text-primary);
}
.side-tool-btn:hover .side-tool-label { opacity: 1; transform: translateX(0); }

/* Back to Top */
.back-to-top {
  position: fixed; bottom: 32px; right: 32px;
  width: 48px; height: 48px; background: var(--text-primary); color: var(--white);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  z-index: 100; opacity: 0; pointer-events: none;
  transform: translateY(12px); transition: all var(--transition); box-shadow: var(--shadow-md);
}
.back-to-top.visible { opacity: 1; pointer-events: all; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-2px); }

/* Scroll Reveal */
.reveal { opacity: 0; transform: translateY(32px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* Responsive */
@media (max-width: 1024px) {
  .article-layout { grid-template-columns: 1fr; gap: 48px; }
  .related-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .sidebar { position: static; }
}

@media (max-width: 768px) {
  :root { --nav-height: 60px; }
  .nav-links, .nav-cta { display: none; }
  .nav-menu-btn { display: flex; }
  .mobile-menu { display: flex; }

  .hero-cover { height: 320px; }
  .hero-cover-content { padding-bottom: 32px; }
  .hero-cover-content h1 { font-size: 28px; }

  .article-layout { padding: 40px 0 80px; }
  .article-body h2 { font-size: 20px; margin-top: 36px; }
  .prev-next { grid-template-columns: 1fr; }
  .prev-next .next-link { justify-content: flex-start; text-align: left; }

  .related-grid { grid-template-columns: 1fr; }
  .related-header { flex-direction: column; align-items: flex-start; }

  .side-tools { display: none !important; }
  .back-to-top { bottom: 20px; right: 20px; }

  .footer-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}

@media (max-width: 480px) {
  .container { padding: 0 20px; }
  .hero-cover { height: 260px; }
  .hero-cover-content h1 { font-size: 24px; }
  .author-bar { flex-direction: column; align-items: flex-start; }
}