/* 
   山水云 (SHANSHUIYUN) Design System
   Style: Sharp Monochrome Editorial Technology
*/

:root {
  --color-bg: #FFFFFF;
  --color-ink: #191919;
  --color-pale: #F1F1EF;
  --color-accent: #A44943;
  --color-accent-hover: #8C3A35;
  --color-border: #E5E5E5;
  --color-border-dark: #333333;
  --color-muted: #666666;
  --color-dark-card: #222222;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
}

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

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-ink);
  background-color: var(--color-bg);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography Defaults */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--color-ink);
}

h1 {
  font-size: 39px;
}

@media (min-width: 1024px) {
  h1 {
    font-size: 66px;
  }
}

h2 {
  font-size: 28px;
  margin-bottom: 1rem;
}

@media (min-width: 768px) {
  h2 {
    font-size: 38px;
  }
}

h3 {
  font-size: 20px;
  margin-bottom: 0.75rem;
}

@media (min-width: 768px) {
  h3 {
    font-size: 24px;
  }
}

p {
  margin-bottom: 1.25rem;
  color: #333333;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--color-ink);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--color-accent);
}

.mono-tag {
  font-family: var(--font-mono);
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-muted);
}

.section-number {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-accent);
  font-weight: 700;
  margin-bottom: 0.5rem;
  display: inline-block;
}

/* Container & Grid Helpers */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

.section-padding {
  padding: 80px 0;
}

@media (min-width: 768px) {
  .section-padding {
    padding: 110px 0;
  }
}

.divider {
  width: 100%;
  height: 1px;
  background-color: var(--color-border);
  margin: 0;
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.03em;
  color: var(--color-ink);
}

.logo-brand span.tag {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 6px;
  background: var(--color-ink);
  color: #FFFFFF;
  border-radius: 2px;
  font-weight: 400;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 32px;
}

@media (min-width: 900px) {
  .nav-desktop {
    display: flex;
  }
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-ink);
  position: relative;
  padding: 4px 0;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: var(--color-accent);
  transition: width 0.2s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 14px;
  font-weight: 600;
  font-family: var(--font-sans);
  border-radius: 2px;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  text-align: center;
}

.btn-accent {
  background-color: var(--color-accent);
  color: #FFFFFF !important;
  border-color: var(--color-accent);
}

.btn-accent:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
}

.btn-outline {
  background-color: transparent;
  color: var(--color-ink) !important;
  border-color: var(--color-ink);
}

.btn-outline:hover {
  background-color: var(--color-ink);
  color: #FFFFFF !important;
}

.btn-dark {
  background-color: var(--color-ink);
  color: #FFFFFF !important;
}

.btn-dark:hover {
  background-color: #333333;
}

.mobile-menu-btn {
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  width: 28px;
  height: 22px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1100;
}

@media (min-width: 900px) {
  .mobile-menu-btn {
    display: none;
  }
}

.mobile-menu-btn span {
  width: 100%;
  height: 2px;
  background-color: var(--color-ink);
  transition: all 0.3s ease;
}

.mobile-menu-btn[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-btn[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.mobile-drawer {
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  z-index: 999;
  display: flex;
  flex-direction: column;
  padding: 32px 24px;
  gap: 24px;
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  border-top: 1px solid var(--color-border);
}

.mobile-drawer.open {
  transform: translateX(0);
}

.mobile-drawer .nav-link {
  font-size: 20px;
  font-weight: 600;
  border-bottom: 1px solid var(--color-pale);
  padding-bottom: 12px;
}

/* Hero Section */
.hero {
  padding: 60px 0 80px;
  background: radial-gradient(circle at 90% 10%, var(--color-pale) 0%, transparent 60%);
  border-bottom: 1px solid var(--color-border);
}

@media (min-width: 1024px) {
  .hero {
    padding: 100px 0 120px;
  }
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

@media (min-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr 1fr;
    gap: 64px;
  }
}

.hero-content .tag-line {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 6px 12px;
  background-color: var(--color-pale);
  border: 1px solid var(--color-border);
  margin-bottom: 24px;
}

.hero-content .status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-accent);
  display: inline-block;
}

.hero-title {
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 18px;
  line-height: 1.7;
  color: #444444;
  margin-bottom: 36px;
  max-width: 580px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

/* Dashboard Panel (Dark Monochrome Visual) */
.dashboard-panel {
  background-color: var(--color-ink);
  color: #FFFFFF;
  border: 1px solid var(--color-border-dark);
  border-radius: 4px;
  padding: 24px;
  font-family: var(--font-mono);
  box-shadow: 0 20px 40px rgba(0,0,0,0.15);
  position: relative;
  overflow: hidden;
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border-dark);
  padding-bottom: 16px;
  margin-bottom: 20px;
}

.dashboard-dots {
  display: flex;
  gap: 8px;
}

.dashboard-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #333333;
}

.dashboard-title {
  font-size: 12px;
  color: #888888;
  letter-spacing: 0.1em;
}

.scan-line {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
  animation: scanLine 2.5s cubic-bezier(0.4, 0, 0.2, 1) 1 forwards;
  pointer-events: none;
}

@keyframes scanLine {
  0% { top: 0%; opacity: 1; }
  90% { opacity: 0.8; }
  100% { top: 100%; opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .scan-line {
    display: none !important;
    animation: none !important;
  }
}

.dashboard-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}

.metric-card {
  background-color: #222222;
  border: 1px solid #333333;
  padding: 14px;
  border-radius: 2px;
}

.metric-label {
  font-size: 11px;
  color: #888888;
  margin-bottom: 4px;
}

.metric-value {
  font-size: 18px;
  font-weight: 700;
  color: #FFFFFF;
}

.dashboard-nodes-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.dashboard-node-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  padding: 8px 12px;
  background-color: #222222;
  border-left: 2px solid var(--color-accent);
}

.node-name {
  color: #EEEEEE;
  font-weight: 600;
}

.node-status {
  color: #888888;
  font-size: 11px;
}

.dashboard-disclaimer {
  margin-top: 16px;
  font-size: 10px;
  color: #666666;
  text-align: right;
  border-top: 1px dashed #333333;
  padding-top: 10px;
}

/* Feature Sections */
.features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 48px;
}

@media (min-width: 768px) {
  .features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: 36px 28px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.feature-card:hover {
  border-color: var(--color-ink);
}

.feature-icon-box {
  width: 44px;
  height: 44px;
  background-color: var(--color-pale);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-ink);
}

/* Global Nodes Matrix */
.nodes-matrix-grid {
  display: grid;
  grid-template-columns: repeat(1, 1fr);
  gap: 20px;
  margin-top: 40px;
}

@media (min-width: 640px) {
  .nodes-matrix-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .nodes-matrix-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.region-card {
  background-color: var(--color-pale);
  border: 1px solid var(--color-border);
  padding: 24px;
}

.region-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 12px;
}

.region-title {
  font-size: 18px;
  font-weight: 700;
}

.region-flag {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted);
}

.node-item-mini {
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  padding: 6px 0;
  border-bottom: 1px solid rgba(0,0,0,0.05);
}

/* Use Case Scenarios (AI & Streaming) */
.scenarios-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 48px;
}

@media (min-width: 768px) {
  .scenarios-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.scenario-card {
  border: 1px solid var(--color-border);
  padding: 32px;
  background: var(--color-bg);
  position: relative;
}

.scenario-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  background: var(--color-ink);
  color: #FFFFFF;
  padding: 3px 8px;
  margin-bottom: 16px;
}

.scenario-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.tag-chip {
  font-family: var(--font-mono);
  font-size: 12px;
  background-color: var(--color-pale);
  padding: 4px 10px;
  border: 1px solid var(--color-border);
  color: #333333;
}

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 48px;
}

@media (min-width: 768px) {
  .pricing-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.pricing-card {
  border: 1px solid var(--color-border);
  padding: 40px 28px;
  background: var(--color-bg);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
}

.pricing-card.featured {
  border: 2px solid var(--color-ink);
  background: #FAFAFA;
}

.pricing-badge {
  position: absolute;
  top: -12px;
  right: 24px;
  background: var(--color-accent);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 10px;
  font-weight: 700;
}

.pricing-header {
  margin-bottom: 24px;
}

.pricing-name {
  font-size: 22px;
  margin-bottom: 8px;
}

.pricing-price {
  font-size: 36px;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--color-ink);
  margin-bottom: 8px;
}

.pricing-price span {
  font-size: 14px;
  font-weight: 400;
  color: var(--color-muted);
}

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
}

.pricing-features li {
  font-size: 14px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--color-border);
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-features li::before {
  content: "✓";
  font-family: var(--font-mono);
  color: var(--color-accent);
  font-weight: 700;
}

/* 9 SEO Articles Grid (Immediate after pricing) */
.articles-section {
  background-color: var(--color-pale);
  padding: 90px 0;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 48px;
}

@media (min-width: 640px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.article-card:hover {
  border-color: var(--color-ink);
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted);
  margin-bottom: 16px;
}

.article-num {
  color: var(--color-accent);
  font-weight: 700;
}

.article-card-title {
  font-size: 18px;
  line-height: 1.4;
  margin-bottom: 12px;
}

.article-excerpt {
  font-size: 14px;
  color: #555555;
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-link {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--color-ink);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.article-link:hover {
  color: var(--color-accent);
}

/* Testimonials Section */
.testimonials-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 48px;
}

@media (min-width: 768px) {
  .testimonials-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.testimonial-card {
  border: 1px solid var(--color-border);
  padding: 32px;
  background-color: var(--color-bg);
}

.testimonial-quote {
  font-size: 15px;
  line-height: 1.7;
  color: #333333;
  margin-bottom: 24px;
  font-style: italic;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-avatar {
  width: 40px;
  height: 40px;
  background-color: var(--color-ink);
  color: #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
}

.author-info h4 {
  font-size: 15px;
  font-weight: 700;
  margin: 0;
}

.author-info p {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted);
  margin: 0;
}

/* Accordion FAQ */
.faq-list {
  max-width: 860px;
  margin: 48px auto 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  border: 1px solid var(--color-border);
  background-color: var(--color-bg);
}

.faq-button {
  width: 100%;
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: transparent;
  border: none;
  font-size: 17px;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  color: var(--color-ink);
  gap: 16px;
}

.faq-icon {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 400;
  transition: transform 0.2s ease;
}

.faq-button[aria-expanded="true"] .faq-icon {
  transform: rotate(45deg);
}

.faq-content {
  padding: 0 24px 24px 24px;
  display: none;
  border-top: 1px dashed var(--color-border);
  margin-top: 0;
  padding-top: 16px;
  color: #444444;
  font-size: 15px;
  line-height: 1.7;
}

.faq-content.open {
  display: block;
}

/* Article Template Styles */
.article-header {
  padding: 60px 0 40px;
  background-color: var(--color-pale);
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-muted);
  margin-bottom: 20px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.breadcrumb a {
  color: var(--color-muted);
}

.breadcrumb a:hover {
  color: var(--color-accent);
}

.article-body-wrapper {
  padding: 60px 0;
}

.article-content {
  max-width: 820px;
  margin: 0 auto;
  font-size: 16px;
  line-height: 1.8;
  color: #242424;
}

.article-content h2 {
  margin-top: 48px;
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}

.article-content h3 {
  margin-top: 32px;
  margin-bottom: 16px;
}

.article-content ul, .article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 8px;
}

.article-content blockquote {
  border-left: 3px solid var(--color-ink);
  padding: 16px 24px;
  background-color: var(--color-pale);
  margin: 28px 0;
  font-style: italic;
}

.callout-box {
  border: 1px solid var(--color-ink);
  background-color: #FAFAFA;
  padding: 24px;
  margin: 32px 0;
}

.callout-title {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 14px;
  color: var(--color-accent);
  margin-bottom: 8px;
  text-transform: uppercase;
}

.related-articles {
  margin-top: 60px;
  padding-top: 40px;
  border-top: 1px solid var(--color-border);
}

/* Footer */
.footer {
  background-color: var(--color-ink);
  color: #888888;
  padding: 80px 0 40px;
  margin-top: auto;
  font-size: 14px;
  border-top: 1px solid var(--color-border-dark);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  margin-bottom: 60px;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer-brand h3 {
  color: #FFFFFF;
  margin-bottom: 12px;
}

.footer-brand p {
  color: #888888;
  font-size: 14px;
  max-width: 320px;
}

.footer-heading {
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #FFFFFF;
  margin-bottom: 20px;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: #AAAAAA;
  transition: color 0.15s ease;
}

.footer-links a:hover {
  color: #FFFFFF;
}

.footer-bottom {
  border-top: 1px solid var(--color-border-dark);
  padding-top: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 12px;
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
  }
}