/* 九霄云 (9xiaoyun.cfd) - 高级方格纸极简风格样式 */

:root {
  --color-white: #FFFFFF;
  --color-graphite: #30383B;
  --color-muted-blue: #6F93A1;
  --color-muted-blue-hover: #5A7E8C;
  --color-pale-grid: #E8EEF0;
  --color-border: #D8E2E6;
  --color-bg-subtle: #F6F9FA;
  --color-text-muted: #5C676D;
  --color-accent-light: #EBF3F6;

  --font-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", Consolas, "Liberation Mono", Menlo, Monaco, Courier, monospace;

  --h1-desktop: 51px;
  --h1-mobile: 34px;
  --body-size: 18px;

  --max-width: 1200px;
  --radius-sm: 4px;
  --radius-md: 8px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-size: var(--body-size);
  line-height: 1.65;
  color: var(--color-graphite);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--color-graphite);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.01em;
}

h1 {
  font-size: var(--h1-desktop);
  margin-bottom: 20px;
}

h2 {
  font-size: 32px;
  margin-bottom: 16px;
}

h3 {
  font-size: 22px;
  margin-bottom: 12px;
}

p {
  margin-bottom: 16px;
  color: var(--color-graphite);
}

a {
  color: var(--color-muted-blue);
  text-decoration: none;
  transition: color 0.2s ease, border-color 0.2s ease;
}

a:hover, a:focus-visible {
  color: var(--color-muted-blue-hover);
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  letter-spacing: 0.03em;
}

/* Layout Container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Buttons & CTAs */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  font-size: 16px;
  font-weight: 600;
  font-family: var(--font-heading);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  line-height: 1;
}

.btn-primary {
  background-color: var(--color-graphite);
  color: var(--color-white);
  border-color: var(--color-graphite);
}

.btn-primary:hover, .btn-primary:focus-visible {
  background-color: var(--color-muted-blue);
  border-color: var(--color-muted-blue);
  color: var(--color-white);
}

.btn-secondary {
  background-color: var(--color-white);
  color: var(--color-graphite);
  border-color: var(--color-graphite);
}

.btn-secondary:hover, .btn-secondary:focus-visible {
  background-color: var(--color-pale-grid);
  color: var(--color-graphite);
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  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-link {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 700;
  color: var(--color-graphite);
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border: 1.5px solid var(--color-graphite);
  color: var(--color-muted-blue);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: bold;
}

.nav-desktop {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-graphite);
  padding: 6px 0;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-muted-blue);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-muted-blue);
}

.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  cursor: pointer;
  color: var(--color-graphite);
  font-size: 16px;
}

.mobile-nav {
  display: none;
  position: absolute;
  top: 72px;
  left: 0;
  right: 0;
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  padding: 20px 24px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.mobile-nav.open {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.mobile-nav .nav-link {
  font-size: 17px;
  padding: 8px 0;
  border-bottom: 1px solid var(--color-pale-grid);
}

/* CSS Grid Background strictly ONLY behind Hero and Dashboard */
.grid-bg-hero {
  background-color: var(--color-white);
  background-image: 
    linear-gradient(to right, var(--color-pale-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--color-pale-grid) 1px, transparent 1px);
  background-size: 24px 24px;
  border-bottom: 1px solid var(--color-border);
  padding: 60px 0 80px 0;
}

/* Hero Section */
.hero-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-copy {
  padding-right: 16px;
}

.hero-tag {
  display: inline-block;
  padding: 4px 10px;
  background-color: var(--color-white);
  border: 1px solid var(--color-muted-blue);
  color: var(--color-muted-blue);
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hero-title {
  font-size: var(--h1-desktop);
  color: var(--color-graphite);
  line-height: 1.15;
  margin-bottom: 24px;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  max-width: 520px;
}

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

/* Dashboard Panel */
.dashboard-panel {
  background-color: var(--color-white);
  border: 1.5px solid var(--color-graphite);
  border-radius: var(--radius-sm);
  padding: 24px;
  box-shadow: 6px 6px 0px var(--color-pale-grid);
  position: relative;
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 12px;
  margin-bottom: 20px;
}

.dashboard-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-graphite);
}

.dashboard-status {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted-blue);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-muted-blue);
}

/* SVG Route Network Graphic */
.network-svg {
  width: 100%;
  height: auto;
  display: block;
}

.route-path {
  stroke: var(--color-muted-blue);
  stroke-width: 2.5;
  stroke-dasharray: 600;
  stroke-dashoffset: 600;
  fill: none;
  animation: drawRoutePath 2.2s cubic-bezier(0.25, 1, 0.5, 1) forwards;
  animation-iteration-count: 1;
}

@keyframes drawRoutePath {
  to {
    stroke-dashoffset: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .route-path {
    animation: none;
    stroke-dashoffset: 0;
  }
}

.node-point {
  fill: var(--color-white);
  stroke: var(--color-graphite);
  stroke-width: 2;
}

.node-point.active {
  fill: var(--color-muted-blue);
  stroke: var(--color-white);
}

.dashboard-regions {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px dashed var(--color-border);
}

.region-box {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  padding: 10px;
  border-radius: var(--radius-sm);
  text-align: center;
}

.region-code {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-muted);
  display: block;
}

.region-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-graphite);
}

.dashboard-note {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-muted);
  margin-top: 12px;
  text-align: right;
}

/* Section Shared Styling */
.section {
  padding: 80px 0;
  border-bottom: 1px solid var(--color-border);
}

.section-header {
  margin-bottom: 48px;
  max-width: 680px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-muted-blue);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-size: 32px;
  color: var(--color-graphite);
}

/* Benefits / Advantages Section (Open text + annotated lines) */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.advantage-card {
  border-left: 2px solid var(--color-graphite);
  padding-left: 20px;
  position: relative;
}

.advantage-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -6px;
  width: 10px;
  height: 2px;
  background-color: var(--color-graphite);
}

.advantage-ref {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted-blue);
  margin-bottom: 8px;
  display: block;
}

.advantage-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.advantage-card p {
  font-size: 16px;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* Global Nodes Matrix */
.nodes-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.matrix-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  padding: 24px;
  border-radius: var(--radius-sm);
  position: relative;
}

.matrix-card::after {
  content: '';
  position: absolute;
  bottom: -1px;
  right: -1px;
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--color-muted-blue);
  border-bottom: 2px solid var(--color-muted-blue);
}

.matrix-region-id {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted-blue);
  margin-bottom: 6px;
}

.matrix-region-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.matrix-desc {
  font-size: 15px;
  color: var(--color-text-muted);
}

/* AI & Streaming Scenarios (Large Explanatory Panels) */
.scenarios-wrapper {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.scenario-panel {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  padding: 36px;
  border-radius: var(--radius-md);
}

.scenario-category {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-muted-blue);
  text-transform: uppercase;
  margin-bottom: 12px;
  display: block;
}

.scenario-items {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 24px;
}

.scenario-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  padding: 20px;
  border-radius: var(--radius-sm);
}

.scenario-item-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.service-name {
  font-weight: 700;
  font-size: 17px;
  color: var(--color-graphite);
}

.service-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 2px 6px;
  background-color: var(--color-accent-light);
  color: var(--color-muted-blue);
  border-radius: 2px;
}

.service-desc {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 0;
  line-height: 1.5;
}

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.pricing-card.recommended {
  border: 2px solid var(--color-graphite);
  box-shadow: 4px 4px 0px var(--color-pale-grid);
}

.badge-recommended {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-graphite);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 14px;
  border-radius: 12px;
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.tier-name {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
}

.tier-period {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-muted-blue);
  margin-bottom: 16px;
}

.tier-traffic {
  font-size: 26px;
  font-weight: 800;
  color: var(--color-graphite);
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-pale-grid);
}

.tier-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.tier-features li {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 10px;
  position: relative;
  padding-left: 20px;
}

.tier-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-muted-blue);
  font-weight: bold;
}

.tier-placeholder {
  font-family: var(--font-mono);
  font-size: 11px;
  color: #8C99A0;
  background-color: var(--color-bg-subtle);
  padding: 6px 10px;
  border-radius: 2px;
  margin-bottom: 20px;
}

.pricing-card .btn {
  width: 100%;
}

/* 9 Article Cards Section */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.article-card:hover {
  border-color: var(--color-muted-blue);
  box-shadow: 0 4px 16px rgba(111, 147, 161, 0.1);
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.article-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-muted-blue);
  background-color: var(--color-accent-light);
  padding: 2px 8px;
  border-radius: 2px;
}

.article-date {
  font-family: var(--font-mono);
  font-size: 12px;
  color: #8C99A0;
}

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

.article-card-title a {
  color: var(--color-graphite);
}

.article-card-title a:hover {
  color: var(--color-muted-blue);
}

.article-excerpt {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 20px;
  flex-grow: 1;
  line-height: 1.6;
}

.article-read-more {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-muted-blue);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Testimonials Section */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.testimonial-card {
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  padding: 24px;
  border-radius: var(--radius-sm);
  position: relative;
}

.testimonial-sample-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  color: #8C99A0;
  display: block;
  margin-bottom: 12px;
}

.testimonial-quote {
  font-size: 15px;
  color: var(--color-graphite);
  font-style: italic;
  margin-bottom: 16px;
  line-height: 1.6;
}

.testimonial-author {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-graphite);
}

.testimonial-role {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-muted);
}

/* FAQ Accordion Section */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 900px;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-white);
  overflow: hidden;
}

.faq-button {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  background: none;
  border: none;
  text-align: left;
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 600;
  color: var(--color-graphite);
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.faq-button:hover, .faq-button:focus-visible {
  background-color: var(--color-bg-subtle);
}

.faq-icon {
  width: 20px;
  height: 20px;
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0.25, 1, 0.5, 1), padding 0.3s ease;
  padding: 0 24px;
  background-color: var(--color-white);
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 0 24px 20px 24px;
}

.faq-answer p {
  font-size: 16px;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* Article Detail Pages Styling */
.article-page-header {
  padding: 40px 0 24px 0;
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

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

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

.article-content {
  padding: 48px 0 64px 0;
  max-width: 860px;
}

.article-content h2 {
  font-size: 26px;
  margin-top: 36px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-pale-grid);
}

.article-content h3 {
  font-size: 20px;
  margin-top: 28px;
  margin-bottom: 12px;
}

.article-content p {
  font-size: 17px;
  line-height: 1.75;
  margin-bottom: 20px;
  color: #384245;
}

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

.article-content li {
  font-size: 16px;
  line-height: 1.7;
  margin-bottom: 8px;
  color: #384245;
}

.tech-note-box {
  background-color: var(--color-bg-subtle);
  border-left: 3px solid var(--color-muted-blue);
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 15px;
}

.tech-note-box .note-title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--color-muted-blue);
  text-transform: uppercase;
  margin-bottom: 4px;
  display: block;
}

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

/* Footer Section */
.footer {
  background-color: var(--color-bg-subtle);
  border-top: 1px solid var(--color-border);
  padding: 60px 0 32px 0;
  margin-top: 80px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer-brand p {
  font-size: 14px;
  color: var(--color-text-muted);
  max-width: 320px;
}

.footer-heading {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--color-graphite);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

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

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

.footer-links a {
  font-size: 14px;
  color: var(--color-text-muted);
}

.footer-links a:hover {
  color: var(--color-muted-blue);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  border-top: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: 12px;
  color: #8C99A0;
}

/* Responsive Media Queries */

/* Tablet (1024px) */
@media (max-width: 1024px) {
  .hero-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

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

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

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

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

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

/* Mobile & Small Tablet (768px) */
@media (max-width: 768px) {
  :root {
    --body-size: 16px;
  }

  h1 {
    font-size: var(--h1-mobile);
  }

  .nav-desktop {
    display: none;
  }

  .mobile-toggle {
    display: block;
  }

  .advantages-grid {
    grid-template-columns: 1fr;
  }

  .article-grid {
    grid-template-columns: 1fr;
  }

  .pricing-grid {
    grid-template-columns: 1fr;
  }

  .scenario-items {
    grid-template-columns: 1fr;
  }

  .testimonials-grid {
    grid-template-columns: 1fr;
  }

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

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

/* Small Mobile (430px, 390px, 375px) */
@media (max-width: 430px) {
  .container {
    padding: 0 16px;
  }

  .article-grid {
    grid-template-columns: 1fr;
  }

  .nodes-matrix {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .dashboard-panel {
    padding: 16px;
  }
}