/* ==========================================================================
   狗狗加速 Brand Data Journal - Core Stylesheet
   Style: Lake Blue Data Journal Style (湖蓝数据期刊风格)
   Primary Color: #164F5B | Secondary: #73AEB7 | Text: #233439 | Background: #F0F7F8
   ========================================================================== */

:root {
  --bg-main: #F0F7F8;
  --bg-alt: #E4F1F3;
  --bg-card: #FFFFFF;
  --color-primary: #164F5B;
  --color-primary-hover: #0E363E;
  --color-secondary: #73AEB7;
  --color-secondary-light: #EBF5F7;
  --color-text: #233439;
  --color-text-muted: #566E75;
  --color-border: #D1E4E7;
  --color-border-dark: #164F5B;
  --color-accent-tag: #164F5B;
  
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  --font-size-h1-desktop: 50px;
  --font-size-h1-mobile: 34px;
  --font-size-body: 16px;

  --container-max-width: 1200px;
  --grid-gap: 24px;

  --transition-speed: 0.25s;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-body);
  line-height: 1.65;
  color: var(--color-text);
  background-color: var(--bg-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Focus outline for keyboard navigation */
:focus-visible {
  outline: 3px solid var(--color-secondary);
  outline-offset: 3px;
}

a {
  color: var(--color-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color var(--transition-speed) ease;
}

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

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

/* Typography Rules */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-primary);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

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

@media (min-width: 768px) {
  h1 {
    font-size: var(--font-size-h1-desktop);
  }
}

h2 {
  font-size: 1.875rem; /* 30px */
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-primary);
}

h3 {
  font-size: 1.35rem; /* ~21.6px */
  margin-bottom: 12px;
}

h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

p {
  margin-bottom: 16px;
}

/* Monospace Data Label Utility */
.journal-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem; /* 13px */
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary);
  background: var(--color-secondary-light);
  border: 1px solid var(--color-secondary);
  padding: 4px 10px;
  display: inline-block;
  margin-bottom: 12px;
}

.mono-text {
  font-family: var(--font-mono);
}

/* Layout Containers */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 60px 0;
  border-bottom: 1px solid var(--color-border);
}

.section-alt {
  background-color: var(--bg-alt);
}

.section-header {
  margin-bottom: 40px;
  text-align: left;
}

.section-subtitle {
  color: var(--color-text-muted);
  font-size: 1.1rem;
  margin-top: -8px;
}

/* Navigation Header */
.site-header {
  background-color: var(--bg-main);
  border-bottom: 2px solid var(--color-primary);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(22, 79, 91, 0.05);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--color-primary);
}

.brand-logo .logo-text {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.brand-logo .logo-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background-color: var(--color-primary);
  color: #FFFFFF;
  padding: 2px 6px;
  border-radius: 2px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-link {
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--color-text);
  padding: 6px 0;
  position: relative;
}

.nav-link:hover, .nav-link:focus-visible {
  color: var(--color-primary);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background-color: var(--color-primary);
  transition: width var(--transition-speed) ease;
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
}

/* Buttons & Controls */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  border: 2px solid var(--color-primary);
  transition: all var(--transition-speed) ease;
  cursor: pointer;
}

.btn-primary {
  background-color: var(--color-primary);
  color: #FFFFFF;
}

.btn-primary:hover, .btn-primary:focus-visible {
  background-color: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: #FFFFFF;
}

.btn-outline {
  background-color: transparent;
  color: var(--color-primary);
}

.btn-outline:hover, .btn-outline:focus-visible {
  background-color: var(--color-secondary-light);
  color: var(--color-primary);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.875rem;
}

/* Hero Section */
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
  padding: 40px 0;
}

@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.1fr 0.9fr;
  }
}

.hero-content {
  text-align: left;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-top: 28px;
  flex-wrap: wrap;
}

/* Right Side Network Data Panel */
.network-panel {
  background: var(--bg-card);
  border: 2px solid var(--color-primary);
  padding: 24px;
  box-shadow: 6px 6px 0px var(--color-secondary);
}

.panel-title {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--color-primary);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 10px;
  margin-bottom: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.panel-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.node-card-schematic {
  border: 1px solid var(--color-border);
  padding: 14px;
  background-color: var(--bg-main);
}

.node-region-code {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-primary);

.node-region-name {
  font-size: 0.95rem;
  color: var(--color-text);
  font-weight: 600;
  margin-top: 2px;
}

.node-specs {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-muted);
  margin-top: 8px;
  border-top: 1px dashed var(--color-border);
  padding-top: 6px;
}

/* Gentle CSS Wave Animation */
.wave-container {
  width: 100%;
  overflow: hidden;
  line-height: 0;
  background-color: var(--bg-main);
  border-bottom: 1px solid var(--color-border);
}

.wave-svg {
  position: relative;
  display: block;
  width: calc(100% + 1.3px);
  height: 50px;
}

.wave-path {
  fill: var(--bg-alt);
  animation: waveMotion 12s cubic-bezier(0.36, 0.45, 0.63, 0.53) infinite;
  transform: translate3d(0, 0, 0);
}

@keyframes waveMotion {
  0% { transform: translateX(0); }
  50% { transform: translateX(-25%); }
  100% { transform: translateX(0); }
}

@media (prefers-reduced-motion: reduce) {
  .wave-path {
    animation: none;
  }
}

/* Three Advantages Grid */
.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

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

.advantage-card {
  background: var(--bg-card);
  border: 1px solid var(--color-border);
  border-top: 4px solid var(--color-primary);
  padding: 24px;
}

.advantage-num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: 12px;
}

/* Global Nodes Region Directory */
.directory-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  border: 1px solid var(--color-border);
  margin-top: 20px;
}

.directory-table th, .directory-table td {
  padding: 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.directory-table th {
  background-color: var(--color-primary);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  text-transform: uppercase;
}

.directory-table tr:hover {
  background-color: var(--color-secondary-light);
}

/* AI & Streaming Scenarios */
.scenarios-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

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

.scenario-card {
  background-color: var(--bg-card);
  border: 1px solid var(--color-border);
  padding: 28px;
}

.pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 16px 0;
}

.pill-item {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  background: var(--bg-main);
  border: 1px solid var(--color-border);
  padding: 4px 10px;
  color: var(--color-primary);
  font-weight: 600;
}

.disclaimer-box {
  margin-top: 24px;
  padding: 14px 18px;
  background-color: var(--color-secondary-light);
  border-left: 4px solid var(--color-primary);
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* Pricing Section (4 Column Layout) */
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 30px;
}

@media (min-width: 576px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .pricing-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--color-border);
  padding: 24px;
  display: flex;
  flex-direction: column;
  position: relative;
}

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

.badge-recommended {
  position: absolute;
  top: -14px;
  right: 16px;
  background-color: var(--color-primary);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 2px 10px;
  font-weight: 700;
  text-transform: uppercase;
}

.price-title {
  font-size: 1.25rem;
  margin-bottom: 8px;
}

.price-value {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.price-notice {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  background-color: var(--bg-main);
  padding: 8px;
  border: 1px dashed var(--color-border);
  margin-bottom: 20px;
  line-height: 1.4;
}

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

/* Nine Articles Entrance Grid */
.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

@media (min-width: 600px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 992px) {
  .articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  background-color: var(--bg-card);
  border: 1px solid var(--color-border);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-speed) ease, border-color var(--transition-speed) ease;
}

.article-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-3px);
}

.article-vol {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: 8px;
}

.article-card-title {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.article-card-title a {
  text-decoration: none;
  color: var(--color-primary);
}

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

.article-desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
  flex-grow: 1;
}

.article-readmore {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

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

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

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

.testimonial-text {
  font-style: italic;
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.testimonial-author {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary);
}

.testimonial-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: #C0392B;
  background-color: #FDEDEC;
  border: 1px solid #F5C6CB;
  padding: 2px 8px;
  margin-top: 8px;
}

/* Expandable FAQ Section */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 900px;
  margin: 0 auto;
}

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

.faq-item summary {
  padding: 18px 24px;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--color-secondary);
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-content {
  padding: 0 24px 20px 24px;
  color: var(--color-text);
  border-top: 1px dashed var(--color-border);
  margin-top: 8px;
  padding-top: 16px;
}

/* Article Page Layout & Typography */
.article-header {
  padding: 40px 0 20px 0;
  border-bottom: 1px solid var(--color-border);
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.breadcrumb li::after {
  content: '/';
  margin-left: 8px;
  color: var(--color-border);
}

.breadcrumb li:last-child::after {
  content: '';
}

.article-content {
  padding: 40px 0;
  max-width: 860px;
  margin: 0 auto;
}

.article-content p {
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 24px;
}

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

.article-content li {
  margin-bottom: 8px;
  line-height: 1.7;
}

.article-content code {
  font-family: var(--font-mono);
  background-color: var(--bg-alt);
  padding: 2px 6px;
  border: 1px solid var(--color-border);
  font-size: 0.9em;
}

.article-content blockquote {
  border-left: 4px solid var(--color-primary);
  background-color: var(--color-secondary-light);
  padding: 16px 20px;
  margin: 24px 0;
  font-style: italic;
}

.article-image-box {
  margin: 30px 0;
  border: 1px solid var(--color-border);
  background-color: var(--bg-card);
  padding: 12px;
}

.article-image-box img {
  width: 100%;
  height: auto;
  border: 1px solid var(--color-border);
}

.article-image-box figcaption {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  margin-top: 8px;
  text-align: center;
}

.related-articles {
  margin-top: 50px;
  padding-top: 30px;
  border-top: 2px solid var(--color-primary);
}

/* Footer Section */
.site-footer {
  background-color: var(--color-primary);
  color: #FFFFFF;
  padding: 60px 0 30px 0;
  margin-top: auto;
}

.site-footer a {
  color: var(--color-secondary);
}

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

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-bottom: 40px;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
  }
}

.footer-col h4 {
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  text-transform: uppercase;
  margin-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  padding-bottom: 6px;
}

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

.footer-links li {
  margin-bottom: 8px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 20px;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.7);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
}

/* Mobile Nav Open State */
@media (max-width: 767px) {
  .mobile-toggle {
    display: block;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background-color: var(--bg-main);
    flex-direction: column;
    padding: 20px;
    border-bottom: 2px solid var(--color-primary);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
  }

  .nav-menu.is-active {
    display: flex;
  }

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