/* ==========================================================================
   旧巷 (jiuxiang.cyou) - 3D微拟物/Neumorphism UI Stylesheet
   Design Style: Soft Neumorphic UI, Extruded & Inset Shadows, Tactile Controls
   ========================================================================== */

:root {
  --bg-main: #e6ecf5;
  --bg-dark: #111827;
  --neu-light: #ffffff;
  --neu-dark: #b8c4d6;
  --text-main: #2d3748;
  --text-muted: #64748b;
  --text-heading: #1e293b;
  --accent-primary: #2563eb;
  --accent-glow: rgba(37, 99, 235, 0.35);
  --accent-secondary: #06b6d4;
  --success: #10b981;
  --warning: #f59e0b;
  
  /* Neumorphism Extruded & Inset Shadows */
  --neu-flat: 8px 8px 16px var(--neu-dark), -8px -8px 16px var(--neu-light);
  --neu-flat-sm: 4px 4px 10px var(--neu-dark), -4px -4px 10px var(--neu-light);
  --neu-flat-lg: 12px 12px 24px var(--neu-dark), -12px -12px 24px var(--neu-light);
  --neu-inset: inset 4px 4px 8px var(--neu-dark), inset -4px -4px 8px var(--neu-light);
  --neu-inset-sm: inset 2px 2px 5px var(--neu-dark), inset -2px -2px 5px var(--neu-light);
  --neu-pressed: inset 3px 3px 6px var(--neu-dark), inset -3px -3px 6px var(--neu-light);
  
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: var(--transition-fast);
}

a:hover {
  color: #1d4ed8;
}

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Typography Utility */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading);
  font-weight: 700;
  line-height: 1.3;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  background: var(--bg-main);
  box-shadow: var(--neu-flat-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-primary);
}

/* Neumorphic Buttons */
.neu-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.85rem 1.75rem;
  border-radius: var(--radius-md);
  background: var(--bg-main);
  box-shadow: var(--neu-flat);
  color: var(--text-heading);
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: var(--transition-fast);
  user-select: none;
  text-align: center;
  white-space: nowrap;
}

.neu-btn:hover {
  box-shadow: 6px 6px 12px var(--neu-dark), -6px -6px 12px var(--neu-light);
  transform: translateY(-2px);
  color: var(--accent-primary);
}

.neu-btn:active {
  box-shadow: var(--neu-inset);
  transform: translateY(0);
}

.neu-btn-primary {
  background: linear-gradient(145deg, #2563eb, #1d4ed8);
  color: #ffffff !important;
  box-shadow: 6px 6px 14px rgba(37, 99, 235, 0.4), -4px -4px 10px rgba(255, 255, 255, 0.8);
}

.neu-btn-primary:hover {
  background: linear-gradient(145deg, #1d4ed8, #1e40af);
  box-shadow: 8px 8px 18px rgba(37, 99, 235, 0.5), -4px -4px 10px rgba(255, 255, 255, 0.9);
  color: #ffffff !important;
}

.neu-btn-primary:active {
  box-shadow: inset 3px 3px 6px rgba(0, 0, 0, 0.4), inset -3px -3px 6px rgba(255, 255, 255, 0.2);
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(230, 236, 245, 0.9);
  backdrop-filter: blur(12px);
  padding: 1rem 0;
  transition: var(--transition-normal);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-heading);
}

.brand-logo img {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  box-shadow: var(--neu-flat-sm);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-main);
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
}

.nav-links a:hover {
  box-shadow: var(--neu-inset-sm);
  color: var(--accent-primary);
}

/* Hero Section (Asymmetric Double Column) */
.hero-section {
  padding: 5rem 0 4rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-content h1 {
  font-size: 3rem;
  letter-spacing: -0.02em;
  margin-top: 1.25rem;
  margin-bottom: 1.25rem;
  color: var(--text-heading);
}

.hero-content h1 span {
  background: linear-gradient(135deg, #2563eb, #06b6d4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.25rem;
  max-width: 600px;
}

/* Hero 3 Buttons Parallel Group */
.hero-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  width: 100%;
}

.hero-actions .neu-btn {
  flex: 1 1 auto;
  min-width: 180px;
}

.hero-highlights {
  display: flex;
  gap: 1.5rem;
  margin-top: 2.5rem;
  flex-wrap: wrap;
}

.highlight-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Hero Right Neumorphic Showcase Card */
.showcase-card {
  background: var(--bg-main);
  border-radius: var(--radius-lg);
  box-shadow: var(--neu-flat-lg);
  padding: 2rem;
  position: relative;
}

.showcase-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--neu-dark);
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--success);
  box-shadow: 0 0 10px var(--success);
  display: inline-block;
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  background: var(--bg-main);
  box-shadow: var(--neu-flat-sm);
  transition: var(--transition-fast);
}

.node-item:hover {
  box-shadow: var(--neu-inset-sm);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
}

.node-ping {
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--success);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  box-shadow: var(--neu-inset-sm);
}

/* Section Title Base */
.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-header h2 {
  font-size: 2.25rem;
  margin-top: 0.5rem;
}

.section-header p {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-top: 0.5rem;
}

/* Features Section (Neumorphic Extruded Cards) */
.features-section {
  padding: 4rem 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: var(--bg-main);
  border-radius: var(--radius-lg);
  box-shadow: var(--neu-flat);
  padding: 2.25rem;
  transition: var(--transition-normal);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--neu-flat-lg);
}

.feature-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  box-shadow: var(--neu-flat-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 1.5rem;
  color: var(--accent-primary);
}

.feature-card h3 {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Pricing Section (Horizontal Wide Comparison Table & Tab Switch) */
.pricing-section {
  padding: 5rem 0;
}

.billing-switch-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.neu-toggle-container {
  display: inline-flex;
  padding: 0.4rem;
  border-radius: var(--radius-full);
  background: var(--bg-main);
  box-shadow: var(--neu-inset);
}

.neu-toggle-btn {
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius-full);
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-fast);
}

.neu-toggle-btn.active {
  background: var(--bg-main);
  box-shadow: var(--neu-flat-sm);
  color: var(--accent-primary);
}

.save-badge {
  background: linear-gradient(135deg, #10b981, #059669);
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
}

/* Neumorphic Comparison Table */
.table-responsive {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--neu-flat-lg);
  background: var(--bg-main);
  padding: 1.5rem;
}

.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  min-width: 720px;
}

.comparison-table th,
.comparison-table td {
  padding: 1.25rem 1rem;
  text-align: center;
  border-bottom: 1px solid var(--neu-dark);
}

.comparison-table th:first-child,
.comparison-table td:first-child {
  text-align: left;
  font-weight: 600;
}

.comparison-table th {
  background: var(--bg-main);
  font-size: 1.1rem;
  color: var(--text-heading);
}

.plan-header {
  padding: 1rem;
}

.plan-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.plan-price {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--accent-primary);
}

.plan-price span {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 400;
}

.table-cta-cell {
  padding-top: 1.5rem !important;
  border-bottom: none !important;
}

.table-cta-cell .neu-btn {
  width: 100%;
  padding: 0.65rem 1rem;
  font-size: 0.9rem;
}

/* Devices Section */
.devices-section {
  padding: 4rem 0;
}

.devices-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1.5rem;
}

.device-card {
  background: var(--bg-main);
  border-radius: var(--radius-md);
  box-shadow: var(--neu-flat);
  padding: 1.75rem 1rem;
  text-align: center;
  transition: var(--transition-fast);
}

.device-card:hover {
  box-shadow: var(--neu-inset);
  color: var(--accent-primary);
}

.device-icon {
  font-size: 2.25rem;
  margin-bottom: 0.75rem;
}

/* Articles Preview Section */
.articles-section {
  padding: 4rem 0;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.article-card {
  background: var(--bg-main);
  border-radius: var(--radius-lg);
  box-shadow: var(--neu-flat);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition-normal);
}

.article-card:hover {
  box-shadow: var(--neu-flat-lg);
  transform: translateY(-4px);
}

.article-tag {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.article-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
  color: var(--text-heading);
}

.article-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-top: 1px solid var(--neu-dark);
  padding-top: 1rem;
}

/* FAQ Accordion Section */
.faq-section {
  padding: 4rem 0 5rem;
}

.faq-container {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.faq-item {
  background: var(--bg-main);
  border-radius: var(--radius-md);
  box-shadow: var(--neu-flat);
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-question {
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  user-select: none;
}

.faq-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  box-shadow: var(--neu-flat-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  transition: var(--transition-fast);
}

.faq-item.active .faq-icon {
  box-shadow: var(--neu-inset-sm);
  transform: rotate(180deg);
  color: var(--accent-primary);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease-out;
  padding: 0 1.5rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 1.5rem 1.5rem;
}

/* Reviews Section */
.reviews-section {
  padding: 4rem 0;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.review-card {
  background: var(--bg-main);
  border-radius: var(--radius-md);
  box-shadow: var(--neu-flat);
  padding: 1.75rem;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  box-shadow: var(--neu-flat-sm);
  background: var(--bg-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: bold;
  color: var(--accent-primary);
}

.stars {
  color: var(--warning);
  font-size: 0.9rem;
}

/* Semantic Footer & PBN Weight Link Pipeline */
.site-footer {
  background: var(--bg-main);
  box-shadow: inset 0 8px 16px var(--neu-dark);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
  text-align: center;
  border-top: 1px solid rgba(184, 196, 214, 0.4);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--text-heading);
}

.footer-copyright {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Low-profile Subtle PBN External Link Bar */
.pbn-links-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed var(--neu-dark);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.pbn-links-area span {
  opacity: 0.7;
}

.pbn-links-area a {
  color: var(--text-muted);
  font-weight: 500;
  text-decoration: none;
  opacity: 0.85;
  transition: var(--transition-fast);
}

.pbn-links-area a:hover {
  color: var(--accent-primary);
  opacity: 1;
  text-decoration: underline;
}

/* Mobile Responsive Adaptations */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .hero-content h1 {
    font-size: 2.4rem;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero-section {
    padding: 3rem 0 2rem;
  }

  .hero-content h1 {
    font-size: 2rem;
  }

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

  .hero-actions .neu-btn {
    width: 100%;
    min-width: unset;
    white-space: normal;
  }

  .features-grid, .articles-grid, .reviews-grid {
    grid-template-columns: 1fr;
  }
}