/* 
  肥猫云 FatCatCloud - Modern Minimalist Dynamic CSS
  High Performance, Glassmorphism, Responsive & Dark Modern Aesthetic
*/

:root {
  --bg-dark: #07090e;
  --bg-card: rgba(18, 24, 38, 0.7);
  --bg-card-hover: rgba(28, 36, 56, 0.85);
  --accent-primary: #8b5cf6;
  --accent-primary-hover: #7c3aed;
  --accent-cyan: #06b6d4;
  --accent-pink: #ec4899;
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: rgba(139, 92, 246, 0.4);
  --glass-glow: 0 0 25px rgba(139, 92, 246, 0.15);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --font-stack: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition-fast: 0.25s ease;
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-stack);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

body {
  position: relative;
  min-height: 100vh;
  background: 
    radial-gradient(circle at 15% 15%, rgba(139, 92, 246, 0.12) 0%, transparent 40%),
    radial-gradient(circle at 85% 65%, rgba(6, 182, 212, 0.1) 0%, transparent 40%),
    var(--bg-dark);
  background-attachment: fixed;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(7, 9, 14, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition-fast);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.9rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  cursor: pointer;
  user-select: none;
  transition: transform var(--transition-fast);
}

.logo-brand:hover {
  transform: scale(1.03);
}

.logo-brand:active {
  transform: scale(0.97);
}

.cat-svg {
  width: 36px;
  height: 36px;
  fill: none;
  stroke: var(--text-main);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  filter: drop-shadow(0 0 8px rgba(139, 92, 246, 0.6));
}

.brand-text {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, #ffffff 30%, var(--accent-cyan) 70%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.8rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.nav-links a:hover {
  color: var(--text-main);
}

.nav-cta-btn {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-cyan));
  color: #fff !important;
  padding: 0.5rem 1.2rem;
  border-radius: 30px;
  font-weight: 600 !important;
  box-shadow: 0 4px 15px rgba(139, 92, 246, 0.3);
  transition: all var(--transition-fast) !important;
}

.nav-cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.5);
}

/* Page Section Layout */
.section {
  padding: 6rem 1.5rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.badge {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  background: rgba(139, 92, 246, 0.12);
  border: 1px solid rgba(139, 92, 246, 0.3);
  color: #a78bfa;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.5px;
  margin-bottom: 1rem;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 0.8rem;
  letter-spacing: -0.5px;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 650px;
  margin: 0 auto;
}

/* Hero Section */
.hero-section {
  padding-top: 9rem;
  padding-bottom: 5rem;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.2rem;
  line-height: 1.15;
  font-weight: 900;
  margin-bottom: 1.2rem;
  letter-spacing: -1px;
}

.hero-highlight {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-primary), var(--accent-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.btn-primary, .btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.9rem 1.8rem;
  border-radius: 40px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-primary-hover));
  color: #fff;
  box-shadow: 0 8px 25px rgba(139, 92, 246, 0.4);
  border: 1px solid rgba(255,255,255,0.15);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(139, 92, 246, 0.6);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--accent-cyan);
  transform: translateY(-3px);
  color: var(--accent-cyan);
}

.hero-stats {
  display: flex;
  gap: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
}

.stat-item h4 {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-cyan);
}

.stat-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Dynamic Interactive Hero Graphic */
.hero-graphic {
  position: relative;
}

.glass-card-main {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--glass-glow);
  position: relative;
  overflow: hidden;
}

.card-header-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 1.5rem;
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}
.dot-red { background: #ff5f56; }
.dot-yellow { background: #ffbd2e; }
.dot-green { background: #27c93f; }

.speed-meter {
  text-align: center;
  padding: 1.5rem 0;
}

.speed-value {
  font-size: 3.5rem;
  font-weight: 900;
  font-family: monospace;
  background: linear-gradient(135deg, #4ade80, var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.speed-label {
  font-size: 0.9rem;
  color: var(--text-muted);
  letter-spacing: 1px;
}

.ping-tags {
  display: flex;
  justify-content: space-around;
  margin-top: 1.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--border-color);
}

.ping-badge {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 0.4rem 0.8rem;
  border-radius: 12px;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 6px;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #22c55e;
  box-shadow: 0 0 8px #22c55e;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.2); }
  100% { opacity: 1; transform: scale(1); }
}

/* Feature Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.2rem 1.8rem;
  transition: all var(--transition-smooth);
  position: relative;
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-focus);
  transform: translateY(-6px);
  box-shadow: 0 12px 30px rgba(139, 92, 246, 0.2);
}

.feature-icon {
  width: 54px;
  height: 54px;
  background: rgba(139, 92, 246, 0.12);
  border: 1px solid rgba(139, 92, 246, 0.25);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  color: var(--accent-primary);
  font-size: 1.5rem;
}

.feature-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 0.8rem;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Streaming & AI Cards */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.media-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  transition: all var(--transition-fast);
}

.media-card:hover {
  transform: scale(1.04);
  border-color: var(--accent-cyan);
  box-shadow: 0 8px 25px rgba(6, 182, 212, 0.2);
}

.media-icon-wrapper {
  font-size: 2.2rem;
  margin-bottom: 0.8rem;
}

.media-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
}

.media-card p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Pricing Grid */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-smooth);
  position: relative;
}

.pricing-card.popular {
  border-color: var(--accent-primary);
  background: linear-gradient(180deg, rgba(139, 92, 246, 0.15) 0%, rgba(18, 24, 38, 0.85) 100%);
  box-shadow: 0 10px 40px rgba(139, 92, 246, 0.25);
  transform: scale(1.04);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-pink));
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.3rem 1rem;
  border-radius: 20px;
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.plan-price {
  margin: 1.2rem 0;
}

.price-amount {
  font-size: 3rem;
  font-weight: 900;
  color: var(--text-main);
}

.price-period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  margin: 1.8rem 0;
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
}

.plan-features li {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.plan-features li check-icon {
  color: #4ade80;
  font-weight: bold;
}

/* SEO Articles Grid Section */
.seo-articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.8rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-fast);
}

.article-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(139, 92, 246, 0.15);
}

.article-tag {
  font-size: 0.75rem;
  color: var(--accent-cyan);
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 0.6rem;
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.8rem;
  color: var(--text-main);
}

.article-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 1.2rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-read-btn {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: color var(--transition-fast);
}

.article-read-btn:hover {
  color: var(--accent-cyan);
}

/* FAQ Accordion */
.faq-list {
  max-width: 850px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-item details summary {
  padding: 1.4rem 1.8rem;
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-item details summary::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--accent-cyan);
  transition: transform var(--transition-fast);
}

.faq-item details[open] summary::after {
  transform: rotate(45deg);
}

.faq-content {
  padding: 0 1.8rem 1.4rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 0.5rem;
  padding-top: 1rem;
}

/* User Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.8rem;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.8rem;
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 0.8rem;
  font-size: 1rem;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.2rem;
  font-style: italic;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.user-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-cyan));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
}

.user-info h5 {
  font-size: 0.95rem;
  font-weight: 700;
}

.user-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Vertical Section Navigation Arrows on Right */
.side-nav-controls {
  position: fixed;
  right: 1.8rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 99;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.nav-arrow-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(18, 24, 38, 0.85);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  backdrop-filter: blur(12px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
  transition: all var(--transition-fast);
}

.nav-arrow-btn:hover {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: #fff;
  transform: scale(1.12);
  box-shadow: 0 6px 20px rgba(139, 92, 246, 0.5);
}

.nav-arrow-btn:active {
  transform: scale(0.92);
}

/* Footer */
footer {
  background: rgba(4, 6, 10, 0.95);
  border-top: 1px solid var(--border-color);
  padding: 4rem 1.5rem 2.5rem;
  margin-top: 4rem;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
}

.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2.5rem;
  margin-bottom: 3.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--border-color);
}

.footer-col h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--text-main);
}

.footer-col p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 0.6rem;
}

.footer-col ul li a {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--accent-cyan);
}

.pbn-footer-matrix {
  text-align: center;
  padding: 1.5rem 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.pbn-copyright {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0.8rem;
}

.pbn-links-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

.pbn-link-item {
  color: var(--accent-cyan);
  font-size: 0.92rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  padding: 0.3rem 0.8rem;
  background: rgba(6, 182, 212, 0.08);
  border-radius: 8px;
  border: 1px solid rgba(6, 182, 212, 0.2);
}

.pbn-link-item:hover {
  color: #fff;
  background: var(--accent-cyan);
  box-shadow: 0 4px 15px rgba(6, 182, 212, 0.4);
}

/* Mobile & Tablet Responsive Media Queries */
@media (max-width: 1024px) {
  .hero-section {
    grid-template-columns: 1fr;
    text-align: center;
    padding-top: 7rem;
  }
  
  .hero-actions {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

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

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

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

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

  .section {
    padding: 4rem 1.2rem 2.5rem;
  }

  .hero-content h1 {
    font-size: 2.2rem;
  }

  .features-grid, .pricing-grid, .seo-articles-grid, .reviews-grid, .media-ai-grid, .footer-nav-grid {
    grid-template-columns: 1fr;
  }

  .pricing-card.popular {
    transform: none;
  }

  .side-nav-controls {
    right: 0.8rem;
  }

  .nav-arrow-btn {
    width: 40px;
    height: 40px;
  }
}