/* ==========================================================================
   奈云 (NaiYun) - Premium Technology SaaS Stylesheet
   Pure Vanilla CSS - Mobile First, SEO Friendly, High Performance
   ========================================================================== */

:root {
  --bg-main: #07090e;
  --bg-card: rgba(15, 23, 42, 0.65);
  --bg-card-hover: rgba(26, 38, 66, 0.75);
  --bg-nav: rgba(7, 9, 14, 0.85);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-highlight: rgba(56, 189, 248, 0.4);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --primary: #38bdf8;
  --primary-glow: rgba(56, 189, 248, 0.25);
  --secondary: #818cf8;
  --accent-green: #34d399;
  --accent-purple: #c084fc;
  --accent-amber: #fbbf24;
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --container-max: 1200px;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
  background-image: 
    radial-gradient(circle at 15% 15%, rgba(56, 189, 248, 0.07) 0%, transparent 40%),
    radial-gradient(circle at 85% 65%, rgba(129, 140, 248, 0.07) 0%, transparent 45%);
  background-attachment: fixed;
}

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

ul {
  list-style: none;
}

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

/* Typography & Utilities */
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.25;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 0%, #38bdf8 50%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 0.8125rem;
  font-weight: 600;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.3);
  color: var(--primary);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
}

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

.section {
  padding: 80px 0;
}

@media (max-width: 768px) {
  .section {
    padding: 50px 0;
  }
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 50px;
}

.section-header h2 {
  font-size: 2.25rem;
  margin-top: 12px;
  margin-bottom: 16px;
}

.section-header p {
  font-size: 1.0625rem;
  color: var(--text-muted);
}

@media (max-width: 768px) {
  .section-header h2 {
    font-size: 1.75rem;
  }
  .section-header p {
    font-size: 0.9375rem;
  }
}

/* Glass Card */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.glass-card:hover {
  border-color: var(--border-highlight);
  background: var(--bg-card-hover);
  box-shadow: 0 12px 30px -10px var(--primary-glow);
  transform: translateY(-2px);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: var(--radius-md);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #38bdf8 0%, #2563eb 100%);
  color: #ffffff;
  box-shadow: 0 4px 20px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  opacity: 0.92;
  box-shadow: 0 6px 24px rgba(56, 189, 248, 0.45);
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--border-color);
  color: var(--text-main);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
}

.btn-block {
  width: 100%;
}

/* Header & Nav */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: #fff;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.4);
}

.brand-icon svg {
  width: 20px;
  height: 20px;
  fill: #fff;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 500;
  transition: var(--transition);
}

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

.mobile-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  cursor: pointer;
  padding: 8px;
}

@media (max-width: 992px) {
  .mobile-toggle {
    display: block;
  }
  
  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    opacity: 0;
    pointer-events: none;
  }
  
  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  
  .nav-menu .btn {
    width: 100%;
    margin-top: 10px;
  }
}

/* Hero Section */
.hero {
  padding-top: 140px;
  padding-bottom: 80px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.25rem;
  margin-top: 16px;
  margin-bottom: 20px;
}

.hero-content p {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  max-width: 580px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-stats {
  display: flex;
  gap: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.stat-item h4 {
  font-size: 1.5rem;
  color: var(--primary);
}

.stat-item p {
  font-size: 0.8125rem;
  color: var(--text-dim);
  margin-bottom: 0;
}

@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-content p {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-actions {
    justify-content: center;
  }
  .hero-stats {
    justify-content: center;
  }
}

@media (max-width: 576px) {
  .hero-content h1 {
    font-size: 2.25rem;
  }
  .hero-stats {
    gap: 16px;
    flex-wrap: wrap;
  }
}

/* Network Tech Dashboard Visual (Hero Right) */
.dashboard-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 24px;
  position: relative;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
  background-image: linear-gradient(180deg, rgba(30, 41, 59, 0.4) 0%, rgba(15, 23, 42, 0.8) 100%);
}

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

.dash-dots {
  display: flex;
  gap: 6px;
}

.dash-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
}

.dash-dot:nth-child(1) { background: #ef4444; }
.dash-dot:nth-child(2) { background: #f59e0b; }
.dash-dot:nth-child(3) { background: #10b981; }

.dash-title {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-muted);
  font-family: monospace;
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.node-item:hover {
  background: rgba(56, 189, 248, 0.06);
  border-color: rgba(56, 189, 248, 0.2);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.flag {
  font-size: 1.2rem;
}

.node-name {
  font-weight: 600;
  font-size: 0.875rem;
}

.node-type {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.node-ping {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 600;
  font-family: monospace;
  color: var(--accent-green);
}

.ping-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(52, 211, 153, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.dash-footer-status {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-around;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.status-chip {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Bento Grid */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
}

.bento-col-4 { grid-column: span 4; }
.bento-col-6 { grid-column: span 6; }
.bento-col-8 { grid-column: span 8; }
.bento-col-12 { grid-column: span 12; }

@media (max-width: 992px) {
  .bento-col-4, .bento-col-6, .bento-col-8 {
    grid-column: span 12;
  }
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
  stroke: var(--primary);
  fill: none;
  stroke-width: 2;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.9375rem;
}

/* AI & Streaming Cards */
.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.tech-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
}

.tech-pill:hover {
  background: rgba(56, 189, 248, 0.1);
  border-color: rgba(56, 189, 248, 0.3);
  color: #fff;
}

.pill-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.dot-purple { background: var(--accent-purple); box-shadow: 0 0 6px var(--accent-purple); }
.dot-sky { background: var(--primary); box-shadow: 0 0 6px var(--primary); }
.dot-green { background: var(--accent-green); box-shadow: 0 0 6px var(--accent-green); }

/* Pricing Table */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: stretch;
  padding-top: 16px;
}

@media (max-width: 992px) {
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
    padding-top: 16px;
  }
}

.pricing-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.pricing-card.popular {
  border-color: var(--primary);
  box-shadow: 0 0 30px rgba(56, 189, 248, 0.25);
  position: relative;
  overflow: visible;
}

.popular-badge {
  position: absolute;
  top: 0;
  right: 24px;
  transform: translateY(-50%);
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 9999px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  z-index: 10;
  box-shadow: 0 4px 12px rgba(56, 189, 248, 0.4);
}

.price-header h3 {
  font-size: 1.35rem;
  margin-bottom: 8px;
}

.price-amount {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 20px 0 10px;
}

.currency {
  font-size: 1.25rem;
  color: var(--primary);
  font-weight: 700;
}

.num {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1;
}

.period {
  color: var(--text-dim);
  font-size: 0.875rem;
}

.price-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.pricing-features {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  margin-top: 20px;
  margin-bottom: 30px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.pricing-features li svg {
  width: 16px;
  height: 16px;
  stroke: var(--accent-green);
  fill: none;
  stroke-width: 2.5;
  flex-shrink: 0;
}

/* Blog / SEO Articles Grid */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 992px) {
  .blog-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .blog-grid {
    grid-template-columns: 1fr;
  }
}

.blog-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.blog-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-bottom: 12px;
}

.blog-category {
  color: var(--primary);
  font-weight: 600;
}

.blog-title {
  font-size: 1.125rem;
  margin-bottom: 12px;
  line-height: 1.4;
}

.blog-title a:hover {
  color: var(--primary);
}

.blog-excerpt {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  flex-grow: 1;
}

.blog-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: var(--primary);
  font-weight: 600;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 992px) {
  .testimonials-grid {
    grid-template-columns: 1fr;
  }
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 1rem;
}

.user-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.user-name {
  font-weight: 600;
  font-size: 0.9375rem;
}

.user-role {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.rating {
  color: var(--accent-amber);
  font-size: 0.875rem;
  margin-bottom: 10px;
}

.testimonial-text {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* FAQ Accordion */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-question {
  width: 100%;
  padding: 20px 24px;
  text-align: left;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 1.0625rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

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

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

.faq-answer {
  padding: 0 24px 20px;
  color: var(--text-muted);
  font-size: 0.9375rem;
  display: none;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  display: block;
}

/* Footer */
.footer {
  background: #040609;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
  margin-top: 60px;
}

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

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-top: 12px;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.9375rem;
  margin-bottom: 16px;
  color: var(--text-main);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.8125rem;
  color: var(--text-dim);
}

.footer-rec-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  align-items: center;
}

.footer-rec-links a {
  color: var(--text-muted);
  transition: var(--transition);
}

.footer-rec-links a:hover {
  color: var(--primary);
}

/* Article Page Layout (SEO Blog Post View) */
.article-container {
  max-width: 860px;
  margin: 120px auto 60px;
  padding: 0 20px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--text-dim);
  margin-bottom: 24px;
}

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

.article-header {
  margin-bottom: 40px;
}

.article-header h1 {
  font-size: 2.5rem;
  margin-top: 12px;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  gap: 20px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.article-body {
  color: var(--text-muted);
  font-size: 1.0625rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.75rem;
  color: var(--text-main);
  margin-top: 40px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 8px;
}

.article-body h3 {
  font-size: 1.35rem;
  color: var(--text-main);
  margin-top: 28px;
  margin-bottom: 12px;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul, .article-body ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-body ul {
  list-style: disc;
}

.article-body ol {
  list-style: decimal;
}

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

.article-body blockquote {
  border-left: 4px solid var(--primary);
  padding: 16px 20px;
  background: rgba(56, 189, 248, 0.05);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
  color: var(--text-main);
  font-style: italic;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(129, 140, 248, 0.1));
  border: 1px solid var(--primary);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  margin: 40px 0;
}

.article-cta-box h3 {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.article-cta-box p {
  font-size: 0.9375rem;
  margin-bottom: 20px;
}