/* ==========================================================================
   贝贝云机场 (Beibei Cloud) - 统一黑白高端极简 UI 样式表
   ========================================================================== */

:root {
  /* Color Palette - Premium Monochrome Dark */
  --bg-dark: #09090b;
  --bg-card: rgba(24, 24, 27, 0.75);
  --bg-card-hover: rgba(39, 39, 42, 0.85);
  --bg-element: #18181b;
  --bg-element-light: #27272a;
  
  --border-color: rgba(255, 255, 255, 0.12);
  --border-color-hover: rgba(255, 255, 255, 0.35);
  
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-muted: #71717a;
  
  --white: #ffffff;
  --black: #000000;
  
  --accent-glow: rgba(255, 255, 255, 0.15);
  --accent-border: rgba(255, 255, 255, 0.25);
  
  --status-online: #10b981;
  --status-warning: #f59e0b;
  --status-glow: rgba(16, 185, 129, 0.25);
  
  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  
  /* Layout & Spacing */
  --max-width: 1240px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-pill: 9999px;
  
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-primary);
  font-family: var(--font-family);
  -webkit-font-smoothing: antialiased;
}

body {
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

/* Background Canvas */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
}

/* Utility Classes */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

.text-gradient {
  background: linear-gradient(180deg, #ffffff 0%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.9rem;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--status-online);
  box-shadow: 0 0 10px var(--status-online);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { opacity: 0.6; transform: scale(0.95); }
  50% { opacity: 1; transform: scale(1.15); }
  100% { opacity: 0.6; transform: scale(0.95); }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.85rem 1.8rem;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--white);
  color: var(--black);
  box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  transform: translateY(-2px);
  background: #e4e4e7;
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.3);
}

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

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--border-color-hover);
  transform: translateY(-2px);
}

/* Header & Navbar */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(9, 9, 11, 0.8);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--white);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, #ffffff 0%, #71717a 100%);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--black);
  font-weight: 900;
  font-size: 1.1rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: var(--transition);
}

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

/* Hero Section */
.hero-section {
  padding: 180px 0 100px;
  text-align: center;
  position: relative;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1.5px;
  margin: 1.5rem 0 1.2rem;
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.2rem;
  margin-bottom: 4rem;
  flex-wrap: wrap;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
  padding: 1.8rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(12px);
}

.stat-item {
  text-align: center;
}

.stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--white);
  font-family: var(--font-family);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

/* Section Header Structure */
.section {
  padding: 90px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 4rem;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.8px;
  margin-top: 0.6rem;
}

.section-desc {
  color: var(--text-secondary);
  margin-top: 0.8rem;
  font-size: 1.05rem;
}

/* Glass Card Global Component */
.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  backdrop-filter: blur(14px);
  transition: var(--transition);
}

.glass-card:hover {
  border-color: var(--border-color-hover);
  background: var(--bg-card-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
}

/* Node Latency Section */
.nodes-header-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

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

.node-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.node-flag-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.1rem;
}

.node-flag {
  font-size: 1.4rem;
}

.node-ping {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: monospace;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--status-online);
}

.ping-bar-wrapper {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-pill);
  overflow: hidden;
}

.ping-bar-fill {
  height: 100%;
  background: var(--status-online);
  border-radius: var(--radius-pill);
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.node-details {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);;
}

/* Core Advantages Section */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.8rem;
}

.adv-icon {
  width: 52px;
  height: 52px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.2rem;
}

.adv-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
}

.adv-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Pricing Section */
.pricing-toggle-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3.5rem;
}

.toggle-label {
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
}

.toggle-label.active {
  color: var(--white);
}

.switch {
  position: relative;
  display: inline-block;
  width: 54px;
  height: 28px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: var(--bg-element-light);
  border: 1px solid var(--border-color);
  transition: 0.4s;
  border-radius: 34px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 3px;
  bottom: 3px;
  background-color: var(--white);
  transition: 0.4s;
  border-radius: 50%;
}

input:checked + .slider {
  background-color: var(--white);
}

input:checked + .slider:before {
  transform: translateX(26px);
  background-color: var(--black);
}

.save-badge {
  background: var(--white);
  color: var(--black);
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-pill);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 2rem;
  align-items: stretch;
}

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

.pricing-card.popular {
  border-color: rgba(255, 255, 255, 0.4);
  background: rgba(30, 30, 35, 0.85);
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.08);
}

.popular-tag {
  position: absolute;
  top: -14px;
  right: 24px;
  background: var(--white);
  color: var(--black);
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.25rem 0.8rem;
  border-radius: var(--radius-pill);
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.plan-price-box {
  margin-bottom: 2rem;
  display: flex;
  align-items: baseline;
  gap: 0.3rem;
}

.plan-price {
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--white);
}

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

.plan-features {
  list-style: none;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.plan-features li::before {
  content: "✓";
  color: var(--white);
  font-weight: bold;
}

/* User Reviews Section */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.8rem;
}

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

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

.review-text {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 1.5rem;
  font-style: italic;
}

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

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bg-element-light);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--white);
}

.author-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

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

/* FAQ Accordion Section */
.faq-wrapper {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  overflow: hidden;
  transition: var(--transition);
}

.faq-header {
  padding: 1.4rem 1.8rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--white);
  user-select: none;
}

.faq-icon {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
}

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

.faq-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1), padding 0.4s ease;
  padding: 0 1.8rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-body {
  padding: 0 1.8rem 1.4rem 1.8rem;
  max-height: 500px;
}

/* Knowledge Base Grid */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.article-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  color: inherit;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.8rem;
}

.article-tag {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
}

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

.article-card:hover .article-card-title {
  color: #ffffff;
  text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.article-card-snippet {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-read-more {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--white);;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 70px 0 40px;
  background: rgba(9, 9, 11, 0.95);
  margin-top: 80px;
  position: relative;
  z-index: 10;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 4rem;
}

.footer-brand-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 1rem;
  max-width: 320px;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 1.2rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: var(--transition);
}

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

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Detailed Article Page Layout Styles */
.article-page {
  padding-top: 140px;
  padding-bottom: 100px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}

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

.article-header {
  max-width: 860px;
  margin-bottom: 2.5rem;
}

.article-main-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  margin: 1rem 0;
  letter-spacing: -1px;
}

.article-content-wrapper {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 3rem;
  align-items: start;
}

.article-body {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  backdrop-filter: blur(14px);
  color: var(--text-primary);
  font-size: 1.02rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--white);
  margin: 2.5rem 0 1.2rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--white);
  margin: 1.8rem 0 0.8rem;
}

.article-body p {
  margin-bottom: 1.4rem;
  color: #d4d4d8;
}

.article-body ul, .article-body ol {
  margin: 1.2rem 0 1.5rem 1.8rem;
  color: #d4d4d8;
}

.article-body li {
  margin-bottom: 0.6rem;
}

.article-body blockquote {
  border-left: 4px solid var(--white);
  background: rgba(255, 255, 255, 0.04);
  padding: 1.2rem 1.5rem;
  margin: 1.8rem 0;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
  color: var(--text-secondary);
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(39, 39, 42, 0.9) 0%, rgba(18, 18, 21, 0.95) 100%);
  border: 1px solid var(--border-color-hover);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  margin: 3rem 0;
  box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.article-cta-box h3 {
  color: var(--white);
  font-size: 1.4rem;
  margin-bottom: 0.8rem;
}

.article-cta-box p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
}

.article-sidebar {
  position: sticky;
  top: 100px;
  display: flex;
  flex-direction: column;
  gap: 1.8rem;
}

.sidebar-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  backdrop-filter: blur(10px);
}

.sidebar-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.sidebar-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.88rem;
  line-height: 1.4;
  transition: var(--transition);
}

.sidebar-links a:hover {
  color: var(--white);
}

/* Table styling inside articles */
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.8rem 0;
  font-size: 0.92rem;
}

.article-body th, .article-body td {
  padding: 0.85rem 1rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

.article-body th {
  background: rgba(255, 255, 255, 0.08);
  color: var(--white);
  font-weight: 700;
}

.article-body td {
  background: rgba(24, 24, 27, 0.4);
}

/* Code snippet styling */
.article-body code {
  background: rgba(255, 255, 255, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: monospace;
  font-size: 0.88rem;
  color: #ffffff;
}

.article-body pre {
  background: #121215;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 1.2rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-body pre code {
  background: none;
  padding: 0;
  color: #e4e4e7;
}

/* Responsive Rules */
@media (max-width: 992px) {
  .article-content-wrapper {
    grid-template-columns: 1fr;
  }
  .article-sidebar {
    position: static;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none; /* Can be toggled if menu exists */
  }
  .hero-section {
    padding-top: 140px;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  .article-body {
    padding: 1.8rem 1.2rem;
  }
}