/* ==========================================================================
   flybit 肥猫云 - 原生极简轻量样式表 (Zero-Dependency Modern CSS)
   ========================================================================== */

:root {
  --bg-base: #090d16;
  --bg-surface: #0f172a;
  --bg-card: #131d31;
  --bg-card-hover: #1a2742;
  --bg-glass: rgba(19, 29, 49, 0.75);
  
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(6, 182, 212, 0.35);
  
  --accent-cyan: #06b6d4;
  --accent-cyan-glow: rgba(6, 182, 212, 0.22);
  --accent-blue: #3b82f6;
  --accent-purple: #8b5cf6;
  --accent-green: #10b981;
  --accent-yellow: #f59e0b;
  
  --accent-gradient: linear-gradient(135deg, #06b6d4 0%, #3b82f6 50%, #8b5cf6 100%);
  --accent-gradient-glow: linear-gradient(135deg, rgba(6, 182, 212, 0.15), rgba(139, 92, 246, 0.15));
  
  --text-main: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-highlight: #38bdf8;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px rgba(6, 182, 212, 0.25);
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --container-max: 1200px;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background: radial-gradient(circle at 50% 0%, rgba(6, 182, 212, 0.08) 0%, transparent 60%),
              radial-gradient(circle at 100% 30%, rgba(139, 92, 246, 0.05) 0%, transparent 50%),
              var(--bg-base);
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

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

.section {
  padding: 80px 0;
  position: relative;
}

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

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 50px auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.25);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.section-title {
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  line-height: 1.3;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 13, 22, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--accent-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 14px rgba(6, 182, 212, 0.35);
}

.logo-badge {
  font-size: 0.72rem;
  font-weight: 600;
  padding: 2px 7px;
  background: rgba(6, 182, 212, 0.15);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: 4px;
  margin-left: 4px;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 28px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 6px 0;
}

.nav-link:hover {
  color: #fff;
}

.nav-link:hover::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-cyan);
  border-radius: 2px;
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Mobile Nav Toggle via CSS */
.mobile-nav-toggle {
  display: none;
}

@media (max-width: 900px) {
  .nav-menu {
    display: none;
  }
}

/* Buttons & CTAs */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 18px rgba(6, 182, 212, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(6, 182, 212, 0.5);
  filter: brightness(1.08);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  color: #f8fafc;
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
  transform: translateY(-2px);
}

.btn-lg {
  padding: 14px 30px;
  font-size: 1.05rem;
  border-radius: 12px;
}

.btn-block {
  width: 100%;
}

/* Hero Section (Left/Right Layout) */
.hero-wrapper {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: 48px;
  align-items: center;
  padding-top: 30px;
  padding-bottom: 40px;
}

@media (max-width: 960px) {
  .hero-wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: var(--accent-cyan);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 22px;
}

.hero-tag-pulse {
  width: 8px;
  height: 8px;
  background-color: var(--accent-cyan);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.7);
  animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(6, 182, 212, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(6, 182, 212, 0); }
}

.hero-title {
  font-size: 3.1rem;
  font-weight: 850;
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: #ffffff;
}

.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 34px;
  max-width: 580px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 40px;
  width: 100%;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  width: 100%;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

@media (max-width: 600px) {
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-val {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Hero Right Column: CSS Dynamic Tech Card */
.hero-visual {
  position: relative;
}

.dynamic-card {
  position: relative;
  background: linear-gradient(145deg, rgba(26, 38, 66, 0.85), rgba(15, 23, 42, 0.95));
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--shadow-card), 0 0 35px rgba(6, 182, 212, 0.12);
  backdrop-filter: blur(20px);
  overflow: hidden;
}

.dynamic-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-gradient);
}

.card-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 22px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

.card-topbar-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-main);
}

.card-topbar-status {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.12);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.card-topbar-status::before {
  content: '';
  width: 6px;
  height: 6px;
  background-color: var(--accent-green);
  border-radius: 50%;
  animation: pulseDotGreen 1.8s infinite;
}

@keyframes pulseDotGreen {
  0% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
  100% { opacity: 1; transform: scale(1); }
}

/* Speed Radar / Live Node List */
.node-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 11px 15px;
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.node-item:hover {
  background: rgba(30, 41, 67, 0.85);
  border-color: rgba(6, 182, 212, 0.3);
  transform: translateX(3px);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 10px;
}

.node-flag {
  font-size: 1.25rem;
  line-height: 1;
}

.node-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
}

.node-type {
  font-size: 0.72rem;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.12);
  padding: 1px 6px;
  border-radius: 4px;
}

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

.node-latency {
  font-size: 0.84rem;
  font-weight: 700;
  font-family: monospace;
  color: var(--accent-green);
}

.node-latency.moderate {
  color: #38bdf8;
}

.node-bar-wrapper {
  width: 45px;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  overflow: hidden;
}

.node-bar {
  height: 100%;
  background: var(--accent-green);
  border-radius: 3px;
  animation: barFluctuate 3s ease-in-out infinite alternate;
}

@keyframes barFluctuate {
  0% { width: 85%; }
  50% { width: 95%; }
  100% { width: 90%; }
}

/* Speed Dashboard Bar */
.speed-meter {
  background: rgba(10, 16, 31, 0.6);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.speed-metric-item {
  display: flex;
  flex-direction: column;
}

.speed-metric-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.speed-metric-value {
  font-size: 1.15rem;
  font-weight: 800;
  font-family: monospace;
  color: var(--accent-cyan);
}

/* Floating Badges with CSS animations */
.floating-badge {
  position: absolute;
  padding: 8px 16px;
  background: rgba(15, 23, 42, 0.92);
  border: 1px solid rgba(6, 182, 212, 0.35);
  border-radius: var(--radius-full);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  backdrop-filter: blur(12px);
  z-index: 10;
}

.badge-stream {
  top: -15px;
  right: -15px;
  color: #fff;
  animation: floatSlow 4s ease-in-out infinite;
}

.badge-ai {
  bottom: -15px;
  left: -15px;
  color: #fff;
  animation: floatSlow 4.5s ease-in-out infinite reverse;
}

@keyframes floatSlow {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@media (max-width: 640px) {
  .floating-badge {
    position: static;
    margin-top: 12px;
    width: 100%;
    justify-content: center;
  }
}

/* ==========================================================================
   Section 1: 核心优势 (3 Cards)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

@media (max-width: 900px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 34px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-card), 0 0 25px rgba(6, 182, 212, 0.1);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  background: rgba(6, 182, 212, 0.1);
  border: 1px solid rgba(6, 182, 212, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
  margin-bottom: 22px;
  font-size: 1.6rem;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #fff;
}

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-points {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  border-top: 1px solid var(--border-color);
  padding-top: 18px;
}

.feature-point {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-main);
}

.feature-point svg {
  color: var(--accent-cyan);
  flex-shrink: 0;
}

/* ==========================================================================
   Section 2: 流媒体与 AI 支持图卡
   ========================================================================== */
.ecosystem-wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
}

@media (max-width: 860px) {
  .ecosystem-wrapper {
    grid-template-columns: 1fr;
  }
}

.eco-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  position: relative;
  overflow: hidden;
}

.eco-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.eco-card-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 750;
  color: #fff;
}

.eco-badge {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.eco-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.6;
}

.eco-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

@media (max-width: 480px) {
  .eco-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.eco-item {
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  padding: 14px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 6px;
  transition: var(--transition);
}

.eco-item:hover {
  background: rgba(30, 41, 67, 0.8);
  border-color: rgba(6, 182, 212, 0.3);
  transform: translateY(-2px);
}

.eco-item-icon {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.eco-item-name {
  font-size: 0.84rem;
  font-weight: 600;
  color: #fff;
}

.eco-item-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Section 3: 套餐价格对比表 (参考肥猫云真实资费)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  align-items: stretch;
}

@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

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

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card), 0 0 25px rgba(6, 182, 212, 0.12);
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(23, 37, 68, 0.95), rgba(15, 23, 42, 0.95));
  border: 2px solid var(--accent-cyan);
  box-shadow: 0 10px 30px rgba(6, 182, 212, 0.25);
}

.pricing-featured-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #fff;
  font-size: 0.76rem;
  font-weight: 700;
  padding: 3px 14px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  text-transform: uppercase;
  box-shadow: 0 4px 12px rgba(6, 182, 212, 0.4);
}

.pricing-header {
  margin-bottom: 20px;
  text-align: center;
}

.pricing-name {
  font-size: 1.25rem;
  font-weight: 750;
  color: #fff;
  margin-bottom: 6px;
}

.pricing-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.pricing-price-wrap {
  margin: 18px 0;
  text-align: center;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
}

.price-currency {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.price-num {
  font-size: 2.8rem;
  font-weight: 850;
  color: #fff;
  letter-spacing: -0.03em;
  line-height: 1;
}

.price-period {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-left: 4px;
}

.pricing-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 22px 0 28px 0;
  flex-grow: 1;
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
}

.pricing-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-main);
}

.pricing-feature-item svg {
  color: var(--accent-cyan);
  flex-shrink: 0;
}

.pricing-feature-item.highlight {
  font-weight: 600;
  color: #38bdf8;
}

/* ==========================================================================
   Section 4: 用户评价 (Testimonials)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

@media (max-width: 1024px) {
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .reviews-grid {
    grid-template-columns: 1fr;
  }
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.review-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255, 255, 255, 0.18);
  background: var(--bg-card-hover);
}

.review-rating {
  color: var(--accent-yellow);
  font-size: 0.88rem;
  margin-bottom: 12px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent-gradient-glow);
  border: 1px solid rgba(6, 182, 212, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--accent-cyan);
}

.user-info {
  display: flex;
  flex-direction: column;
}

.user-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: #fff;
}

.user-role {
  font-size: 0.76rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Section 5: 常见问题 (FAQ - 原生 0-JS Details/Summary)
   ========================================================================== */
.faq-wrapper {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-item[open] {
  border-color: rgba(6, 182, 212, 0.35);
  background: rgba(19, 29, 49, 0.95);
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  user-select: none;
}

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

.faq-item summary::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--accent-cyan);
  transition: transform 0.2s ease;
  line-height: 1;
}

.faq-item[open] summary::after {
  content: '−';
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 24px 22px 24px;
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Banner CTA Before Footer
   ========================================================================== */
.pre-footer-cta {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.15) 0%, rgba(139, 92, 246, 0.15) 100%);
  border: 1px solid rgba(6, 182, 212, 0.25);
  border-radius: var(--radius-lg);
  padding: 48px 32px;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 40px;
}

.pre-footer-cta h3 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: #fff;
}

.pre-footer-cta p {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 28px auto;
}

/* ==========================================================================
   Footer (严格仅保留 4 个新开独立页面标题链接)
   ========================================================================== */
.site-footer {
  background: #060910;
  border-top: 1px solid var(--border-color);
  padding: 40px 0 30px 0;
  margin-top: auto;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 36px;
  margin-bottom: 22px;
}

.footer-link {
  font-size: 0.96rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}

.footer-link:hover {
  color: var(--accent-cyan);
  text-decoration: underline;
}

.footer-pbn-link:hover {
  color: var(--accent-cyan) !important;
  text-decoration: underline !important;
  text-underline-offset: 3px;
}

.footer-copyright {
  text-align: center;
  font-size: 0.84rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Subpages Style (About, Terms, Privacy, Sitemap)
   ========================================================================== */
.page-container {
  max-width: 900px;
  margin: 40px auto 80px auto;
  padding: 0 20px;
}

.page-header-box {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.page-title {
  font-size: 2.3rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: #fff;
}

.page-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

.content-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  margin-bottom: 28px;
}

@media (max-width: 640px) {
  .content-card {
    padding: 24px 18px;
  }
}

.content-card h2 {
  font-size: 1.4rem;
  font-weight: 750;
  color: #fff;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.content-card h3 {
  font-size: 1.12rem;
  font-weight: 650;
  color: var(--text-highlight);
  margin: 22px 0 10px 0;
}

.content-card p, .content-card li {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.content-card ul {
  padding-left: 24px;
  margin: 12px 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.policy-highlight {
  padding: 18px 22px;
  background: rgba(6, 182, 212, 0.08);
  border-left: 4px solid var(--accent-cyan);
  border-radius: 4px;
  margin: 20px 0;
}

.policy-highlight strong {
  color: #fff;
}

/* Sitemap List Styles */
.sitemap-group {
  margin-bottom: 30px;
}

.sitemap-group-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--accent-cyan);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.sitemap-links {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

@media (max-width: 600px) {
  .sitemap-links {
    grid-template-columns: 1fr;
  }
}

.sitemap-link-item a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  transition: var(--transition);
}

.sitemap-link-item a:hover {
  background: rgba(30, 41, 67, 0.85);
  border-color: var(--accent-cyan);
  transform: translateX(4px);
  color: var(--accent-cyan);
}

/* ==========================================================================
   Section: SEO 推荐文章图卡矩阵 (Below Pricing)
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

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

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-card), 0 0 20px rgba(6, 182, 212, 0.1);
}

.article-card-badge-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.article-badge {
  font-size: 0.76rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(6, 182, 212, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(6, 182, 212, 0.25);
  letter-spacing: 0.3px;
}

.article-badge.featured {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border-color: rgba(245, 158, 11, 0.3);
}

.article-date {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.article-card-title {
  font-size: 1.12rem;
  font-weight: 750;
  line-height: 1.45;
  color: #fff;
  margin-bottom: 12px;
  transition: var(--transition);
}

.article-card:hover .article-card-title {
  color: var(--text-highlight);
}

.article-card-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
  font-size: 0.84rem;
  color: var(--text-muted);
}

.article-card-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-cyan);
  font-weight: 600;
  font-size: 0.88rem;
}

.article-card-link:hover {
  text-decoration: underline;
  gap: 8px;
}

/* ==========================================================================
   Article Detail Page Styles (长文排版与 SEO 导读)
   ========================================================================== */
.article-detail-wrap {
  max-width: 860px;
  margin: 30px auto 80px auto;
  padding: 0 20px;
}

.article-header {
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-main-title {
  font-size: 2.2rem;
  font-weight: 850;
  line-height: 1.35;
  color: #fff;
  margin-top: 14px;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: #cbd5e1;
}

.article-body h2 {
  font-size: 1.55rem;
  font-weight: 800;
  color: #fff;
  margin: 44px 0 18px 0;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-highlight);
  margin: 28px 0 14px 0;
}

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

.article-body a {
  color: var(--accent-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.article-body a:hover {
  color: #38bdf8;
  filter: brightness(1.2);
}

.article-body ul, .article-body ol {
  margin: 16px 0 24px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.article-body li {
  line-height: 1.75;
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.94rem;
}

.article-body th, .article-body td {
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  text-align: left;
}

.article-body th {
  background: rgba(15, 23, 42, 0.9);
  color: #fff;
  font-weight: 700;
}

.article-body tr:nth-child(even) {
  background: rgba(15, 23, 42, 0.4);
}

.article-callout {
  background: rgba(6, 182, 212, 0.07);
  border-left: 4px solid var(--accent-cyan);
  border-radius: 4px;
  padding: 18px 22px;
  margin: 26px 0;
}

.article-callout strong {
  color: #fff;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.12) 0%, rgba(139, 92, 246, 0.12) 100%);
  border: 1px solid rgba(6, 182, 212, 0.3);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  text-align: center;
  margin: 40px 0;
}

.article-cta-box h3 {
  font-size: 1.45rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 10px;
}

.article-cta-box p {
  font-size: 0.96rem;
  color: var(--text-secondary);
  margin-bottom: 22px;
}