/* ==========================================================================
   尔湾云机场 (Ervine Cloud) - Clean White & Blue Theme Design System
   ========================================================================== */

:root {
  --primary: #0066FF;
  --primary-hover: #0052CC;
  --primary-light: #EBF3FF;
  --primary-glow: rgba(0, 102, 255, 0.25);
  
  --secondary: #0284C7;
  --secondary-hover: #0369A1;
  --accent: #38BDF8;
  --accent-glow: rgba(56, 189, 248, 0.3);
  
  --bg-gradient: linear-gradient(135deg, #F8FAFC 0%, #EFF6FF 50%, #F0F9FF 100%);
  --bg-main: #F8FAFC;
  --surface: #FFFFFF;
  --surface-alt: #F1F5F9;
  --surface-hover: #F8FAFC;
  
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #64748B;
  --text-light: #94A3B8;
  
  --border-light: #E2E8F0;
  --border-focus: #93C5FD;
  
  --success: #10B981;
  --success-bg: #ECFDF5;
  --warning: #F59E0B;
  --warning-bg: #FFFBEB;
  --danger: #EF4444;
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 24px -6px rgba(0, 102, 255, 0.08);
  --shadow-lg: 0 16px 36px -8px rgba(0, 102, 255, 0.14);
  --shadow-glow: 0 0 25px rgba(0, 102, 255, 0.2);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  background: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* Dynamic Canvas Background */
#bgCanvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0.85;
}

.content-wrapper {
  position: relative;
  z-index: 1;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 90px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 56px auto;
}

.section-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  border: 1px solid rgba(0, 102, 255, 0.15);
  box-shadow: 0 2px 10px rgba(0, 102, 255, 0.06);
}

.section-title {
  font-size: 2.35rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 16px;
}

.section-title .gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

/* Glassmorphism Card Base */
.glass-card {
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: rgba(0, 102, 255, 0.25);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 14px 28px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-decoration: none;
  border: none;
  outline: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, #0052CC 100%);
  color: #FFFFFF;
  box-shadow: 0 4px 18px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #1A75FF 0%, #0047B3 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 102, 255, 0.35);
  color: #FFFFFF;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.9);
  color: var(--primary);
  border: 1.5px solid rgba(0, 102, 255, 0.3);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary-hover);
  transform: translateY(-2px);
}

.btn-accent {
  background: linear-gradient(135deg, #0284C7 0%, #0369A1 100%);
  color: #FFFFFF;
  box-shadow: 0 4px 16px rgba(2, 132, 199, 0.25);
}

.btn-accent:hover {
  background: linear-gradient(135deg, #0369A1 0%, #075985 100%);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.875rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.1rem;
  border-radius: var(--radius-md);
}

/* Top Announcement Bar */
.announcement-bar {
  background: linear-gradient(90deg, #0052CC 0%, #0066FF 50%, #0284C7 100%);
  color: #FFFFFF;
  padding: 10px 0;
  font-size: 0.875rem;
  font-weight: 500;
  text-align: center;
}

.announcement-content {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.badge-flash {
  background: rgba(255, 255, 255, 0.2);
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
}

.announcement-link {
  color: #FFFFFF;
  text-decoration: underline;
  font-weight: 600;
  margin-left: 6px;
  cursor: pointer;
}

/* Header & Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: all var(--transition-normal);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.logo-icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #FFFFFF;
  font-size: 22px;
  box-shadow: 0 4px 14px var(--primary-glow);
}

.logo-text {
  display: flex;
  flex-direction: column;
}

.logo-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.logo-sub {
  font-size: 0.72rem;
  color: var(--primary);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
  padding: 6px 0;
  position: relative;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width var(--transition-fast);
  border-radius: 2px;
}

.nav-link:hover::after, .nav-link.active::after {
  width: 100%;
}

/* Nav Dropdown for Keywords */
.nav-dropdown-wrapper {
  position: relative;
}

.nav-dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: 12px;
  display: grid;
  grid-template-columns: repeat(2, 190px);
  gap: 8px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-fast);
  z-index: 200;
}

.nav-dropdown-wrapper:hover .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: background var(--transition-fast);
  cursor: pointer;
}

.dropdown-item:hover {
  background: var(--primary-light);
  color: var(--primary);
}

.nav-cta-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Hero Section */
.hero {
  padding: 70px 0 90px 0;
  background: radial-gradient(circle at 50% 20%, rgba(56, 189, 248, 0.12) 0%, rgba(248, 250, 252, 0) 70%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  max-width: 660px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: #EFF6FF;
  border: 1px solid #BFDBFE;
  border-radius: var(--radius-full);
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-tag i {
  color: #F59E0B;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.hero-title span.blue-highlight {
  color: var(--primary);
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 36px;
}

.hero-cta-box {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-buttons {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.link-channel-note {
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 12px;
}

.channel-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  background: rgba(16, 185, 129, 0.1);
  color: var(--success);
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.78rem;
}

/* Hero Stats Row */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
}

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

.stat-number {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* Hero Card Visual */
.hero-visual {
  position: relative;
}

.hero-preview-card {
  padding: 32px;
  background: linear-gradient(145deg, rgba(255,255,255,0.95) 0%, rgba(240,249,255,0.9) 100%);
  border: 1px solid rgba(147, 197, 253, 0.6);
  box-shadow: var(--shadow-lg);
  border-radius: 24px;
}

.visual-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-light);
}

.visual-title {
  font-weight: 700;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 8px;
}

.status-dot {
  width: 10px;
  height: 10px;
  background: var(--success);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--success);
  animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.speed-meter-box {
  background: #FFFFFF;
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 20px;
  border: 1px solid var(--border-light);
}

.speed-metric {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 12px;
}

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

.metric-val {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
}

.speed-bar-bg {
  width: 100%;
  height: 10px;
  background: var(--surface-alt);
  border-radius: 5px;
  overflow: hidden;
}

.speed-bar-fill {
  height: 100%;
  width: 96%;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
  border-radius: 5px;
  transition: width 1s ease;
}

.feature-mini-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.mini-feat {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.mini-feat i {
  color: var(--primary);
}

/* ==========================================================================
   Node Status & Latency Board (节点延迟和状态板块)
   ========================================================================== */
.node-board-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 32px;
}

.node-filter-tabs {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  background: rgba(255, 255, 255, 0.9);
  padding: 6px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}

.filter-tab {
  padding: 8px 18px;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-tab:hover {
  color: var(--primary);
}

.filter-tab.active {
  background: var(--primary);
  color: #FFFFFF;
  box-shadow: 0 2px 8px var(--primary-glow);
}

.refresh-ping-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.refresh-ping-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.refresh-ping-btn i.spinning {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  100% { transform: rotate(360deg); }
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 20px;
}

.node-card {
  padding: 20px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
  overflow: hidden;
}

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

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

.flag-icon {
  font-size: 1.5rem;
}

.node-name {
  font-weight: 700;
  font-size: 1rem;
  color: var(--text-primary);
}

.node-tags {
  display: flex;
  gap: 6px;
  margin-top: 2px;
}

.tag-badge {
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
  text-transform: uppercase;
}

.tag-iplc {
  background: #E0F2FE;
  color: #0284C7;
}

.tag-trojan {
  background: #F3E8FF;
  color: #7E22CE;
}

.tag-ss {
  background: #FEF3C7;
  color: #D97706;
}

.latency-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
}

.latency-good {
  background: #ECFDF5;
  color: #059669;
}

.latency-medium {
  background: #EFF6FF;
  color: #2563EB;
}

.node-metrics {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 10px;
  border-top: 1px dashed var(--border-light);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.load-bar-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 140px;
}

.load-bar {
  flex: 1;
  height: 6px;
  background: var(--surface-alt);
  border-radius: 3px;
  overflow: hidden;
}

.load-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 3px;
}

/* Pricing Section (套餐价格板块) */
.pricing-toggle-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
}

.toggle-label {
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-secondary);
  cursor: pointer;
}

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

.discount-tag {
  background: #FEE2E2;
  color: #DC2626;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
}

.switch-btn {
  position: relative;
  width: 56px;
  height: 30px;
  background: var(--primary);
  border-radius: 15px;
  border: none;
  cursor: pointer;
  padding: 3px;
  transition: background var(--transition-fast);
}

.switch-circle {
  width: 24px;
  height: 24px;
  background: #FFFFFF;
  border-radius: 50%;
  transition: transform var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.switch-btn.annual .switch-circle {
  transform: translateX(26px);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  align-items: stretch;
}

.pricing-card {
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-card.popular {
  border: 2px solid var(--primary);
  transform: scale(1.03);
  box-shadow: var(--shadow-lg);
}

.pricing-card.popular:hover {
  transform: scale(1.05);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: #FFFFFF;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px var(--primary-glow);
}

.plan-title {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  min-height: 42px;
}

.plan-price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 28px;
}

.price-currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
}

.price-num {
  font-size: 3rem;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1;
}

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

.plan-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 36px;
  flex: 1;
}

.plan-feature-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.plan-feature-item i {
  color: var(--primary);
  font-size: 1.1rem;
}

.plan-btn-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* Core Advantages Section (核心优势板块) */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.advantage-card {
  padding: 36px 28px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.adv-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  box-shadow: 0 4px 14px rgba(0, 102, 255, 0.1);
}

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

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

/* User Reviews Section (用户评价板块) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 20px;
}

.review-stars {
  color: #F59E0B;
  display: flex;
  gap: 4px;
  font-size: 1rem;
}

.review-text {
  font-size: 0.98rem;
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.6;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 16px;
  border-top: 1px solid var(--border-light);
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.user-meta-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-primary);
}

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

/* FAQ Section (常见问题板块) */
.faq-wrapper {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-question {
  width: 100%;
  padding: 22px 28px;
  background: #FFFFFF;
  border: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.faq-question:hover {
  background: var(--surface-hover);
  color: var(--primary);
}

.faq-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: transform var(--transition-fast);
}

.faq-item.open .faq-icon {
  transform: rotate(180deg);
  background: var(--primary);
  color: #FFFFFF;
}

.faq-answer {
  padding: 0 28px;
  max-height: 0;
  overflow: hidden;
  transition: all var(--transition-normal);
  background: #FFFFFF;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

.faq-item.open .faq-answer {
  padding: 0 28px 24px 28px;
  max-height: 300px;
}

/* ==========================================================================
   Knowledge Base & Tutorials Section (知识库与教程板块 - 8篇关键词文章)
   ========================================================================== */
.kb-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.kb-card {
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 100%;
  cursor: pointer;
}

.kb-card-top {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 20px;
}

.kb-kw-tag {
  display: inline-flex;
  align-self: flex-start;
  padding: 4px 10px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  border-radius: var(--radius-full);
}

.kb-card-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-primary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.kb-card-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.kb-card-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid var(--border-light);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.kb-read-link {
  color: var(--primary);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
}

/* Article Reader Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  padding: 24px;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.article-modal-box {
  width: 100%;
  max-width: 860px;
  max-height: 90vh;
  background: #FFFFFF;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: translateY(20px);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .article-modal-box {
  transform: translateY(0);
}

.modal-header {
  padding: 24px 32px;
  background: #F8FAFC;
  border-bottom: 1px solid var(--border-light);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-close-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--surface-alt);
  border: none;
  font-size: 1.2rem;
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-fast);
}

.modal-close-btn:hover {
  background: #E2E8F0;
  color: var(--text-primary);
}

.modal-body {
  padding: 36px;
  overflow-y: auto;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.article-header {
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-light);
}

.article-title {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.article-content h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 28px 0 14px 0;
}

.article-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 20px 0 10px 0;
}

.article-content p {
  margin-bottom: 16px;
}

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

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

.article-cta-box {
  margin-top: 36px;
  padding: 24px;
  background: var(--primary-light);
  border: 1px solid rgba(0, 102, 255, 0.2);
  border-radius: var(--radius-md);
  text-align: center;
}

.article-cta-box h3 {
  margin-top: 0;
  color: var(--primary);
}

/* Line Selector Modal (一跳二弹窗) */
.line-modal-box {
  width: 100%;
  max-width: 480px;
  background: #FFFFFF;
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
}

.line-option-card {
  padding: 20px;
  border: 1.5px solid var(--border-light);
  border-radius: var(--radius-md);
  margin-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-decoration: none;
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.line-option-card:hover {
  border-color: var(--primary);
  background: var(--primary-light);
}

.line-title {
  font-weight: 700;
  font-size: 1.05rem;
}

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

/* Sitemap HTML Section Footer Link */
.sitemap-bar {
  background: #0F172A;
  color: #94A3B8;
  padding: 40px 0;
  font-size: 0.875rem;
}

.sitemap-links-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 36px;
}

.sitemap-col-title {
  color: #FFFFFF;
  font-weight: 700;
  margin-bottom: 16px;
  font-size: 0.95rem;
}

.sitemap-col-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.sitemap-col-list a {
  color: #94A3B8;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.sitemap-col-list a:hover {
  color: var(--accent);
}

.footer-bottom {
  text-align: center;
  padding-top: 24px;
  border-top: 1px solid #1E293B;
}

/* Responsive Breakdown */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-grid, .advantages-grid, .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .kb-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .pricing-card.popular {
    transform: none;
  }
  
  .sitemap-links-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero-title {
    font-size: 2.2rem;
  }
  
  .pricing-grid, .advantages-grid, .reviews-grid, .kb-grid {
    grid-template-columns: 1fr;
  }
  
  .sitemap-links-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-buttons .btn {
    width: 100%;
  }
}