/* ==========================================================================
   CyberGuard Enterprise Dark Security UI Framework (Cyber Command Theme)
   Domain: cyberguard.sbs
   Primary Brand Palette:
   - Main Background: #080B10
   - Secondary Background: #111722
   - Surface/Card Background: #171F2B
   - Brand Cyan: #00D9D0
   - Secondary Blue: #477BFF
   - Primary Text: #F3F7FC
   - Secondary Text: #9AA9BD
   ========================================================================== */

:root {
  --bg-primary: #080B10;
  --bg-secondary: #111722;
  --bg-surface: #171F2B;
  --bg-surface-elevated: #1F2A3B;
  --bg-surface-glass: rgba(23, 31, 43, 0.75);
  --bg-header-glass: rgba(8, 11, 16, 0.85);

  --color-cyan: #00D9D0;
  --color-cyan-hover: #14eee5;
  --color-cyan-glow: rgba(0, 217, 208, 0.28);
  --color-cyan-glow-subtle: rgba(0, 217, 208, 0.08);

  --color-blue: #477BFF;
  --color-blue-hover: #5e8cff;
  --color-blue-glow: rgba(71, 123, 255, 0.28);

  --text-primary: #F3F7FC;
  --text-secondary: #9AA9BD;
  --text-muted: #5F7188;
  --text-inverse: #080B10;

  --border-subtle: #1E2838;
  --border-medium: #2A384D;
  --border-active: #00D9D0;

  --status-green: #00E599;
  --status-amber: #FFB800;
  --status-red: #FF4D6D;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 18px;

  --shadow-card: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-cyan-glow: 0 0 24px rgba(0, 217, 208, 0.35);
  --shadow-blue-glow: 0 0 24px rgba(71, 123, 255, 0.35);

  --transition-fast: 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-size: 16px;
  line-height: 1.65;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--bg-primary);
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(71, 123, 255, 0.08) 0%, transparent 60%),
    radial-gradient(circle at 85% 20%, rgba(0, 217, 208, 0.05) 0%, transparent 50%),
    linear-gradient(rgba(30, 40, 56, 0.15) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 40, 56, 0.15) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 48px 48px, 48px 48px;
  background-position: 0 0, 0 0, -1px -1px, -1px -1px;
}

/* Accessibility: Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--color-cyan);
  color: var(--text-inverse);
  padding: 10px 18px;
  z-index: 9999;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: 20px;
}

/* Selection */
::selection {
  background: rgba(0, 217, 208, 0.3);
  color: #fff;
}

/* Links */
a {
  color: var(--color-cyan);
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
a:hover {
  color: var(--color-cyan-hover);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.015em;
}

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}
p:last-child {
  margin-bottom: 0;
}

code, kbd, pre {
  font-family: var(--font-mono);
}

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

.container-narrow {
  width: 100%;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section {
  padding: 96px 0;
  position: relative;
}
.section-alt {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

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

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 14px;
  background: rgba(0, 217, 208, 0.08);
  border: 1px solid rgba(0, 217, 208, 0.25);
  border-radius: 999px;
  color: var(--color-cyan);
  font-size: 0.825rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  font-size: 2.25rem;
  margin-bottom: 16px;
}
@media (min-width: 768px) {
  .section-title {
    font-size: 2.75rem;
  }
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --------------------------------------------------
   Button Component System
   -------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap;
  user-select: none;
}

.btn-primary {
  background: var(--color-cyan);
  color: var(--text-inverse);
  box-shadow: 0 4px 16px rgba(0, 217, 208, 0.22);
}
.btn-primary:hover {
  background: var(--color-cyan-hover);
  color: var(--text-inverse);
  box-shadow: var(--shadow-cyan-glow);
  transform: translateY(-2px);
}
.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: rgba(23, 31, 43, 0.8);
  color: var(--text-primary);
  border: 1px solid var(--border-medium);
  backdrop-filter: blur(8px);
}
.btn-secondary:hover {
  border-color: var(--color-cyan);
  color: var(--color-cyan);
  box-shadow: 0 0 16px rgba(0, 217, 208, 0.15);
  transform: translateY(-2px);
}

.btn-blue {
  background: var(--color-blue);
  color: #fff;
  box-shadow: 0 4px 16px rgba(71, 123, 255, 0.22);
}
.btn-blue:hover {
  background: var(--color-blue-hover);
  color: #fff;
  box-shadow: var(--shadow-blue-glow);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
}
.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

/* Sponsored Disclaimer Pill */
.sponsored-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 8px;
}
.sponsored-badge svg {
  width: 14px;
  height: 14px;
  stroke: var(--text-muted);
}

/* --------------------------------------------------
   Card Component System (Cyber Command Card)
   -------------------------------------------------- */
.cyber-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
  position: relative;
  transition: all var(--transition-normal);
  overflow: hidden;
}
.cyber-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, transparent, transparent);
  transition: background var(--transition-normal);
}
.cyber-card:hover {
  border-color: rgba(0, 217, 208, 0.35);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.45), 0 0 18px rgba(0, 217, 208, 0.08);
  transform: translateY(-4px);
}
.cyber-card:hover::before {
  background: linear-gradient(90deg, transparent, var(--color-cyan), transparent);
}

/* Tech Corner styling */
.corner-accent {
  position: relative;
}
.corner-accent::after {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 12px;
  height: 12px;
  border-top: 2px solid var(--color-cyan);
  border-right: 2px solid var(--color-cyan);
  opacity: 0.6;
}

/* --------------------------------------------------
   Header & Navigation
   -------------------------------------------------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  transition: background-color var(--transition-normal), backdrop-filter var(--transition-normal), border-bottom var(--transition-normal), padding var(--transition-normal);
  padding: 20px 0;
  background: transparent;
}
.site-header.scrolled {
  background: var(--bg-header-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 12px 0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Brand Logo */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-primary);
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}
.brand-logo:hover {
  color: var(--text-primary);
}
.brand-shield {
  width: 34px;
  height: 34px;
  color: var(--color-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
}
.brand-shield svg {
  width: 100%;
  height: 100%;
}
.brand-name {
  display: flex;
  flex-direction: column;
}
.brand-name span:first-child {
  font-size: 1.25rem;
  line-height: 1.1;
  background: linear-gradient(135deg, #ffffff 40%, #00D9D0 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.brand-badge {
  font-size: 0.65rem;
  color: var(--color-cyan);
  font-family: var(--font-mono);
  letter-spacing: 0.05em;
  font-weight: 500;
  opacity: 0.9;
}

/* Nav Menu Desktop */
.nav-menu {
  display: none;
  align-items: center;
  gap: 28px;
  list-style: none;
}
@media (min-width: 992px) {
  .nav-menu {
    display: flex;
  }
}

.nav-link {
  color: var(--text-secondary);
  font-size: 0.925rem;
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
  padding: 6px 0;
}
.nav-link:hover, .nav-link.active {
  color: var(--color-cyan);
}
.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-cyan);
  border-radius: 2px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Mobile Toggle */
.mobile-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: transparent;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 8px;
  cursor: pointer;
}
@media (min-width: 992px) {
  .mobile-toggle {
    display: none;
  }
}
.mobile-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--text-primary);
  transition: all var(--transition-fast);
}
.mobile-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.mobile-toggle.active span:nth-child(2) {
  opacity: 0;
}
.mobile-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Drawer */
.mobile-drawer {
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(8, 11, 16, 0.98);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 999;
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  gap: 24px;
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  overflow-y: auto;
}
.mobile-drawer.open {
  transform: translateX(0);
}
.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.mobile-nav-link {
  font-size: 1.15rem;
  color: var(--text-secondary);
  font-weight: 600;
  display: block;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-subtle);
}
.mobile-nav-link:hover, .mobile-nav-link.active {
  color: var(--color-cyan);
}

/* --------------------------------------------------
   Section 01: Hero
   -------------------------------------------------- */
.hero-section {
  padding-top: 140px;
  padding-bottom: 70px;
  min-height: 88vh;
  display: flex;
  align-items: center;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}
@media (min-width: 992px) {
  .hero-grid {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 56px;
  }
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero-badge-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(23, 31, 43, 0.9);
  border: 1px solid var(--border-medium);
  border-radius: 999px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
}
.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--status-green);
  box-shadow: 0 0 8px var(--status-green);
  animation: pulse-glow 2s infinite ease-in-out;
}
@keyframes pulse-glow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

.hero-title {
  font-size: 2.6rem;
  line-height: 1.18;
  letter-spacing: -0.025em;
  margin-bottom: 24px;
}
@media (min-width: 768px) {
  .hero-title {
    font-size: 3.4rem;
  }
}
@media (min-width: 1200px) {
  .hero-title {
    font-size: 3.8rem;
  }
}

.hero-title-highlight {
  display: block;
  background: linear-gradient(135deg, #00D9D0 0%, #477BFF 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  font-size: 1.15rem;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 620px;
}

.hero-features-list {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}
.feature-tag {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-primary);
  background: rgba(23, 31, 43, 0.6);
  border: 1px solid var(--border-subtle);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
}
.feature-tag svg {
  color: var(--color-cyan);
  width: 16px;
  height: 16px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.hero-disclaimer-box {
  padding: 14px 18px;
  background: rgba(17, 23, 34, 0.6);
  border-left: 3px solid var(--color-cyan);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* 3D Core Canvas Visualizer */
.hero-visual {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 420px;
}
.core-canvas-container {
  width: 100%;
  max-width: 520px;
  height: 440px;
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: radial-gradient(circle at center, rgba(0, 217, 208, 0.08) 0%, rgba(17, 23, 34, 0.4) 60%, transparent 80%);
}
#cyber-core-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* Live HUD overlay on canvas */
.hud-telemetry {
  position: absolute;
  bottom: 16px;
  left: 16px;
  right: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  background: rgba(8, 11, 16, 0.8);
  border: 1px solid rgba(0, 217, 208, 0.2);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  backdrop-filter: blur(8px);
}
.hud-item {
  display: flex;
  flex-direction: column;
}
.hud-label {
  color: var(--text-muted);
  font-size: 0.68rem;
}
.hud-val {
  color: var(--color-cyan);
  font-weight: 600;
}

/* Hero Stats Bar */
.hero-stats-bar {
  margin-top: 48px;
  padding: 24px 32px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
@media (min-width: 768px) {
  .hero-stats-bar {
    grid-template-columns: repeat(4, 1fr);
  }
}
.stat-item {
  display: flex;
  flex-direction: column;
}
.stat-number {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.1;
  margin-bottom: 6px;
  font-family: var(--font-mono);
}
.stat-number span {
  color: var(--color-cyan);
}
.stat-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* --------------------------------------------------
   Section 02: Network Overview (三栏布局)
   -------------------------------------------------- */
.overview-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
@media (min-width: 768px) {
  .overview-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.overview-card {
  height: 100%;
  display: flex;
  flex-direction: column;
}
.overview-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: rgba(0, 217, 208, 0.1);
  border: 1px solid rgba(0, 217, 208, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-cyan);
  margin-bottom: 24px;
}
.overview-icon-box svg {
  width: 28px;
  height: 28px;
}
.overview-card h3 {
  font-size: 1.35rem;
  margin-bottom: 14px;
}
.overview-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  flex-grow: 1;
}
.overview-sublist {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.overview-sublist li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}
.overview-sublist li svg {
  color: var(--color-cyan);
  width: 14px;
  height: 14px;
  flex-shrink: 0;
}

/* --------------------------------------------------
   Section 03: Network Architecture (技术架构深度解析)
   -------------------------------------------------- */
.arch-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}
@media (min-width: 992px) {
  .arch-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.arch-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  flex-direction: column;
  position: relative;
}
.arch-badge {
  display: inline-block;
  align-self: flex-start;
  padding: 4px 10px;
  background: rgba(71, 123, 255, 0.15);
  border: 1px solid rgba(71, 123, 255, 0.35);
  border-radius: var(--radius-sm);
  color: var(--color-blue);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  margin-bottom: 16px;
}
.arch-badge.cyan {
  background: rgba(0, 217, 208, 0.12);
  border-color: rgba(0, 217, 208, 0.35);
  color: var(--color-cyan);
}

.arch-card h3 {
  font-size: 1.35rem;
  margin-bottom: 12px;
}
.arch-card p {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.tech-spec-table {
  width: 100%;
  margin-top: 20px;
  border-collapse: collapse;
  font-size: 0.85rem;
}
.tech-spec-table th, .tech-spec-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-subtle);
  text-align: left;
}
.tech-spec-table th {
  color: var(--text-muted);
  font-weight: 600;
  width: 32%;
}
.tech-spec-table td {
  color: var(--text-primary);
}

.arch-notice-box {
  margin-top: 40px;
  padding: 20px 24px;
  background: rgba(17, 23, 34, 0.8);
  border: 1px dashed var(--border-medium);
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* --------------------------------------------------
   Section 04: Global Connectivity (全球网络拓扑)
   -------------------------------------------------- */
.global-map-container {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 36px 24px;
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}

.global-map-svg-wrap {
  width: 100%;
  height: 380px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}
.global-map-svg-wrap svg {
  width: 100%;
  height: 100%;
  max-width: 900px;
}

/* Network topology node dots */
.map-node {
  cursor: pointer;
  transition: all var(--transition-fast);
}
.map-node:hover circle:first-child {
  r: 10;
  fill: var(--color-cyan);
}

.region-cards-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}
@media (min-width: 640px) {
  .region-cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1024px) {
  .region-cards-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.region-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  flex-direction: column;
}
.region-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.region-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}
.region-ping {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: rgba(0, 229, 153, 0.12);
  color: var(--status-green);
}
.region-hubs {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --------------------------------------------------
   Section 05: Pricing (企业级套餐横向对比与卡片)
   -------------------------------------------------- */
.pricing-cycle-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 48px;
  background: var(--bg-surface);
  padding: 6px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}
.cycle-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}
.cycle-btn:hover {
  color: var(--text-primary);
}
.cycle-btn.active {
  background: var(--color-cyan);
  color: var(--text-inverse);
  box-shadow: 0 2px 10px rgba(0, 217, 208, 0.3);
}

.pricing-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 56px;
}
@media (min-width: 992px) {
  .pricing-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.plan-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}
.plan-card.featured {
  border-color: rgba(0, 217, 208, 0.5);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4), 0 0 24px rgba(0, 217, 208, 0.12);
  background: linear-gradient(180deg, rgba(23, 31, 43, 1) 0%, rgba(17, 23, 34, 1) 100%);
}
@media (min-width: 992px) {
  .plan-card.featured {
    transform: translateY(-8px);
  }
}
.plan-badge-popular {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-cyan);
  color: var(--text-inverse);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 999px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  box-shadow: 0 4px 12px rgba(0, 217, 208, 0.35);
}

.plan-header {
  margin-bottom: 24px;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 24px;
}
.plan-name {
  font-size: 1.5rem;
  margin-bottom: 10px;
}
.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 8px;
}
.currency-symbol {
  font-size: 1.4rem;
  color: var(--color-cyan);
  font-weight: 700;
}
.price-value {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  color: var(--text-primary);
  font-family: var(--font-mono);
}
.price-period {
  font-size: 0.95rem;
  color: var(--text-muted);
}
.plan-cycle-note {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.plan-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 32px;
  flex-grow: 1;
}
.plan-features-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}
.plan-features-list li svg {
  color: var(--color-cyan);
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  margin-top: 2px;
}
.plan-features-list li strong {
  color: var(--text-primary);
}

.plan-action {
  margin-top: auto;
}
.plan-action .btn {
  width: 100%;
}

/* Detailed Comparison Table */
.comparison-table-wrap {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  overflow-x: auto;
  margin-top: 40px;
}
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px;
  font-size: 0.925rem;
}
.comparison-table th, .comparison-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-subtle);
  text-align: center;
}
.comparison-table th:first-child, .comparison-table td:first-child {
  text-align: left;
  font-weight: 600;
  color: var(--text-primary);
  width: 28%;
}
.comparison-table thead th {
  background: var(--bg-surface-elevated);
  color: var(--text-primary);
  font-size: 1rem;
}
.comparison-table thead th.featured-col {
  color: var(--color-cyan);
  border-bottom: 2px solid var(--color-cyan);
}
.comparison-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.pricing-notice-note {
  margin-top: 24px;
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --------------------------------------------------
   Section 06: Device Guide (多平台客户端配置知识)
   -------------------------------------------------- */
.device-tabs-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
}
.device-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.device-tab-btn svg {
  width: 20px;
  height: 20px;
}
.device-tab-btn:hover {
  border-color: var(--color-cyan);
  color: var(--text-primary);
}
.device-tab-btn.active {
  background: rgba(0, 217, 208, 0.12);
  border-color: var(--color-cyan);
  color: var(--color-cyan);
  box-shadow: 0 0 16px rgba(0, 217, 208, 0.15);
}

.device-tab-pane {
  display: none;
  animation: fadeIn 0.3s ease-in-out;
}
.device-tab-pane.active {
  display: block;
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.device-guide-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-xl);
  padding: 40px;
}
.guide-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 20px;
}
.guide-software-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.software-tag {
  padding: 4px 10px;
  background: rgba(71, 123, 255, 0.12);
  border: 1px solid rgba(71, 123, 255, 0.3);
  border-radius: var(--radius-sm);
  color: var(--color-blue);
  font-size: 0.8rem;
  font-family: var(--font-mono);
}

.guide-steps-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
@media (min-width: 768px) {
  .guide-steps-list {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1200px) {
  .guide-steps-list {
    grid-template-columns: repeat(4, 1fr);
  }
}

.guide-step-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
}
.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-cyan);
  color: var(--text-inverse);
  font-weight: 700;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  margin-bottom: 16px;
}
.guide-step-box h4 {
  font-size: 1.1rem;
  margin-bottom: 10px;
}
.guide-step-box p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --------------------------------------------------
   Section 07: Knowledge Center (原创知识库文章展示)
   -------------------------------------------------- */
.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}
@media (min-width: 768px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1024px) {
  .articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  position: relative;
}
.article-card:hover {
  border-color: rgba(0, 217, 208, 0.4);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
}
.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.article-category {
  color: var(--color-cyan);
  font-weight: 600;
}
.article-card h3 {
  font-size: 1.2rem;
  line-height: 1.4;
  margin-bottom: 12px;
}
.article-card h3 a {
  color: var(--text-primary);
}
.article-card h3 a:hover {
  color: var(--color-cyan);
}
.article-summary {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}
.article-read-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-cyan);
  margin-top: auto;
}
.article-read-more:hover {
  color: var(--color-cyan-hover);
  text-decoration: underline;
}

/* --------------------------------------------------
   Section 08: FAQ (常见问题交互手风琴)
   -------------------------------------------------- */
.faq-list {
  max-width: 880px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}
.faq-item:hover {
  border-color: var(--border-medium);
}
.faq-item.open {
  border-color: rgba(0, 217, 208, 0.35);
}

.faq-question {
  width: 100%;
  text-align: left;
  background: transparent;
  border: none;
  padding: 22px 26px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.faq-icon-cross {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  position: relative;
  transition: transform var(--transition-fast);
  color: var(--color-cyan);
}
.faq-item.open .faq-icon-cross {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease-out, padding 0.35s ease-out;
  padding: 0 26px;
}
.faq-item.open .faq-answer {
  max-height: 600px;
  padding: 0 26px 24px 26px;
}
.faq-answer p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 12px;
}
.faq-answer p:last-child {
  margin-bottom: 0;
}
.faq-answer ul {
  margin-left: 20px;
  color: var(--text-secondary);
  font-size: 0.925rem;
  margin-bottom: 12px;
}
.faq-answer li {
  margin-bottom: 6px;
}

/* --------------------------------------------------
   Section 09: Final CTA
   -------------------------------------------------- */
.final-cta-box {
  background: radial-gradient(circle at 50% 0%, rgba(0, 217, 208, 0.12) 0%, rgba(23, 31, 43, 0.9) 75%);
  border: 1px solid rgba(0, 217, 208, 0.3);
  border-radius: var(--radius-xl);
  padding: 72px 32px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5), 0 0 30px rgba(0, 217, 208, 0.08);
}
.final-cta-box h2 {
  font-size: 2.2rem;
  margin-bottom: 18px;
}
@media (min-width: 768px) {
  .final-cta-box h2 {
    font-size: 3rem;
  }
}
.final-cta-box p {
  font-size: 1.1rem;
  max-width: 640px;
  margin: 0 auto 36px auto;
  color: var(--text-secondary);
}

/* --------------------------------------------------
   Section 10: Footer
   -------------------------------------------------- */
.site-footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-subtle);
  padding: 72px 0 36px 0;
  position: relative;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-bottom: 56px;
}
@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 992px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1.2fr 1fr;
  }
}

.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-top: 16px;
  max-width: 340px;
}

.footer-col h4 {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 20px;
}
.footer-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.footer-nav-list a {
  color: var(--text-secondary);
  font-size: 0.88rem;
  transition: color var(--transition-fast);
}
.footer-nav-list a:hover {
  color: var(--color-cyan);
}

.footer-bottom-bar {
  border-top: 1px solid var(--border-subtle);
  padding-top: 32px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  font-size: 0.825rem;
  color: var(--text-muted);
  text-align: center;
}
@media (min-width: 768px) {
  .footer-bottom-bar {
    flex-direction: row;
    text-align: left;
  }
}

/* --------------------------------------------------
   Prefers Reduced Motion
   -------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .status-dot {
    animation: none;
  }
  .plan-card:hover {
    transform: none;
  }
}