/* ==========================================================================
   FLYINGBIRD / ADAXI 全球网络控制中心 - 原生 CSS 样式表
   视觉概念: 工业级网络控制台 (Global Network Control Center)
   色彩规范: Dark Navy (#080e1a) | Electric Blue (#2563eb) | Bright Cyan (#06b6d4)
   零依赖 | 高性能 | 响应式 | 无乱用 Emoji 与假评分
   ========================================================================== */

/* 1. 变量与基础重置 */
:root {
  --bg-primary: #080e1a;
  --bg-secondary: #0f172a;
  --bg-surface: #1e293b;
  --bg-card: rgba(15, 23, 42, 0.85);
  --bg-card-hover: #1e293b;

  --accent-blue: #2563eb;
  --accent-blue-hover: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-cyan-glow: rgba(6, 182, 212, 0.2);
  --accent-emerald: #10b981;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-cyan: rgba(6, 182, 212, 0.25);

  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --shadow-panel: 0 10px 30px rgba(0, 0, 0, 0.45);
  --max-width: 1240px;

  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
}

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

/* 2. 通用布局与组件 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 90px 0;
  border-bottom: 1px solid var(--border-subtle);
  position: relative;
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
}

.section-header {
  margin-bottom: 50px;
}

.section-header.center {
  text-align: center;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.08);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-cyan);
  margin-bottom: 14px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  line-height: 1.25;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin-top: 12px;
  line-height: 1.6;
}

.section-header.center .section-desc {
  margin-left: auto;
  margin-right: auto;
}

/* 3. 按钮样式 (Buttons) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-normal);
}

.btn-primary {
  background: var(--accent-blue);
  color: #fff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  background: var(--accent-blue-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-primary);
  border-color: var(--border-subtle);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
}

/* 4. 页眉 Header & 控制台导航 */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(8, 14, 26, 0.9);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 16px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
}

.logo-symbol {
  width: 32px;
  height: 32px;
  background: var(--bg-surface);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
}

.logo-sub {
  font-size: 0.75rem;
  color: var(--accent-cyan);
  font-family: var(--font-mono);
  display: block;
  font-weight: 600;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
}

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

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

.mobile-menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  padding: 6px;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

@media (max-width: 992px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-subtle);
    flex-direction: column;
    padding: 20px;
    gap: 16px;
    align-items: flex-start;
  }
  .nav-menu.mobile-active {
    display: flex;
  }
  .mobile-menu-toggle {
    display: block;
  }
}

/* 5. 非对称双栏 Hero Section (Asymmetric Split-Screen) */
.hero-section {
  padding: 80px 0;
  background: radial-gradient(circle at 80% 20%, rgba(6, 182, 212, 0.08) 0%, transparent 60%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 60px;
  align-items: center;
}

.hero-content {
  text-align: left;
}

.hero-system-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-emerald);
  background: rgba(16, 185, 129, 0.08);
  padding: 4px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(16, 185, 129, 0.25);
  margin-bottom: 24px;
}

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

.hero-title {
  font-size: 3.25rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: #fff;
}

.hero-title .accent-text {
  color: var(--accent-cyan);
}

.hero-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 580px;
}

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

/* 右侧：纯 CSS 控制中心网络可视化 (Network Visualizer) */
.hero-visualizer {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-panel);
  position: relative;
}

.visualizer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-subtle);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.visualizer-body {
  padding: 20px 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.node-status-item {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.node-name-code {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.node-ping-val {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-emerald);
}

.visualizer-line {
  height: 4px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 2px;
  overflow: hidden;
  position: relative;
}

.visualizer-line-inner {
  height: 100%;
  width: 75%;
  background: linear-gradient(90deg, var(--accent-blue) 0%, var(--accent-cyan) 100%);
  border-radius: 2px;
}

@media (max-width: 992px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .hero-title { font-size: 2.25rem; }
}

/* 6. 横向全球路由 Display (Horizontal Route Ticker) */
.route-ticker-section {
  background: var(--bg-secondary);
  padding: 20px 0;
  border-bottom: 1px solid var(--border-subtle);
}

.route-ticker-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}

.route-item {
  border-right: 1px solid var(--border-subtle);
  padding-right: 16px;
  text-align: left;
}

.route-item:last-child { border-right: none; }

.route-location {
  font-size: 0.85rem;
  font-weight: 700;
  color: #fff;
}

.route-latency {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent-cyan);
  margin-top: 2px;
}

@media (max-width: 900px) {
  .route-ticker-grid { grid-template-columns: repeat(3, 1fr); gap: 20px; }
  .route-item { border-right: none; }
}

@media (max-width: 500px) {
  .route-ticker-grid { grid-template-columns: repeat(2, 1fr); }
}

/* 7. 性能控制面板 Dashboard (Integrated Performance Dashboard) */
.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.dash-panel {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 30px;
}

.dash-panel-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.dash-icon {
  width: 38px;
  height: 38px;
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid var(--border-cyan);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
}

.dash-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #fff;
}

.dash-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
}

.dash-spec-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.dash-spec-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  padding: 8px 12px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.dash-spec-key { color: var(--text-muted); }
.dash-spec-val { color: var(--text-primary); font-family: var(--font-mono); font-weight: 600; }

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

/* 8. 单色平台墙 (Monochrome Ecosystem Wall) */
.monochrome-wall {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}

.platform-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
  transition: all var(--transition-normal);
  filter: grayscale(100%);
  opacity: 0.7;
}

.platform-card:hover {
  filter: grayscale(0%);
  opacity: 1;
  border-color: var(--accent-cyan);
  background: var(--bg-surface);
  transform: translateY(-2px);
}

.platform-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  margin-top: 8px;
}

.platform-cat {
  font-size: 0.75rem;
  color: var(--text-muted);
}

@media (max-width: 992px) {
  .monochrome-wall { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 550px) {
  .monochrome-wall { grid-template-columns: repeat(2, 1fr); }
}

/* 9. 适用人群与场景对比 (Suitability Comparison) */
.suitability-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.suitability-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px;
}

.suitability-box.for-who {
  border-top: 3px solid var(--accent-emerald);
}

.suitability-box.not-for {
  border-top: 3px solid var(--text-muted);
}

.suitability-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
}

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

.suitability-li {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.suitability-li strong { color: #fff; }

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

/* 10. 4步极速开通流程 (4-Step Onboarding) */
.onboarding-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.step-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-cyan);
  margin-bottom: 12px;
}

.step-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

.step-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
}

@media (max-width: 900px) {
  .onboarding-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 500px) {
  .onboarding-steps { grid-template-columns: 1fr; }
}

/* 11. 紧凑型价格对比表与周期 Tabs (Tabbed Pricing Section) */
.pricing-tabs-wrap {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 36px;
  background: var(--bg-secondary);
  padding: 6px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  width: fit-content;
  margin-left: auto;
  margin-right: auto;
}

.pricing-tab-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 8px 20px;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-normal);
}

.pricing-tab-btn.active {
  background: var(--accent-blue);
  color: #fff;
}

.pricing-cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pricing-plan-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
}

.pricing-plan-card.recommended {
  border: 2px solid var(--accent-cyan);
  background: rgba(15, 23, 42, 0.95);
  box-shadow: 0 0 25px rgba(6, 182, 212, 0.15);
}

.rec-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-cyan);
  color: #000;
  font-size: 0.72rem;
  font-weight: 800;
  padding: 2px 12px;
  border-radius: var(--radius-sm);
  letter-spacing: 1px;
}

.plan-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 6px;
}

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

.plan-price-box {
  margin: 18px 0;
}

.plan-price-num {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--accent-cyan);
  font-family: var(--font-mono);
}

.plan-period-text { font-size: 0.82rem; color: var(--text-muted); }

.plan-feat-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 24px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

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

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

/* 12. 精选 3 篇指南预读 (3 Concise Article Previews) */
.articles-preview-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-preview-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.art-prev-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-cyan);
  margin-bottom: 10px;
}

.art-prev-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #fff;
  line-height: 1.4;
  margin-bottom: 10px;
}

.art-prev-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
}

.art-prev-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-cyan);
}

@media (max-width: 900px) {
  .articles-preview-grid { grid-template-columns: 1fr; }
}

/* 13. 常见问题 FAQ Accordion */
.faq-accordion {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-accordion-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-summary-btn {
  width: 100%;
  background: none;
  border: none;
  padding: 18px 24px;
  font-size: 0.98rem;
  font-weight: 600;
  color: #fff;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.faq-icon-chevron {
  transition: transform var(--transition-normal);
  color: var(--accent-cyan);
}

.faq-accordion-item.open .faq-icon-chevron {
  transform: rotate(180deg);
}

.faq-answer-panel {
  display: none;
  padding: 0 24px 18px 24px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.faq-accordion-item.open .faq-answer-panel {
  display: block;
}

/* 14. 页脚 Footer 与 PBN 外链 */
.footer {
  background: #04070d;
  border-top: 1px solid var(--border-subtle);
  padding: 50px 0 25px 0;
  margin-top: auto;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

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

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

.footer-pbn-links {
  text-align: center;
  margin: 20px 0 16px 0;
  padding-top: 16px;
  border-top: 1px dashed var(--border-subtle);
  font-size: 0.85rem;
}

.footer-pbn-links a {
  color: var(--accent-cyan);
  font-weight: 600;
  margin: 0 10px;
}

.footer-copyright {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.03);
  padding-top: 18px;
}

/* 15. 移动端吸底注册按钮 (Mobile Sticky CTA) */
.mobile-sticky-cta {
  display: none;
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 99;
  background: rgba(8, 14, 26, 0.95);
  backdrop-filter: blur(12px);
  padding: 12px 20px;
  border-top: 1px solid var(--border-subtle);
}

@media (max-width: 768px) {
  .mobile-sticky-cta { display: block; }
  body { padding-bottom: 60px; }
}

/* 16. 子页面专有样式 */
.subpage-header {
  padding: 60px 0 30px 0;
  border-bottom: 1px solid var(--border-subtle);
  background: radial-gradient(circle at 50% 0%, rgba(6, 182, 212, 0.06) 0%, transparent 70%);
  text-align: center;
}

.subpage-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 10px;
}

.subpage-sub {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

.subpage-content {
  max-width: 900px;
  margin: 0 auto;
  padding: 50px 24px;
}

.content-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 36px;
  margin-bottom: 24px;
}

.content-card h2 {
  font-size: 1.35rem;
  color: #fff;
  margin-bottom: 14px;
}

.content-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 14px;
}

.content-card ul {
  margin-left: 20px;
  margin-bottom: 14px;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.content-card li { margin-bottom: 6px; }