/* ==========================================================================
   番茄 v2 航线机场网 (fanqiev2.homes) - 官方落地页纯原生高效样式表
   零重型外部依赖 | 纯 CSS 秒开架构 | 现代化响应式设计 | GPU 硬件加速动效
   ========================================================================== */

/* 1. CSS 变量与设计系统定义 */
:root {
  --primary: #ff4d4f;
  --primary-hover: #ff7875;
  --primary-dark: #d9363e;
  --primary-glow: rgba(255, 77, 79, 0.35);
  
  --secondary: #38bdf8;
  --secondary-hover: #7dd3fc;
  --secondary-glow: rgba(56, 189, 248, 0.3);
  
  --accent-purple: #a855f7;
  --accent-green: #22c55e;
  --accent-amber: #f59e0b;

  --bg-dark: #070a12;
  --bg-card: rgba(15, 23, 42, 0.72);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --bg-glass: rgba(15, 23, 42, 0.6);

  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 77, 79, 0.4);
  --border-active: rgba(56, 189, 248, 0.5);

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;

  --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 var(--primary-glow);

  --container-width: 1240px;
  --transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 2. 基础重置与文档规范 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.65;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

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

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

ul, ol {
  list-style: none;
}

button, input {
  font-family: inherit;
  font-size: inherit;
}

/* 3. 动态背景层 (GPU 硬件加速与纯净动效) */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -3;
  pointer-events: none;
}

.dynamic-ambient {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  pointer-events: none;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.28;
  transform: translateZ(0);
}

.orb-1 {
  width: 550px;
  height: 550px;
  background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
  top: -150px;
  left: 10%;
  animation: floatOrb1 18s ease-in-out infinite alternate;
}

.orb-2 {
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, var(--secondary) 0%, transparent 70%);
  top: 35%;
  right: -100px;
  animation: floatOrb2 22s ease-in-out infinite alternate;
}

.orb-3 {
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, #f43f5e 0%, transparent 70%);
  bottom: 5%;
  left: 20%;
  animation: floatOrb1 20s ease-in-out infinite alternate-reverse;
}

@keyframes floatOrb1 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(60px, 80px) scale(1.12); }
  100% { transform: translate(-40px, 40px) scale(0.95); }
}

@keyframes floatOrb2 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-80px, -60px) scale(1.15); }
  100% { transform: translate(50px, -30px) scale(0.92); }
}

.grid-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* 4. 通用布局与网格容器 */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

section {
  padding: 85px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 55px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  background: rgba(255, 77, 79, 0.12);
  border: 1px solid rgba(255, 77, 79, 0.3);
  border-radius: var(--radius-full);
  color: var(--primary-hover);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  font-size: 2.35rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
  background: linear-gradient(135deg, #ffffff 30%, #e2e8f0 70%, #ff7875 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  font-size: 1.08rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 5. 按钮规范与呼吁性 (CTA) 元素 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 700;
  border-radius: var(--radius-full);
  padding: 13px 28px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, #ff4d4f 0%, #f5222d 100%);
  color: #ffffff;
  box-shadow: 0 4px 18px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #ff7875 0%, #ff4d4f 100%);
  box-shadow: 0 6px 26px rgba(255, 77, 79, 0.55);
  transform: translateY(-2px);
  color: #ffffff;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
  color: #ffffff;
}

.btn-outline-primary {
  background: transparent;
  color: var(--primary-hover);
  border: 1px solid rgba(255, 77, 79, 0.45);
}

.btn-outline-primary:hover {
  background: rgba(255, 77, 79, 0.15);
  border-color: var(--primary);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.9rem;
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.12rem;
}

.btn-block {
  width: 100%;
}

/* 6. 顶部导航栏 (Header) */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(7, 10, 18, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

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

.header-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-logo-img {
  height: 48px;
  width: auto;
}

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

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.96rem;
  padding: 6px 0;
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.25s ease;
  border-radius: 2px;
}

.nav-link:hover,
.nav-link.active {
  color: #ffffff;
}

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.mobile-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 1.25rem;
}

/* 7. Hero 首屏核心区域 */
.hero-section {
  padding: 100px 0 80px;
  text-align: center;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 20px;
  background: rgba(255, 77, 79, 0.12);
  border: 1px solid rgba(255, 77, 79, 0.35);
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  font-weight: 700;
  color: #ff7875;
  margin-bottom: 28px;
  box-shadow: 0 0 20px rgba(255, 77, 79, 0.2);
}

.hero-tag .pulse-dot {
  width: 8px;
  height: 8px;
  background: #ff4d4f;
  border-radius: 50%;
  box-shadow: 0 0 10px #ff4d4f;
  animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.5px;
  margin-bottom: 24px;
}

.hero-title .text-gradient {
  background: linear-gradient(135deg, #ff4d4f 10%, #ff7875 50%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.22rem;
  color: var(--text-muted);
  max-width: 860px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-bottom: 50px;
  flex-wrap: wrap;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 980px;
  margin: 0 auto;
}

.stat-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 22px 18px;
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.stat-item:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.stat-num {
  font-size: 2rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.2;
  margin-bottom: 6px;
}

.stat-num.highlight {
  color: var(--primary-hover);
}

.stat-num.accent {
  color: var(--secondary);
}

.stat-label {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* 8. 核心优势特性 (Features Grid) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  backdrop-filter: blur(12px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--primary), transparent);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card);
}

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

.feature-icon-box {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  background: rgba(255, 77, 79, 0.12);
  border: 1px solid rgba(255, 77, 79, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.7rem;
  margin-bottom: 22px;
  color: var(--primary);
  transition: var(--transition);
}

.feature-card:hover .feature-icon-box {
  background: var(--primary);
  color: #ffffff;
  box-shadow: 0 0 20px var(--primary-glow);
  transform: scale(1.08);
}

.feature-title {
  font-size: 1.28rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #ffffff;
}

.feature-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 9. 全球优质节点与航线分布 (Nodes Flight Board) */
.nodes-section {
  background: rgba(11, 17, 33, 0.5);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.nodes-board {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  box-shadow: var(--shadow-card);
}

.nodes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-bottom: 25px;
}

.node-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: var(--transition);
}

.node-item:hover {
  border-color: var(--secondary);
  background: rgba(56, 189, 248, 0.06);
  transform: translateY(-3px);
}

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

.node-country {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.05rem;
  color: #ffffff;
}

.node-flag {
  font-size: 1.3rem;
}

.node-latency {
  font-size: 0.82rem;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  background: rgba(34, 197, 94, 0.15);
  color: #4ade80;
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.node-specs {
  display: flex;
  justify-content: space-between;
  font-size: 0.84rem;
  color: var(--text-muted);
}

.node-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.node-tag {
  font-size: 0.75rem;
  padding: 2px 7px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.05);
  color: #cbd5e1;
}

.nodes-note {
  text-align: center;
  font-size: 0.92rem;
  color: var(--text-muted);
  padding-top: 15px;
  border-top: 1px solid var(--border-color);
}

/* ==========================================================================
   10. 核心重点：价格区域 (Pricing Grid) - 严格要求所有价格同排！
   ========================================================================== */
.pricing-section {
  position: relative;
}

/* 4 列同排平铺网格：桌面端 4 列严格同排并列展示 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch; /* 保证所有卡片高度自动拉平一致 */
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 34px 24px;
  backdrop-filter: blur(14px);
  transition: var(--transition);
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between; /* 保证底部 CTA 按钮在同排水平线 */
}

.pricing-card:hover {
  transform: translateY(-8px);
  border-color: var(--border-hover);
  box-shadow: 0 15px 35px -5px rgba(255, 77, 79, 0.25);
}

/* 热门推荐高亮卡片 */
.pricing-card.popular {
  border: 2px solid var(--primary);
  background: linear-gradient(180deg, rgba(255, 77, 79, 0.12) 0%, rgba(15, 23, 42, 0.85) 100%);
  box-shadow: 0 10px 40px -10px var(--primary-glow);
  transform: scale(1.02);
  z-index: 2;
}

.pricing-card.popular:hover {
  transform: scale(1.04) translateY(-8px);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #ff4d4f, #f5222d);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 5px 16px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px var(--primary-glow);
  white-space: nowrap;
}

.plan-header {
  text-align: center;
  margin-bottom: 20px;
  min-height: 72px; /* 标题与描述高度对齐 */
}

.plan-name {
  font-size: 1.45rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* 核心价格框：固定同排基准线 */
.plan-price-box {
  text-align: center;
  padding: 16px 0;
  margin-bottom: 24px;
  border-top: 1px dashed var(--border-color);
  border-bottom: 1px dashed var(--border-color);
  min-height: 96px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.plan-price {
  font-size: 2.75rem;
  font-weight: 900;
  color: #ffffff;
  line-height: 1;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
}

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

.plan-cycle {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-left: 4px;
}

.plan-subtext {
  font-size: 0.82rem;
  color: var(--secondary);
  font-weight: 600;
  margin-top: 6px;
}

/* 特性列表：占据中间弹性空间，确保按钮始终置底同排 */
.plan-features {
  flex-grow: 1;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 13px;
}

.plan-features li {
  font-size: 0.92rem;
  color: #cbd5e1;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  line-height: 1.45;
}

.plan-features li strong {
  color: #ffffff;
}

.check-icon {
  color: var(--accent-green);
  font-weight: 900;
  flex-shrink: 0;
}

/* 不限时流量包特惠横幅 (差旅备用) */
.traffic-pack-banner {
  margin-top: 36px;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.12) 0%, rgba(15, 23, 42, 0.85) 100%);
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: var(--radius-lg);
  padding: 26px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  backdrop-filter: blur(12px);
}

.traffic-pack-info {
  display: flex;
  align-items: center;
  gap: 20px;
}

.traffic-icon {
  font-size: 2.8rem;
  flex-shrink: 0;
}

.traffic-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 6px;
}

.traffic-desc {
  font-size: 0.94rem;
  color: var(--text-muted);
  max-width: 680px;
}

.traffic-pack-cta {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-shrink: 0;
}

.traffic-price {
  font-size: 2.2rem;
  font-weight: 900;
  color: #ffffff;
  white-space: nowrap;
}

/* 11. 客户端生态与一键适配教程 */
.clients-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.client-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  text-align: center;
  transition: var(--transition);
}

.client-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.client-logo {
  font-size: 2.4rem;
  margin-bottom: 12px;
}

.client-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 4px;
}

.client-platform {
  font-size: 0.82rem;
  color: var(--secondary);
  margin-bottom: 8px;
}

.client-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* 12. 推荐文章与评测专栏 (Articles Highlight) */
.articles-highlight-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 35px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.article-card:hover {
  border-color: var(--primary-hover);
  transform: translateY(-5px);
  box-shadow: 0 12px 28px -6px rgba(0, 0, 0, 0.4);
}

.article-tag {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--primary-hover);
  background: rgba(255, 77, 79, 0.12);
  margin-bottom: 14px;
  align-self: flex-start;
}

.article-title {
  font-size: 1.18rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
  line-height: 1.45;
}

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

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-dim);
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

.article-link-arrow {
  color: var(--primary-hover);
  font-weight: 700;
}

.view-all-articles {
  text-align: center;
}

/* 13. 用户评价与口碑 (Testimonials) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  backdrop-filter: blur(10px);
  transition: var(--transition);
}

.review-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.15rem;
  color: #ffffff;
}

.review-user-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
}

.review-user-role {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.review-stars {
  color: #f59e0b;
  font-size: 0.95rem;
  margin-bottom: 12px;
}

.review-text {
  font-size: 0.94rem;
  color: #cbd5e1;
  line-height: 1.65;
}

/* 14. 常见问题 (FAQ Accordion) */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

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

.faq-item.active {
  border-color: rgba(255, 77, 79, 0.5);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.faq-question {
  padding: 22px 24px;
  font-size: 1.12rem;
  font-weight: 700;
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.faq-toggle-icon {
  font-size: 1.35rem;
  color: var(--primary-hover);
  transition: transform 0.28s ease;
  line-height: 1;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.32s ease;
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.faq-answer-inner {
  padding: 0 24px 22px;
  border-top: 1px dashed rgba(255, 255, 255, 0.06);
  padding-top: 16px;
}

/* 15. 底部权威外链与全站导航 (Footer) */
.site-footer {
  background: #05070d;
  border-top: 1px solid var(--border-color);
  padding: 70px 0 35px;
  font-size: 0.92rem;
  color: var(--text-muted);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 50px;
}

.footer-brand-info {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-logo-img {
  height: 44px;
  width: auto;
}

.footer-slogan {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text-muted);
  max-width: 360px;
}

.footer-col-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 20px;
  position: relative;
}

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

.footer-links-list a {
  color: var(--text-muted);
}

.footer-links-list a:hover {
  color: var(--primary-hover);
  padding-left: 4px;
}

/* 权威外链推荐栏 (Industry Outbound Links) */
.footer-external-links {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 40px;
}

.external-links-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.external-links-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 20px;
}

.external-link-item {
  font-size: 0.85rem;
  color: var(--text-dim);
  transition: var(--transition);
}

.external-link-item:hover {
  color: var(--secondary);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 15px;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.footer-legal-links {
  display: flex;
  gap: 20px;
}

.footer-legal-links a:hover {
  color: var(--text-muted);
}

/* 16. 响应式适配媒体查询 (Mobile & Tablet Responsiveness) */
@media (max-width: 1100px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
  .features-grid,
  .articles-highlight-grid,
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .nodes-grid,
  .clients-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  html {
    font-size: 15px;
  }
  .nav-menu {
    display: none;
    position: absolute;
    top: 76px;
    left: 0;
    width: 100%;
    background: #0a0e1a;
    flex-direction: column;
    padding: 24px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
  }
  .nav-menu.open {
    display: flex;
  }
  .mobile-toggle {
    display: block;
  }
  .hero-title {
    font-size: 2.35rem;
  }
  .section-title {
    font-size: 1.85rem;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .pricing-card.popular {
    transform: none;
  }
  .features-grid,
  .articles-highlight-grid,
  .reviews-grid,
  .nodes-grid,
  .clients-grid {
    grid-template-columns: 1fr;
  }
  .traffic-pack-banner {
    flex-direction: column;
    align-items: flex-start;
  }
  .traffic-pack-cta {
    width: 100%;
    justify-content: space-between;
  }
  .footer-top {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}