/* ==========================================================================
   灯塔加速 (dengtajiasu.shop) - 官方网站核心样式表
   Pure Native CSS - 0外部重型框架 · 极致秒开与高转化体验
   ========================================================================== */

:root {
  /* 品牌深海与航标核心配色 */
  --bg-primary: #040914;
  --bg-secondary: #081226;
  --bg-card: rgba(11, 23, 48, 0.72);
  --bg-card-hover: rgba(16, 32, 66, 0.88);
  --bg-glass: rgba(8, 18, 38, 0.82);
  
  --border-color: rgba(255, 117, 160, 0.16);
  --border-hover: rgba(255, 117, 160, 0.45);
  --border-glow: rgba(255, 117, 160, 0.65);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  /* 冰粉色 (Ice Pink / Frosted Pink) 核心色板 */
  --ice-pink: #ff75a0;
  --ice-pink-hover: #ff5285;
  --ice-pink-light: #ffa8c5;
  --ice-pink-gradient: linear-gradient(135deg, #ffa8c5 0%, #ff6b8b 50%, #f43f68 100%);
  --ice-pink-glow: rgba(255, 107, 139, 0.42);
  
  --primary: #ff75a0;
  --primary-hover: #ff5285;
  --primary-gradient: var(--ice-pink-gradient);
  --gold-gradient: linear-gradient(135deg, #fef08a 0%, #f59e0b 55%, #d97706 100%);
  --accent-emerald: #10b981;
  --accent-gold: #f59e0b;
  --accent-indigo: #6366f1;
  --accent-rose: #f43f5e;
  
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-card: 0 12px 36px -10px rgba(0, 0, 0, 0.65);
  --shadow-glow: 0 0 35px rgba(255, 117, 160, 0.35);
  --shadow-gold-glow: 0 0 35px rgba(245, 158, 11, 0.35);

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

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition: all 0.28s 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-main);
}

body {
  font-family: var(--font-sans);
  line-height: 1.68;
  overflow-x: hidden;
  position: relative;
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
}

/* 容器规范 */
.container {
  width: 100%;
  max-width: 1280px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   动态背景系统 (Dynamic Canvas + Atmospheric Glows)
   ========================================================================== */
.dynamic-bg-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

#bg-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0.98;
  display: block;
  z-index: 1;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  will-change: transform;
  pointer-events: none;
  z-index: 0;
  opacity: 0.22;
  animation: floatOrb 18s ease-in-out infinite alternate;
}

.ambient-orb-1 {
  width: 650px;
  height: 650px;
  top: -150px;
  left: -100px;
  background: radial-gradient(circle, rgba(255, 117, 160, 0.18) 0%, rgba(244, 63, 104, 0.05) 70%, transparent 100%);
}

.ambient-orb-2 {
  width: 700px;
  height: 700px;
  top: 35%;
  right: -150px;
  background: radial-gradient(circle, rgba(168, 85, 247, 0.12) 0%, rgba(255, 117, 160, 0.06) 60%, transparent 100%);
  animation-duration: 22s;
  animation-direction: alternate-reverse;
}

.ambient-orb-3 {
  width: 550px;
  height: 550px;
  bottom: -100px;
  left: 20%;
  background: radial-gradient(circle, rgba(245, 158, 11, 0.1) 0%, rgba(255, 117, 160, 0.05) 65%, transparent 100%);
  animation-duration: 26s;
}

.cyber-grid-overlay {
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(255, 117, 160, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 117, 160, 0.04) 1px, transparent 1px);
  background-size: 50px 50px;
  mask-image: radial-gradient(ellipse at 50% 30%, black 40%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 30%, black 40%, transparent 80%);
  pointer-events: none;
  z-index: 2;
  opacity: 0.6;
}

/* 确保各区块处于动态画布图层之上且不遮挡背景 */
.hero-section,
.pricing-section,
.features-section,
.nodes-section,
.articles-section,
.testimonials-section,
.faq-section,
.resources-section,
.bottom-cta-banner,
.site-footer {
  position: relative;
  z-index: 1;
}

@keyframes floatOrb {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, 30px) scale(1.08); }
  100% { transform: translate(-30px, 50px) scale(0.96); }
}

/* ==========================================================================
   顶部导航 Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(4, 9, 20, 0.85);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

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

.logo-link {
  display: flex;
  align-items: center;
  text-decoration: none;
  transition: transform 0.2s ease;
}

.logo-link:hover {
  transform: scale(1.02);
}

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

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

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

.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 0.25s ease;
}

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

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

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

/* ==========================================================================
   按钮组件 (Buttons & CTA)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: var(--ice-pink-gradient);
  color: #ffffff;
  font-weight: 700;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.18);
  box-shadow: 0 4px 20px var(--ice-pink-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 107, 139, 0.65);
  filter: brightness(1.08);
  color: #ffffff;
}

.btn-gold {
  background: var(--gold-gradient);
  color: #2b1800;
  font-weight: 700;
  box-shadow: 0 4px 18px rgba(245, 158, 11, 0.35);
}

.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 26px rgba(245, 158, 11, 0.55);
  filter: brightness(1.08);
}

.btn-outline {
  background: rgba(255, 117, 160, 0.08);
  color: #ff75a0;
  border: 1.5px solid rgba(255, 117, 160, 0.45);
  font-weight: 700;
  transition: var(--transition);
}

.btn-outline:hover {
  background: var(--ice-pink-gradient);
  border-color: transparent;
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(255, 107, 139, 0.48);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
}

.btn-md {
  padding: 12px 26px;
  font-size: 1rem;
}

.btn-lg {
  padding: 15px 34px;
  font-size: 1.1rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

.btn-glow {
  position: relative;
  overflow: hidden;
}

.btn-glow::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 10%, transparent 60%);
  transform: rotate(45deg);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.btn-glow:hover::before {
  opacity: 1;
}

/* ==========================================================================
   Hero 主视觉区域
   ========================================================================== */
.hero-section {
  padding: 80px 0 60px;
  text-align: center;
  position: relative;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 20px;
  background: rgba(255, 117, 160, 0.08);
  border: 1px solid rgba(255, 117, 160, 0.32);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  color: #ffa8c5;
  margin-bottom: 24px;
  box-shadow: 0 0 20px rgba(255, 117, 160, 0.18);
}

.pulse-dot {
  width: 9px;
  height: 9px;
  background-color: var(--accent-emerald);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  animation: pulseGreen 2s infinite;
}

@keyframes pulseGreen {
  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 10px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.22;
  margin-bottom: 22px;
  letter-spacing: -0.5px;
}

.text-gradient {
  background: linear-gradient(135deg, #ffffff 15%, #ffa8c5 45%, #ff6b8b 78%, #f43f68 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

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

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--text-muted);
  max-width: 820px;
  margin: 0 auto 36px;
  line-height: 1.8;
}

.hero-keywords-tagline {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 34px;
}

.tag-badge {
  display: inline-block;
  font-size: 0.82rem;
  padding: 4px 12px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
  color: #cbd5e1;
}

.tag-badge.highlight {
  background: rgba(255, 117, 160, 0.12);
  border-color: rgba(255, 117, 160, 0.35);
  color: #ff75a0;
  font-weight: 600;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-bottom: 48px;
}

/* 核心信誉指标条 */
.hero-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 26px 30px;
  backdrop-filter: blur(12px);
  margin-top: 20px;
  box-shadow: var(--shadow-card);
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.1rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--primary);
  line-height: 1.1;
  margin-bottom: 6px;
}

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

/* ==========================================================================
   价格区域 (透明定价 - 严格要求：所有价格同排排列)
   ========================================================================== */
.pricing-section {
  padding: 80px 0 90px;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 50px;
}

.section-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255, 117, 160, 0.12);
  border: 1px solid rgba(255, 117, 160, 0.32);
  border-radius: var(--radius-full);
  color: #ff75a0;
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-bottom: 14px;
}

.section-title {
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 16px;
  color: #ffffff;
}

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

/* 核心：4 个价格卡片必须同排展示 (Desktop 4-Col Row) */
.pricing-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  align-items: stretch;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: blur(14px);
  position: relative;
  transition: var(--transition);
  box-shadow: var(--shadow-card);
}

.price-card:hover {
  transform: translateY(-8px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
  background: var(--bg-card-hover);
}

.price-card.featured {
  border: 2px solid #ff75a0;
  background: linear-gradient(180deg, rgba(38, 14, 28, 0.85) 0%, rgba(18, 8, 20, 0.95) 100%);
  box-shadow: 0 10px 40px -10px rgba(255, 117, 160, 0.45);
  transform: scale(1.02);
}

.price-card.featured:hover {
  transform: scale(1.02) translateY(-8px);
  box-shadow: 0 14px 45px rgba(255, 117, 160, 0.6);
}

.featured-pill {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gold-gradient);
  color: #1c1000;
  font-size: 0.76rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  letter-spacing: 0.8px;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
  white-space: nowrap;
}

.plan-top-info {
  margin-bottom: 20px;
}

.plan-tier-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  background: rgba(255, 117, 160, 0.12);
  color: #ff75a0;
  border: 1px solid rgba(255, 117, 160, 0.42);
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 8px;
}

.plan-summary {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.5;
  min-height: 38px;
}

.price-amount-box {
  margin: 18px 0 22px;
  padding: 16px 0;
  border-top: 1px dashed rgba(255, 255, 255, 0.1);
  border-bottom: 1px dashed rgba(255, 255, 255, 0.1);
}

.price-main {
  display: flex;
  align-items: baseline;
  justify-content: flex-start;
  gap: 4px;
}

.price-currency {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ff75a0;
}

.price-number {
  font-size: 2.6rem;
  font-weight: 900;
  font-family: var(--font-mono);
  color: #ffffff;
  line-height: 1;
}

.price-cycle {
  font-size: 0.88rem;
  color: var(--text-dim);
  margin-left: 2px;
}

.price-equivalent {
  font-size: 0.82rem;
  color: var(--accent-emerald);
  margin-top: 6px;
  font-weight: 600;
}

.plan-features-list {
  list-style: none;
  margin-bottom: 26px;
  flex-grow: 1;
}

.plan-features-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.88rem;
  color: #cbd5e1;
  margin-bottom: 12px;
  line-height: 1.45;
}

.feature-icon-check {
  color: var(--accent-emerald);
  font-weight: 900;
  flex-shrink: 0;
  font-size: 1rem;
}

.feature-icon-cross {
  color: var(--text-dim);
  flex-shrink: 0;
}

.plan-features-list li.dimmed {
  color: var(--text-dim);
  text-decoration: line-through;
  opacity: 0.6;
}

.plan-cta-wrap {
  margin-top: auto;
}

.price-footnote {
  font-size: 0.76rem;
  color: var(--text-dim);
  text-align: center;
  margin-top: 8px;
}

/* ==========================================================================
   核心特色 Features & 专线优势
   ========================================================================== */
.features-section {
  padding: 80px 0;
}

.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-lg);
  padding: 32px 26px;
  backdrop-filter: blur(12px);
  transition: var(--transition);
}

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

.feature-icon-box {
  width: 54px;
  height: 54px;
  background: rgba(255, 117, 160, 0.12);
  border: 1px solid rgba(255, 117, 160, 0.32);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
  color: #ff75a0;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ==========================================================================
   全球节点与支持客户端矩阵
   ========================================================================== */
.nodes-section {
  padding: 80px 0;
  background: rgba(5, 11, 24, 0.5);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.nodes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-bottom: 40px;
}

.node-chip {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition);
}

.node-chip:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
}

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

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

.node-name {
  font-size: 0.95rem;
  font-weight: 600;
  color: #ffffff;
}

.node-type {
  font-size: 0.75rem;
  color: var(--text-dim);
}

.node-ping {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-emerald);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 5px;
}

.ping-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-emerald);
}

.clients-banner {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.clients-logos {
  display: flex;
  align-items: center;
  gap: 22px;
  flex-wrap: wrap;
}

.client-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.04);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

/* ==========================================================================
   精选文章专栏 (Articles Grid)
   ========================================================================== */
.articles-section {
  padding: 80px 0;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  text-decoration: none;
  color: inherit;
}

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

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-bottom: 14px;
}

.article-tag {
  color: #ff75a0;
  background: rgba(255, 117, 160, 0.14);
  border: 1px solid rgba(255, 117, 160, 0.3);
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.article-card h3 {
  font-size: 1.18rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.45;
  margin-bottom: 12px;
  transition: color 0.2s ease;
}

.article-card:hover h3 {
  color: var(--primary);
}

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

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 600;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 14px;
}

/* ==========================================================================
   真实用户评价 (Testimonials)
   ========================================================================== */
.testimonials-section {
  padding: 80px 0;
  position: relative;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  backdrop-filter: blur(12px);
  transition: var(--transition);
}

.testimonial-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
}

.rating-stars {
  color: var(--accent-gold);
  font-size: 1.1rem;
  margin-bottom: 14px;
}

.testimonial-quote {
  font-size: 0.92rem;
  color: #e2e8f0;
  line-height: 1.65;
  margin-bottom: 20px;
  font-style: italic;
}

.testimonial-user {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #ffffff;
  font-size: 1.1rem;
  flex-shrink: 0;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.testimonial-card:hover .user-avatar {
  transform: scale(1.08);
}

/* 6 位真实用户专属 6 种独立特色渐变色 */
/* 1. 张工：极光紫 (Cyber Violet) */
.user-avatar.avatar-violet,
.testimonials-grid .testimonial-card:nth-child(1) .user-avatar {
  background: linear-gradient(135deg, #a855f7 0%, #7c3aed 100%);
  box-shadow: 0 4px 16px rgba(168, 85, 247, 0.45);
}

/* 2. 林女士：冰粉色 (Ice Pink) */
.user-avatar.avatar-pink,
.testimonials-grid .testimonial-card:nth-child(2) .user-avatar {
  background: linear-gradient(135deg, #ffa8c5 0%, #ff5285 50%, #f43f68 100%);
  box-shadow: 0 4px 16px rgba(255, 107, 139, 0.45);
}

/* 3. 王先生：晴空蓝 (Sky Blue / Cyan) */
.user-avatar.avatar-cyan,
.testimonials-grid .testimonial-card:nth-child(3) .user-avatar {
  background: linear-gradient(135deg, #38bdf8 0%, #0284c7 100%);
  box-shadow: 0 4px 16px rgba(56, 189, 248, 0.45);
}

/* 4. 刘同学：翡翠绿 (Emerald Green) */
.user-avatar.avatar-emerald,
.testimonials-grid .testimonial-card:nth-child(4) .user-avatar {
  background: linear-gradient(135deg, #34d399 0%, #059669 100%);
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.45);
}

/* 5. 陈总监：落日橙 (Sunset Orange) */
.user-avatar.avatar-orange,
.testimonials-grid .testimonial-card:nth-child(5) .user-avatar {
  background: linear-gradient(135deg, #fb923c 0%, #ea580c 100%);
  box-shadow: 0 4px 16px rgba(234, 88, 12, 0.45);
}

/* 6. 赵经理：宝石红 (Ruby Rose) */
.user-avatar.avatar-ruby,
.testimonials-grid .testimonial-card:nth-child(6) .user-avatar {
  background: linear-gradient(135deg, #fb7185 0%, #e11d48 100%);
  box-shadow: 0 4px 16px rgba(225, 29, 72, 0.45);
}

.user-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
}

.user-info span {
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* ==========================================================================
   常见问题 FAQ (Accordion)
   ========================================================================== */
.faq-section {
  padding: 80px 0;
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: transparent;
  border: none;
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  transition: var(--transition);
}

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

.faq-chevron {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--primary);
}

.faq-item.active .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  color: var(--text-muted);
  font-size: 0.94rem;
  line-height: 1.7;
  padding: 0 24px;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 24px 22px;
}

/* ==========================================================================
   外部工具与权威资源外链 (Outbound Links)
   ========================================================================== */
.resources-section {
  padding: 60px 0;
  background: rgba(4, 10, 22, 0.7);
  border-top: 1px solid var(--border-color);
}

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

.resource-card {
  background: rgba(15, 23, 42, 0.55);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  text-decoration: none;
  transition: var(--transition);
  display: block;
}

.resource-card:hover {
  border-color: var(--primary);
  transform: translateY(-3px);
  background: rgba(15, 23, 42, 0.85);
}

.resource-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.resource-title span.arrow {
  color: var(--primary);
}

.resource-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ==========================================================================
   底部 CTA 横幅
   ========================================================================== */
.bottom-cta-banner {
  padding: 80px 0;
  text-align: center;
}

.cta-box {
  background: radial-gradient(ellipse at 50% 50%, rgba(255, 117, 160, 0.18) 0%, rgba(4, 9, 20, 0.95) 80%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 60px 30px;
  box-shadow: var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.cta-box h2 {
  font-size: 2.3rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 16px;
}

.cta-box p {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 32px;
}

/* ==========================================================================
   页脚 Footer
   ========================================================================== */
.site-footer {
  background: #020610;
  border-top: 1px solid var(--border-color);
  padding: 70px 0 30px;
}

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

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 16px;
  max-width: 320px;
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 18px;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 10px;
}

.footer-col a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.88rem;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--primary);
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.07);
  padding-top: 28px;
  font-size: 0.82rem;
  color: var(--text-dim);
  flex-wrap: wrap;
  gap: 14px;
}

/* ==========================================================================
   响应式调整 (Responsive Design)
   ========================================================================== */
@media (max-width: 1100px) {
  .pricing-row {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid, .articles-grid, .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .nodes-grid, .resources-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 76px;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
  }
  .nav-menu.show {
    display: flex;
  }
  .mobile-menu-btn {
    display: block;
  }
  .hero-title {
    font-size: 2.2rem;
  }
  .pricing-row {
    grid-template-columns: 1fr;
  }
  .features-grid, .articles-grid, .testimonials-grid {
    grid-template-columns: 1fr;
  }
  .nodes-grid, .resources-grid {
    grid-template-columns: 1fr;
  }
  .hero-stats-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
}