/* ==========================================================================
   CTC 金龙鱼机场网 (xn--ctc-wq5jp45bvqe.best)
   Pure Native CSS - 0 External Bulky Frameworks - Instant Sub-Second Load
   Theme: Cyber Deep Space & Luxury Golden Arowana (金龙鱼流光黑金)
   ========================================================================== */

:root {
  --bg-dark: #070b18;
  --bg-deep: #050813;
  --bg-card: rgba(13, 20, 38, 0.75);
  --bg-card-hover: rgba(22, 33, 62, 0.9);
  --bg-input: rgba(15, 23, 42, 0.6);
  
  --primary-gold: #f59e0b;
  --primary-light: #fbbf24;
  --primary-dark: #d97706;
  --primary-gold-bright: #ffe066;
  
  --accent-cyan: #38bdf8;
  --accent-blue: #3b82f6;
  --accent-emerald: #10b981;
  --accent-purple: #8b5cf6;
  
  --text-pure: #ffffff;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-subtle: #64748b;
  
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-gold: rgba(245, 158, 11, 0.35);
  --border-gold-strong: rgba(245, 158, 11, 0.8);
  --border-cyan: rgba(56, 189, 248, 0.3);
  
  --gold-glow: 0 0 25px rgba(245, 158, 11, 0.35);
  --gold-glow-lg: 0 10px 40px rgba(245, 158, 11, 0.45);
  --cyan-glow: 0 0 20px rgba(56, 189, 248, 0.3);
  --card-shadow: 0 20px 45px -15px rgba(0, 0, 0, 0.6);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition: all 0.28s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  position: relative;
  min-height: 100vh;
  overflow-x: hidden;
  background: var(--bg-dark);
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul, ol {
  list-style: none;
}

/* ==========================================================================
   DYNAMIC BACKGROUND (纯原生 CSS 动态流光与多重光斑体系)
   ========================================================================== */
.bg-dynamic-wrap {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

#bg-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: block;
  opacity: 0.9;
}

.dynamic-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.28;
  will-change: transform;
  pointer-events: none;
}

.dynamic-orb-1 {
  top: -10%;
  left: 10%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(245, 158, 11, 0.45) 0%, rgba(217, 119, 6, 0.15) 60%, transparent 80%);
  animation: orbFloat1 24s infinite alternate ease-in-out;
}

.dynamic-orb-2 {
  top: 35%;
  right: -5%;
  width: 650px;
  height: 650px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.35) 0%, rgba(59, 130, 246, 0.12) 60%, transparent 80%);
  animation: orbFloat2 28s infinite alternate ease-in-out;
}

.dynamic-orb-3 {
  bottom: -15%;
  left: 5%;
  width: 550px;
  height: 550px;
  background: radial-gradient(circle, rgba(251, 191, 36, 0.3) 0%, rgba(16, 185, 129, 0.1) 60%, transparent 80%);
  animation: orbFloat3 22s infinite alternate ease-in-out;
}

.cyber-grid-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(rgba(245, 158, 11, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245, 158, 11, 0.03) 1px, transparent 1px);
  background-size: 55px 55px;
  mask-image: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.85) 0%, transparent 85%);
  -webkit-mask-image: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.85) 0%, transparent 85%);
}

@keyframes orbFloat1 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(90px, 70px) scale(1.15); }
  100% { transform: translate(-50px, 110px) scale(0.95); }
}

@keyframes orbFloat2 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-100px, 80px) scale(1.2); }
  100% { transform: translate(40px, -60px) scale(0.9); }
}

@keyframes orbFloat3 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(80px, -70px) scale(1.1); }
  100% { transform: translate(-70px, 40px) scale(1); }
}

/* ==========================================================================
   LAYOUT CONTAINERS & UTILITIES
   ========================================================================== */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

.section {
  padding: 85px 0;
  position: relative;
  z-index: 2;
}

.section-title-wrap {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 55px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: var(--radius-full);
  color: var(--primary-light);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-tag::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  background: var(--primary-light);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--primary-light);
}

.section-title {
  font-size: 36px;
  font-weight: 900;
  color: var(--text-pure);
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.7;
}

.text-gold-gradient {
  background: linear-gradient(135deg, #ffe066 0%, #f59e0b 50%, #d97706 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

/* ==========================================================================
   BUTTONS (严格符合 rel="nofollow" 与 target="_blank" 的 CTA 规范)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-size: 15px;
  font-weight: 700;
  padding: 13px 28px;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  border: none;
  white-space: nowrap;
}

.btn-gold {
  background: linear-gradient(135deg, #ffe066 0%, #f59e0b 50%, #d97706 100%);
  color: #0b1120;
  box-shadow: var(--gold-glow);
  font-weight: 800;
}

.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: var(--gold-glow-lg);
  filter: brightness(1.08);
  color: #000000;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-main);
  border: 1px solid var(--border-subtle);
  backdrop-filter: blur(10px);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.2);
  color: var(--text-pure);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 13.5px;
}

.btn-lg {
  padding: 16px 36px;
  font-size: 17px;
}

.btn-block {
  width: 100%;
}

/* ==========================================================================
   HEADER / NAVBAR (左上方要有这个logo)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background: rgba(7, 11, 24, 0.85);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-subtle);
  transition: var(--transition);
}

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

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

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

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

.nav-link {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text-muted);
  transition: var(--transition);
  position: relative;
  padding: 6px 0;
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--primary-gold);
  transition: var(--transition);
}

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

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

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-pure);
  font-size: 26px;
  cursor: pointer;
}

/* ==========================================================================
   HERO SECTION (极速吸睛、高转化呼吁)
   ========================================================================== */
.hero-section {
  padding: 100px 0 80px;
  text-align: center;
  position: relative;
  z-index: 2;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 20px;
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 28px;
}

.hero-pill-badge {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: #000;
  font-size: 11px;
  font-weight: 900;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  text-transform: uppercase;
}

.hero-title {
  font-size: 52px;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -1px;
  color: var(--text-pure);
  margin-bottom: 24px;
  max-width: 950px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-muted);
  line-height: 1.75;
  max-width: 820px;
  margin: 0 auto 36px;
}

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

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1020px;
  margin: 0 auto;
}

.metric-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 22px 18px;
  backdrop-filter: blur(14px);
  text-align: center;
  transition: var(--transition);
}

.metric-card:hover {
  border-color: var(--border-gold);
  transform: translateY(-4px);
  box-shadow: 0 10px 25px -10px rgba(245, 158, 11, 0.25);
}

.metric-value {
  font-size: 32px;
  font-weight: 900;
  color: var(--text-pure);
  margin-bottom: 4px;
  line-height: 1.1;
}

.metric-label {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 600;
}

/* ==========================================================================
   ADVANTAGES SECTION (6大核心技术优势)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 34px 28px;
  backdrop-filter: blur(16px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--primary-gold), transparent);
  opacity: 0;
  transition: var(--transition);
}

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

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

.feature-icon-box {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-md);
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 22px;
  color: var(--primary-light);
}

.feature-title {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 12px;
}

.feature-desc {
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.68;
}

/* ==========================================================================
   PRICING SECTION (严格要求：所有价格要同排)
   桌面端 4 列严格同排并列展示，卡片等高，CTA规范对齐
   ========================================================================== */
.pricing-section {
  position: relative;
}

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

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  backdrop-filter: blur(16px);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

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

/* 热门推荐卡片高亮 */
.price-card-popular {
  border-color: var(--border-gold-strong);
  background: rgba(22, 33, 62, 0.85);
  box-shadow: var(--gold-glow);
  transform: scale(1.02);
}

.price-card-popular:hover {
  transform: scale(1.02) translateY(-8px);
  box-shadow: var(--gold-glow-lg);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #ffe066, #f59e0b, #d97706);
  color: #0b1120;
  font-size: 12px;
  font-weight: 900;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  letter-spacing: 0.5px;
  white-space: nowrap;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.5);
}

.price-header {
  margin-bottom: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
}

.price-tier-name {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 6px;
}

.price-tier-desc {
  font-size: 13px;
  color: var(--text-muted);
}

.price-amount-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 18px 0 10px;
}

.price-currency {
  font-size: 24px;
  font-weight: 800;
  color: var(--primary-light);
}

.price-amount {
  font-size: 44px;
  font-weight: 900;
  color: var(--text-pure);
  line-height: 1;
}

.price-period {
  font-size: 14px;
  color: var(--text-subtle);
  font-weight: 600;
}

.price-traffic-badge {
  display: inline-block;
  background: rgba(245, 158, 11, 0.12);
  color: var(--primary-light);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.price-features {
  flex-grow: 1;
  margin: 22px 0 28px;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 13.5px;
  color: var(--text-main);
  margin-bottom: 12px;
  line-height: 1.5;
}

.feature-item svg {
  width: 17px;
  height: 17px;
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--primary-light);
}

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

/* ==========================================================================
   NODE MATRIX & SPEED TEST (全球专线网络分布)
   ========================================================================== */
.nodes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-bottom: 40px;
}

.node-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 20px;
  backdrop-filter: blur(14px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition);
}

.node-card:hover {
  border-color: var(--border-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-3px);
}

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

.node-flag {
  font-size: 26px;
  line-height: 1;
}

.node-name {
  font-size: 15px;
  font-weight: 800;
  color: var(--text-pure);
}

.node-protocol {
  font-size: 12px;
  color: var(--text-muted);
}

.node-ping-badge {
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 6px;
}

.ping-low {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.ping-mid {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.ping-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 6px currentColor;
}

/* ==========================================================================
   CLIENT TUTORIALS SECTION (多平台一键配置)
   ========================================================================== */
.clients-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.client-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px 22px;
  text-align: center;
  backdrop-filter: blur(14px);
  transition: var(--transition);
}

.client-box:hover {
  border-color: var(--border-gold);
  transform: translateY(-5px);
  box-shadow: var(--card-shadow);
}

.client-icon {
  font-size: 38px;
  margin-bottom: 14px;
}

.client-title {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 8px;
}

.client-supported {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================================================================
   ARTICLES SECTION (SEO 文章模块展示)
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 26px;
  backdrop-filter: blur(14px);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

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

.article-badge-group {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}

.article-badge {
  font-size: 11.5px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent-cyan);
  border: 1px solid rgba(56, 189, 248, 0.25);
}

.article-title-link {
  font-size: 18px;
  font-weight: 800;
  color: var(--text-pure);
  line-height: 1.45;
  margin-bottom: 12px;
  transition: var(--transition);
}

.article-title-link:hover {
  color: var(--primary-light);
}

.article-excerpt {
  font-size: 13.5px;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--text-subtle);
  padding-top: 14px;
  border-top: 1px solid var(--border-subtle);
}

.read-more-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: var(--primary-light);
  font-weight: 700;
  font-size: 13px;
}

.read-more-link:hover {
  text-decoration: underline;
}

/* ==========================================================================
   USER REVIEWS / TESTIMONIALS (真实用户口碑评价)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px;
  backdrop-filter: blur(14px);
  transition: var(--transition);
}

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

.review-stars {
  color: #fbbf24;
  font-size: 16px;
  margin-bottom: 14px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 14.5px;
  color: var(--text-main);
  line-height: 1.7;
  margin-bottom: 20px;
}

.reviewer-profile {
  display: flex;
  align-items: center;
  gap: 12px;
}

.reviewer-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #f59e0b, #3b82f6);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 800;
  color: #fff;
}

.reviewer-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-pure);
}

.reviewer-role {
  font-size: 12.5px;
  color: var(--text-muted);
}

/* ==========================================================================
   FAQ SECTION (常见问题解答)
   ========================================================================== */
.faq-grid {
  max-width: 920px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  backdrop-filter: blur(14px);
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(245, 158, 11, 0.4);
}

.faq-question {
  padding: 22px 26px;
  font-size: 17px;
  font-weight: 800;
  color: var(--text-pure);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  user-select: none;
}

.faq-toggle-icon {
  font-size: 20px;
  color: var(--primary-light);
  transition: transform 0.3s ease;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-inner {
  padding: 0 26px 22px;
  font-size: 14.5px;
  color: var(--text-muted);
  line-height: 1.75;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: -6px;
  padding-top: 16px;
}

/* ==========================================================================
   FRIENDLY EXTERNAL LINKS (权威外链与资源推荐)
   ========================================================================== */
.external-links-section {
  padding: 45px 0;
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(5, 8, 19, 0.6);
}

.links-title {
  font-size: 14px;
  font-weight: 800;
  color: var(--text-muted);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

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

.ext-link {
  font-size: 13.5px;
  color: var(--text-subtle);
  transition: var(--transition);
}

.ext-link:hover {
  color: var(--primary-light);
  text-decoration: underline;
}

/* ==========================================================================
   FOOTER SECTION
   ========================================================================== */
.site-footer {
  padding: 60px 0 35px;
  background: var(--bg-deep);
  position: relative;
  z-index: 2;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 45px;
}

.footer-brand-desc {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-top: 16px;
  max-width: 360px;
}

.footer-col-title {
  font-size: 16px;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 18px;
}

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

.footer-links-list a {
  font-size: 14px;
  color: var(--text-muted);
  transition: var(--transition);
}

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

.footer-bottom {
  padding-top: 25px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--text-subtle);
}

/* ==========================================================================
   RESPONSIVE DESIGN (自适应与保底同排展现)
   ========================================================================== */
@media (max-width: 1200px) {
  .pricing-grid {
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
  }
  .price-card {
    padding: 24px 16px;
  }
  .price-amount {
    font-size: 36px;
  }
  .features-grid,
  .articles-grid,
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .nodes-grid,
  .clients-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 900px) {
  .pricing-grid {
    /* 平板及大屏手机保持水平横滑或两列并排 */
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .hero-title {
    font-size: 38px;
  }
  .hero-metrics {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
  .nav-menu {
    display: none;
  }
  .mobile-menu-btn {
    display: block;
  }
}

@media (max-width: 640px) {
  .pricing-grid {
    grid-template-columns: 1fr;
  }
  .features-grid,
  .articles-grid,
  .reviews-grid,
  .nodes-grid,
  .clients-grid {
    grid-template-columns: 1fr;
  }
  .hero-title {
    font-size: 30px;
  }
  .hero-subtitle {
    font-size: 15px;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
}