/* ==========================================================================
   MESL Cloud (mesl.club) - Metallic Red Cyberpunk Architecture & CSS System
   ========================================================================== */

:root {
  /* Metallic Red Design System Tokens */
  --bg-main: #07080c;
  --bg-surface: #0e111a;
  --bg-card: rgba(18, 22, 33, 0.75);
  --bg-card-hover: rgba(26, 32, 48, 0.85);
  
  --red-primary: #ff2a4b;
  --red-secondary: #ff5e78;
  --red-dark: #99001b;
  --red-glow: rgba(255, 42, 75, 0.4);
  --red-accent: #ff758c;
  --metallic-red: linear-gradient(135deg, #ffffff 0%, #ff6b81 30%, #ff2a4b 60%, #99001b 100%);
  --metallic-chrome: linear-gradient(135deg, #ffffff 0%, #e2e8f0 40%, #94a3b8 70%, #475569 100%);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --border-color: rgba(255, 42, 75, 0.2);
  --border-hover: rgba(255, 42, 75, 0.5);
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  
  --shadow-glow: 0 0 25px rgba(255, 42, 75, 0.3);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-main);
  color: var(--text-primary);
  font-family: var(--font-family);
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  line-height: 1.6;
  background: radial-gradient(circle at 50% 0%, rgba(255, 42, 75, 0.12) 0%, transparent 50%),
              radial-gradient(circle at 100% 40%, rgba(153, 0, 27, 0.1) 0%, transparent 40%),
              var(--bg-main);
  background-attachment: fixed;
  color: var(--text-primary);
}

/* Background Cyber Grid Overlay */
.cyber-grid-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-image: linear-gradient(rgba(255, 42, 75, 0.03) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255, 42, 75, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* Metallic Red Font Display Styles (指令 3: 字体金属红色展示) */
.metallic-red-text {
  background: var(--metallic-red);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 0 20px rgba(255, 42, 75, 0.3);
  font-weight: 800;
  letter-spacing: -0.02em;
  position: relative;
  display: inline-block;
}

.metallic-red-title {
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height: 1.15;
  background: linear-gradient(135deg, #ffffff 0%, #ff9ebb 25%, #ff2a4b 55%, #b30024 85%, #660014 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 15px rgba(255, 42, 75, 0.4));
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
}

.metallic-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  border-radius: 50px;
  background: linear-gradient(135deg, rgba(255, 42, 75, 0.15), rgba(153, 0, 27, 0.3));
  border: 1px solid rgba(255, 42, 75, 0.4);
  color: #ff758c;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  box-shadow: 0 0 15px rgba(255, 42, 75, 0.2);
}

.metallic-badge i {
  color: var(--red-primary);
  animation: pulse-glow 2s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { opacity: 1; filter: drop-shadow(0 0 5px var(--red-primary)); }
  50% { opacity: 0.5; filter: drop-shadow(0 0 0px var(--red-primary)); }
}

/* Header & Navigation Bar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 76px;
  background: rgba(7, 8, 12, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: all 0.3s ease;
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo svg {
  width: 42px;
  height: 42px;
  filter: drop-shadow(0 0 10px rgba(255, 42, 75, 0.5));
}

.brand-name {
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  color: #fff;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.nav-link:hover, .nav-link.active {
  color: #ffffff;
  text-shadow: 0 0 10px rgba(255, 42, 75, 0.8);
}

.btn-register-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.65rem 1.6rem;
  border-radius: 50px;
  background: linear-gradient(135deg, #ff2a4b 0%, #e60026 50%, #99001b 100%);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  box-shadow: 0 0 20px rgba(255, 42, 75, 0.4), inset 0 1px 0 rgba(255,255,255,0.3);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  border: 1px solid rgba(255, 117, 140, 0.4);
  cursor: pointer;
}

.btn-register-cta:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 0 30px rgba(255, 42, 75, 0.7), inset 0 1px 0 rgba(255,255,255,0.5);
  background: linear-gradient(135deg, #ff4d6d 0%, #ff002b 50%, #b30020 100%);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.65rem 1.6rem;
  border-radius: 50px;
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  background: rgba(255, 42, 75, 0.15);
  border-color: rgba(255, 42, 75, 0.5);
  transform: translateY(-2px);
}

/* Hero Section with Cyber Dashboard Aesthetics */
.hero-section {
  padding-top: 140px;
  padding-bottom: 70px;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-subtitle {
  color: var(--text-secondary);
  font-size: 1.15rem;
  margin-bottom: 2rem;
  max-width: 580px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

/* Live Traffic & Active User Counters Widget (指令 4: 实时流量节点和下载人数) */
.live-stats-bar {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  width: 100%;
  padding: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.stat-value {
  font-size: 1.6rem;
  font-weight: 800;
  color: #fff;
  font-family: monospace;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.stat-label i {
  color: var(--red-primary);
}

/* Live Node Latency & Status Terminal Container (指令 4 & 指令 5) */
.hero-node-terminal {
  background: rgba(10, 12, 18, 0.9);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-card), var(--shadow-glow);
  position: relative;
}

.terminal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 1rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.terminal-title {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-secondary);
}

.pulse-dot {
  width: 10px;
  height: 10px;
  background: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 10px #10b981;
  animation: blink 1.5s infinite ease-in-out;
}

@keyframes blink {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

.node-list-mini {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.node-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.7rem 1rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
}

.node-row:hover {
  background: rgba(255, 42, 75, 0.08);
  border-color: rgba(255, 42, 75, 0.3);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  font-weight: 600;
}

.flag-icon {
  font-size: 1.1rem;
}

.node-ping {
  font-family: monospace;
  font-size: 0.85rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

/* Feature Cards Grid Section */
.features-section {
  padding: 80px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 3.5rem auto;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-top: 0.5rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--red-primary), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
  background: var(--bg-card-hover);
}

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

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: linear-gradient(135deg, rgba(255, 42, 75, 0.2), rgba(153, 0, 27, 0.4));
  border: 1px solid rgba(255, 42, 75, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--red-accent);
  margin-bottom: 1.25rem;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.feature-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Pricing Section & Interactive Calculator */
.pricing-section {
  padding: 90px 0;
  background: radial-gradient(circle at 50% 50%, rgba(255, 42, 75, 0.08) 0%, transparent 60%);
  position: relative;
}

.pricing-toggle-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.pricing-toggle-btn {
  padding: 0.6rem 1.4rem;
  border-radius: 50px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.pricing-toggle-btn.active {
  background: linear-gradient(135deg, var(--red-primary), var(--red-dark));
  color: #fff;
  border-color: rgba(255, 117, 140, 0.5);
  box-shadow: 0 0 15px rgba(255, 42, 75, 0.4);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 2.25rem 1.75rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.pricing-card.featured {
  border-color: var(--red-primary);
  box-shadow: var(--shadow-glow), 0 10px 40px rgba(0,0,0,0.6);
  background: rgba(22, 16, 26, 0.9);
  transform: scale(1.04);
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: linear-gradient(135deg, #ff2a4b, #cc0029);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.3rem 0.9rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  box-shadow: 0 0 10px rgba(255, 42, 75, 0.5);
}

.pricing-header {
  margin-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 1.25rem;
}

.plan-name {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.5rem;
}

.plan-price-box {
  display: flex;
  align-items: baseline;
  gap: 0.3rem;
  margin-top: 0.8rem;
}

.plan-currency {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--red-primary);
}

.plan-price {
  font-size: 2.8rem;
  font-weight: 900;
  color: #fff;
  line-height: 1;
}

.plan-period {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.plan-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  margin-bottom: 2rem;
  flex-grow: 1;
}

.plan-feature-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.plan-feature-item i {
  color: var(--red-primary);
  font-size: 1rem;
}

/* Dynamic Stream Unlock & Node Matrix Section (指令 4) */
.stream-unlock-section {
  padding: 80px 0;
  border-top: 1px solid rgba(255, 42, 75, 0.15);
  border-bottom: 1px solid rgba(255, 42, 75, 0.15);
  background: rgba(10, 12, 18, 0.5);
}

.stream-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.stream-card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-align: center;
  transition: all 0.25 ease;
}

.stream-card:hover {
  background: rgba(255, 42, 75, 0.1);
  border-color: rgba(255, 42, 75, 0.4);
  transform: translateY(-3px);
}

.stream-icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.stream-title {
  font-weight: 700;
  font-size: 1rem;
  color: #fff;
  margin-bottom: 0.2rem;
}

.stream-status {
  font-size: 0.8rem;
  color: #34d399;
  font-weight: 600;
}

/* SEO Articles Dashboard & Reader Hub (5 to 8 Articles, 800-1500 words each) */
.articles-section {
  padding: 100px 0;
  position: relative;
}

.articles-tab-nav {
  display: flex;
  gap: 0.75rem;
  overflow-x: auto;
  padding-bottom: 1rem;
  margin-bottom: 2rem;
  scrollbar-width: thin;
  scrollbar-color: var(--red-primary) transparent;
}

.article-tab-btn {
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 0.92rem;
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.article-tab-btn:hover {
  background: rgba(255, 42, 75, 0.12);
  color: #fff;
  border-color: rgba(255, 42, 75, 0.3);
}

.article-tab-btn.active {
  background: linear-gradient(135deg, rgba(255, 42, 75, 0.25), rgba(153, 0, 27, 0.5));
  border-color: var(--red-primary);
  color: #fff;
  box-shadow: 0 0 15px rgba(255, 42, 75, 0.3);
}

.article-view-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 3rem;
  box-shadow: var(--shadow-card);
  position: relative;
}

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.article-main-title {
  font-size: clamp(1.6rem, 3.5vw, 2.4rem);
  font-weight: 800;
  color: #fff;
  margin-bottom: 1rem;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.88rem;
  flex-wrap: wrap;
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.article-meta-item i {
  color: var(--red-primary);
}

.article-content {
  color: #cbd5e1;
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-content h2 {
  font-size: 1.6rem;
  color: #fff;
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid rgba(255, 42, 75, 0.3);
}

.article-content h3 {
  font-size: 1.25rem;
  color: var(--red-accent);
  margin: 1.5rem 0 0.75rem 0;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-content blockquote {
  border-left: 4px solid var(--red-primary);
  background: rgba(255, 42, 75, 0.06);
  padding: 1rem 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 1.5rem 0;
  font-style: italic;
  color: #e2e8f0;
}

.internal-link {
  color: var(--red-secondary);
  text-decoration: none;
  font-weight: 600;
  border-bottom: 1px dashed var(--red-primary);
  transition: all 0.2s ease;
  padding: 0 2px;
}

.internal-link:hover {
  color: #ffffff;
  background: rgba(255, 42, 75, 0.2);
  border-bottom-style: solid;
}

.keyword-tag {
  display: inline-block;
  background: rgba(255, 42, 75, 0.12);
  color: #ff758c;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  font-size: 0.82rem;
  font-weight: 600;
  margin: 0.2rem;
  border: 1px solid rgba(255, 42, 75, 0.25);
}

/* User Testimonials Section (在最下方添加用户评价) */
.testimonials-section {
  padding: 90px 0;
  background: rgba(10, 12, 18, 0.6);
  position: relative;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.75rem;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  transition: all 0.3s ease;
}

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

.testimonial-stars {
  color: #fbbf24;
  display: flex;
  gap: 0.2rem;
  font-size: 1rem;
}

.testimonial-text {
  color: var(--text-secondary);
  font-size: 0.96rem;
  line-height: 1.7;
  font-style: italic;
  flex-grow: 1;
}

.testimonial-user {
  display: flex;
  align-items: center;
  gap: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 1rem;
}

.user-avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--red-primary), var(--red-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.user-info-name {
  font-weight: 700;
  color: #fff;
  font-size: 0.98rem;
}

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

/* FAQ Accordion Section (常见问题 FAQ) */
.faq-section {
  padding: 90px 0;
  position: relative;
}

.faq-accordion {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: rgba(255, 42, 75, 0.4);
}

.faq-question {
  width: 100%;
  padding: 1.4rem 1.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.1rem;
  font-weight: 700;
  text-align: left;
  cursor: pointer;
  transition: color 0.2s ease;
}

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

.faq-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: rgba(255, 42, 75, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--red-primary);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
  background: var(--red-primary);
  color: #fff;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1), padding 0.3s ease;
  padding: 0 1.75rem;
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.75;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 1.75rem 1.5rem 1.75rem;
  transition: max-height 0.35s ease-in-out, padding 0.3s ease;
}

/* Call to Action Banner */
.cta-banner {
  margin: 60px 0 90px 0;
  padding: 4rem 2rem;
  background: linear-gradient(135deg, rgba(255, 42, 75, 0.15) 0%, rgba(153, 0, 27, 0.3) 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-glow);
}

.cta-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255, 42, 75, 0.2) 0%, transparent 60%);
  pointer-events: none;
}

/* Dynamic Footer & Precision PBN Backlinks Pipe (【🔧 核心任务 2：页脚 PBN 权重精准输血管道】) */
footer {
  background: #050609;
  border-top: 1px solid rgba(255, 42, 75, 0.2);
  padding: 3.5rem 0 2rem 0;
  color: var(--text-muted);
  position: relative;
  z-index: 10;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.75rem;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.2rem;
  font-weight: 800;
  color: #fff;
}

.footer-desc {
  max-width: 600px;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Friendly Links Section - Low-key, subtle, aesthetic, exact PBN Dofollow Links */
.footer-friendly-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  padding: 0.75rem 1.5rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 50px;
  margin-top: 0.5rem;
}

.footer-friendly-title {
  font-size: 0.78rem;
  color: #64748b;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-pbn-link {
  color: #94a3b8;
  font-size: 0.82rem;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.2s ease;
  padding: 0.1rem 0.4rem;
}

.footer-pbn-link:hover {
  color: var(--red-accent);
  text-shadow: 0 0 8px rgba(255, 42, 75, 0.6);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 1.5rem;
  margin-top: 1.5rem;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: #475569;
}

/* Mobile Responsiveness */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  
  .nav-menu {
    display: none;
  }
  
  .pricing-card.featured {
    transform: none;
  }
  
  .article-view-box {
    padding: 1.75rem;
  }
}

@media (max-width: 640px) {
  .live-stats-bar {
    grid-template-columns: 1fr;
  }
  
  .hero-actions {
    width: 100%;
    flex-direction: column;
  }
  
  .btn-register-cta, .btn-secondary {
    width: 100%;
  }
  
  .footer-bottom {
    flex-direction: column;
    gap: 0.75rem;
    text-align: center;
  }
}