/* Global CSS Variables & Theme */
:root {
  --bg-primary: #f4f7fc;       /* 极光白/淡天蓝 */
  --bg-secondary: #eef2f7;     /* 淡雅银灰 */
  --bg-card: rgba(255, 255, 255, 0.85); /* 纯白玻璃卡片 */
  --border-color: rgba(0, 102, 255, 0.08); /* 冰晶蓝微发光边框 */
  --border-focus: rgba(0, 102, 255, 0.4);
  
  --text-primary: #0f172a;     /* 深邃石板蓝 */
  --text-secondary: #475569;   /* 优雅灰蓝 */
  --text-muted: #64748b;       /* 沉稳冷灰 */
  
  --color-primary: #0066ff;
  --color-primary-glow: rgba(0, 102, 255, 0.2);
  --color-secondary: #d97706;  /* 琥珀金 */
  --color-accent: #059669;     /* 极客绿 */
  
  --gradient-text: linear-gradient(135deg, #0f172a 0%, #334155 100%);
  --gradient-hero: linear-gradient(135deg, #0f172a 30%, #334155 100%);
  --gradient-accent: linear-gradient(135deg, #0066ff 0%, #00b4ff 100%);
  
  --font-sans: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --border-radius: 16px;
}

/* Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  overflow-x: hidden;
  background-color: var(--bg-primary);
  /* Light Grid Pattern with soft ice-blue tint */
  background-image: 
    linear-gradient(rgba(0, 102, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 102, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  background-position: center top;
  line-height: 1.6;
}

/* Floating Glow Keyframes */
@keyframes orb-float-1 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(60px, 100px) scale(1.15); }
  100% { transform: translate(0, 0) scale(1); }
}
@keyframes orb-float-2 {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(-100px, -60px) scale(0.85); }
  100% { transform: translate(0, 0) scale(1); }
}

/* Background Glowing Effects */
body::before {
  content: "";
  position: absolute;
  top: -10%;
  left: 10%;
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, rgba(0, 102, 255, 0.06) 0%, transparent 70%);
  z-index: -2;
  pointer-events: none;
  animation: orb-float-1 20s infinite ease-in-out;
}

body::after {
  content: "";
  position: absolute;
  top: 40%;
  right: -10%;
  width: 60vw;
  height: 60vw;
  background: radial-gradient(circle, rgba(0, 210, 255, 0.06) 0%, transparent 70%);
  z-index: -2;
  pointer-events: none;
  animation: orb-float-2 25s infinite ease-in-out;
}

/* Third floating glowing purple orb on HTML element */
html::before {
  content: "";
  position: absolute;
  top: 70%;
  left: -10%;
  width: 45vw;
  height: 45vw;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.04) 0%, transparent 70%);
  z-index: -2;
  pointer-events: none;
  animation: orb-float-1 22s infinite ease-in-out;
}

/* Scrollbar Customization */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
  background: #27272a;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #3f3f46;
}

/* Typography Selection */
::selection {
  background: var(--color-primary);
  color: #ffffff;
}

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

/* Interactive Canvas overlay for mouse trail */
#trail-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 9999;
  pointer-events: none;
}

/* Header & Navigation */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.75);
  transition: var(--transition);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.25rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.logo span {
  color: var(--color-primary);
}

nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

nav a {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 500;
}

nav a:hover, nav a.active {
  color: var(--color-primary);
}

.btn-nav-register {
  padding: 0.5rem 1.25rem;
  background: var(--gradient-accent);
  color: #fff;
  border-radius: 99px;
  font-weight: 600;
  font-size: 0.9rem;
  box-shadow: 0 4px 14px var(--color-primary-glow);
}

.btn-nav-register:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--color-primary-glow);
}

/* Burger menu for Mobile */
.burger-menu {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  z-index: 1100;
}

.burger-menu div {
  width: 24px;
  height: 2px;
  background-color: var(--text-primary);
  transition: var(--transition);
}

/* Layout Containers */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Hero Section */
.hero {
  position: relative;
  padding: 10rem 0 6rem 0;
  text-align: center;
  min-height: 90vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 1;
}

.hero-subtitle {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: 1.5rem;
  display: inline-block;
  background: rgba(0, 102, 255, 0.1);
  padding: 0.4rem 1rem;
  border-radius: 99px;
  border: 1px solid rgba(0, 102, 255, 0.2);
}

.hero h1 {
  font-size: 4rem;
  line-height: 1.15;
  font-weight: 900;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 1.5rem;
  letter-spacing: -2px;
}

.hero-gradient-span {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2.5rem auto;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 1.25rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  padding: 0.9rem 2.2rem;
  background: var(--gradient-accent);
  color: #fff;
  border-radius: var(--border-radius);
  font-weight: 700;
  font-size: 1.05rem;
  box-shadow: 0 8px 24px var(--color-primary-glow);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px var(--color-primary-glow);
}

.btn-secondary {
  padding: 0.9rem 2.2rem;
  background: rgba(0, 102, 255, 0.04);
  color: var(--color-primary);
  border-radius: var(--border-radius);
  font-weight: 700;
  font-size: 1.05rem;
  border: 1px solid rgba(0, 102, 255, 0.2);
  cursor: pointer;
}

.btn-secondary:hover {
  background: rgba(0, 102, 255, 0.08);
  border-color: var(--color-primary);
  transform: translateY(-3px);
}

.btn-recommend {
  padding: 0.9rem 2.2rem;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  color: var(--color-secondary);
  border-radius: var(--border-radius);
  font-weight: 700;
  font-size: 1.05rem;
  border: 1px solid var(--color-secondary);
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(217, 119, 6, 0.1);
}

.btn-recommend:hover {
  transform: translateY(-3px);
  background: linear-gradient(135deg, #f1f5f9 0%, #cbd5e1 100%);
  box-shadow: 0 8px 25px rgba(217, 119, 6, 0.2);
}

.hero-meta {
  margin-top: 3rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.hero-meta span {
  margin: 0 0.75rem;
  color: var(--text-secondary);
}

/* Features Grid */
.section-title-wrap {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title-wrap h2 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -1px;
}

.section-title-wrap p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

.features {
  padding: 6rem 0;
  border-top: 1px solid var(--border-color);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 2.5rem 2rem;
  border-radius: var(--border-radius);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, rgba(0, 102, 255, 0.05) 0%, transparent 100%);
  opacity: 0;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-focus);
  box-shadow: 0 10px 30px rgba(0, 102, 255, 0.1);
}

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

.feature-icon {
  width: 50px;
  height: 50px;
  background: rgba(0, 102, 255, 0.1);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 1.5rem;
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

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

/* Pricing Section */
.pricing {
  padding: 6rem 0;
  border-top: 1px solid var(--border-color);
  background: linear-gradient(180deg, transparent 0%, rgba(238, 242, 247, 0.4) 100%);
}

/* Forces the pricing list to stack horizontally on desktop as '一排' */
.pricing-row {
  display: flex;
  gap: 1.5rem;
  justify-content: space-between;
  width: 100%;
  margin-top: 1rem;
}

.pricing-card {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 3rem 2rem;
  position: relative;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.pricing-card.popular {
  border-color: var(--color-primary);
  background: rgba(0, 102, 255, 0.03);
  box-shadow: 0 15px 40px rgba(0, 102, 255, 0.15);
  transform: translateY(-8px);
}

.pricing-card.popular::after {
  content: "推荐套餐";
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: var(--gradient-accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.3rem 0.8rem;
  border-radius: 99px;
}

.pricing-card:hover {
  transform: translateY(-5px);
}

/* Breathing Glow keyframe animations for card color library */
@keyframes glow-blue {
  0% {
    box-shadow: 0 4px 20px rgba(0, 102, 255, 0.05), 0 0 5px rgba(0, 102, 255, 0.03);
    border-color: rgba(0, 102, 255, 0.15);
  }
  50% {
    box-shadow: 0 10px 30px rgba(0, 102, 255, 0.3), 0 0 15px rgba(0, 102, 255, 0.25);
    border-color: rgba(0, 102, 255, 0.6);
  }
  100% {
    box-shadow: 0 4px 20px rgba(0, 102, 255, 0.05), 0 0 5px rgba(0, 102, 255, 0.03);
    border-color: rgba(0, 102, 255, 0.15);
  }
}

@keyframes glow-gold {
  0% {
    box-shadow: 0 4px 20px rgba(251, 191, 36, 0.05), 0 0 5px rgba(251, 191, 36, 0.03);
    border-color: rgba(251, 191, 36, 0.15);
  }
  50% {
    box-shadow: 0 15px 40px rgba(251, 191, 36, 0.4), 0 0 25px rgba(251, 191, 36, 0.35);
    border-color: rgba(251, 191, 36, 0.7);
  }
  100% {
    box-shadow: 0 4px 20px rgba(251, 191, 36, 0.05), 0 0 5px rgba(251, 191, 36, 0.03);
    border-color: rgba(251, 191, 36, 0.15);
  }
}

@keyframes glow-purple {
  0% {
    box-shadow: 0 4px 20px rgba(139, 92, 246, 0.05), 0 0 5px rgba(139, 92, 246, 0.03);
    border-color: rgba(139, 92, 246, 0.15);
  }
  50% {
    box-shadow: 0 10px 30px rgba(139, 92, 246, 0.3), 0 0 15px rgba(139, 92, 246, 0.25);
    border-color: rgba(139, 92, 246, 0.6);
  }
  100% {
    box-shadow: 0 4px 20px rgba(139, 92, 246, 0.05), 0 0 5px rgba(139, 92, 246, 0.03);
    border-color: rgba(139, 92, 246, 0.15);
  }
}

@keyframes glow-green {
  0% {
    box-shadow: 0 4px 20px rgba(16, 185, 129, 0.05), 0 0 5px rgba(16, 185, 129, 0.03);
    border-color: rgba(16, 185, 129, 0.15);
  }
  50% {
    box-shadow: 0 10px 30px rgba(16, 185, 129, 0.3), 0 0 15px rgba(16, 185, 129, 0.25);
    border-color: rgba(16, 185, 129, 0.6);
  }
  100% {
    box-shadow: 0 4px 20px rgba(16, 185, 129, 0.05), 0 0 5px rgba(16, 185, 129, 0.03);
    border-color: rgba(16, 185, 129, 0.15);
  }
}

/* Link animations to pricing rows */
.pricing-row > .pricing-card:nth-child(1) {
  animation: glow-blue 4s infinite ease-in-out;
}
.pricing-row > .pricing-card:nth-child(2) {
  animation: glow-gold 4s infinite ease-in-out;
  transform: translateY(-8px);
}
.pricing-row > .pricing-card:nth-child(3) {
  animation: glow-purple 4s infinite ease-in-out;
}
.pricing-row > .pricing-card:nth-child(4) {
  animation: glow-green 4s infinite ease-in-out;
}

/* Hover effects with color overrides (Adjusted for light mode) */
.pricing-row > .pricing-card:nth-child(1):hover {
  box-shadow: 0 15px 35px rgba(0, 102, 255, 0.2), 0 0 20px rgba(0, 102, 255, 0.15) !important;
  border-color: rgba(0, 102, 255, 0.5) !important;
}
.pricing-row > .pricing-card:nth-child(2):hover {
  box-shadow: 0 25px 50px rgba(217, 119, 6, 0.25), 0 0 30px rgba(217, 119, 6, 0.2) !important;
  border-color: rgba(217, 119, 6, 0.6) !important;
  transform: translateY(-12px) !important;
}
.pricing-row > .pricing-card:nth-child(3):hover {
  box-shadow: 0 15px 35px rgba(139, 92, 246, 0.2), 0 0 20px rgba(139, 92, 246, 0.15) !important;
  border-color: rgba(139, 92, 246, 0.5) !important;
}
.pricing-row > .pricing-card:nth-child(4):hover {
  box-shadow: 0 15px 35px rgba(16, 185, 129, 0.2), 0 0 20px rgba(16, 185, 129, 0.15) !important;
  border-color: rgba(16, 185, 129, 0.5) !important;
}

.pricing-header h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.pricing-header .plan-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.pricing-price {
  margin-bottom: 2rem;
  display: flex;
  align-items: baseline;
}

.pricing-price .currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.pricing-price .amount {
  font-size: 3rem;
  font-weight: 800;
  color: var(--text-primary);
}

.pricing-price .period {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-left: 0.5rem;
}

.pricing-features {
  list-style: none;
  margin-bottom: 2.5rem;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.pricing-features li::before {
  content: "✓";
  color: var(--color-primary);
  font-weight: 900;
}

.pricing-features li.unsupported {
  color: var(--text-muted);
  text-decoration: line-through;
}

.pricing-features li.unsupported::before {
  content: "✗";
  color: var(--text-muted);
}

.btn-price {
  width: 100%;
  padding: 0.9rem;
  border-radius: 12px;
  font-weight: 700;
  text-align: center;
  font-size: 1rem;
  cursor: pointer;
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.03);
  color: var(--text-primary);
  transition: var(--transition);
}

.pricing-card.popular .btn-price {
  background: var(--gradient-accent);
  color: #fff;
  border: none;
  box-shadow: 0 4px 15px var(--color-primary-glow);
}

.pricing-card.popular .btn-price:hover {
  box-shadow: 0 6px 20px rgba(0, 102, 255, 0.6);
  transform: translateY(-2px);
}

.pricing-card:not(.popular) .btn-price:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-2px);
}

/* SEO Articles Grid */
.articles-section {
  padding: 6rem 0;
  border-top: 1px solid var(--border-color);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

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

.article-img-fallback {
  height: 180px;
  background: linear-gradient(135deg, #18181b 0%, #09090b 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  border-bottom: 1px solid var(--border-color);
}

.article-img-tag {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(0, 102, 255, 0.15);
  color: var(--color-primary);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.3rem 0.75rem;
  border-radius: 99px;
  border: 1px solid rgba(0, 102, 255, 0.3);
}

.article-img-icon {
  font-size: 3rem;
  opacity: 0.2;
}

.article-content {
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.article-meta-info {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.4;
  color: var(--text-primary);
}

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

.article-content p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-link {
  margin-top: auto;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

.article-link:hover {
  gap: 0.5rem;
}

/* Specific Article Page Styles */
.article-page {
  padding-top: 8rem;
  padding-bottom: 6rem;
}

.article-page-container {
  display: grid;
  grid-template-columns: 8fr 4fr;
  gap: 3rem;
}

.article-main-body {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 3rem;
  backdrop-filter: blur(8px);
}

.article-main-body h1 {
  font-size: 2.25rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  line-height: 1.3;
}

.article-post-meta {
  color: var(--text-muted);
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
  margin-bottom: 2rem;
}

.article-post-meta span {
  margin-right: 1.5rem;
}

.article-text {
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-text p {
  margin-bottom: 1.5rem;
}

.article-text h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem 0;
  color: #fff;
  border-left: 4px solid var(--color-primary);
  padding-left: 0.75rem;
}

.article-text h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 2rem 0 1rem 0;
  color: #fff;
}

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

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

/* Sidebar styling for articles */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.sidebar-widget {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 2rem;
}

.sidebar-widget h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  color: #fff;
  position: relative;
  padding-bottom: 0.5rem;
}

.sidebar-widget h4::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--color-primary);
}

.sidebar-links {
  list-style: none;
}

.sidebar-links li {
  margin-bottom: 1rem;
}

.sidebar-links a {
  font-size: 0.95rem;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
}

.sidebar-links a:hover {
  color: var(--color-primary);
}

.sidebar-links a span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.sidebar-cta-card {
  background: linear-gradient(135deg, rgba(0, 102, 255, 0.1) 0%, rgba(251, 191, 36, 0.05) 100%);
  border: 1px solid var(--border-focus);
  padding: 2.5rem 2rem;
  border-radius: var(--border-radius);
  text-align: center;
}

.sidebar-cta-card h4 {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  color: #fff;
}

.sidebar-cta-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.sidebar-cta-card .btn-primary {
  justify-content: center;
  font-size: 0.95rem;
  padding: 0.75rem 1.5rem;
}

/* Collapsible FAQ Section */
.faq {
  padding: 6rem 0;
  border-top: 1px solid var(--border-color);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

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

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.15);
}

.faq-question {
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  user-select: none;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-primary);
}

.faq-toggle-icon {
  font-size: 1.25rem;
  color: var(--text-secondary);
  transition: transform 0.3s ease;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease;
  padding: 0 2rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

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

.faq-item.active .faq-answer {
  padding: 0 2rem 1.5rem 2rem;
  max-height: 300px; /* arbitrary height to slide down */
}

/* User Reviews Section */
.reviews {
  padding: 6rem 0;
  border-top: 1px solid var(--border-color);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  padding: 2.25rem;
  position: relative;
  transition: var(--transition);
}

.review-card:hover {
  border-color: rgba(255, 255, 255, 0.15);
  transform: translateY(-3px);
}

.review-stars {
  color: var(--color-secondary);
  margin-bottom: 1.25rem;
  font-size: 1.1rem;
}

.review-comment {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.user-avatar-fallback {
  width: 44px;
  height: 44px;
  background: #27272a;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--color-primary);
  border: 1px solid rgba(0, 102, 255, 0.2);
}

.user-info h5 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

.user-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Footer Section */
footer {
  border-top: 1px solid var(--border-color);
  background: #f8fafc;
  padding: 4rem 0 2rem 0;
  color: var(--text-secondary);
}

.footer-top {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--border-color);
}

.footer-brand {
  max-width: 320px;
}

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 1rem;
}

.footer-links-wrap {
  display: flex;
  gap: 4rem;
  flex-wrap: wrap;
}

.footer-col h5 {
  color: var(--text-primary);
  font-size: 1rem;
  margin-bottom: 1.25rem;
  font-weight: 700;
}

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

.footer-col li {
  margin-bottom: 0.75rem;
}

.footer-col a {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  padding-top: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  text-align: center;
}

.footer-copyright {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Under footer PBN backlink area */
.pbn-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.5rem;
  font-size: 0.78rem;
  color: var(--text-muted);
  padding: 0.5rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.03);
  width: 100%;
  margin-top: 1rem;
}

.pbn-container span {
  opacity: 0.6;
}

.pbn-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: normal;
  transition: color 0.2s ease;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.15);
}

.pbn-link:hover {
  color: var(--text-secondary);
  border-bottom-color: var(--text-secondary);
}

/* Mobile responsive navigation overlay */
.mobile-nav {
  position: fixed;
  top: 0;
  right: -100%;
  width: 75%;
  height: 100%;
  background: var(--bg-secondary);
  border-left: 1px solid var(--border-color);
  z-index: 1050;
  display: flex;
  flex-direction: column;
  padding: 6rem 2.5rem 2rem 2.5rem;
  gap: 2rem;
  transition: right 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
  box-shadow: -10px 0 30px rgba(0, 0, 0, 0.5);
}

.mobile-nav.open {
  right: 0;
}

.mobile-nav a {
  font-size: 1.15rem;
  color: var(--text-primary);
  font-weight: 600;
}

.mobile-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.6);
  z-index: 1040;
  display: none;
  backdrop-filter: blur(4px);
}

.mobile-overlay.show {
  display: block;
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .article-page-container {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

@media (max-width: 900px) {
  /* Let the pricing grid scroll horizontally or stack if it fits, but user requested '一排' */
  /* So we preserve flex row with overflow scroll for scrollable columns in tablet, so they are always in '一排' */
  .pricing-row {
    overflow-x: auto;
    padding-bottom: 1.5rem;
    -webkit-overflow-scrolling: touch;
    scroll-snap-type: x mandatory;
  }
  
  .pricing-card {
    min-width: 280px;
    flex-shrink: 0;
    scroll-snap-align: center;
  }
  
  .pricing-card.popular {
    transform: none;
  }
  .pricing-card.popular:hover {
    transform: translateY(-4px);
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }

  .burger-menu {
    display: flex;
  }

  nav {
    display: none;
  }

  .hero h1 {
    font-size: 2.75rem;
    letter-spacing: -1px;
  }

  .hero p {
    font-size: 1.1rem;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
    max-width: 320px;
    margin: 0 auto;
  }

  .btn-primary, .btn-secondary, .btn-recommend {
    width: 100%;
    justify-content: center;
  }

  .footer-top {
    flex-direction: column;
    gap: 2rem;
  }
  
  .footer-links-wrap {
    gap: 2.5rem;
  }

  .article-main-body {
    padding: 1.5rem;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }
}

/* Sidebar Consoles Style (左右浮动VPN节点与安全面板) */
.side-console {
  position: fixed;
  top: 55%;
  transform: translateY(-50%);
  width: 220px;
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(0, 102, 255, 0.1);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 900;
  transition: var(--transition);
  animation: console-appear 0.8s cubic-bezier(0.25, 0.8, 0.25, 1) forwards;
}

@keyframes console-appear {
  0% { opacity: 0; transform: translateY(-50%) scale(0.95); }
  100% { opacity: 1; transform: translateY(-50%) scale(1); }
}

.left-console {
  left: 2.5rem;
  border-left: 2px solid var(--color-primary);
  box-shadow: -10px 10px 30px rgba(0, 0, 0, 0.05), -5px 0 15px rgba(0, 102, 255, 0.03);
}

.right-console {
  right: 2.5rem;
  border-right: 2px solid var(--color-secondary);
  box-shadow: 10px 10px 30px rgba(0, 0, 0, 0.05), 5px 0 15px rgba(217, 119, 6, 0.02);
}

.console-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.console-header h5 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}

/* Pulsing indicators */
.pulse-green, .pulse-blue {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  position: relative;
}
.pulse-green { background-color: var(--color-accent); }
.pulse-blue { background-color: var(--color-primary); }

.pulse-green::after, .pulse-blue::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  animation: pulse-ring 1.5s infinite ease-in-out;
}
.pulse-green::after { background-color: var(--color-accent); }
.pulse-blue::after { background-color: var(--color-primary); }

@keyframes pulse-ring {
  0% { transform: scale(1); opacity: 1; }
  100% { transform: scale(2.5); opacity: 0; }
}

/* Node List inside Left Sidebar */
.node-status-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.node-status-list li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
}

.node-status-list .flag {
  font-size: 1rem;
}

.node-status-list .node-name {
  color: var(--text-secondary);
  flex-grow: 1;
}

.node-status-list .ping {
  font-weight: 600;
  font-family: monospace;
}
.node-status-list .ping.green { color: var(--color-accent); }
.node-status-list .ping.blue { color: var(--color-primary); }

/* Security grid inside Right Sidebar */
.security-info-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.9rem;
}

.info-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
}

.info-label {
  color: var(--text-secondary);
}

.info-val {
  color: var(--text-primary);
  font-weight: 600;
}
.info-val.green { color: var(--color-accent); }

.console-footer {
  margin-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  padding-top: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

/* Hide side consoles on smaller displays to avoid page collision */
@media (max-width: 1350px) {
  .side-console {
    display: none !important;
  }
}