/* =========================================================
   隐形人机场 - 全站样式系统
   Design System: Dark Space + Neon Purple/Blue
   ========================================================= */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Noto+Sans+SC:wght@300;400;500;700;900&display=swap');

/* ── CSS 变量 ── */
:root {
  --bg-primary: #08081a;
  --bg-secondary: #0d0d24;
  --bg-card: rgba(255,255,255,0.04);
  --bg-card-hover: rgba(255,255,255,0.08);

  --accent-1: #6366f1;
  --accent-2: #8b5cf6;
  --accent-3: #06b6d4;
  --accent-glow: rgba(99,102,241,0.35);

  --gradient-main: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #06b6d4 100%);
  --gradient-card: linear-gradient(135deg, rgba(99,102,241,0.15) 0%, rgba(139,92,246,0.08) 100%);
  --gradient-text: linear-gradient(90deg, #6366f1, #8b5cf6, #06b6d4);

  --text-primary: #f0f0ff;
  --text-secondary: #a8a8c8;
  --text-muted: #6b6b8a;

  --border: rgba(99,102,241,0.2);
  --border-hover: rgba(99,102,241,0.5);

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --shadow-glow: 0 0 40px rgba(99,102,241,0.25);
  --shadow-card: 0 8px 32px rgba(0,0,0,0.4);
  --shadow-btn: 0 4px 24px rgba(99,102,241,0.4);

  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);

  --nav-height: 72px;
  --content-max: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', 'Noto Sans SC', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; transition: var(--transition); }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-primary); }
::-webkit-scrollbar-thumb { background: var(--accent-1); border-radius: 3px; }

/* ── Typography ── */
h1,h2,h3,h4,h5,h6 { font-weight: 700; line-height: 1.25; letter-spacing: -0.02em; }

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

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(99,102,241,0.12);
  border: 1px solid rgba(99,102,241,0.3);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #a5b4fc;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* ── Layout ── */
.container {
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 100px 0; position: relative; }

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

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 100px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-main);
  color: white;
  box-shadow: var(--shadow-btn);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(99,102,241,0.55);
}

.btn-outline {
  border: 1.5px solid var(--border);
  color: var(--text-primary);
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(10px);
}
.btn-outline:hover {
  border-color: var(--border-hover);
  background: rgba(99,102,241,0.1);
  transform: translateY(-2px);
}

.btn-sm { padding: 10px 22px; font-size: 0.85rem; }
.btn-lg { padding: 18px 48px; font-size: 1.05rem; }

/* ── Cards ── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  backdrop-filter: blur(20px);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-card);
  opacity: 0;
  transition: var(--transition);
  pointer-events: none;
  border-radius: inherit;
  z-index: 0;
}
.card > * {
  position: relative;
  z-index: 1;
}
.card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-glow);
  transform: translateY(-4px);
}
.card:hover::before { opacity: 1; }

/* ── Navigation ── */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition: var(--transition);
  background: rgba(8, 8, 26, 0.82);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(99, 102, 241, 0.15);
}
.navbar.scrolled {
  background: rgba(8, 8, 26, 0.96);
  border-bottom-color: var(--border);
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.45);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 20px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.2rem;
  font-weight: 800;
  flex-shrink: 0;
  white-space: nowrap;
}
.nav-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-main);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links li {
  white-space: nowrap;
}
.nav-links a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  white-space: nowrap;
  transition: var(--transition);
}
.nav-links a:hover {
  color: var(--text-primary);
  text-shadow: 0 0 12px rgba(99, 102, 241, 0.6);
}
.nav-cta {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  cursor: pointer;
  background: none;
  border: none;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: var(--transition);
  border-radius: 2px;
}

/* 移动菜单基础隐藏（桌面端绝不展示，杜绝重叠串出） */
.mobile-menu {
  display: none;
}

/* ── Hero Section ── */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
}

#hero-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero-glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
  pointer-events: none;
}
.hero-glow-1 {
  width: 600px; height: 600px;
  background: var(--accent-1);
  top: -100px; left: -100px;
}
.hero-glow-2 {
  width: 400px; height: 400px;
  background: var(--accent-2);
  bottom: 0; right: -50px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.95fr;
  gap: 40px;
  align-items: center;
  position: relative;
  z-index: 2;
  padding: 50px 0 70px;
  width: 100%;
}

.hero-content {
  position: relative;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 18px;
  background: rgba(99,102,241,0.15);
  border: 1px solid rgba(99,102,241,0.4);
  border-radius: 100px;
  font-size: 0.82rem;
  font-weight: 600;
  color: #a5b4fc;
  margin-bottom: 24px;
  animation: fadeInDown 0.8s ease both;
}
.hero-badge .dot {
  width: 7px; height: 7px;
  background: #22c55e;
  border-radius: 50%;
  animation: pulse 2s infinite;
}

.hero-title {
  font-size: clamp(2.3rem, 4.2vw, 3.8rem);
  font-weight: 900;
  line-height: 1.12;
  margin-bottom: 20px;
  animation: fadeInDown 0.8s 0.1s ease both;
}

.hero-subtitle {
  font-size: clamp(0.95rem, 1.4vw, 1.12rem);
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 580px;
  line-height: 1.7;
  animation: fadeInDown 0.8s 0.2s ease both;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 44px;
  animation: fadeInDown 0.8s 0.3s ease both;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  animation: fadeInDown 0.8s 0.4s ease both;
}
.stat-item .stat-num {
  font-size: 1.75rem;
  font-weight: 800;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}
.stat-item .stat-label {
  font-size: 0.76rem;
  color: var(--text-muted);
  margin-top: 4px;
  white-space: nowrap;
}

/* ── Hero Visual & Live Monitor Card (SEO / GEO Entity Center) ── */
.hero-visual {
  position: relative;
  z-index: 2;
  animation: fadeInUp 0.8s 0.3s ease both;
}

.network-monitor-card {
  position: relative;
  background: rgba(13, 13, 38, 0.82);
  border: 1px solid rgba(99, 102, 241, 0.4);
  border-radius: var(--radius-xl);
  padding: 24px 22px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.55), 0 0 35px rgba(99, 102, 241, 0.18);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  overflow: visible !important;
}

.monitor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 6px;
  flex-wrap: wrap;
  gap: 8px;
}

.monitor-status {
  display: flex;
  align-items: center;
  gap: 8px;
}

.status-pulse-dot {
  width: 8px;
  height: 8px;
  background: #22c55e;
  border-radius: 50%;
  box-shadow: 0 0 10px #22c55e;
  animation: pulse 1.8s infinite;
}

.status-title {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
}

.monitor-ping-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 10px;
  background: rgba(34, 197, 94, 0.12);
  border: 1px solid rgba(34, 197, 94, 0.3);
  border-radius: 100px;
  font-size: 0.74rem;
  color: #4ade80;
}

.monitor-ping-badge strong {
  color: #86efac;
}

.monitor-caption {
  font-size: 0.74rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.monitor-caption span {
  color: #a5b4fc;
  font-weight: 500;
}

/* Node Rows */
.monitor-nodes-list {
  display: flex;
  flex-direction: column;
  gap: 7px;
  margin-bottom: 14px;
}

.node-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
}

.node-row:hover {
  background: rgba(99, 102, 241, 0.12);
  border-color: rgba(99, 102, 241, 0.35);
  transform: translateX(3px);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 8px;
}

.node-flag {
  font-size: 1.1rem;
  line-height: 1;
}

.node-name {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary);
}

.node-tag {
  font-size: 0.66rem;
  padding: 2px 6px;
  background: rgba(99, 102, 241, 0.18);
  color: #c7d2fe;
  border-radius: 4px;
  border: 1px solid rgba(99, 102, 241, 0.25);
  white-space: nowrap;
}

.node-metrics {
  display: flex;
  align-items: center;
  gap: 10px;
}

.node-speed {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-family: 'Courier New', monospace;
}

.node-latency {
  font-size: 0.76rem;
  font-weight: 700;
  font-family: 'Courier New', monospace;
  padding: 2px 7px;
  border-radius: 5px;
  background: rgba(34, 197, 94, 0.12);
  color: #4ade80;
  border: 1px solid rgba(34, 197, 94, 0.25);
}

/* Unlock Matrix */
.monitor-unlock-section {
  background: rgba(99, 102, 241, 0.08);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  margin-bottom: 12px;
}

.unlock-title {
  font-size: 0.74rem;
  font-weight: 700;
  color: #c7d2fe;
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 5px;
}

.unlock-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

.unlock-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 8px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.7rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.unlock-tag:hover {
  background: rgba(99, 102, 241, 0.2);
  color: var(--text-primary);
  border-color: rgba(99, 102, 241, 0.4);
}

/* Monitor Specs Footer */
.monitor-footer {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.spec-pill {
  padding: 7px 10px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  font-size: 0.7rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.spec-pill strong {
  color: var(--accent-1);
  display: inline-block;
}

/* Floating Badges */
.floating-badge {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  background: rgba(15, 15, 42, 0.94);
  border: 1px solid rgba(99, 102, 241, 0.45);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.65), 0 0 18px rgba(99, 102, 241, 0.35);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 5;
  pointer-events: none;
}

.badge-top-right {
  top: -16px;
  right: -14px;
  animation: float 4s ease-in-out infinite;
}

.badge-bottom-left {
  bottom: -16px;
  left: -14px;
  animation: float 4s ease-in-out infinite 2s;
}

.floating-icon {
  font-size: 1.25rem;
  line-height: 1;
}

.floating-title {
  font-size: 0.66rem;
  color: var(--text-muted);
  line-height: 1.2;
}

.floating-val {
  font-size: 0.86rem;
  font-weight: 800;
  color: #38bdf8;
  line-height: 1.2;
}

/* Responsive adjustments */
@media (max-width: 1080px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 48px;
    padding: 30px 0 50px;
  }
  .hero-content {
    max-width: 100%;
    text-align: center;
  }
  .hero-subtitle {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-actions {
    justify-content: center;
  }
  .hero-stats {
    justify-content: center;
  }
  .badge-top-right {
    top: -10px;
    right: 0px;
  }
  .badge-bottom-left {
    bottom: -10px;
    left: 0px;
  }
}

@media (max-width: 640px) {
  .badge-top-right,
  .badge-bottom-left {
    display: none;
  }
  .monitor-footer {
    grid-template-columns: 1fr;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
}

/* ── Features ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  margin-top: 60px;
}

.feature-card {
  padding: 32px;
}
.feature-icon {
  width: 56px;
  height: 56px;
  background: rgba(99,102,241,0.15);
  border: 1px solid rgba(99,102,241,0.3);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  transition: var(--transition);
}
.feature-card:hover .feature-icon {
  background: rgba(99,102,241,0.3);
  box-shadow: 0 0 20px rgba(99,102,241,0.4);
  transform: scale(1.1);
}
.feature-card h3 { font-size: 1.15rem; margin-bottom: 10px; }
.feature-card p { font-size: 0.9rem; color: var(--text-secondary); }

/* ── Pricing ── */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 40px;
  align-items: stretch;
  padding-top: 24px;
  overflow: visible;
}

.pricing-card,
.card.pricing-card {
  position: relative;
  padding: 40px 24px 30px;
  text-align: center;
  overflow: visible !important;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  border: 1px solid var(--border);
  transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.35s ease, box-shadow 0.35s ease;
}

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

.pricing-card.featured,
.card.pricing-card.featured {
  padding-top: 46px;
  border-color: rgba(129, 140, 248, 0.7);
  box-shadow: 0 0 36px rgba(99, 102, 241, 0.28), 0 12px 36px rgba(0, 0, 0, 0.5);
  background: radial-gradient(circle at 50% 0%, rgba(99, 102, 241, 0.22) 0%, rgba(13, 13, 36, 0.88) 75%);
  transform: translateY(-4px);
  z-index: 2;
}

.pricing-card.featured:hover {
  transform: translateY(-8px);
  border-color: rgba(165, 180, 252, 0.9);
  box-shadow: 0 0 52px rgba(99, 102, 241, 0.48), 0 16px 44px rgba(0, 0, 0, 0.65);
}

.pricing-card.featured::after {
  display: none !important;
}

/* 优雅浮动推荐徽标（彻底解决裁剪与文字溢出） */
.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #06b6d4 100%);
  color: #ffffff;
  padding: 5px 18px;
  border-radius: 9999px;
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  white-space: nowrap;
  box-shadow: 0 4px 18px rgba(99, 102, 241, 0.55), 0 0 12px rgba(6, 182, 212, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.45);
  z-index: 10;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  line-height: 1.2;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
  pointer-events: none;
}

.pricing-badge.badge-cyan {
  background: linear-gradient(135deg, #0284c7 0%, #06b6d4 50%, #10b981 100%);
  box-shadow: 0 4px 18px rgba(6, 182, 212, 0.55), 0 0 12px rgba(16, 185, 129, 0.35);
}

.pricing-name {
  font-size: 1.1rem;
  color: var(--text-primary);
  margin-bottom: 12px;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.pricing-price {
  font-size: 2.85rem;
  font-weight: 900;
  margin-bottom: 6px;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.pricing-price span {
  font-size: 1.05rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.pricing-period {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin: 2px auto 22px;
  padding: 4px 14px;
  border-radius: 100px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.22);
  font-size: 0.78rem;
  color: #c7d2fe;
  font-weight: 500;
  line-height: 1.3;
}

.pricing-features {
  text-align: left;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  flex-grow: 1;
}

.pricing-feature {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 9px 0;
  font-size: 0.88rem;
  color: var(--text-secondary);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  line-height: 1.5;
}

.pricing-feature strong {
  color: var(--text-primary);
}

.pricing-feature .check {
  color: #22c55e;
  font-size: 1rem;
  flex-shrink: 0;
  text-shadow: 0 0 8px rgba(34, 197, 94, 0.4);
  line-height: 1.4;
}

.pricing-feature .cross {
  color: #ef4444;
  font-size: 1rem;
  flex-shrink: 0;
  line-height: 1.4;
}

/* ── Target Audience ── */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 60px;
}
.audience-card {
  padding: 28px 24px;
  text-align: center;
}
.audience-emoji { font-size: 2.5rem; margin-bottom: 16px; }
.audience-card h3 { font-size: 1rem; margin-bottom: 8px; }
.audience-card p { font-size: 0.85rem; color: var(--text-secondary); }

/* ── Tutorials ── */
.tutorial-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 40px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 6px;
}
.tab-btn {
  flex: 1;
  min-width: 120px;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: var(--transition);
  text-align: center;
}
.tab-btn.active {
  background: var(--gradient-main);
  color: white;
  box-shadow: 0 4px 16px rgba(99,102,241,0.35);
}
.tab-btn:hover:not(.active) {
  color: var(--text-primary);
  background: rgba(255,255,255,0.05);
}

.tab-content { display: none; animation: fadeIn 0.4s ease; }
.tab-content.active { display: block; }

.tutorial-steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
}
.step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}
.step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 800;
  color: white;
  margin-top: 2px;
}
.step-content h4 { font-size: 1rem; margin-bottom: 6px; }
.step-content p { font-size: 0.88rem; color: var(--text-secondary); }
.step-content code {
  display: inline-block;
  background: rgba(99,102,241,0.15);
  border: 1px solid rgba(99,102,241,0.25);
  border-radius: 6px;
  padding: 2px 8px;
  font-size: 0.82rem;
  color: #a5b4fc;
  font-family: 'Courier New', monospace;
  word-break: break-all;
  margin-top: 6px;
}

/* ── Reviews ── */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
  margin-top: 60px;
}
.review-card { padding: 28px; }
.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}
.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  flex-shrink: 0;
}
.review-name { font-weight: 600; font-size: 0.95rem; }
.review-platform { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }
.review-stars { color: #fbbf24; font-size: 0.9rem; margin-bottom: 12px; }
.review-text { font-size: 0.88rem; color: var(--text-secondary); line-height: 1.7; }

/* ── FAQ ── */
.faq-list {
  max-width: 800px;
  margin: 60px auto 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  overflow: hidden;
  transition: var(--transition);
}
.faq-item.open { border-color: var(--border-hover); }
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 22px 28px;
  font-weight: 600;
  font-size: 0.97rem;
  cursor: pointer;
  gap: 16px;
}
.faq-icon {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  background: rgba(99,102,241,0.15);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: var(--transition);
  color: var(--accent-1);
}
.faq-item.open .faq-icon { transform: rotate(45deg); background: var(--accent-1); color: white; }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}
.faq-answer-inner {
  padding: 0 28px 22px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.8;
}
.faq-item.open .faq-answer { max-height: 300px; }

/* ── Articles ── */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
  margin-top: 60px;
}
.article-card {
  padding: 0 !important;
  cursor: pointer;
  position: relative;
}
.article-card > a {
  display: flex;
  flex-direction: column;
  padding: 28px;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  color: inherit;
  text-decoration: none;
  position: relative;
  z-index: 2;
}
.article-tag {
  display: inline-block;
  align-self: flex-start;
  padding: 4px 12px;
  background: rgba(99,102,241,0.15);
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  color: #a5b4fc;
  margin-bottom: 14px;
}
.article-card h2,
.article-card h3 {
  font-size: 1.05rem;
  margin-bottom: 10px;
  line-height: 1.4;
  color: var(--text-primary);
}
.article-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.65;
  flex-grow: 1;
}
.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: auto;
}
.article-meta .read-more {
  color: var(--accent-1);
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: var(--transition);
}
.article-card:hover .read-more {
  color: #a5b4fc;
  transform: translateX(4px);
}

/* ── CTA Banner ── */
.cta-banner {
  background: linear-gradient(135deg, rgba(99,102,241,0.2) 0%, rgba(139,92,246,0.15) 100%);
  border: 1px solid rgba(99,102,241,0.3);
  border-radius: var(--radius-xl);
  padding: 80px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-banner::before {
  content: '';
  position: absolute;
  top: -60px; left: 50%;
  transform: translateX(-50%);
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(99,102,241,0.25) 0%, transparent 70%);
  pointer-events: none;
}
.cta-banner h2 { font-size: clamp(1.8rem, 3.5vw, 2.8rem); margin-bottom: 16px; }
.cta-banner p { color: var(--text-secondary); margin-bottom: 36px; }
.cta-banner .btn-group { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ── Footer ── */
footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 80px 0 40px;
}
.footer-top {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 48px;
  margin-bottom: 60px;
}
.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-top: 16px;
  line-height: 1.8;
  max-width: 280px;
}
.footer-col h4 { font-size: 0.9rem; font-weight: 700; margin-bottom: 20px; }
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col a {
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer-col a:hover { color: var(--text-primary); }
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 40px;
  border-top: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 16px;
}
.footer-bottom p { font-size: 0.8rem; color: var(--text-muted); }
.footer-legal { display: flex; gap: 20px; }
.footer-legal a { font-size: 0.78rem; color: var(--text-muted); }
.footer-legal a:hover { color: var(--text-primary); }

/* ── Divider ── */
.divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 0;
}

/* ── Animations ── */
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(0.85); }
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
@keyframes shimmer {
  0% { background-position: -200% center; }
  100% { background-position: 200% center; }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}
.animate-on-scroll.delay-1 { transition-delay: 0.1s; }
.animate-on-scroll.delay-2 { transition-delay: 0.2s; }
.animate-on-scroll.delay-3 { transition-delay: 0.3s; }
.animate-on-scroll.delay-4 { transition-delay: 0.4s; }
.animate-on-scroll.delay-5 { transition-delay: 0.5s; }

/* ── Article / Tutorial Page Styles ── */
.page-hero {
  padding: 140px 0 80px;
  background: linear-gradient(180deg, rgba(99,102,241,0.08) 0%, transparent 100%);
  border-bottom: 1px solid var(--border);
}
.page-hero .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.page-hero .breadcrumb a { color: var(--accent-1); }
.page-hero .breadcrumb .sep { color: var(--text-muted); }

.article-body { max-width: 800px; margin: 0 auto; }
.article-body h2 {
  font-size: 1.6rem;
  margin: 48px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.article-body h3 { font-size: 1.2rem; margin: 32px 0 14px; color: #a5b4fc; }
.article-body p { font-size: 0.95rem; color: var(--text-secondary); margin-bottom: 16px; line-height: 1.85; }
.article-body ul, .article-body ol {
  padding-left: 20px;
  margin-bottom: 16px;
}
.article-body li {
  font-size: 0.93rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.7;
}
.article-body ul { list-style: disc; }
.article-body ol { list-style: decimal; }
.article-body strong { color: var(--text-primary); }
.article-body a { color: var(--accent-1); border-bottom: 1px solid transparent; }
.article-body a:hover { border-color: var(--accent-1); }
.article-body .tip-box {
  background: rgba(99,102,241,0.1);
  border: 1px solid rgba(99,102,241,0.25);
  border-left: 3px solid var(--accent-1);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.article-body .warning-box {
  background: rgba(251,191,36,0.08);
  border: 1px solid rgba(251,191,36,0.25);
  border-left: 3px solid #fbbf24;
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin: 24px 0;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.article-body code {
  background: rgba(99,102,241,0.15);
  border: 1px solid rgba(99,102,241,0.25);
  border-radius: 4px;
  padding: 2px 7px;
  font-size: 0.85em;
  color: #a5b4fc;
  font-family: 'Courier New', monospace;
}
.article-body pre {
  background: rgba(0,0,0,0.4);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px;
  overflow-x: auto;
  margin: 20px 0;
}
.article-body pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: 0.88rem;
  color: #a5b4fc;
}

.related-articles { margin-top: 60px; padding-top: 40px; border-top: 1px solid var(--border); }
.related-articles h3 { font-size: 1.2rem; margin-bottom: 24px; }
.related-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 16px; }
.related-item {
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
}
.related-item:hover { color: var(--text-primary); border-color: var(--border-hover); }

.toc {
  position: sticky;
  top: 96px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
}
.toc h4 { font-size: 0.9rem; margin-bottom: 16px; color: var(--text-primary); }
.toc ul { display: flex; flex-direction: column; gap: 8px; }
.toc a { font-size: 0.82rem; color: var(--text-muted); }
.toc a:hover { color: var(--accent-1); }

.article-layout {
  display: grid;
  grid-template-columns: 1fr 260px;
  gap: 48px;
  padding: 60px 0;
  align-items: start;
}

/* ── Table ── */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
  font-size: 0.88rem;
}
.compare-table th {
  background: rgba(99,102,241,0.15);
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border);
}
.compare-table td {
  padding: 12px 16px;
  color: var(--text-secondary);
  border-bottom: 1px solid rgba(255,255,255,0.04);
}
.compare-table tr:hover td { background: rgba(255,255,255,0.02); }

/* ── Responsive ── */
@media (max-width: 1024px) {
  .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
  .article-layout { grid-template-columns: 1fr; }
  .toc { position: static; }
  .pricing-card.featured { transform: scale(1); }
}

@media (max-width: 960px) {
  section { padding: 70px 0; }
  .nav-links, .nav-cta { display: none; }
  .nav-toggle { display: flex; }
  .mobile-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0; right: 0;
    background: rgba(8,8,26,0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 24px;
    display: none;
    flex-direction: column;
    gap: 16px;
    z-index: 999;
  }
  .mobile-menu.open { display: flex; }
  .mobile-menu a { font-size: 1rem; padding: 10px 0; color: var(--text-secondary); border-bottom: 1px solid var(--border); }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .hero-stats { gap: 24px; }
  .cta-banner { padding: 60px 24px; }
}

@media (max-width: 480px) {
  :root { --content-max: 100%; }
  .container { padding: 0 16px; }
  .footer-top { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; justify-content: center; }
  .tutorial-tabs { flex-direction: column; }
  .tab-btn { min-width: unset; }
}

/* ── Progress Bar ── */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: var(--gradient-main);
  z-index: 2000;
  transition: width 0.1s linear;
}

/* ── Back to top ── */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
  box-shadow: 0 4px 20px rgba(99,102,241,0.4);
  opacity: 0;
  transform: translateY(20px);
  transition: var(--transition);
  z-index: 100;
  cursor: pointer;
}
.back-to-top.visible { opacity: 1; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-4px); box-shadow: 0 8px 28px rgba(99,102,241,0.5); }