/* ==========================================================================
   全球云 (Quanqiu Cloud) - 官方极简极速样式表
   纯原生 CSS，零重型框架，秒开体验与移动端优先响应式适配
   品牌主色调：全球云皇家天蓝 (#2563eb / #3b82f6 / #1d4ed8)
   ========================================================================== */

:root {
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --primary-gradient: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --secondary-gradient: linear-gradient(135deg, #1d4ed8 0%, #60a5fa 100%);
  --accent-glow: rgba(37, 99, 235, 0.25);
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-glass: rgba(255, 255, 255, 0.9);
  --bg-blue-subtle: #eff6ff;
  --border-color: #e2e8f0;
  --border-focus: #bfdbfe;

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --text-white: #ffffff;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --shadow-sm: 0 2px 8px rgba(37, 99, 235, 0.06);
  --shadow-md: 0 8px 24px rgba(37, 99, 235, 0.08);
  --shadow-lg: 0 16px 36px rgba(37, 99, 235, 0.12);
  --shadow-hover: 0 20px 40px rgba(37, 99, 235, 0.18);

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-main);
  scroll-behavior: smooth;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background: radial-gradient(circle at 10% 20%, rgba(219, 234, 254, 0.6) 0%, transparent 40%),
              radial-gradient(circle at 90% 80%, rgba(191, 219, 254, 0.4) 0%, transparent 45%),
              #f8fafc;
}

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

img, svg {
  vertical-align: middle;
  max-width: 100%;
}

ul, ol {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  user-select: none;
  text-decoration: none;
}

.logo-img {
  width: 38px;
  height: 38px;
  object-fit: contain;
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
  transition: var(--transition);
  flex-shrink: 0;
}

.logo-link:hover .logo-img {
  transform: scale(1.08) rotate(5deg);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.45);
}

.logo-badge {
  width: 38px;
  height: 38px;
  background: var(--primary-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
  transition: var(--transition);
  flex-shrink: 0;
}

.logo-link:hover .logo-badge {
  transform: scale(1.08) rotate(5deg);
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.45);
}

.logo-text {
  font-size: 1.45rem;
  font-weight: 850;
  letter-spacing: -0.5px;
  color: #0f172a;
}

.logo-text span {
  color: var(--primary);
  font-weight: 700;
  font-size: 1rem;
  margin-left: 6px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 26px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  position: relative;
  padding: 6px 2px;
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  transition: width 0.3s ease;
  border-radius: 2px;
}

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

.header-cta-btn {
  background: var(--primary-gradient);
  color: #ffffff;
  padding: 10px 24px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.92rem;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.28);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.header-cta-btn:hover {
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.45);
  transform: translateY(-2px);
  color: #ffffff;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 80px 0 60px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 50px;
  align-items: center;
}

.hero-badge-group {
  display: flex;
  gap: 12px;
  margin-bottom: 22px;
  flex-wrap: wrap;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: #ffffff;
  border: 1px solid var(--border-focus);
  border-radius: var(--radius-full);
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--primary-dark);
  box-shadow: var(--shadow-sm);
}

.hero-title {
  font-size: 2.85rem;
  font-weight: 900;
  line-height: 1.25;
  color: #0f172a;
  margin-bottom: 20px;
  letter-spacing: -0.8px;
}

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

.hero-subtitle {
  font-size: 1.12rem;
  line-height: 1.75;
  color: var(--text-muted);
  margin-bottom: 34px;
  max-width: 600px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff;
  padding: 15px 32px;
  border-radius: var(--radius-full);
  font-weight: 750;
  font-size: 1.05rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(37, 99, 235, 0.45);
  color: #ffffff;
}

.btn-secondary {
  background: #ffffff;
  color: var(--primary-dark);
  padding: 15px 28px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 1.02rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1.5px solid var(--border-focus);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-blue-subtle);
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.hero-perks {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.88rem;
  color: var(--text-light);
  margin-top: 8px;
  flex-wrap: wrap;
}

.hero-perks span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Hero Right Dynamic Card */
.hero-visual {
  position: relative;
}

.dynamic-card {
  background: var(--bg-card-glass);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(191, 219, 254, 0.8);
  box-shadow: var(--shadow-lg);
  padding: 28px;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(14px);
}

.dynamic-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-gradient);
}

.card-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

.card-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #059669;
  background: #ecfdf5;
  padding: 4px 12px;
  border-radius: var(--radius-full);
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: #10b981;
  border-radius: 50%;
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.speed-meter {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 18px;
}

.speed-val {
  font-size: 2.85rem;
  font-weight: 900;
  color: var(--primary-dark);
  line-height: 1;
}

.speed-unit {
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--text-muted);
}

.node-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #ffffff;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  transition: var(--transition);
}

.node-item:hover {
  border-color: var(--primary-light);
  transform: translateX(4px);
  background: var(--bg-blue-subtle);
}

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

.node-flag {
  font-size: 1.15rem;
}

.node-ping {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  color: #059669;
  font-weight: 700;
  font-size: 0.84rem;
}

/* ==========================================================================
   Section Common
   ========================================================================== */
.section {
  padding: 85px 0;
  position: relative;
}

.section-alt {
  background: linear-gradient(180deg, rgba(239, 246, 255, 0.5) 0%, rgba(248, 250, 252, 0.8) 100%);
  border-top: 1px solid rgba(226, 232, 240, 0.8);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.section-head {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 55px;
}

.section-tag {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 1.5px;
  color: var(--primary);
  background: var(--bg-blue-subtle);
  padding: 5px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
  border: 1px solid var(--border-focus);
}

.section-title {
  font-size: 2.25rem;
  font-weight: 850;
  color: #0f172a;
  line-height: 1.35;
  margin-bottom: 14px;
}

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

/* ==========================================================================
   Core Advantages (3 Feature Cards)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 34px 28px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

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

.feature-icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: 14px;
  background: var(--bg-blue-subtle);
  border: 1px solid var(--border-focus);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  margin-bottom: 22px;
  transition: transform 0.3s ease;
}

.feature-card:hover .feature-icon-wrapper {
  transform: scale(1.1) rotate(6deg);
  background: var(--primary-gradient);
  color: #ffffff;
}

.feature-card h3 {
  font-size: 1.32rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-main);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.feature-bullets {
  border-top: 1px dashed var(--border-color);
  padding-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-light);
}

.feature-bullets li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.feature-bullets li svg {
  color: var(--primary);
  flex-shrink: 0;
}

/* ==========================================================================
   Streaming & AI Support Section
   ========================================================================== */
.support-container {
  display: flex;
  flex-direction: column;
  gap: 36px;
}

.support-category {
  background: #ffffff;
  border-radius: var(--radius-lg);
  padding: 32px;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.category-title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.3rem;
  font-weight: 750;
  color: var(--text-main);
  margin-bottom: 20px;
}

.category-icon {
  width: 34px;
  height: 34px;
  background: var(--bg-blue-subtle);
  color: var(--primary);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.platform-card {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  align-items: center;
  gap: 14px;
  transition: var(--transition);
}

.platform-card:hover {
  background: #ffffff;
  border-color: var(--primary-light);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.platform-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.icon-netflix { background: #e50914; color: #fff; }
.icon-youtube { background: #ff0000; color: #fff; }
.icon-disney { background: #113ccf; color: #fff; }
.icon-tiktok { background: #000000; color: #fff; }

.icon-chatgpt { background: #10a37f; color: #fff; }
.icon-claude { background: #d97706; color: #fff; }
.icon-midjourney { background: #4f46e5; color: #fff; }
.icon-gemini { background: #2563eb; color: #fff; }

.platform-info h4 {
  font-size: 0.98rem;
  font-weight: 750;
  color: var(--text-main);
  margin-bottom: 2px;
}

.platform-info p {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ==========================================================================
   Pricing Table Section
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
}

.price-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 34px 24px 28px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  position: relative;
}

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

.price-card.popular {
  border: 2px solid var(--primary);
  box-shadow: 0 12px 36px rgba(37, 99, 235, 0.16);
  background: linear-gradient(180deg, #ffffff 0%, #f0f7ff 100%);
  transform: scale(1.03);
  z-index: 2;
}

.price-card.popular:hover {
  transform: scale(1.03) translateY(-6px);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-gradient);
  color: #ffffff;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.35);
  white-space: nowrap;
}

.plan-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 0.84rem;
  color: var(--text-light);
  min-height: 40px;
  margin-bottom: 16px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  margin-bottom: 22px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-color);
}

.currency {
  font-size: 1.25rem;
  font-weight: 750;
  color: var(--primary);
}

.amount {
  font-size: 2.7rem;
  font-weight: 900;
  color: #0f172a;
  line-height: 1;
  margin: 0 4px;
}

.period {
  font-size: 0.82rem;
  color: var(--text-light);
}

.plan-features {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 26px;
  flex-grow: 1;
  font-size: 0.88rem;
  color: var(--text-muted);
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.plan-features li svg {
  color: var(--primary);
  flex-shrink: 0;
}

.btn-card-cta {
  background: var(--bg-blue-subtle);
  color: var(--primary-dark);
  border: 1px solid var(--border-focus);
  padding: 12px 20px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.95rem;
  text-align: center;
  transition: var(--transition);
}

.btn-card-cta:hover {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
}

.price-card.popular .btn-card-cta {
  background: var(--primary-gradient);
  color: #ffffff;
  border: none;
  box-shadow: 0 6px 18px rgba(37, 99, 235, 0.35);
}

.price-card.popular .btn-card-cta:hover {
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.5);
}

/* ==========================================================================
   SEO Articles Grid Section (12 Articles)
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 26px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-md);
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.article-tag {
  background: var(--bg-blue-subtle);
  color: var(--primary-dark);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
}

.article-date {
  font-size: 0.78rem;
  color: var(--text-light);
}

.article-title {
  font-size: 1.15rem;
  font-weight: 750;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 10px;
  transition: color 0.2s ease;
}

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

.article-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-footer-links {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 14px;
  border-top: 1px solid #f1f5f9;
}

.article-read-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.article-read-link:hover {
  gap: 8px;
}

.article-cta-btn {
  font-size: 0.8rem;
  font-weight: 700;
  background: var(--bg-blue-subtle);
  color: var(--primary-dark);
  padding: 5px 12px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-focus);
}

.article-cta-btn:hover {
  background: var(--primary);
  color: #ffffff;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.faq-item {
  background: #ffffff;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

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

.faq-q {
  font-size: 1.05rem;
  font-weight: 750;
  color: var(--text-main);
  margin-bottom: 10px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.faq-q-badge {
  background: var(--primary-gradient);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  width: 22px;
  height: 22px;
  border-radius: 6px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

.faq-a {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
  padding-left: 32px;
}

/* ==========================================================================
   Testimonials (Reviews) Section
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 14px;
  font-size: 1rem;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-gradient);
  color: #ffffff;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.author-meta h5 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

.author-meta span {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ==========================================================================
   Floating Chapter Arrows (Right Side Nav)
   ========================================================================== */
.floating-nav {
  position: fixed;
  right: 28px;
  bottom: 40px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  z-index: 999;
}

.nav-arrow-btn {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: #ffffff;
  color: var(--primary);
  border: 1.5px solid var(--border-focus);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  outline: none;
}

.nav-arrow-btn:hover {
  background: var(--primary-gradient);
  color: #ffffff;
  transform: scale(1.1);
  box-shadow: var(--shadow-hover);
}

.nav-arrow-btn:active {
  transform: scale(0.92);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
  margin-top: auto;
}

.footer-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  padding-bottom: 40px;
  border-bottom: 1px solid #f1f5f9;
  text-align: center;
}

.footer-nav-card {
  padding: 20px;
  background: #f8fafc;
  border-radius: var(--radius-md);
  border: 1px solid #e2e8f0;
  transition: var(--transition);
}

.footer-nav-card:hover {
  border-color: var(--primary-light);
  background: var(--bg-blue-subtle);
  transform: translateY(-2px);
}

.footer-nav-card h4 {
  font-size: 1.1rem;
  font-weight: 750;
  color: var(--text-main);
  margin-bottom: 6px;
}

.footer-nav-card p {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* PBN & Friend Links in Footer */
.footer-pbn-section {
  padding: 28px 0 16px;
  text-align: center;
}

.footer-pbn-links {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  justify-content: center;
  gap: 16px;
  font-size: 0.92rem;
  color: var(--text-muted);
  font-weight: 600;
}

.pbn-link {
  color: var(--primary-dark);
  text-decoration: none;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  background: var(--bg-blue-subtle);
  border: 1px solid var(--border-focus);
  transition: var(--transition);
}

.pbn-link:hover {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

.footer-copyright {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: 14px;
}

/* ==========================================================================
   Article Detail Page Styles
   ========================================================================== */
.article-header {
  padding: 60px 0 30px;
  text-align: center;
  background: linear-gradient(180deg, var(--bg-blue-subtle) 0%, transparent 100%);
}

.article-content-body {
  max-width: 860px;
  margin: 0 auto;
  background: #ffffff;
  padding: 44px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  font-size: 1.05rem;
  line-height: 1.85;
  color: #334155;
}

.article-content-body h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 36px 0 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border-focus);
}

.article-content-body h3 {
  font-size: 1.25rem;
  font-weight: 750;
  color: var(--primary-dark);
  margin: 24px 0 12px;
}

.article-content-body p {
  margin-bottom: 18px;
}

.article-content-body ul, .article-content-body ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-content-body ul {
  list-style: disc;
}

.article-content-body ol {
  list-style: decimal;
}

.article-content-body li {
  margin-bottom: 8px;
}

.article-callout {
  background: var(--bg-blue-subtle);
  border-left: 4px solid var(--primary);
  padding: 20px 24px;
  border-radius: var(--radius-sm);
  margin: 28px 0;
}

.article-cta-box {
  text-align: center;
  background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
  border: 1px solid var(--border-focus);
  padding: 36px 24px;
  border-radius: var(--radius-lg);
  margin: 40px 0;
}

/* ==========================================================================
   Responsive Queries (@media) - Mobile First Priority
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .platforms-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }

  .header-container {
    height: 64px;
  }

  .nav-menu {
    display: none; /* 移动端极简，保证秒开与简洁体验 */
  }

  .hero-section {
    padding: 40px 0 30px;
  }

  .hero-title {
    font-size: 2.15rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .btn-primary, .btn-secondary {
    width: 100%;
    padding: 14px 20px;
  }

  .hero-perks {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

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

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

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

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

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

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

  .footer-nav-grid {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

  .floating-nav {
    right: 16px;
    bottom: 24px;
  }

  .nav-arrow-btn {
    width: 42px;
    height: 42px;
  }

  .article-content-body {
    padding: 24px 18px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.85rem;
  }

  .footer-nav-grid {
    grid-template-columns: 1fr;
  }
}