/* ==========================================================================
   灵动云 (lingdongyun.click) Design System & Stylesheet
   Theme: Sky Cloud Elegance + Modern Dark Glassmorphic
   ========================================================================== */

:root {
  --bg-dark: #070913;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --border-color: rgba(255, 255, 255, 0.12);
  --border-glow: rgba(59, 130, 246, 0.4);
  
  --primary-blue: #3b82f6;
  --sky-blue: #38bdf8;
  --light-cyan: #a5f3fc;
  --accent-purple: #818cf8;
  --text-main: #f8fafc;
  --text-sub: #94a3b8;
  --text-muted: #64748b;
  
  --success-green: #10b981;
  --warning-amber: #f59e0b;
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --max-width: 1200px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* ==========================================================================
   1. Sky & Cloud Animated Background (天空与云朵元素)
   ========================================================================== */
.sky-bg-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -2;
  overflow: hidden;
  background: radial-gradient(circle at 50% 15%, #0f172a 0%, #070913 70%);
}

.cloud-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 200%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1440 320'%3E%3Cpath fill='%2338bdf8' fill-opacity='0.03' d='M0,192L48,176C96,160,192,128,288,138.7C384,149,480,203,576,213.3C672,224,768,192,864,165.3C960,139,1056,117,1152,128C1248,139,1344,181,1392,202.7L1440,224L1440,0L1392,0C1344,0,1248,0,1152,0C1056,0,960,0,864,0C768,0,672,0,576,0C480,0,384,0,288,0C192,0,96,0,48,0L0,0Z'%3E%3C/path%3E%3C/svg%3E") repeat-x;
  background-size: contain;
  animation: moveClouds 40s linear infinite;
}

.cloud-layer-2 {
  top: 10%;
  opacity: 0.5;
  animation: moveClouds 65s linear infinite reverse;
}

.sky-glow {
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 600px;
  background: radial-gradient(circle, rgba(56, 189, 248, 0.15) 0%, rgba(59, 130, 246, 0.05) 50%, transparent 80%);
  filter: blur(80px);
  pointer-events: none;
}

@keyframes moveClouds {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* ==========================================================================
   2. Typography & Gradient Utilities (蓝白渐变字)
   ========================================================================== */
.gradient-text {
  background: linear-gradient(135deg, #ffffff 0%, #a5f3fc 40%, #38bdf8 70%, #3b82f6 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.gradient-text-alt {
  background: linear-gradient(135deg, #ffffff 30%, #93c5fd 70%, #60a5fa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   3. Common Components & Layout
   ========================================================================== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.section {
  padding: 5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: 9999px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--sky-blue);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.section-desc {
  color: var(--text-sub);
  font-size: 1.05rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.85rem 1.8rem;
  border-radius: 12px;
  font-weight: 700;
  font-size: 1rem;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, #0284c7 0%, #2563eb 50%, #1d4ed8 100%);
  color: #ffffff;
  box-shadow: 0 4px 20px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(56, 189, 248, 0.6);
  filter: brightness(1.1);
}

.btn-outline {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: var(--sky-blue);
  transform: translateY(-2px);
}

.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
}

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

.badge-sky {
  background: rgba(56, 189, 248, 0.15);
  color: #38bdf8;
  border: 1px solid rgba(56, 189, 248, 0.3);
}

/* ==========================================================================
   4. Navbar Layout
   ========================================================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1rem 0;
  transition: all 0.3s ease;
  backdrop-filter: blur(16px);
  background: rgba(7, 9, 19, 0.6);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.navbar-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #38bdf8, #2563eb);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.5);
}

.logo-text {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

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

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

.nav-links a:hover {
  color: var(--sky-blue);
}

/* ==========================================================================
   5. Hero Section
   ========================================================================== */
.hero {
  padding-top: 9rem;
  padding-bottom: 5rem;
  text-align: center;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.2rem;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: 9999px;
  font-size: 0.9rem;
  color: var(--light-cyan);
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-sub);
  max-width: 780px;
  margin: 0 auto 2.5rem auto;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 3rem;
  flex-wrap: wrap;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  max-width: 900px;
  margin: 3rem auto 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  backdrop-filter: blur(12px);
}

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

.stat-number {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-sub);
}

/* ==========================================================================
   6. 实时节点速度表 (Directive 5: Live Node Speed Dashboard)
   ========================================================================== */
.speed-table-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.5rem;
  backdrop-filter: blur(16px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  overflow-x: auto;
}

.speed-table-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.live-indicator {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--success-green);
  font-weight: 600;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background-color: var(--success-green);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--success-green);
  animation: pulse 1.5s 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 10px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.speed-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.speed-table th {
  padding: 0.85rem 1rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.speed-table td {
  padding: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.95rem;
  vertical-align: middle;
}

.speed-table tr:hover {
  background: rgba(255, 255, 255, 0.03);
}

.node-flag {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 600;
}

.ping-bar-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.ping-bar {
  height: 6px;
  border-radius: 3px;
  background: linear-gradient(90deg, #10b981, #38bdf8);
}

.ping-val {
  font-family: monospace;
  font-size: 0.9rem;
  color: #34d399;
  font-weight: 700;
}

/* ==========================================================================
   7. Pricing Section
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: stretch;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
  backdrop-filter: blur(16px);
}

.price-card.popular {
  border-color: var(--sky-blue);
  box-shadow: 0 0 35px rgba(56, 189, 248, 0.25);
  transform: translateY(-8px);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, #0284c7, #38bdf8);
  color: white;
  padding: 0.3rem 1rem;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.price-name {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.price-desc {
  font-size: 0.9rem;
  color: var(--text-sub);
  margin-bottom: 1.5rem;
}

.price-amount {
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
  margin-bottom: 1.5rem;
}

.price-currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--sky-blue);
}

.price-number {
  font-size: 3rem;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1;
}

.price-unit {
  color: var(--text-sub);
  font-size: 0.9rem;
}

.price-features {
  list-style: none;
  margin-bottom: 2rem;
  flex: 1;
}

.price-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.85rem;
  font-size: 0.95rem;
  color: var(--text-sub);
}

.price-features li svg {
  color: var(--sky-blue);
  flex-shrink: 0;
}

/* ==========================================================================
   8. Customer Reviews Marquee (Directive 4: 客户评论 平排上下自动展示)
   ========================================================================== */
.reviews-marquee-container {
  overflow: hidden;
  position: relative;
  max-height: 520px;
  padding: 1rem 0;
}

.reviews-marquee-container::before,
.reviews-marquee-container::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 60px;
  z-index: 2;
  pointer-events: none;
}

.reviews-marquee-container::before {
  top: 0;
  background: linear-gradient(180deg, var(--bg-dark) 0%, transparent 100%);
}

.reviews-marquee-container::after {
  bottom: 0;
  background: linear-gradient(0deg, var(--bg-dark) 0%, transparent 100%);
}

.marquee-vertical {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  animation: scrollVertical 28s linear infinite;
}

.reviews-marquee-container:hover .marquee-vertical {
  animation-play-state: paused;
}

@keyframes scrollVertical {
  0% { transform: translateY(0); }
  100% { transform: translateY(-50%); }
}

.review-grid-two-col {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 1.25rem 1.5rem;
  backdrop-filter: blur(10px);
}

.review-user {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, #38bdf8, #818cf8);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: white;
  font-size: 1rem;
}

.user-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
}

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

.stars {
  color: #f59e0b;
  margin-left: auto;
  font-size: 0.85rem;
}

.review-text {
  font-size: 0.9rem;
  color: var(--text-sub);
  line-height: 1.5;
}

/* ==========================================================================
   9. SEO Articles Section & Card Matrix (SEO 5-8篇 内部跳转)
   ========================================================================== */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
  text-decoration: none;
  color: inherit;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--sky-blue);
  box-shadow: 0 8px 25px rgba(56, 189, 248, 0.2);
}

.article-tag {
  font-size: 0.8rem;
  color: var(--sky-blue);
  font-weight: 600;
  margin-bottom: 0.6rem;
}

.article-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 0.8rem;
  color: var(--text-main);
}

.article-excerpt {
  font-size: 0.88rem;
  color: var(--text-sub);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 0.8rem;
}

/* ==========================================================================
   10. FAQ Accordion Section
   ========================================================================== */
.faq-list {
  max-width: 850px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.3s ease;
}

.faq-item.active {
  border-color: var(--sky-blue);
}

.faq-question {
  width: 100%;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}

.faq-icon {
  width: 20px;
  height: 20px;
  transition: transform 0.3s ease;
  color: var(--sky-blue);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 1.5rem;
  color: var(--text-sub);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 1.5rem 1.25rem 1.5rem;
}

/* ==========================================================================
   11. SEO Content Article Layout (Detail Page Style)
   ========================================================================== */
.article-detail-body {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 2.5rem 3rem;
  backdrop-filter: blur(16px);
  color: #cbd5e1;
  line-height: 1.8;
}

.article-detail-body h1 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 1.2rem;
  line-height: 1.3;
}

.article-detail-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-color);
}

.article-detail-body h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--sky-blue);
  margin: 1.5rem 0 0.8rem 0;
}

.article-detail-body p {
  margin-bottom: 1.25rem;
  font-size: 1rem;
}

.article-detail-body ul, .article-detail-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

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

.article-detail-body a {
  color: var(--sky-blue);
  text-decoration: underline;
}

.cta-box-inline {
  background: linear-gradient(135deg, rgba(2, 132, 199, 0.2), rgba(37, 99, 235, 0.2));
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-radius: 14px;
  padding: 1.5rem;
  text-align: center;
  margin: 2rem 0;
}

/* ==========================================================================
   12. PBN Footer Injection (核心任务 2: 页脚 PBN 权重输血管道)
   ========================================================================== */
footer.site-footer {
  background: rgba(5, 7, 15, 0.95);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0 2rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 1.5rem;
}

.footer-nav {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-nav a {
  color: var(--text-sub);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-nav a:hover {
  color: var(--sky-blue);
}

/* Discrete, refined low-profile PBN link section */
.pbn-links-wrapper {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed rgba(255, 255, 255, 0.08);
  font-size: 0.78rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.pbn-links-wrapper span {
  opacity: 0.7;
}

.pbn-links-wrapper a {
  color: rgba(148, 163, 184, 0.7);
  text-decoration: none;
  transition: color 0.2s ease;
}

.pbn-links-wrapper a:hover {
  color: var(--sky-blue);
}

/* ==========================================================================
   13. Responsive Breakpoints
   ========================================================================== */
@media (max-width: 992px) {
  .hero-title { font-size: 2.75rem; }
  .pricing-grid { grid-template-columns: 1fr; max-width: 500px; margin: 0 auto; }
  .articles-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .review-grid-two-col { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .hero-title { font-size: 2.1rem; }
  .nav-links { display: none; }
  .articles-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr 1fr; }
  .article-detail-body { padding: 1.5rem; }
}