/* AshNet Landing Page - Underwater Marine Tech Theme */
:root {
  --bg-primary: #030a16;
  --bg-secondary: #071527;
  --bg-card: rgba(10, 28, 52, 0.75);
  --bg-card-hover: rgba(16, 42, 77, 0.85);
  --text-primary: #f0f9ff;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #0284c7;
  --accent-cyan: #06b6d4;
  --accent-aqua: #00f2fe;
  --accent-gold: #fbbf24;
  --accent-green: #10b981;
  --gradient-ocean: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
  --gradient-deep-sea: linear-gradient(180deg, #030a16 0%, #081d38 50%, #030a16 100%);
  --border-color: rgba(6, 182, 212, 0.15);
  --border-hover: rgba(0, 242, 254, 0.45);
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.6), 0 0 25px rgba(6, 182, 212, 0.2);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

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

body {
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(0, 242, 254, 0.12) 0%, transparent 60%),
    radial-gradient(circle at 10% 40%, rgba(2, 132, 199, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 90% 70%, rgba(6, 182, 212, 0.1) 0%, transparent 50%);
  background-attachment: fixed;
  position: relative;
}

/* Water Ambient Animation Effect */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: repeating-linear-gradient(
    45deg,
    rgba(0, 242, 254, 0.015) 0px,
    rgba(0, 242, 254, 0.015) 2px,
    transparent 2px,
    transparent 8px
  );
  pointer-events: none;
  z-index: 0;
}

a {
  color: var(--accent-aqua);
  text-decoration: none;
  transition: all 0.25s ease;
}

a:hover {
  color: #38bdf8;
  text-shadow: 0 0 8px rgba(56, 189, 248, 0.4);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  position: relative;
  z-index: 1;
}

/* Header & Navbar */
header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(3, 10, 22, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 14px 0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.brand-logo {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 0 12px rgba(0, 242, 254, 0.4);
}

.brand-text {
  background: var(--gradient-ocean);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 2px 4px rgba(0, 242, 254, 0.2));
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

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

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  border: none;
  text-align: center;
}

.btn-primary {
  background: var(--gradient-ocean);
  color: #030a16 !important;
  font-weight: 700;
  box-shadow: 0 4px 18px rgba(0, 242, 254, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 25px rgba(0, 242, 254, 0.6);
  color: #030a16;
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-aqua);
  color: #ffffff;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.2);
}

.btn-recommend {
  background: rgba(251, 191, 36, 0.15);
  color: var(--accent-gold) !important;
  border: 1px solid rgba(251, 191, 36, 0.4);
  font-weight: 600;
}

.btn-recommend:hover {
  background: var(--accent-gold);
  color: #030a16 !important;
  box-shadow: 0 0 18px rgba(251, 191, 36, 0.5);
}

/* Hero Section - Underwater Sunbeams & Caustics */
.hero {
  padding: 90px 0 70px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 900px;
  background: radial-gradient(ellipse at 50% 0%, rgba(0, 242, 254, 0.22) 0%, rgba(2, 132, 199, 0.1) 45%, transparent 75%);
  pointer-events: none;
  z-index: 0;
  animation: oceanPulse 8s infinite alternate ease-in-out;
}

@keyframes oceanPulse {
  0% { opacity: 0.7; transform: translateX(-50%) scale(0.95); }
  100% { opacity: 1; transform: translateX(-50%) scale(1.05); }
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 880px;
  margin: 0 auto;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 18px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.3);
  border-radius: 50px;
  color: var(--accent-aqua);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 24px;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.15);
}

.hero-title {
  font-size: 3.3rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 22px;
  letter-spacing: -1px;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

.hero-title span {
  background: var(--gradient-ocean);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 10px rgba(0, 242, 254, 0.3));
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 38px;
  line-height: 1.75;
}

.hero-ctas {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 55px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 26px;
  border-radius: var(--radius-md);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-lg);
}

.stat-item h3 {
  font-size: 1.9rem;
  color: var(--accent-aqua);
  font-weight: 800;
  text-shadow: 0 0 12px rgba(0, 242, 254, 0.3);
}

.stat-item p {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

/* Sections General */
.section {
  padding: 75px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 48px;
}

.section-title {
  font-size: 2.3rem;
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 28px;
  backdrop-filter: blur(12px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.feature-icon {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--accent-aqua);
  margin-bottom: 22px;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.15);
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: 12px;
  font-weight: 700;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* Pricing Grid */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  backdrop-filter: blur(12px);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.pricing-card.popular {
  border: 2px solid var(--accent-cyan);
  background: linear-gradient(180deg, rgba(7, 34, 66, 0.9) 0%, rgba(4, 20, 42, 0.95) 100%);
  box-shadow: 0 0 30px rgba(6, 182, 212, 0.25);
}

.pricing-card.popular::before {
  content: '热门推荐';
  position: absolute;
  top: -14px;
  right: 24px;
  background: var(--gradient-ocean);
  color: #030a16;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: 20px;
  box-shadow: 0 0 12px rgba(0, 242, 254, 0.4);
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  min-height: 42px;
}

.plan-price {
  font-size: 2.6rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
  text-shadow: 0 2px 10px rgba(0, 242, 254, 0.2);
}

.plan-price span {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-weight: 400;
}

.plan-features {
  list-style: none;
  margin-bottom: 30px;
  flex-grow: 1;
}

.plan-features li {
  padding: 8px 0;
  font-size: 0.92rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.plan-features li::before {
  content: '✓';
  color: var(--accent-green);
  font-weight: 800;
}

/* Node Flags Grid */
.nodes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: 16px;
}

.node-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 18px 16px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  gap: 12px;
  backdrop-filter: blur(8px);
  transition: all 0.25s ease;
}

.node-card:hover {
  border-color: var(--accent-aqua);
  background: var(--bg-card-hover);
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.2);
}

.node-flag {
  font-size: 1.5rem;
}

.node-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
}

.node-info p {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Articles Section */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(12px);
  transition: all 0.3s ease;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-aqua);
  box-shadow: var(--shadow-lg);
}

.article-tag {
  font-size: 0.8rem;
  color: var(--accent-cyan);
  font-weight: 700;
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.article-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
  line-height: 1.45;
}

.article-card h3 a {
  color: var(--text-primary);
}

.article-card h3 a:hover {
  color: var(--accent-aqua);
}

.article-excerpt {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
  backdrop-filter: blur(12px);
}

.user-rating {
  color: var(--accent-gold);
  margin-bottom: 12px;
}

.testimonial-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  font-style: italic;
  margin-bottom: 20px;
  line-height: 1.65;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-ocean);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #030a16;
  box-shadow: 0 0 10px rgba(0, 242, 254, 0.3);
}

.user-details h4 {
  font-size: 0.95rem;
  font-weight: 600;
}

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

/* FAQ Accordion */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  backdrop-filter: blur(12px);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  color: var(--accent-aqua);
  transition: transform 0.25s ease;
}

.faq-item.active .faq-question::after {
  content: '−';
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  padding: 0 24px;
  background: rgba(4, 18, 38, 0.6);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 24px 22px;
  transition: max-height 0.3s cubic-bezier(1, 0, 1, 0);
}

.faq-answer p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.75;
}

/* CTA Banner */
.cta-banner {
  background: linear-gradient(135deg, rgba(6, 182, 212, 0.2) 0%, rgba(2, 132, 199, 0.2) 100%);
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-lg);
  padding: 55px 30px;
  text-align: center;
  margin: 40px 0 75px;
  backdrop-filter: blur(12px);
  box-shadow: 0 0 30px rgba(0, 242, 254, 0.15);
}

.cta-banner h2 {
  font-size: 2.3rem;
  font-weight: 800;
  margin-bottom: 14px;
}

.cta-banner p {
  color: var(--text-secondary);
  margin-bottom: 30px;
  font-size: 1.05rem;
}

/* Footer & PBN Links Section */
footer {
  background: #02060e;
  border-top: 1px solid var(--border-color);
  padding: 50px 0 30px;
  margin-top: auto;
  text-align: center;
  position: relative;
  z-index: 2;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.88rem;
}

/* PBN Friendship Links Sub-section */
.pbn-links-section {
  margin-top: 15px;
  padding-top: 15px;
  border-top: 1px dashed rgba(6, 182, 212, 0.15);
  font-size: 0.82rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.pbn-links-title {
  color: var(--text-muted);
  font-weight: 500;
}

.pbn-link {
  color: #64748b;
  text-decoration: none;
  transition: color 0.2s ease;
}

.pbn-link:hover {
  color: var(--accent-aqua);
  text-decoration: underline;
}

.pbn-divider {
  color: #334155;
}

/* Article Detail Styles */
.article-page {
  padding: 60px 0;
}

.article-header {
  max-width: 850px;
  margin: 0 auto 35px;
}

.article-title {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.3;
  margin: 16px 0;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.article-meta-header {
  display: flex;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.article-body {
  max-width: 850px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 45px;
  backdrop-filter: blur(12px);
}

.article-body h2 {
  font-size: 1.7rem;
  margin: 32px 0 16px;
  color: var(--accent-aqua);
  border-left: 4px solid var(--accent-cyan);
  padding-left: 12px;
}

.article-body h3 {
  font-size: 1.3rem;
  margin: 26px 0 14px;
  color: var(--text-primary);
}

.article-body p {
  color: #cbd5e1;
  font-size: 1.05rem;
  line-height: 1.85;
  margin-bottom: 22px;
}

.article-body ul, .article-body ol {
  margin: 0 0 22px 24px;
  color: #cbd5e1;
  font-size: 1rem;
  line-height: 1.85;
}

.article-body blockquote {
  border-left: 4px solid var(--accent-aqua);
  background: rgba(0, 242, 254, 0.08);
  padding: 18px 22px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 26px;
  color: var(--text-secondary);
  font-style: italic;
}

.article-keywords-box {
  background: rgba(4, 18, 38, 0.8);
  border: 1px dashed var(--border-hover);
  padding: 18px;
  border-radius: var(--radius-sm);
  margin-top: 35px;
  font-size: 0.9rem;
}

.article-keywords-box strong {
  color: var(--accent-gold);
}

.article-nav-box {
  display: flex;
  justify-content: space-between;
  margin-top: 45px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

/* Floating Water Bubbles Animation */
.bubble {
  position: fixed;
  bottom: -50px;
  background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.4), rgba(0, 242, 254, 0.1));
  border: 1px solid rgba(0, 242, 254, 0.3);
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  animation: floatBubble 12s infinite linear;
}

@keyframes floatBubble {
  0% {
    transform: translateY(0) scale(0.8);
    opacity: 0;
  }
  20% {
    opacity: 0.6;
  }
  80% {
    opacity: 0.6;
  }
  100% {
    transform: translateY(-110vh) scale(1.2);
    opacity: 0;
  }
}

/* Responsive */
@media (max-width: 992px) {
  .hero-title { font-size: 2.6rem; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
}

@media (max-width: 600px) {
  .hero-title { font-size: 2rem; }
  .hero-stats { grid-template-columns: 1fr; }
  .hero-ctas { flex-direction: column; }
  .article-body { padding: 22px; }
}