/* Linear / Vercel Dark SaaS Aesthetics for nai-yun.sbs */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Sora:wght@500;600;700;800&display=swap');

:root {
  --bg-base: #08080D;
  --bg-panel: #101018;
  --bg-panel-hover: #151522;
  --border-subtle: 1px solid rgba(255, 255, 255, 0.08);
  --border-highlight: 1px solid rgba(167, 139, 250, 0.4);
  --accent-purple: #6E56CF;
  --accent-blue: #3E8BFF;
  --gradient-saas: linear-gradient(135deg, #A78BFA 0%, #38BDF8 100%);
  --glow-saas: 0 0 35px rgba(110, 86, 207, 0.35);
  --radius-panel: 14px;
  --radius-pill: 9999px;
  --font-heading: 'Sora', -apple-system, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --text-primary: #F3F4F6;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Background Subtle Grid with Radial Fade */
.bg-grid-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(circle at 50% 30%, black 40%, transparent 80%);
  -webkit-mask-image: radial-gradient(circle at 50% 30%, black 40%, transparent 80%);
  pointer-events: none;
  z-index: 0;
}

/* Hero Background Glows */
.hero-glow-1 {
  position: absolute;
  width: 650px;
  height: 650px;
  top: -150px;
  left: 50%;
  transform: translateX(-65%);
  background: radial-gradient(circle, rgba(110, 86, 207, 0.28) 0%, transparent 70%);
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}

.hero-glow-2 {
  position: absolute;
  width: 600px;
  height: 600px;
  top: -100px;
  left: 50%;
  transform: translateX(-15%);
  background: radial-gradient(circle, rgba(62, 139, 255, 0.22) 0%, transparent 70%);
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* Panel Utilities */
.saas-panel {
  background: var(--bg-panel);
  border: var(--border-subtle);
  border-radius: var(--radius-panel);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.saas-panel:hover {
  background: var(--bg-panel-hover);
  border-color: rgba(255, 255, 255, 0.16);
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.5);
}

/* Typography */
h1, h2, h3, h4, .font-heading {
  font-family: var(--font-heading);
  letter-spacing: -0.02em;
  font-weight: 700;
}

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 12px 26px;
  border-radius: var(--radius-pill);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.25s ease-out;
}

.btn-primary {
  background: var(--gradient-saas);
  color: #08080D;
  box-shadow: 0 0 25px rgba(110, 86, 207, 0.4);
  border: none;
}

.btn-primary:hover {
  box-shadow: 0 0 35px rgba(56, 189, 248, 0.6);
  transform: translateY(-2px);
  color: #08080D;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.05);
  border: var(--border-subtle);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: #FFF;
  transform: translateY(-2px);
}

/* Eyebrow & Status Dot */
.eyebrow-capsule {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: var(--border-subtle);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.status-dot-green {
  width: 8px;
  height: 8px;
  background: #10B981;
  border-radius: 50%;
  box-shadow: 0 0 8px #10B981;
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.3); opacity: 0.7; }
  100% { transform: scale(1); opacity: 1; }
}

/* Header & Nav */
.site-header {
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(8, 8, 13, 0.75);
  border-bottom: var(--border-subtle);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-size: 1.4rem;
  font-family: var(--font-heading);
  font-weight: 700;
  color: #FFF;
}

.nav-logo-badge {
  font-size: 0.72rem;
  padding: 3px 8px;
  background: rgba(110, 86, 207, 0.15);
  border: 1px solid rgba(110, 86, 207, 0.4);
  border-radius: var(--radius-pill);
  color: #A78BFA;
  font-weight: 600;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-menu a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.92rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

.nav-menu a.nav-news {
  padding: 4px 12px;
  background: rgba(167, 139, 250, 0.12);
  border: 1px solid rgba(167, 139, 250, 0.35);
  border-radius: var(--radius-pill);
  color: #C4B5FD;
}

/* Hero Section */
.hero-section {
  padding: 90px 0 60px;
  text-align: center;
  position: relative;
}

.hero-title {
  font-size: 3.6rem;
  line-height: 1.18;
  margin-bottom: 22px;
  max-width: 920px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 36px;
  font-weight: 400;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-bottom: 60px;
  flex-wrap: wrap;
}

/* CSS Mockup Card: Fake Speed Test UI */
.speed-mockup-wrapper {
  max-width: 780px;
  margin: 0 auto 80px;
}

.mockup-header {
  padding: 14px 20px;
  background: rgba(255, 255, 255, 0.03);
  border-bottom: var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.mockup-dots {
  display: flex;
  gap: 6px;
}

.mockup-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
}

.mockup-dot-red { background: #EF4444; }
.mockup-dot-yellow { background: #F59E0B; }
.mockup-dot-green { background: #10B981; }

.mockup-body {
  padding: 40px 30px;
  text-align: center;
}

.speed-meter-val {
  font-size: 5rem;
  font-weight: 800;
  font-family: var(--font-heading);
  line-height: 1;
  background: var(--gradient-saas);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 6px;
}

.speed-unit {
  font-size: 1.1rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 600;
}

.speed-progress-track {
  width: 100%;
  height: 12px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-pill);
  margin: 30px auto 20px;
  overflow: hidden;
  position: relative;
}

.speed-progress-fill {
  height: 100%;
  width: 94%;
  background: var(--gradient-saas);
  border-radius: var(--radius-pill);
  animation: grow-bar 2.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  box-shadow: 0 0 15px rgba(56, 189, 248, 0.5);
}

@keyframes grow-bar {
  0% { width: 0%; }
  100% { width: 94%; }
}

.mockup-metrics {
  display: flex;
  justify-content: space-around;
  margin-top: 24px;
  border-top: var(--border-subtle);
  padding-top: 20px;
}

.metric-item-val {
  font-size: 1.35rem;
  font-weight: 700;
  color: #FFF;
}

.metric-item-lbl {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* Global Network Latency Capsules */
.latency-capsules-wrap {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
  margin: 0 auto 70px;
  max-width: 900px;
}

.latency-capsule {
  padding: 8px 18px;
  background: rgba(255, 255, 255, 0.04);
  border: var(--border-subtle);
  border-radius: var(--radius-pill);
  font-size: 0.88rem;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
}

.latency-capsule strong {
  color: #38BDF8;
}

/* Bento Grid Feature Section */
.bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-auto-rows: minmax(220px, auto);
  gap: 20px;
}

.bento-span-2 {
  grid-column: span 2;
}

.bento-card {
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.bento-card-title {
  font-size: 1.3rem;
  margin-bottom: 10px;
  color: #FFF;
}

.bento-card-desc {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* CSS Drawn Visuals */
.css-toggle-switch {
  width: 52px;
  height: 28px;
  background: #10B981;
  border-radius: var(--radius-pill);
  position: relative;
  box-shadow: 0 0 12px rgba(16, 185, 129, 0.4);
  margin-top: 20px;
}

.css-toggle-knob {
  width: 22px;
  height: 22px;
  background: #FFF;
  border-radius: 50%;
  position: absolute;
  top: 3px;
  right: 3px;
}

.css-mini-bars {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  height: 48px;
  margin-top: 20px;
}

.mini-bar {
  width: 14px;
  border-radius: 3px 3px 0 0;
  background: rgba(167, 139, 250, 0.4);
}

.mini-bar-active {
  background: var(--gradient-saas);
  box-shadow: 0 0 8px rgba(56, 189, 248, 0.6);
}

/* Streaming & AI Cards */
.media-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.media-card {
  padding: 34px 28px;
}

.media-badge-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.media-pill {
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.04);
  border: var(--border-subtle);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Pricing Grid */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.pricing-highlight {
  border: var(--border-highlight);
  background: rgba(110, 86, 207, 0.08);
  box-shadow: 0 0 40px rgba(110, 86, 207, 0.25);
}

.pricing-glow-capsule {
  position: absolute;
  top: 14px;
  right: 18px;
  background: var(--gradient-saas);
  color: #08080D;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  text-transform: uppercase;
}

.price-box {
  margin: 22px 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.4rem;
  font-weight: 600;
  color: #38BDF8;
}

.price-value {
  font-size: 3.4rem;
  font-weight: 700;
  font-family: var(--font-heading);
  line-height: 1;
}

.price-cycle {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.pricing-features {
  list-style: none;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

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

.pricing-features li span {
  color: #38BDF8;
  font-weight: bold;
}

/* Reviews Grid */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.review-card {
  padding: 30px 24px;
}

.review-stars {
  color: #FBBF24;
  margin-bottom: 14px;
  font-size: 1.1rem;
}

.review-text {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 20px;
}

.reviewer-box {
  display: flex;
  align-items: center;
  gap: 12px;
}

.reviewer-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--gradient-saas);
  color: #08080D;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

/* FAQ Accordion */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  padding: 22px 26px;
  cursor: pointer;
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1.05rem;
  font-weight: 600;
}

.faq-answer {
  margin-top: 14px;
  color: var(--text-secondary);
  font-size: 0.94rem;
  line-height: 1.7;
  display: none;
}

.faq-item.active .faq-answer {
  display: block;
}

/* Footer: STRICTLY ONLY 4 TITLES OPENING IN NEW TAB */
.site-footer {
  margin-top: 100px;
  padding: 40px 0;
  border-top: var(--border-subtle);
  background: rgba(8, 8, 13, 0.95);
}

.footer-nav-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 40px;
  margin-bottom: 20px;
}

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.footer-link:hover {
  color: #38BDF8;
}

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

/* Scroll Animation */
.reveal-on-scroll {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1), transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Mobile Responsive */
@media (max-width: 900px) {
  .hero-title {
    font-size: 2.3rem;
  }
  .nav-menu {
    display: none;
  }
  .bento-grid {
    grid-template-columns: 1fr;
  }
  .bento-span-2 {
    grid-column: span 1;
  }
  .pricing-grid, .reviews-grid, .media-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav-container {
    flex-wrap: wrap;
    gap: 20px;
  }
}