/* ==========================================================================
   奶优 (naiujc.cfd) - 太空电梯与轨道减压风 (Orbital Space Elevator & EVA Spec)
   ========================================================================== */

:root {
  --bg-deep: #04070D;
  --bg-primary: #060A13;
  --bg-surface: #0E1626;
  --bg-card: rgba(14, 22, 38, 0.85);
  --bg-card-hover: rgba(20, 32, 54, 0.95);
  
  --accent-orange: #F97316;
  --accent-orange-glow: rgba(249, 115, 22, 0.35);
  --accent-gold: #FACC15;
  --accent-cyan: #38BDF8;
  --accent-green: #22C55E;
  
  --text-main: #F8FAFC;
  --text-secondary: #CBD5E1;
  --text-muted: #64748B;
  --text-dim: #475569;

  --border-light: rgba(255, 255, 255, 0.08);
  --border-orange: rgba(249, 115, 22, 0.3);
  --border-gold: rgba(250, 204, 21, 0.3);

  --font-mono: 'Space Mono', 'Fira Code', 'Roboto Mono', Consolas, monospace;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.8), 0 0 20px rgba(249, 115, 22, 0.05);
  --shadow-orange: 0 0 25px rgba(249, 115, 22, 0.4);
}

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

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

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(56, 189, 248, 0.08) 0%, transparent 60%),
    radial-gradient(circle at 80% 40%, rgba(249, 115, 22, 0.05) 0%, transparent 50%),
    linear-gradient(rgba(6, 10, 19, 0.94), rgba(6, 10, 19, 0.98)),
    repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(255, 255, 255, 0.015) 2px, rgba(255, 255, 255, 0.015) 4px);
  background-attachment: fixed;
  cursor: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 24 24" fill="%23F97316" stroke="%23FACC15" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round"><path d="M12 2L15 8L21 12L15 16L12 22L9 16L3 12L9 8Z"/></svg>') 12 12, auto;
}

/* Vertical Orbital Space Elevator Cable Background Visual */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100vh;
  background: linear-gradient(180deg, 
    transparent 0%, 
    rgba(249, 115, 22, 0.4) 30%, 
    rgba(56, 189, 248, 0.5) 70%, 
    transparent 100%);
  z-index: 0;
  pointer-events: none;
  opacity: 0.6;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* Typography & Tag Styles */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.mono-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent-orange);
  background: rgba(249, 115, 22, 0.1);
  border: 1px solid var(--border-orange);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.mono-tag::before {
  content: '';
  width: 6px;
  height: 6px;
  background-color: var(--accent-orange);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-orange);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(1.3); }
}

/* Telemetry Header Nav */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(6, 10, 19, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: all 0.3s ease;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 72px;
}

.logo-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-main);
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-orange), #C2410C);
  border: 1px solid var(--accent-gold);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  color: #FFF;
  font-family: var(--font-mono);
  box-shadow: 0 0 15px var(--accent-orange-glow);
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 800;
  background: linear-gradient(90deg, #FFFFFF, #CBD5E1);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--accent-gold);
  display: block;
  letter-spacing: 0.08em;
}

.nav-links {
  display: flex;
  gap: 1.75rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.nav-links a:hover {
  color: var(--accent-orange);
}

.header-cta {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
  font-family: var(--font-sans);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-orange) 0%, #EA580C 100%);
  color: #FFFFFF;
  box-shadow: var(--shadow-orange);
  border: 1px solid rgba(255, 255, 255, 0.2);
  position: relative;
  overflow: hidden;
}

.btn-primary::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: left 0.6s ease;
}

.btn-primary:hover::after {
  left: 100%;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 35px rgba(249, 115, 22, 0.6);
}

.btn-secondary {
  background: rgba(14, 22, 38, 0.9);
  color: var(--text-main);
  border: 1px solid var(--border-orange);
}

.btn-secondary:hover {
  background: rgba(249, 115, 22, 0.15);
  border-color: var(--accent-orange);
  color: #FFF;
}

/* Telemetry Badge Indicator */
.telemetry-bar {
  background: rgba(4, 7, 13, 0.9);
  border-bottom: 1px solid var(--border-light);
  padding: 0.4rem 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  display: flex;
  justify-content: space-around;
  overflow-x: auto;
  white-space: nowrap;
}

.telemetry-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.telemetry-val {
  color: var(--accent-gold);
}

/* Hero Section */
.hero {
  padding: 10rem 0 5rem;
  text-align: center;
  position: relative;
}

.hero-title {
  font-size: 3.2rem;
  line-height: 1.15;
  margin: 1.5rem 0 1.25rem;
  background: linear-gradient(180deg, #FFFFFF 0%, #CBD5E1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-title span {
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-gold));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 780px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 3.5rem;
  flex-wrap: wrap;
}

/* Airlock Window Cards */
.airlock-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-top: 2px solid var(--accent-orange);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  position: relative;
  backdrop-filter: blur(12px);
  transition: all 0.3s ease;
  box-shadow: var(--shadow-card);
}

.airlock-card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-orange);
  box-shadow: 0 15px 35px -10px rgba(0,0,0,0.9), 0 0 25px rgba(249, 115, 22, 0.15);
}

.airlock-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  border-bottom: 1px solid rgba(255,255,255,0.05);
  padding-bottom: 0.5rem;
}

.airlock-window {
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.airlock-progress {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-gold));
  width: 100%;
}

/* Grid Sections */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.75rem;
  margin-top: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.section {
  padding: 5rem 0;
  border-bottom: 1px solid var(--border-light);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3rem;
}

.section-title {
  font-size: 2.2rem;
  margin: 0.75rem 0;
}

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

/* Pricing Card Component */
.pricing-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.75rem;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.pricing-card.featured {
  border-color: var(--accent-orange);
  background: linear-gradient(180deg, rgba(249, 115, 22, 0.08) 0%, var(--bg-surface) 100%);
  transform: scale(1.03);
  box-shadow: 0 0 30px rgba(249, 115, 22, 0.2);
}

.featured-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-orange);
  color: #FFF;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  padding: 0.2rem 1rem;
  border-radius: 12px;
  text-transform: uppercase;
}

.pricing-name {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent-gold);
  font-family: var(--font-mono);
  margin: 1rem 0;
}

.pricing-price span {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 400;
}

.pricing-features {
  list-style: none;
  margin: 1.5rem 0 2rem;
  flex-grow: 1;
}

.pricing-features li {
  padding: 0.6rem 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.pricing-features li::before {
  content: '✓';
  color: var(--accent-orange);
  font-weight: bold;
}

/* Article Cards & Matrix */
.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  border-color: var(--accent-gold);
  transform: translateY(-4px);
}

.article-meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--accent-orange);
  margin-bottom: 0.75rem;
}

.article-title {
  font-size: 1.2rem;
  line-height: 1.4;
  margin-bottom: 0.85rem;
}

.article-title a {
  color: var(--text-main);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

.article-link {
  color: var(--accent-orange);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.85rem;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.article-link:hover {
  color: var(--accent-gold);
}

/* User Review Cards */
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.avatar-badge {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, rgba(249,115,22,0.2), rgba(56,189,248,0.2));
  border: 1px solid var(--accent-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent-gold);
}

.author-info h4 {
  font-size: 0.95rem;
}

.author-info p {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.review-stars {
  color: var(--accent-gold);
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

.review-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* FAQ Accordion */
.faq-container {
  max-width: 850px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  margin-bottom: 1rem;
  overflow: hidden;
  transition: border-color 0.3s;
}

.faq-item.active {
  border-color: var(--accent-orange);
}

.faq-question {
  padding: 1.25rem 1.5rem;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-toggle {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--accent-orange);
  transition: transform 0.3s;
}

.faq-item.active .faq-toggle {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1), padding 0.3s ease;
  padding: 0 1.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 1.5rem 1.25rem 1.5rem;
  transition: max-height 0.5s ease-in, padding 0.3s ease;
}

/* Article Detail Page Specifics */
.article-page {
  padding-top: 8rem;
  padding-bottom: 5rem;
}

.article-content-wrapper {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: var(--shadow-card);
}

.article-header-meta {
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 1.5rem;
  margin-bottom: 2rem;
}

.article-body h2 {
  font-size: 1.6rem;
  margin: 2rem 0 1rem;
  color: var(--accent-gold);
  border-left: 3px solid var(--accent-orange);
  padding-left: 0.75rem;
}

.article-body h3 {
  font-size: 1.25rem;
  margin: 1.5rem 0 0.75rem;
  color: var(--text-main);
}

.article-body p {
  margin-bottom: 1.25rem;
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.8;
}

.article-body ul, .article-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
  color: var(--text-secondary);
}

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

.article-cta-box {
  background: linear-gradient(135deg, rgba(249, 115, 22, 0.15), rgba(14, 22, 38, 0.9));
  border: 1px solid var(--accent-orange);
  border-radius: var(--radius-md);
  padding: 2rem;
  text-align: center;
  margin: 3rem 0 2rem;
}

/* PBN Footer - Low Key Weight Transfusion Pipeline */
.footer {
  background: var(--bg-deep);
  border-top: 1px solid var(--border-light);
  padding: 3rem 0 2rem;
  color: var(--text-muted);
  font-size: 0.82rem;
  position: relative;
  z-index: 10;
}

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

.pbn-links-pipeline {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.85rem 1.5rem;
  max-width: 900px;
  margin: 1rem 0;
  padding: 1rem;
  background: rgba(14, 22, 38, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-md);
}

.pbn-links-pipeline a {
  color: #64748B;
  text-decoration: none;
  font-size: 0.78rem;
  transition: color 0.2s ease;
}

.pbn-links-pipeline a:hover {
  color: var(--accent-orange);
}

.footer-copy {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.2rem;
  }
  
  .nav-links {
    display: none;
  }
  
  .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .article-content-wrapper {
    padding: 1.5rem;
  }
  
  .mobile-cta-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(6, 10, 19, 0.95);
    backdrop-filter: blur(12px);
    border-top: 1px solid var(--accent-orange);
    padding: 0.75rem 1rem;
    z-index: 999;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
}

@media (min-width: 769px) {
  .mobile-cta-bar {
    display: none;
  }
}