/* 白羊星云 (baiyangxin.cfd) Core Design System & Styles */
:root {
  --bg-primary: #070a14;
  --bg-secondary: #0d1226;
  --bg-card: rgba(16, 23, 48, 0.7);
  --bg-card-hover: rgba(24, 34, 68, 0.85);
  --border-color: rgba(64, 110, 200, 0.2);
  --border-hover: rgba(56, 189, 248, 0.5);
  
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --accent-cyan: #10b981;
  --accent-cyan-hover: #059669;
  --accent-blue: #3b82f6;
  --accent-glow: rgba(16, 185, 129, 0.3);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --container-width: 1200px;
  --radius-lg: 16px;
  --radius-md: 10px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
  position: relative;
  overflow-x: hidden;
  min-height: 100vh;
}

/* Background Canvas & Effects */
#starfield {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
}

/* Aries Constellation Background Watermark */
.aries-bg-symbol {
  position: fixed;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: clamp(280px, 45vw, 600px);
  color: rgba(56, 189, 248, 0.025);
  text-shadow: 0 0 120px rgba(16, 185, 129, 0.08);
  font-family: -apple-system, BlinkMacSystemFont, Arial, sans-serif;
  user-select: none;
  pointer-events: none;
  z-index: -1;
  animation: float-aries 8s infinite ease-in-out;
}

@keyframes float-aries {
  0%, 100% { transform: translate(-50%, -50%) scale(1); }
  50% { transform: translate(-50%, -52%) scale(1.03); }
}

.glow-overlay {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  height: 600px;
  background: radial-gradient(circle at 50% -100px, rgba(56, 189, 248, 0.18), rgba(16, 185, 129, 0.1), transparent 70%);
  z-index: -1;
  pointer-events: none;
}

/* Container */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Navbar */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(7, 10, 20, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
}

.brand-logo img {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 0 12px rgba(16, 185, 129, 0.4);
}

.brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: linear-gradient(135deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

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

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

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 30px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan) 0%, #059669 100%);
  color: #ffffff;
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(16, 185, 129, 0.5);
  background: linear-gradient(135deg, #34d399 0%, #10b981 100%);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-main);
  border: 1px solid rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--accent-cyan);
  color: #ffffff;
  transform: translateY(-2px);
}

.btn-recommend {
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  color: #ffffff;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.35);
}

.btn-recommend:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(59, 130, 246, 0.5);
}

/* Mobile Toggle */
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero-section {
  padding: 160px 0 90px 0;
  text-align: center;
  position: relative;
}

.hero-icon-wrapper {
  margin-bottom: 20px;
  display: inline-block;
}

.hero-icon-img {
  width: 72px;
  height: 72px;
  border-radius: 18px;
  box-shadow: 0 0 30px rgba(16, 185, 129, 0.4);
  animation: pulse-glow 3s infinite ease-in-out;
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 25px rgba(16, 185, 129, 0.4); }
  50% { box-shadow: 0 0 40px rgba(56, 189, 248, 0.6); }
}

.hero-title-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 12px;
}

.hero-title-row h1 {
  font-size: 3.2rem;
  font-weight: 800;
  letter-spacing: 1px;
  color: #ffffff;
}

.hero-tagline {
  font-size: 1.35rem;
  color: var(--accent-cyan);
  font-weight: 500;
  letter-spacing: 2px;
  margin-bottom: 24px;
}

.hero-description {
  max-width: 760px;
  margin: 0 auto 38px auto;
  font-size: 1.08rem;
  color: var(--text-muted);
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

/* Section Header */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-badge {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 20px;
  background: rgba(16, 185, 129, 0.12);
  color: var(--accent-cyan);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 14px;
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 14px;
}

.section-sub {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* Section Padding */
.section-padding {
  padding: 90px 0;
}

.section-alt {
  background: rgba(13, 18, 38, 0.4);
  border-top: 1px solid rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: var(--transition);
}

.feature-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.3);
}

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 12px;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 1.25rem;
  color: #ffffff;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

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

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.pricing-card.featured {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 24px rgba(16, 185, 129, 0.2);
  background: rgba(16, 28, 54, 0.85);
}

.pricing-card.featured::before {
  content: '热门推荐';
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-cyan);
  color: #ffffff;
  padding: 4px 16px;
  border-radius: 12px;
  font-size: 0.8rem;
  font-weight: 700;
}

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

.pricing-header h3 {
  font-size: 1.35rem;
  color: #ffffff;
  margin-bottom: 8px;
}

.pricing-header p {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 20px;
}

.pricing-price {
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-price .currency {
  font-size: 1.3rem;
  color: var(--accent-cyan);
  font-weight: 700;
}

.pricing-price .amount {
  font-size: 2.8rem;
  font-weight: 800;
  color: #ffffff;
}

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

.pricing-features {
  list-style: none;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-features li {
  padding: 10px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  font-size: 0.92rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

.pricing-features li span.check {
  color: var(--accent-cyan);
  font-weight: bold;
}

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

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: var(--transition);
}

.review-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-3px);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.review-avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3b82f6, #10b981);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #ffffff;
  font-size: 1.1rem;
}

.review-info h4 {
  color: #ffffff;
  font-size: 1rem;
}

.review-info p {
  color: var(--text-dim);
  font-size: 0.82rem;
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 12px;
  font-size: 0.9rem;
}

.review-content {
  color: var(--text-muted);
  font-size: 0.93rem;
  line-height: 1.7;
}

/* FAQ Accordion */
.faq-list {
  max-width: 800px;
  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;
  transition: var(--transition);
}

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

.faq-question:hover {
  color: var(--accent-cyan);
}

.faq-toggle {
  font-size: 1.4rem;
  transition: transform 0.3s ease;
  color: var(--accent-cyan);
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  padding: 0 24px;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 24px 20px 24px;
}

/* Articles Section / Listing */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

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

.article-tag {
  font-size: 0.8rem;
  color: var(--accent-cyan);
  font-weight: 600;
  margin-bottom: 10px;
}

.article-card h3 {
  font-size: 1.2rem;
  color: #ffffff;
  margin-bottom: 12px;
  line-height: 1.5;
}

.article-card h3 a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

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

.article-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-dim);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding-top: 14px;
}

.article-read-more {
  color: var(--accent-cyan);
  text-decoration: none;
  font-weight: 600;
}

/* Article Detail Page Specifics */
.article-detail-header {
  padding: 140px 0 40px 0;
  text-align: center;
}

.article-detail-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-detail-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.article-body {
  max-width: 860px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 48px;
  color: #e2e8f0;
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-body h2 {
  font-size: 1.6rem;
  color: #ffffff;
  margin: 36px 0 16px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: 8px;
}

.article-body h3 {
  font-size: 1.25rem;
  color: var(--accent-cyan);
  margin: 24px 0 12px 0;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
}

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

.article-body strong {
  color: #ffffff;
}

.article-body a {
  color: var(--accent-cyan);
  text-decoration: underline;
}

.article-cta-box {
  margin: 40px 0;
  padding: 28px;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid var(--accent-cyan);
  border-radius: var(--radius-md);
  text-align: center;
}

.article-cta-box h4 {
  font-size: 1.2rem;
  color: #ffffff;
  margin-bottom: 10px;
}

/* Footer Section */
footer {
  background: #04060d;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 48px 0 32px 0;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.88rem;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer-brand img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
}

.footer-brand span {
  font-weight: 700;
  color: var(--text-main);
  font-size: 1.1rem;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  list-style: none;
}

.footer-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.88rem;
  transition: var(--transition);
}

.footer-nav a:hover {
  color: var(--accent-cyan);
}

/* PBN Friendship Links Box (Required Task 2) */
.friendship-links-area {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px dashed rgba(255, 255, 255, 0.08);
  font-size: 0.82rem;
  color: var(--text-dim);
}

.friendship-links-area span {
  margin-right: 8px;
  opacity: 0.8;
}

.friendship-links {
  display: inline-flex;
  align-items: center;
  gap: 16px;
}

.friendship-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.82rem;
  transition: var(--transition);
  opacity: 0.85;
}

.friendship-links a:hover {
  color: var(--accent-cyan);
  opacity: 1;
}

.copyright {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Responsive */
@media (max-width: 768px) {
  .hero-title-row h1 {
    font-size: 2.2rem;
  }
  
  .hero-tagline {
    font-size: 1.1rem;
  }
  
  .nav-links {
    display: none;
    position: absolute;
    top: 76px;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    flex-direction: column;
    padding: 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-buttons .btn {
    width: 100%;
  }
  
  .article-body {
    padding: 24px;
  }
}