/* ==========================================================================
   冲上云霄机场 - 极光弥散流体光风 (Aurora Mesh Gradient Design System)
   ========================================================================== */

:root {
  --bg-dark: #0a0e1a;
  --bg-card: rgba(18, 26, 47, 0.65);
  --bg-card-hover: rgba(28, 40, 70, 0.85);
  --border-color: rgba(0, 220, 130, 0.18);
  --border-color-hover: rgba(0, 220, 130, 0.5);
  
  --primary-emerald: #00dc82;
  --primary-cyan: #00b4d8;
  --primary-gradient: linear-gradient(135deg, #00dc82 0%, #00b4d8 50%, #7b2cbf 100%);
  --cta-gradient: linear-gradient(135deg, #00dc82 0%, #00b4d8 100%);
  --cta-hover-gradient: linear-gradient(135deg, #02f593 0%, #00c6ed 100%);
  
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --shadow-glow: 0 0 30px rgba(0, 220, 130, 0.25);
  --glass-backdrop: blur(16px);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  line-height: 1.6;
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background-color: var(--bg-dark);
}

/* 极光弥散背景 (Aurora Background Effect) */
.aurora-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}

.aurora-blob {
  position: absolute;
  filter: blur(100px);
  opacity: 0.45;
  border-radius: 50%;
  animation: float 20s infinite alternate ease-in-out;
}

.blob-1 {
  top: -10%;
  left: 20%;
  width: 50vw;
  height: 50vw;
  background: radial-gradient(circle, rgba(0,220,130,0.6) 0%, rgba(0,180,216,0) 70%);
}

.blob-2 {
  bottom: -20%;
  right: -10%;
  width: 60vw;
  height: 60vw;
  background: radial-gradient(circle, rgba(0,180,216,0.5) 0%, rgba(123,44,191,0) 70%);
  animation-delay: -7s;
}

.blob-3 {
  top: 40%;
  left: -15%;
  width: 45vw;
  height: 45vw;
  background: radial-gradient(circle, rgba(123,44,191,0.4) 0%, rgba(0,220,130,0) 70%);
  animation-delay: -12s;
}

@keyframes float {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(5%, 10%) scale(1.1); }
  100% { transform: translate(-5%, -5%) scale(0.95); }
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 导航栏 (Navbar) */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 14, 26, 0.75);
  backdrop-filter: var(--glass-backdrop);
  -webkit-backdrop-filter: var(--glass-backdrop);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding: 16px 0;
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: #fff;
  text-decoration: none;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.brand-icon {
  width: 32px;
  height: 32px;
  fill: var(--primary-emerald);
}

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

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.3s ease;
}

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

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

/* 按钮样式 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--cta-gradient);
  color: #04121a;
  box-shadow: 0 0 20px rgba(0, 220, 130, 0.35);
  animation: pulse-glow 3s infinite alternate;
}

.btn-primary:hover {
  background: var(--cta-hover-gradient);
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(0, 220, 130, 0.6);
}

.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(--primary-emerald);
  color: #fff;
  transform: translateY(-2px);
}

@keyframes pulse-glow {
  0% { box-shadow: 0 0 15px rgba(0, 220, 130, 0.3); }
  100% { box-shadow: 0 0 30px rgba(0, 220, 130, 0.6); }
}

/* Hero Section */
.hero {
  padding: 100px 0 60px;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 30px;
  background: rgba(0, 220, 130, 0.1);
  border: 1px solid rgba(0, 220, 130, 0.3);
  color: var(--primary-emerald);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-title span {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.hero-cta-group .btn {
  padding: 14px 32px;
  font-size: 1.05rem;
}

/* Glassmorphism Cards */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: var(--glass-backdrop);
  -webkit-backdrop-filter: var(--glass-backdrop);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 30px;
  transition: all 0.3s ease;
  box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-color-hover);
  transform: translateY(-5px);
  box-shadow: var(--shadow-glow);
}

/* Core Advantages Grid */
.section {
  padding: 70px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #fff;
}

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

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: rgba(0, 220, 130, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.feature-icon-wrapper svg {
  width: 28px;
  height: 28px;
  fill: var(--primary-emerald);
}

.feature-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: #fff;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Streaming & AI Cards Section */
.eco-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 16px;
  margin-top: 30px;
}

.eco-card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 20px 12px;
  text-align: center;
  transition: all 0.3s ease;
}

.eco-card:hover {
  background: rgba(0, 220, 130, 0.08);
  border-color: rgba(0, 220, 130, 0.3);
  transform: translateY(-3px);
}

.eco-card svg {
  width: 40px;
  height: 40px;
  margin-bottom: 8px;
}

.eco-card span {
  display: block;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
}

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.pricing-card {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.pricing-card.popular {
  border-color: var(--primary-emerald);
  box-shadow: 0 0 25px rgba(0, 220, 130, 0.25);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--cta-gradient);
  color: #04121a;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
}

.pricing-header {
  margin-bottom: 20px;
  text-align: center;
}

.pricing-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 8px;
}

.pricing-price {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--primary-emerald);
  margin-bottom: 4px;
}

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

.pricing-desc {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.pricing-features {
  list-style: none;
  margin: 20px 0 24px;
  padding-top: 16px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.pricing-features li svg {
  width: 16px;
  height: 16px;
  fill: var(--primary-emerald);
  flex-shrink: 0;
}

/* FAQ Accordion */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

details.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 16px 20px;
  transition: all 0.3s ease;
}

details.faq-item[open] {
  background: var(--bg-card-hover);
  border-color: rgba(0, 220, 130, 0.4);
}

summary.faq-question {
  font-size: 1.05rem;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

summary.faq-question::-webkit-details-marker {
  display: none;
}

summary.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--primary-emerald);
  transition: transform 0.3s ease;
}

details[open] summary.faq-question::after {
  content: "−";
}

.faq-answer {
  margin-top: 12px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 12px;
}

/* Customer Reviews */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 40px;
}

.review-card {
  padding: 20px;
}

.review-stars {
  color: #f59e0b;
  font-size: 1rem;
  margin-bottom: 8px;
}

.review-text {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
}

.review-author {
  font-size: 0.85rem;
  font-weight: 600;
  color: #fff;
}

/* Recommended Articles Section */
.articles-preview-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-preview-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.article-category-tag {
  display: inline-block;
  padding: 4px 10px;
  border-radius: 12px;
  background: rgba(0, 180, 216, 0.15);
  color: var(--primary-cyan);
  font-size: 0.78rem;
  font-weight: 600;
  margin-bottom: 12px;
  width: fit-content;
}

.article-preview-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 10px;
  line-height: 1.4;
}

.article-preview-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.6;
}

.article-preview-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-dim);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 12px;
}

.article-preview-meta a {
  color: var(--primary-emerald);
  text-decoration: none;
  font-weight: 600;
}

.article-preview-meta a:hover {
  text-decoration: underline;
}

/* Footer */
.footer {
  background: #060911;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 40px 0;
  margin-top: 80px;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  list-style: none;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--primary-emerald);
}

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

/* Responsive Media Queries (@media max-width: 768px) */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.2rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }

  .nav-links {
    display: none; /* simple clean mobile menu or inline */
  }

  .features-grid,
  .pricing-grid,
  .reviews-grid,
  .articles-preview-grid {
    grid-template-columns: 1fr;
  }

  .pricing-grid {
    overflow-x: visible;
  }

  .hero-cta-group {
    flex-direction: column;
  }

  .hero-cta-group .btn {
    width: 100%;
  }

  .section {
    padding: 40px 0;
  }
}