/* ==========================================================================
   良心云机场 (Liangxinyun Airport) - Brand Design System & CSS Stylesheet
   Style: Premium Light Tech / Educational & Science Clean Style
   ========================================================================== */

:root {
  --primary-color: #3b82f6;
  --primary-hover: #2563eb;
  --primary-light: #eff6ff;
  --primary-border: #bfdbfe;
  
  --bg-gradient: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
  --bg-main: #f3f6fb;
  --card-bg: #ffffff;
  
  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.06), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-hover: 0 20px 30px -10px rgba(59, 130, 246, 0.15);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base Styles */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
}
a:hover {
  color: var(--primary-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Typography Helpers */
.section-title {
  text-align: center;
  margin-bottom: 50px;
}
.section-title h2 {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}
.section-title p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  background: var(--primary-light);
  color: var(--primary-color);
  border: 1px solid var(--primary-border);
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
}
.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
  color: #fff;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}
.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}
.nav-link:hover, .nav-link.active {
  color: var(--primary-color);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  text-decoration: none;
}
.btn-primary {
  background: var(--primary-color);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35);
}
.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.45);
}
.btn-outline {
  background: #ffffff;
  color: var(--primary-color) !important;
  border: 1.5px solid var(--primary-color);
}
.btn-outline:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
}

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

/* Hero Section - Split Left/Right Layout */
.hero {
  padding: 80px 0 60px;
  background: radial-gradient(circle at top right, rgba(59, 130, 246, 0.08), transparent 50%),
              radial-gradient(circle at bottom left, rgba(59, 130, 246, 0.04), transparent 50%);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}
.hero-content h1 {
  font-size: 2.85rem;
  font-weight: 800;
  line-height: 1.25;
  color: var(--text-main);
  margin: 18px 0;
  letter-spacing: -0.02em;
}
.hero-content h1 span {
  background: linear-gradient(135deg, #2563eb, #3b82f6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-desc {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
  line-height: 1.7;
}
.hero-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 36px;
}
.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}
.hero-feature-item svg {
  color: #10b981;
  flex-shrink: 0;
}
.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-visual {
  position: relative;
}
.hero-card-preview {
  background: #ffffff;
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(226, 232, 240, 0.8);
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}
.hero-card-preview:hover {
  transform: translateY(-4px);
  box-shadow: 0 25px 40px -15px rgba(59, 130, 246, 0.2);
}
.hero-card-preview img {
  border-radius: var(--radius-md);
  width: 100%;
  object-fit: cover;
}

/* Floating Stats Badge */
.float-badge {
  position: absolute;
  bottom: -20px;
  left: -20px;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 14px;
}
.float-icon {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ecfdf5;
  color: #10b981;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}
.float-info h4 {
  font-size: 0.9rem;
  color: var(--text-muted);
}
.float-info p {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

/* Advantages Section */
.advantages {
  padding: 90px 0;
}
.adv-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}
.adv-card {
  background: var(--card-bg);
  padding: 36px 30px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}
.adv-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-border);
}
.adv-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 22px;
}
.adv-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}
.adv-card p {
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.65;
}

/* Pricing Section - Referencing exact user screenshot layout */
.pricing {
  padding: 90px 0;
  background: linear-gradient(180deg, #edf2f9 0%, #f8fafc 100%);
}
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
}

.price-card {
  background: #ffffff;
  border-radius: var(--radius-lg);
  padding: 40px 32px 36px;
  border: 1.5px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  position: relative;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  height: 100%;
}

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

/* Featured / Recommended Pricing Card */
.price-card.featured {
  border: 2px solid var(--primary-color);
  box-shadow: 0 12px 30px rgba(59, 130, 246, 0.18);
  transform: scale(1.03);
}
.price-card.featured:hover {
  transform: scale(1.05) translateY(-4px);
}

.featured-badge {
  position: absolute;
  top: -16px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary-color);
  color: #ffffff;
  padding: 4px 20px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  box-shadow: 0 4px 10px rgba(59, 130, 246, 0.4);
}

.price-header {
  text-align: center;
  padding-bottom: 24px;
  border-bottom: 1px solid #e2e8f0;
  margin-bottom: 28px;
}
.price-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 16px;
}
.price-amount {
  font-size: 2.8rem;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 4px;
}
.price-amount .currency {
  font-size: 1.4rem;
  font-weight: 700;
}
.price-amount .period {
  font-size: 1rem;
  color: var(--text-muted);
  font-weight: 500;
}

.price-features {
  list-style: none;
  margin-bottom: 36px;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.price-features li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.98rem;
  color: var(--text-secondary);
}
.price-features li svg {
  color: var(--primary-color);
  flex-shrink: 0;
  margin-top: 3px;
}

.price-btn {
  width: 100%;
  padding: 14px;
  font-size: 1rem;
  border-radius: var(--radius-full);
}

/* Audience Section */
.audience {
  padding: 90px 0;
}
.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.audience-card {
  background: var(--card-bg);
  padding: 32px 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: var(--transition);
}
.audience-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary-border);
  box-shadow: var(--shadow-md);
}
.audience-icon {
  width: 60px;
  height: 60px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}
.audience-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}
.audience-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Tutorial Interactive Hub Section */
.tutorials-section {
  padding: 90px 0;
  background: #ffffff;
}
.tutorial-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}
.tab-btn {
  padding: 12px 28px;
  border-radius: var(--radius-full);
  background: var(--bg-main);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}
.tab-btn:hover, .tab-btn.active {
  background: var(--primary-color);
  color: #ffffff;
  border-color: var(--primary-color);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.tab-content {
  display: none;
  background: var(--bg-main);
  border-radius: var(--radius-lg);
  padding: 40px;
  border: 1px solid var(--border-color);
}
.tab-content.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.step-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.step-item {
  display: flex;
  gap: 20px;
  background: #ffffff;
  padding: 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}
.step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--primary-color);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.step-details h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-main);
}
.step-details p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.code-box {
  background: #0f172a;
  color: #f8fafc;
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  font-family: "Fira Code", Monaco, Consolas, monospace;
  font-size: 0.9rem;
  margin-top: 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  overflow-x: auto;
}
.code-box button {
  background: rgba(255, 255, 255, 0.15);
  border: none;
  color: #fff;
  padding: 6px 12px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.8rem;
  transition: var(--transition);
}
.code-box button:hover {
  background: var(--primary-color);
}

/* User Reviews Section */
.reviews {
  padding: 90px 0;
}
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.review-card {
  background: var(--card-bg);
  padding: 32px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}
.review-stars {
  color: #f59e0b;
  margin-bottom: 16px;
  display: flex;
  gap: 4px;
}
.review-text {
  font-size: 0.98rem;
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.7;
}
.review-author {
  display: flex;
  align-items: center;
  gap: 14px;
}
.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}
.author-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
}
.author-info p {
  font-size: 0.825rem;
  color: var(--text-muted);
}

/* FAQ Accordion Section */
.faq-section {
  padding: 90px 0;
  background: #ffffff;
}
.faq-container {
  max-width: 900px;
  margin: 0 auto;
}
.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  overflow: hidden;
  background: var(--bg-main);
  transition: var(--transition);
}
.faq-question {
  width: 100%;
  padding: 22px 28px;
  background: none;
  border: none;
  text-align: left;
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}
.faq-question svg {
  transition: transform 0.3s ease;
  color: var(--primary-color);
}
.faq-item.active .faq-question svg {
  transform: rotate(180deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease-out;
  background: #ffffff;
}
.faq-answer-inner {
  padding: 0 28px 24px;
  color: var(--text-secondary);
  font-size: 0.98rem;
  line-height: 1.7;
  border-top: 1px dashed var(--border-color);
  padding-top: 18px;
}

/* Article Hub Section */
.articles-section {
  padding: 90px 0;
}
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}
.article-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}
.article-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-border);
}
.article-body {
  padding: 28px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}
.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}
.article-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
  line-height: 1.45;
}
.article-excerpt {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.6;
  flex-grow: 1;
}
.article-link {
  font-size: 0.9rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* SEO Article Template Layout */
.article-page {
  padding: 60px 0 90px;
}
.article-wrapper {
  max-width: 920px;
  margin: 0 auto;
  background: #ffffff;
  padding: 48px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}
.article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 24px;
  margin-bottom: 32px;
}
.article-header h1 {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
  color: var(--text-main);
}
.article-content {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-secondary);
}
.article-content h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 40px 0 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary-light);
}
.article-content h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 28px 0 14px;
}
.article-content p {
  margin-bottom: 20px;
}
.article-content ul, .article-content ol {
  margin: 0 0 24px 24px;
}
.article-content li {
  margin-bottom: 8px;
}
.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.95rem;
}
.article-content th, .article-content td {
  padding: 14px 18px;
  border: 1px solid var(--border-color);
  text-align: left;
}
.article-content th {
  background: var(--bg-main);
  font-weight: 700;
  color: var(--text-main);
}
.callout-box {
  background: var(--primary-light);
  border-left: 4px solid var(--primary-color);
  padding: 20px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 28px 0;
}
.callout-box h4 {
  color: var(--primary-hover);
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.cta-banner-inline {
  background: linear-gradient(135deg, #2563eb, #1d4ed8);
  color: #ffffff;
  padding: 36px;
  border-radius: var(--radius-lg);
  margin: 40px 0;
  text-align: center;
  box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}
.cta-banner-inline h3 {
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: #ffffff;
}
.cta-banner-inline p {
  font-size: 1.05rem;
  margin-bottom: 24px;
  opacity: 0.9;
}
.cta-banner-inline .btn {
  background: #ffffff;
  color: var(--primary-hover) !important;
  font-size: 1.05rem;
  padding: 12px 32px;
}
.cta-banner-inline .btn:hover {
  background: var(--primary-light);
}

/* Footer Section */
.footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 80px 0 40px;
  font-size: 0.92rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 60px;
}
.footer-brand .logo {
  color: #ffffff;
  margin-bottom: 18px;
}
.footer-desc {
  line-height: 1.7;
  max-width: 340px;
  margin-bottom: 24px;
}
.footer-col h4 {
  color: #ffffff;
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 20px;
}
.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.footer-links a {
  color: #94a3b8;
}
.footer-links a:hover {
  color: #ffffff;
}
.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid #334155;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .adv-grid, .pricing-grid, .reviews-grid, .articles-grid { grid-template-columns: repeat(2, 1fr); }
  .audience-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .price-card.featured { transform: scale(1); }
}

@media (max-width: 768px) {
  .nav-menu { display: none; }
  .mobile-toggle { display: block; }
  .adv-grid, .pricing-grid, .reviews-grid, .articles-grid, .audience-grid { grid-template-columns: 1fr; }
  .hero-content h1 { font-size: 2.1rem; }
  .hero-features { grid-template-columns: 1fr; }
  .article-wrapper { padding: 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
}