/* ==========================================================================
   飞鸟机场 (feiniaojichang.lat) - 核心样式文件
   ========================================================================== */

:root {
  --primary-color: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --secondary-color: #0f172a;
  --accent-color: #f59e0b;
  --accent-hover: #d97706;
  --text-main: #334155;
  --text-dark: #0f172a;
  --text-muted: #64748b;
  --bg-light: #f8fafc;
  --bg-white: #ffffff;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius-md: 12px;
  --radius-lg: 16px;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
  color: var(--text-main);
  background-color: var(--bg-light);
  line-height: 1.6;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-hover);
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.site-header {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--secondary-color);
}

.logo span {
  color: var(--primary-color);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-menu a {
  color: var(--text-main);
  font-weight: 500;
  font-size: 0.95rem;
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
  cursor: pointer;
  border: none;
  text-align: center;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #fff !important;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
}

.btn-outline {
  background-color: transparent;
  color: var(--primary-color);
  border: 1px solid var(--primary-color);
}

.btn-outline:hover {
  background-color: var(--primary-light);
}

.btn-lg {
  padding: 0.9rem 2rem;
  font-size: 1.1rem;
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--secondary-color);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
  padding: 5rem 0 4rem;
  background: linear-gradient(135deg, #eff6ff 0%, #ffffff 50%, #f0f9ff 100%);
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.35rem 1rem;
  background-color: #dbeafe;
  color: var(--primary-color);
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 1.2rem;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--secondary-color);
  line-height: 1.25;
  margin-bottom: 1.2rem;
}

.hero-title highlight {
  color: var(--primary-color);
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 800px;
  margin: 0 auto 2rem;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.hero-features-list {
  display: flex;
  justify-content: center;
  gap: 2rem;
  list-style: none;
  color: var(--text-main);
  font-size: 0.95rem;
  font-weight: 500;
  flex-wrap: wrap;
}

.hero-features-list li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.hero-features-list li::before {
  content: "✓";
  color: #10b981;
  font-weight: bold;
}

/* ==========================================================================
   Section Layouts
   ========================================================================== */
.section {
  padding: 4.5rem 0;
}

.section-alt {
  background-color: var(--bg-white);
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 3rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--secondary-color);
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Grid Layouts */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

/* Feature Cards */
.feature-card {
  background: var(--bg-white);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 50px;
  height: 50px;
  background-color: var(--primary-light);
  color: var(--primary-color);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--secondary-color);
  margin-bottom: 0.5rem;
}

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

/* ==========================================================================
   Pricing Cards
   ========================================================================== */
.pricing-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.pricing-card.popular {
  border: 2px solid var(--primary-color);
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--primary-color);
  color: white;
  padding: 0.25rem 1rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.pricing-header h3 {
  font-size: 1.35rem;
  color: var(--secondary-color);
  margin-bottom: 0.5rem;
}

.pricing-header p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--secondary-color);
  margin-bottom: 1.5rem;
}

.pricing-price span {
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--text-muted);
}

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

.pricing-features li {
  padding: 0.5rem 0;
  color: var(--text-main);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pricing-features li::before {
  content: "✓";
  color: var(--primary-color);
  font-weight: bold;
}

/* ==========================================================================
   Tutorial / Audience Cards
   ========================================================================== */
.card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.card-body {
  padding: 1.5rem;
}

.card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--secondary-color);
}

.card-text {
  font-size: 0.925rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-list {
  max-width: 850px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
}

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

.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--primary-color);
  transition: transform 0.2s ease;
}

.faq-item.active .faq-question::after {
  content: "−";
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  background-color: var(--bg-light);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 1.25rem 1.5rem;
  border-top: 1px solid var(--border-color);
}

.faq-answer p {
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ==========================================================================
   Article Detail & Content Page Styling
   ========================================================================== */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  list-style: none;
  flex-wrap: wrap;
}

.breadcrumb li+li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--border-color);
}

.article-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.article-title {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--secondary-color);
  line-height: 1.3;
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  gap: 1.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.article-body {
  background: var(--bg-white);
  padding: 2.5rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  font-size: 1.05rem;
  line-height: 1.8;
  color: var(--text-main);
}

.article-body h2 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--secondary-color);
  margin: 2rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--primary-light);
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--secondary-color);
  margin: 1.5rem 0 0.75rem;
}

.article-body p {
  margin-bottom: 1.25rem;
}

.article-body ul, .article-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
}

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

.article-body blockquote {
  border-left: 4px solid var(--primary-color);
  background-color: var(--primary-light);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: normal;
  color: var(--secondary-color);
}

.article-cta-box {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
  color: white;
  padding: 2rem;
  border-radius: var(--radius-lg);
  text-align: center;
  margin: 2.5rem 0;
}

.article-cta-box h3 {
  color: white;
  font-size: 1.4rem;
  margin-bottom: 0.75rem;
}

.article-cta-box p {
  color: #dbeafe;
  margin-bottom: 1.25rem;
}

.article-cta-box .btn {
  background-color: var(--accent-color);
  color: #0f172a !important;
}

.article-cta-box .btn:hover {
  background-color: var(--accent-hover);
}

.related-posts {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.related-posts h3 {
  font-size: 1.35rem;
  color: var(--secondary-color);
  margin-bottom: 1.25rem;
}

/* Table styling for comparison & tutorials */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.data-table th, .data-table td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border-color);
  text-align: left;
}

.data-table th {
  background-color: var(--primary-light);
  color: var(--secondary-color);
  font-weight: 600;
}

.data-table tr:nth-child(even) {
  background-color: var(--bg-light);
}

/* ==========================================================================
   Footer Section
   ========================================================================== */
.site-footer {
  background-color: var(--secondary-color);
  color: #94a3b8;
  padding: 4rem 0 2rem;
  margin-top: auto;
  border-top: 1px solid #1e293b;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: 2.5rem;
  margin-bottom: 3rem;
}

.footer-about h3 {
  color: white;
  font-size: 1.3rem;
  margin-bottom: 1rem;
}

.footer-about p {
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.footer-column h4 {
  color: white;
  font-size: 1rem;
  margin-bottom: 1.2rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.footer-links a {
  color: #94a3b8;
  font-size: 0.875rem;
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid #1e293b;
  text-align: center;
  font-size: 0.85rem;
}

.footer-bottom p {
  margin-bottom: 0.5rem;
}

/* ==========================================================================
   Responsive Design (Media Queries)
   ========================================================================== */
@media (max-width: 992px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2rem;
  }
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
  .pricing-card.popular {
    transform: none;
  }
  .mobile-toggle {
    display: block;
  }
  .nav-menu {
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background-color: white;
    flex-direction: column;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    display: none;
    border-bottom: 1px solid var(--border-color);
  }
  .nav-menu.active {
    display: flex;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .article-body {
    padding: 1.5rem;
  }
}