:root {
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-dark: #1e40af;
  --primary-light: #eff6ff;
  --accent: #f59e0b;
  --accent-hover: #d97706;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --bg-alt: #f1f5f9;
  --border: #e2e8f0;
  --border-focus: #3b82f6;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --container-max: 1200px;
}

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

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.6;
  color: var(--text-main);
  background-color: var(--bg-body);
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

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

/* Accessibility Skip Link */
.skip-link {
  position: absolute;
  top: -60px;
  left: 20px;
  background: var(--primary);
  color: #ffffff;
  padding: 12px 20px;
  z-index: 9999;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 600;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 10px;
  outline: 3px solid var(--accent);
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* Navigation & Header */
.site-header {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.brand-logo-img {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: block;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
  flex-shrink: 0;
}

.brand-badge {
  background: linear-gradient(135deg, var(--primary), #3b82f6);
  color: #ffffff;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 700;
}

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

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 8px 4px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease;
}

.nav-link:hover, .nav-link:focus {
  color: var(--primary);
  outline: none;
}

.nav-link.active {
  color: var(--primary);
}

.nav-link-special {
  color: var(--primary);
  background: var(--primary-light);
  padding: 6px 14px;
  border-radius: var(--radius-full);
}

/* Buttons & CTA */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 10px 24px;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  text-align: center;
  line-height: 1.2;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

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

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

.btn-accent {
  background-color: var(--accent);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(245, 158, 11, 0.25);
}

.btn-accent:hover {
  background-color: var(--accent-hover);
  box-shadow: 0 6px 16px rgba(245, 158, 11, 0.35);
  transform: translateY(-1px);
}

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

.btn-outline:hover {
  background-color: var(--bg-alt);
  border-color: var(--text-muted);
}

.btn-sm {
  min-height: 38px;
  padding: 8px 18px;
  font-size: 0.92rem;
  white-space: nowrap;
}

.btn-lg {
  min-height: 52px;
  padding: 14px 32px;
  font-size: 1.1rem;
}

/* Headings & Anchors */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 800;
  line-height: 1.25;
  scroll-margin-top: 90px;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 48px auto;
}

.section-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
  font-size: 0.85rem;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-title {
  font-size: 2.25rem;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
}

/* Hero Section with Crane & Yellow Crane Tower Scenic Background */
.hero-section {
  position: relative;
  padding: 110px 0 95px 0;
  background-color: #0f172a;
  background-image: url('hero-crane.jpg');
  background-size: cover;
  background-position: center 38%;
  background-repeat: no-repeat;
  text-align: center;
  overflow: hidden;
  color: #f8fafc;
  min-height: 620px;
  display: flex;
  align-items: center;
}

/* Cinematic Gradient Overlay to Ensure Crystal-Clear Text Readability */
.hero-bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(15, 23, 42, 0.74) 0%,
    rgba(15, 23, 42, 0.50) 42%,
    rgba(15, 23, 42, 0.68) 75%,
    rgba(15, 23, 42, 0.94) 100%
  );
  pointer-events: none;
  z-index: 1;
}

/* Hero Content Typography & Styling */
.hero-container {
  position: relative;
  z-index: 2;
  width: 100%;
}

.hero-content {
  max-width: 860px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(15, 23, 42, 0.75);
  border: 1px solid rgba(56, 189, 248, 0.45);
  color: #38bdf8;
  padding: 6px 18px;
  border-radius: var(--radius-full);
  font-size: 0.92rem;
  font-weight: 600;
  margin-bottom: 24px;
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

.hero-title {
  margin-bottom: 22px;
  letter-spacing: -0.03em;
  line-height: 1.25;
  color: #ffffff;
}

.hero-title-primary {
  display: block;
  font-size: 3.6rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin-bottom: 10px;
  color: #ffffff;
  text-shadow: 0 3px 16px rgba(0, 0, 0, 0.9), 0 0 40px rgba(56, 189, 248, 0.35);
}

.hero-title-sub {
  display: block;
  font-size: 2.2rem;
  font-weight: 700;
  color: #f1f5f9;
  letter-spacing: -0.01em;
  line-height: 1.35;
  text-shadow: 0 2px 14px rgba(0, 0, 0, 0.9);
}

.hero-subtitle {
  font-size: 1.35rem;
  color: #93c5fd;
  font-weight: 600;
  margin-bottom: 18px;
  line-height: 1.45;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.8);
}

.hero-desc {
  font-size: 1.1rem;
  color: #e2e8f0;
  margin-bottom: 38px;
  line-height: 1.75;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.8);
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.hero-actions .btn-outline {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.35);
  background: rgba(15, 23, 42, 0.65);
  backdrop-filter: blur(8px);
}

.hero-actions .btn-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #ffffff;
}

.hero-guarantee {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  color: #cbd5e1;
  font-size: 0.92rem;
  font-weight: 600;
  flex-wrap: wrap;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.8);
}

.hero-guarantee span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(15, 23, 42, 0.5);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(6px);
}

.hero-guarantee svg {
  color: #38bdf8;
}

/* Features Grid */
.features-section {
  padding: 80px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  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);
  border-color: #cbd5e1;
}

.feature-icon-wrapper {
  width: 56px;
  height: 56px;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: 20px;
}

.feature-title {
  font-size: 1.35rem;
  margin-bottom: 12px;
}

.feature-desc {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.6;
}

/* Streaming & AI Section */
.media-section {
  padding: 80px 0;
  background: var(--bg-alt);
}

.media-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.media-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  box-shadow: var(--shadow-sm);
}

.media-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.media-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  background: var(--primary-light);
  color: var(--primary);
}

.media-card-title {
  font-size: 1.4rem;
}

.media-tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 20px 0 24px 0;
}

.media-tag {
  background: var(--bg-body);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.media-card-desc {
  color: var(--text-muted);
  line-height: 1.7;
}

/* Pricing Section */
.pricing-section {
  padding: 80px 0;
}

.pricing-table-container {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  box-shadow: var(--shadow-sm);
  margin-bottom: 32px;
}

.pricing-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.pricing-table caption {
  padding: 20px 24px;
  font-size: 1.15rem;
  font-weight: 700;
  text-align: left;
  border-bottom: 1px solid var(--border);
  color: var(--text-main);
}

.pricing-table th,
.pricing-table td {
  padding: 18px 20px;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}

.pricing-table th:last-child,
.pricing-table td:last-child {
  white-space: nowrap;
  min-width: 125px;
  text-align: center;
}

.pricing-table th {
  background: var(--bg-alt);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-muted);
}

.pricing-plan-name {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  display: block;
}

.pricing-price {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--primary);
}

.pricing-period {
  font-size: 0.9rem;
  color: var(--text-light);
  font-weight: 500;
}

.pricing-badge {
  display: inline-block;
  background: var(--accent);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  margin-left: 8px;
  vertical-align: middle;
}

.pricing-table tr:hover td {
  background-color: #fafbfc;
}

/* Reviews / Testimonials Section */
.reviews-section {
  padding: 80px 0;
  background: var(--bg-alt);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  color: #f59e0b;
  font-size: 1.1rem;
  margin-bottom: 14px;
}

.review-text {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 20px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
}

.review-author-name {
  font-weight: 700;
  font-size: 0.95rem;
}

.review-author-role {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* FAQ Section */
.faq-section {
  padding: 80px 0;
}

.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

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

.faq-item summary::after {
  content: "▾";
  font-size: 1.25rem;
  color: var(--text-light);
  transition: transform 0.2s ease;
}

.faq-item[open] summary::after {
  transform: rotate(180deg);
  color: var(--primary);
}

.faq-answer {
  padding: 0 24px 20px 24px;
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.7;
  border-top: 1px solid var(--bg-alt);
}

.faq-answer a {
  color: var(--primary);
  text-decoration: underline;
  font-weight: 600;
}

/* CTA Banner */
.cta-banner {
  padding: 60px 0;
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: #ffffff;
  text-align: center;
}

.cta-banner h2 {
  color: #ffffff;
  font-size: 2.25rem;
  margin-bottom: 16px;
}

.cta-banner p {
  color: #bfdbfe;
  font-size: 1.15rem;
  max-width: 680px;
  margin: 0 auto 32px auto;
}

/* Footer - strictly 4 links opening new pages */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 48px 0 32px 0;
  margin-top: auto;
  border-top: 1px solid #1e293b;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  list-style: none;
  margin-bottom: 28px;
  flex-wrap: wrap;
}

.footer-link {
  color: #e2e8f0;
  text-decoration: none;
  font-size: 1.05rem;
  font-weight: 600;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease;
}

.footer-link:hover, .footer-link:focus {
  color: #60a5fa;
  outline: 2px solid #60a5fa;
}

.footer-bottom {
  text-align: center;
  font-size: 0.9rem;
  color: #64748b;
  border-top: 1px solid #1e293b;
  padding-top: 24px;
}

/* Article & Content Pages */
.article-header {
  padding: 60px 0 36px 0;
  background: #ffffff;
  border-bottom: 1px solid var(--border);
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 16px;
}

.breadcrumbs a {
  color: var(--primary);
  text-decoration: none;
}

.article-title {
  font-size: 2.4rem;
  margin-bottom: 16px;
  line-height: 1.3;
}

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

.article-content {
  max-width: 820px;
  margin: 40px auto 60px auto;
  padding: 0 20px;
}

.article-body {
  font-size: 1.08rem;
  line-height: 1.85;
  color: #1e293b;
}

.article-body h2 {
  font-size: 1.65rem;
  margin: 36px 0 16px 0;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--bg-alt);
}

.article-body h3 {
  font-size: 1.3rem;
  margin: 24px 0 12px 0;
}

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

.article-body ul, .article-body ol {
  margin: 16px 0 24px 24px;
}

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

.article-body blockquote {
  border-left: 4px solid var(--primary);
  background: var(--primary-light);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 24px 0;
  color: var(--text-main);
  font-weight: 500;
}

.article-body a {
  color: var(--primary);
  text-decoration: underline;
  font-weight: 600;
}

.article-cta-box {
  background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
  color: #ffffff;
  border-radius: var(--radius-lg);
  padding: 38px 30px;
  margin: 40px 0;
  text-align: center;
  box-shadow: 0 12px 28px -6px rgba(37, 99, 235, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.article-cta-box h3 {
  margin-top: 0;
  margin-bottom: 12px;
  color: #ffffff;
  font-size: 1.55rem;
  font-weight: 800;
}

.article-cta-box p {
  color: #dbeafe;
  font-size: 1.05rem;
  margin-bottom: 24px;
}

.article-cta-box a.btn {
  font-size: 1.15rem;
  min-height: 52px;
  padding: 14px 38px;
  background-color: var(--accent);
  color: #ffffff;
  border: none;
  box-shadow: 0 6px 22px rgba(245, 158, 11, 0.5);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.25s ease;
}

.article-cta-box a.btn:hover {
  background-color: var(--accent-hover);
  box-shadow: 0 8px 28px rgba(245, 158, 11, 0.65);
  transform: translateY(-2px);
}

/* Knowledge Hub Grid */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin: 40px 0 60px 0;
}

.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.knowledge-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: #cbd5e1;
}

.knowledge-card-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
}

.knowledge-card-title {
  font-size: 1.25rem;
  margin-bottom: 12px;
  line-height: 1.4;
}

.knowledge-card-title a {
  color: var(--text-main);
  text-decoration: none;
}

.knowledge-card-title a:hover {
  color: var(--primary);
}

.knowledge-card-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

.knowledge-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border);
  padding-top: 14px;
  font-size: 0.85rem;
  color: var(--text-light);
}

/* Responsive Media Queries */
@media (max-width: 1024px) {
  .features-grid, .reviews-grid, .knowledge-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .section-title {
    font-size: 1.85rem;
  }
  .hero-title-primary {
    font-size: 2.6rem;
  }
  .hero-title-sub {
    font-size: 1.55rem;
  }
  .hero-subtitle {
    font-size: 1.15rem;
  }
  .features-grid, .media-grid, .reviews-grid, .knowledge-grid {
    grid-template-columns: 1fr;
  }
  .nav-container {
    height: auto;
    padding: 14px 0;
    flex-direction: column;
    gap: 12px;
  }
  .nav-menu {
    gap: 14px;
    flex-wrap: wrap;
    justify-content: center;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .hero-actions .btn {
    width: 100%;
  }
  .pricing-table th, .pricing-table td {
    padding: 14px 12px;
  }
  .footer-nav {
    flex-direction: column;
    gap: 12px;
  }
}

@media (max-width: 390px) {
  .hero-title-primary {
    font-size: 2.15rem;
  }
  .hero-title-sub {
    font-size: 1.25rem;
  }
  .container {
    padding-left: 14px;
    padding-right: 14px;
  }
}