:root {
  --primary: #1e40af;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --accent: #0284c7;
  --accent-hover: #0369a1;
  --accent-light: #f0f9ff;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;
  --bg-main: #ffffff;
  --bg-subtle: #f8fafc;
  --bg-card: #ffffff;
  --border: #e2e8f0;
  --border-focus: #3b82f6;
  --success: #15803d;
  --success-bg: #f0fdf4;
  --warning: #b45309;
  --max-width: 1200px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08);
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --header-height: 72px;
}

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

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

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

/* Skip link for accessibility */
.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  background: var(--primary);
  color: #ffffff;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  z-index: 9999;
  text-decoration: none;
  font-weight: 600;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 16px;
}

/* Base Headings & Links */
h1, h2, h3, h4 {
  color: var(--text-main);
  line-height: 1.3;
  font-weight: 700;
  scroll-margin-top: calc(var(--header-height) + 16px);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.85rem; margin-bottom: 0.75rem; }
h3 { font-size: 1.35rem; margin-bottom: 0.5rem; }
h4 { font-size: 1.1rem; }

p {
  color: var(--text-muted);
  margin-bottom: 1rem;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover {
  color: var(--primary-hover);
  text-decoration: underline;
}
a:focus-visible, button:focus-visible, summary:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 3px;
}

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

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--primary);
  text-decoration: none;
}
.site-logo:hover {
  text-decoration: none;
}
.site-logo svg {
  width: 32px;
  height: 32px;
  fill: var(--primary);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.98rem;
  padding: 8px 4px;
  transition: color 0.15s ease;
}
.nav-link:hover, .nav-link.active {
  color: var(--primary);
  text-decoration: none;
}

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

/* Buttons & CTA */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 10px 22px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}
.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}
.btn-primary:hover {
  background-color: var(--primary-hover);
  color: #ffffff;
  box-shadow: 0 4px 10px rgba(30, 64, 175, 0.25);
}

.btn-secondary {
  background-color: var(--bg-subtle);
  color: var(--text-main);
  border-color: var(--border);
}
.btn-secondary:hover {
  background-color: #e2e8f0;
  color: var(--text-main);
}

.btn-lg {
  padding: 14px 30px;
  font-size: 1.1rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

/* Hero Section */
.hero-section {
  position: relative;
  padding: 96px 0 84px;
  min-height: 640px;
  background-color: #0c1a2e;
  background-image: 
    linear-gradient(180deg, rgba(15, 23, 42, 0.45) 0%, rgba(15, 23, 42, 0.18) 50%, rgba(15, 23, 42, 0.5) 100%),
    url('hero-bg.png');
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center 25%;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  align-items: center;
  text-align: center;
}

.hero-container {
  position: relative;
  z-index: 2;
  width: 100%;
}

.hero-card {
  background: none;
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  border: none;
  box-shadow: none;
  padding: 0;
  max-width: 860px;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(15, 23, 42, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: #38bdf8;
  padding: 6px 18px;
  border-radius: 9999px;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 22px;
  border: 1px solid rgba(56, 189, 248, 0.4);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
}

.hero-title {
  font-size: 2.75rem;
  max-width: 880px;
  margin: 0 auto 16px;
  letter-spacing: -0.02em;
  color: #ffffff;
  text-shadow: 0 2px 14px rgba(0, 0, 0, 0.85), 0 1px 3px rgba(0, 0, 0, 0.9);
}

.hero-subtitle {
  font-size: 1.3rem;
  color: #7dd3fc;
  font-weight: 700;
  margin-bottom: 18px;
  line-height: 1.5;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.85);
}

.hero-desc {
  font-size: 1.08rem;
  max-width: 780px;
  margin: 0 auto 30px;
  color: #f1f5f9;
  line-height: 1.8;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.85);
}

.hero-cta-group {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}

.hero-section .btn-secondary {
  background-color: rgba(255, 255, 255, 0.92);
  color: #0f172a;
  border-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(4px);
}
.hero-section .btn-secondary:hover {
  background-color: #ffffff;
  color: #0f172a;
}

.trust-badges {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 28px;
  flex-wrap: wrap;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.25);
  max-width: 800px;
  margin: 0 auto;
}

.trust-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.95rem;
  color: #f8fafc;
  font-weight: 600;
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.85);
}
.trust-item svg {
  width: 18px;
  height: 18px;
  color: #4ade80;
  filter: drop-shadow(0 1px 3px rgba(0, 0, 0, 0.7));
}

/* Sections Common */
.section {
  padding: 64px 0;
}
.section-subtle {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 44px;
}
.section-title {
  margin-bottom: 10px;
}
.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
}

/* Feature Cards */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  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-wrap {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background-color: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}
.feature-icon-wrap svg {
  width: 28px;
  height: 28px;
}

.feature-title {
  font-size: 1.25rem;
  margin-bottom: 10px;
}
.feature-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 0;
}

/* Streaming & AI Support Cards */
.support-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  flex-direction: column;
}

.support-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}
.support-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background-color: var(--accent-light);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.support-icon svg {
  width: 26px;
  height: 26px;
}

.badge-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}
.badge-tag {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
}

/* Pricing Table */
.pricing-wrapper {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin-bottom: 20px;
}

.pricing-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
}

.pricing-table caption {
  caption-side: top;
  text-align: left;
  font-size: 0.9rem;
  color: var(--text-light);
  padding-bottom: 12px;
}

.pricing-table th, .pricing-table td {
  padding: 18px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 0.95rem;
}

.pricing-table th {
  background: var(--bg-subtle);
  font-weight: 600;
  color: var(--text-main);
}

.pricing-table tbody tr:hover {
  background-color: var(--primary-light);
}

.pricing-table .plan-name {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-main);
}

.pricing-table .plan-price {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--primary);
}
.pricing-table .plan-price small {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-table .badge-hot {
  background: #fef2f2;
  color: #dc2626;
  border: 1px solid #fecaca;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 9999px;
  font-weight: 600;
  margin-left: 6px;
}

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

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px 20px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.price-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}
.price-card.featured {
  border: 2px solid var(--primary);
  background: linear-gradient(180deg, #ffffff 0%, #f0f7ff 100%);
}
.price-card.featured::before {
  content: "最受欢迎";
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 3px 12px;
  border-radius: 9999px;
}

.price-card-title {
  font-size: 1.15rem;
  margin-bottom: 8px;
}
.price-card-cost {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 16px;
}
.price-card-cost span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-muted);
}

.price-card-specs {
  list-style: none;
  margin-bottom: 24px;
  flex-grow: 1;
}
.price-card-specs li {
  font-size: 0.9rem;
  color: var(--text-muted);
  padding: 6px 0;
  border-bottom: 1px dashed var(--border);
  display: flex;
  align-items: center;
  gap: 8px;
}
.price-card-specs li svg {
  width: 15px;
  height: 15px;
  color: var(--success);
  flex-shrink: 0;
}

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

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
}

.review-stars {
  color: #f59e0b;
  font-size: 1rem;
  margin-bottom: 10px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 16px;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 10px;
  border-top: 1px solid var(--border);
  padding-top: 12px;
}

.author-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.author-info h4 {
  font-size: 0.9rem;
  font-weight: 600;
}
.author-info p {
  font-size: 0.78rem;
  color: var(--text-light);
  margin-bottom: 0;
}

/* FAQ Section (Default Open details/summary) */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  transition: border-color 0.15s ease;
}
.faq-item[open] {
  border-color: #cbd5e1;
  background-color: var(--bg-card);
  box-shadow: var(--shadow-sm);
}

.faq-summary {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 0;
}
.faq-summary::-webkit-details-marker {
  display: none;
}
.faq-summary::after {
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  color: var(--primary);
  line-height: 1;
  transition: transform 0.2s ease;
}
.faq-item[open] .faq-summary::after {
  content: "−";
}

.faq-content {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
}
.faq-content p:last-child {
  margin-bottom: 0;
}

/* Footer Section */
.site-footer {
  margin-top: auto;
  background: #0f172a;
  color: #94a3b8;
  border-top: 1px solid #1e293b;
  padding: 48px 0 28px;
}

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

.footer-nav-item a {
  color: #cbd5e1;
  font-size: 1.05rem;
  font-weight: 500;
  text-decoration: none;
  padding: 6px 10px;
  transition: color 0.15s ease;
}
.footer-nav-item a:hover {
  color: #38bdf8;
  text-decoration: underline;
}

.footer-bottom {
  text-align: center;
  font-size: 0.88rem;
  color: #64748b;
  border-top: 1px solid #1e293b;
  padding-top: 24px;
}

/* Article & Content Pages */
.article-header {
  padding: 48px 0 32px;
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border);
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-light);
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.breadcrumb a {
  color: var(--text-muted);
}
.breadcrumb a:hover {
  color: var(--primary);
}

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

.article-content {
  font-size: 1.05rem;
  line-height: 1.8;
  color: #334155;
}
.article-content h2 {
  margin-top: 36px;
  margin-bottom: 14px;
  border-bottom: 2px solid var(--primary-light);
  padding-bottom: 8px;
}
.article-content h3 {
  margin-top: 24px;
  margin-bottom: 10px;
}
.article-content ul, .article-content ol {
  margin-bottom: 20px;
  padding-left: 24px;
}
.article-content li {
  margin-bottom: 8px;
}
.article-content strong {
  color: var(--text-main);
}
.article-content blockquote {
  background: var(--bg-subtle);
  border-left: 4px solid var(--primary);
  padding: 14px 18px;
  margin: 20px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-muted);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.88rem;
  color: var(--text-light);
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.article-cta-box {
  background: linear-gradient(135deg, #eff6ff 0%, #e0f2fe 100%);
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
  margin: 40px 0;
}
.article-cta-box h3 {
  color: var(--primary);
  margin-bottom: 10px;
}

.related-articles {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 16px;
}
.related-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px;
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: all 0.15s ease;
}
.related-card:hover {
  background: #ffffff;
  border-color: var(--primary);
  transform: translateY(-2px);
  text-decoration: none;
}
.related-card h4 {
  font-size: 0.95rem;
  margin-bottom: 6px;
  color: var(--text-main);
}
.related-card span {
  font-size: 0.8rem;
  color: var(--primary);
  margin-top: auto;
}

/* Knowledge Hub Grid */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 32px;
}

.knowledge-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 26px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.knowledge-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary);
}

.knowledge-tag {
  align-self: flex-start;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 9999px;
  margin-bottom: 14px;
}
.knowledge-card h3 {
  font-size: 1.15rem;
  line-height: 1.4;
  margin-bottom: 10px;
}
.knowledge-card h3 a {
  color: var(--text-main);
  text-decoration: none;
}
.knowledge-card h3 a:hover {
  color: var(--primary);
}
.knowledge-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 18px;
}
.knowledge-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: var(--text-light);
  border-top: 1px solid var(--border);
  padding-top: 12px;
}

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

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }
  .hero-section {
    padding: 60px 0 52px;
    min-height: 540px;
    background-position: 72% 12%;
  }
  .hero-card {
    padding: 0;
    background: none;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-radius: 0;
    box-shadow: none;
    border: none;
  }
  .hero-title {
    font-size: 1.95rem;
  }
  .hero-subtitle {
    font-size: 1.15rem;
  }
  .hero-desc {
    font-size: 0.98rem;
    line-height: 1.7;
    margin-bottom: 26px;
  }
  .site-nav {
    display: none; /* Mobile nav minimal */
  }
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .support-grid {
    grid-template-columns: 1fr;
  }
  .pricing-cards-grid {
    grid-template-columns: 1fr;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  .knowledge-grid {
    grid-template-columns: 1fr;
  }
  .related-grid {
    grid-template-columns: 1fr;
  }
  .footer-nav-list {
    flex-direction: column;
    gap: 16px;
  }
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
  }
  .hero-cta-group .btn {
    width: 100%;
  }
  .trust-badges {
    flex-direction: column;
    gap: 12px;
  }
}