* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  color: #0f172a;
  background:
    radial-gradient(circle at 18% 0%, rgba(37, 99, 235, 0.12), transparent 34%),
    linear-gradient(180deg, #f8fbff 0%, #f8fafc 42%, #eef4ff 100%);
  line-height: 1.75;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px max(20px, calc((100vw - 1120px) / 2));
  background: rgba(255, 255, 255, 0.9);
  border-bottom: 1px solid #e2e8f0;
  backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 rgba(15, 23, 42, 0.03);
}

.brand,
.site-header nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  min-width: 0;
}

.brand img {
  width: 36px !important;
  height: 36px !important;
  flex: 0 0 36px;
  object-fit: contain;
  border-radius: 9px;
}

.brand span {
  overflow: hidden;
  color: #0f172a;
  font-weight: 700;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.site-header nav a {
  font-size: 14px;
  color: #475569;
}

.site-header .nav-cta {
  padding: 8px 16px;
  color: #fff;
  background: #2563eb;
  border-radius: 10px;
  font-weight: 700;
}

main {
  padding: 42px 20px 80px;
}

.article,
.guide-index,
.not-found {
  max-width: 1040px;
  margin: 0 auto;
}

.article {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: -2px;
  font-size: 14px;
  color: #64748b;
}

.breadcrumb a {
  color: #2563eb;
}

.article-hero {
  position: relative;
  overflow: hidden;
  padding: 48px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(239, 246, 255, 0.92)),
    #fff;
  border: 1px solid rgba(147, 197, 253, 0.45);
  border-radius: 22px;
  box-shadow: 0 24px 70px rgba(37, 99, 235, 0.1);
}

.article-hero::after {
  content: "";
  position: absolute;
  right: -90px;
  top: -120px;
  width: 260px;
  height: 260px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.18), transparent 68%);
  pointer-events: none;
}

.article-meta {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.article-meta span {
  padding: 5px 12px;
  color: #1d4ed8;
  background: #eff6ff;
  border-radius: 999px;
  font-size: 13px;
}

h1 {
  position: relative;
  z-index: 1;
  max-width: 820px;
  margin: 0 0 18px;
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.18;
  letter-spacing: -0.03em;
}

.article-hero p {
  position: relative;
  z-index: 1;
  max-width: 760px;
  margin: 0;
  color: #475569;
  font-size: 18px;
}

.hero-actions {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.primary-btn,
.secondary-btn,
.inline-cta a,
.quick-card a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 11px 20px;
  border-radius: 12px;
  font-weight: 700;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.primary-btn,
.inline-cta a,
.quick-card a {
  color: #fff;
  background: #2563eb;
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.22);
}

.secondary-btn {
  color: #1d4ed8;
  background: #eff6ff;
}

.primary-btn:hover,
.secondary-btn:hover,
.inline-cta a:hover,
.quick-card a:hover {
  transform: translateY(-1px);
}

.quick-card {
  display: grid;
  grid-template-columns: 140px 1fr auto;
  align-items: center;
  gap: 18px;
  margin: 0;
  padding: 20px;
  color: #fff;
  background: linear-gradient(135deg, #0f172a, #1e3a8a);
  border-radius: 16px;
  box-shadow: 0 18px 42px rgba(15, 23, 42, 0.16);
}

.quick-card span {
  color: #cbd5e1;
}

.quick-card a {
  white-space: nowrap;
}

.article-body,
.faq,
.related,
.bottom-cta {
  margin-top: 0;
  padding: 36px;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(226, 232, 240, 0.9);
  border-radius: 18px;
  box-shadow: 0 14px 40px rgba(15, 23, 42, 0.05);
}

.article-body section + section {
  margin-top: 34px;
  padding-top: 28px;
  border-top: 1px solid #e2e8f0;
}

h2 {
  margin: 0 0 14px;
  font-size: 26px;
  line-height: 1.35;
}

p {
  margin: 0 0 14px;
  color: #334155;
}

.inline-cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 22px;
  padding: 18px;
  background: #f8fafc;
  border: 1px solid #dbeafe;
  border-radius: 14px;
}

.inline-cta strong,
.inline-cta span {
  display: block;
}

.inline-cta span {
  color: #64748b;
}

.faq details {
  padding: 18px 0;
  border-top: 1px solid #e2e8f0;
}

.faq summary {
  cursor: pointer;
  font-weight: 700;
}

.faq p {
  margin-top: 10px;
}

.related-grid,
.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.related-grid a,
.guide-card {
  display: block;
  min-height: 100%;
  padding: 20px;
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 14px;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}

.related-grid a:hover,
.guide-card:hover {
  border-color: #93c5fd;
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(37, 99, 235, 0.1);
}

.related-grid span,
.guide-card span {
  display: inline-block;
  margin-bottom: 10px;
  color: #2563eb;
  font-size: 13px;
  font-weight: 700;
}

.related-grid strong,
.guide-card h2 {
  display: block;
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.45;
}

.related-grid em,
.guide-card em {
  display: block;
  color: #64748b;
  font-size: 13px;
  font-style: normal;
}

.bottom-cta {
  text-align: center;
  background: linear-gradient(135deg, #dbeafe, #fff);
}

.bottom-cta h2 {
  font-size: 32px;
}

.guide-grid {
  margin-top: 24px;
}

.guide-card p {
  min-height: 84px;
}

.not-found {
  padding: 80px 20px;
  text-align: center;
}

.eyebrow {
  color: #2563eb;
  font-weight: 700;
}

.site-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  padding: 28px 20px;
  color: #64748b;
  background: #fff;
  border-top: 1px solid #e2e8f0;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: #2563eb;
}

@media (max-width: 820px) {
  .site-header {
    padding: 12px 16px;
  }

  .site-header nav {
    gap: 10px;
  }

  .brand img {
    width: 32px !important;
    height: 32px !important;
    flex-basis: 32px;
  }

  .brand span {
    font-size: 14px;
  }

  .article-hero,
  .article-body,
  .faq,
  .related,
  .bottom-cta {
    padding: 24px;
    border-radius: 14px;
  }

  .quick-card,
  .inline-cta {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
  }

  .quick-card a,
  .inline-cta a {
    width: 100%;
  }

  .related-grid,
  .guide-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  body {
    line-height: 1.68;
  }

  .site-header {
    gap: 10px;
  }

  .site-header nav a:first-child {
    display: none;
  }

  .site-header .nav-cta {
    min-height: 36px;
    padding: 6px 12px;
    border-radius: 9px;
    font-size: 13px;
  }

  .brand {
    gap: 10px;
  }

  main {
    padding: 18px 12px 56px;
  }

  .breadcrumb {
    font-size: 12px;
  }

  .article-hero,
  .article-body,
  .faq,
  .related,
  .bottom-cta {
    padding: 20px;
  }

  h1 {
    font-size: 28px;
    letter-spacing: -0.02em;
  }

  h2 {
    font-size: 22px;
  }

  .article-hero p {
    font-size: 15px;
  }

  .article-meta span {
    font-size: 12px;
  }

  .hero-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .primary-btn,
  .secondary-btn {
    width: 100%;
  }

  .bottom-cta h2 {
    font-size: 24px;
  }
}