:root {
  --bg: #f6f8fc;
  --bg-soft: #eef3fb;
  --panel: #ffffff;
  --panel-2: #f9fbff;
  --panel-3: #edf4ff;
  --text: #1b2a41;
  --text-strong: #0f172a;
  --muted: #5f6f86;
  --muted-2: #7b8aa1;
  --line: rgba(15, 23, 42, 0.10);
  --line-soft: rgba(15, 23, 42, 0.06);
  --primary: #1677ff;
  --primary-2: #4d9cff;
  --accent: #3f6fff;
  --accent-soft: rgba(22, 119, 255, 0.10);
  --shadow: 0 18px 48px rgba(15, 23, 42, 0.08);
  --shadow-soft: 0 12px 28px rgba(15, 23, 42, 0.06);
  --radius: 18px;
  --container: 1160px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #ffffff;
  color: var(--text);
  line-height: 1.7;
}

a { color: inherit; text-decoration: none; }
a:hover { color: var(--primary); }
img { max-width: 100%; }

.container {
  width: min(var(--container), calc(100% - 32px));
  margin: 0 auto;
}

.narrow { width: min(820px, calc(100% - 32px)); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.nav nav a {
  color: var(--muted);
  font-size: 15px;
}

.brand {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: 0.3px;
  color: var(--text-strong);
}

.hero {
  padding: 72px 0 48px;
}

.hero-grid,
.two-col,
.footer-grid,
.guide-split {
  display: grid;
  gap: 28px;
}

.hero-grid {
  grid-template-columns: 1.35fr 0.95fr;
  align-items: center;
}

.hero-home {
  padding-top: 82px;
}

.badge,
.tag,
.post-meta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-soft);
  color: var(--primary);
  border: 1px solid rgba(22,119,255,0.18);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
}

.hero h1,
.page-hero h1,
.article h1 {
  margin: 16px 0;
  line-height: 1.12;
  font-size: clamp(30px, 4vw, 52px);
  color: var(--text-strong);
}

.lead,
.page-hero p {
  color: var(--muted);
  font-size: 18px;
  max-width: 720px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  margin: 28px 0 24px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 20px;
  border-radius: 12px;
  font-weight: 700;
  border: 1px solid transparent;
  transition: 0.2s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 16px 34px rgba(22,119,255,0.22);
}

.btn-secondary {
  background: #fff;
  border-color: rgba(15,23,42,0.10);
  color: var(--text-strong);
  box-shadow: var(--shadow-soft);
}

.btn:hover { transform: translateY(-1px); }

.hero-points {
  margin: 0;
  padding-left: 18px;
  color: var(--text);
}

.hero-card,
.card,
.post-row,
.article,
.faq-item {
  background: linear-gradient(180deg, rgba(255,255,255,0.98), rgba(248,251,255,0.96));
  border: 1px solid rgba(15,23,42,0.08);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-card,
.card,
.article { padding: 24px; }

.hero-card h2,
.card h3,
.article h2,
.section-title h2,
.subsection-title {
  margin-top: 0;
  color: var(--text-strong);
}

.hero-card ol {
  padding-left: 20px;
  color: var(--text);
}

.tip,
.small-muted,
.section-title p,
.newsletter p,
.post-card p,
.post-row p,
.sidebar-link-meta,
.footer-copy,
.footer-brand p,
.footer-record,
.faq-item p {
  color: var(--muted);
}

.tip {
  margin-top: 18px;
  padding: 14px;
  background: rgba(22,119,255,0.06);
  border: 1px solid rgba(22,119,255,0.12);
  border-radius: 12px;
}

.section {
  padding: 38px 0 68px;
}

.section-alt,
.page-hero {
  background: #f8fbff;
  border-top: 1px solid rgba(15,23,42,0.04);
  border-bottom: 1px solid rgba(15,23,42,0.04);
}

.section-title {
  margin-bottom: 24px;
  text-align: center;
}

.section-title-left {
  text-align: left;
}

.site-footer {
  margin-top: 28px;
  padding: 24px 0 36px;
  border-top: 1px solid rgba(15,23,42,0.08);
  background: #ffffff;
}

.footer-shell {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.9fr);
  gap: 22px;
  align-items: center;
  padding: 22px 26px;
  border: 1px solid rgba(15,23,42,0.08);
  border-radius: 20px;
  background: linear-gradient(135deg, #ffffff, #f7faff);
  box-shadow: var(--shadow);
}

.footer-brand strong {
  display: block;
  font-size: 20px;
  color: var(--text-strong);
  margin: 10px 0 8px;
}

.footer-badge {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid rgba(22,119,255,0.15);
  background: rgba(22,119,255,0.08);
  color: var(--primary);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.footer-meta {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-end;
}

.footer-records {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px;
}

.footer-record {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid rgba(15,23,42,0.08);
  background: rgba(255,255,255,0.96);
  color: var(--muted);
  font-size: 14px;
  transition: 0.2s ease;
}

.footer-record:hover {
  border-color: rgba(22,119,255,0.28);
  background: rgba(22,119,255,0.07);
  color: var(--text-strong);
}

.card-grid {
  display: grid;
  gap: 22px;
}

.card-grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card-grid.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card-grid.four {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.pricing-card.featured {
  border-color: rgba(22,119,255,0.24);
  transform: translateY(-4px);
  box-shadow: 0 18px 40px rgba(22,119,255,0.12);
}

.card ul,
.newsletter ul,
.article ul,
.scene-card ul,
.product-card ul {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--text);
}

.two-col {
  grid-template-columns: 1.2fr 0.8fr;
  align-items: start;
}

.list-cards {
  display: grid;
  gap: 16px;
}

.list-card,
.post-row {
  padding: 0;
}

.post-row-link,
.post-card-link,
.sidebar-link,
.quick-item {
  display: block;
  padding: 22px;
  min-height: 100%;
  border-radius: inherit;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.read-more-hint {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 14px;
  font-size: 14px;
  color: var(--primary);
  opacity: 0.95;
}

.post-row:hover,
.post-card:hover,
.sidebar-link:hover,
.quick-item:hover,
.scene-card:hover,
.product-card:hover,
.trust-card:hover {
  border-color: rgba(22,119,255,0.20);
  box-shadow: 0 20px 42px rgba(15,23,42,0.10);
  transform: translateY(-3px);
}

.post-row-link:hover,
.post-card-link:hover,
.sidebar-link:hover,
.quick-item:hover {
  color: inherit;
  background: rgba(22,119,255,0.03);
}

.post-row-link:active,
.post-card-link:active {
  transform: scale(0.985);
  background: rgba(22,119,255,0.08);
}

.post-row-link h2,
.post-card-link h3,
.quick-item strong,
.scene-card h3,
.product-card h3,
.trust-card h3 {
  margin: 0 0 8px;
}

.page-main { padding-bottom: 64px; }
.page-hero { padding: 52px 0 24px; }

.post-listing {
  display: grid;
  gap: 18px;
}

.article-shell {
  margin-top: 40px;
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr) 220px;
  gap: 20px;
  align-items: start;
}

.article-main {
  min-width: 0;
}

.article-shell-tight {
  grid-template-columns: 180px minmax(0, 1140px) 180px;
  gap: 18px;
  margin-top: 28px;
}

.article-main-tight {
  padding: 30px 38px;
}

.article-header-compact {
  padding-bottom: 18px;
  margin-bottom: 22px;
  border-bottom: 1px solid rgba(15,23,42,0.08);
}

.article-header-compact .post-meta {
  margin-bottom: 10px;
}

.article-header-compact p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.article-summary-strip {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 22px;
}

.summary-chip {
  padding: 14px 16px;
  border-radius: 14px;
  background: rgba(22,119,255,0.05);
  border: 1px solid rgba(22,119,255,0.10);
  color: var(--text);
  font-size: 14px;
  line-height: 1.65;
}

.article-keytakeaways {
  margin-bottom: 26px;
  padding: 18px 20px;
  border-radius: 16px;
  background: linear-gradient(180deg, #ffffff, #f8fbff);
  border: 1px solid rgba(15,23,42,0.08);
}

.article-keytakeaways h2 {
  margin-bottom: 10px;
  font-size: 22px;
}

.article-keytakeaways ul {
  margin: 0;
}

.prose {
  font-size: 16px;
}

.prose > section,
.prose > .card,
.prose > .article-related,
.prose > .article-keytakeaways {
  margin-top: 22px;
}

.prose h2 {
  margin: 0 0 10px;
  font-size: 26px;
  line-height: 1.28;
}

.prose h3 {
  line-height: 1.35;
}

.prose p {
  margin: 0 0 12px;
  line-height: 1.85;
}

.prose ul,
.prose ol {
  margin: 10px 0 0;
  line-height: 1.8;
}

.sidebar-card {
  padding: 18px;
}

.toc-card h3,
.hot-card h3,
.reading-guide-card h3 {
  margin-bottom: 12px;
  font-size: 18px;
}

.toc-nav {
  display: grid;
  gap: 10px;
}

.toc-nav a {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

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

.sidebar-bullet-list {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.sidebar-bullet-list li + li {
  margin-top: 8px;
}

.article-sidebar-left,
.article-sidebar-right {
  position: sticky;
  top: 92px;
}

.quick-list {
  display: grid;
  gap: 12px;
  margin-top: 12px;
}

.quick-item {
  border-radius: 14px;
  border: 1px solid rgba(15,23,42,0.08);
  background: rgba(255,255,255,0.92);
  padding: 16px 18px;
}

.quick-item strong {
  display: block;
  color: var(--text-strong);
}

.quick-item span {
  color: var(--muted);
  font-size: 14px;
}

.hero-card-home,
.hero-home .hero-copy {
  align-self: stretch;
}

.hero-points-home li + li {
  margin-top: 8px;
}

.scene-card,
.product-card,
.trust-card {
  height: 100%;
}

.trust-card p,
.scene-card p,
.product-card p {
  margin-bottom: 0;
}

.guide-split {
  grid-template-columns: 1fr 1fr;
  align-items: start;
}

.compact-grid .post-card h3 {
  font-size: 22px;
}

.subsection-title {
  margin-bottom: 14px;
  font-size: 22px;
}

.article-entry-bar {
  margin-top: 24px;
  display: flex;
  justify-content: center;
}

.faq-list {
  display: grid;
  gap: 16px;
}

.faq-item {
  padding: 18px 22px;
}

.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--text-strong);
  list-style: none;
}

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

.faq-item p {
  margin: 12px 0 0;
}

@media (max-width: 1100px) {
  .hero-grid,
  .guide-split,
  .footer-shell,
  .two-col,
  .article-shell {
    grid-template-columns: 1fr;
  }

  .card-grid.three,
  .card-grid.four {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-meta {
    align-items: flex-start;
  }

  .footer-records {
    justify-content: flex-start;
  }

  .article-sidebar-left,
  .article-sidebar-right {
    position: static;
    top: auto;
  }
}

@media (max-width: 720px) {
  .nav {
    align-items: flex-start;
    padding: 12px 0;
    flex-direction: column;
  }

  .nav nav {
    gap: 12px;
  }

  .hero {
    padding-top: 52px;
  }

  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .card-grid.two,
  .card-grid.three,
  .card-grid.four {
    grid-template-columns: 1fr;
  }

  .hero-card,
  .card,
  .article,
  .faq-item,
  .footer-shell {
    padding: 20px;
  }

  .section {
    padding: 30px 0 54px;
  }

  .post-row-link,
  .post-card-link,
  .sidebar-link,
  .quick-item {
    padding: 18px;
  }
}