:root {
  color-scheme: light;
  --bg: #f7f8fb;
  --surface: #ffffff;
  --text: #1f2933;
  --muted: #5d6b7a;
  --line: #dfe5ec;
  --brand: #12695d;
  --brand-strong: #0b4e46;
  --accent: #b45309;
  --soft: #eef7f5;
  --shadow: 0 16px 40px rgba(31, 41, 51, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 16px clamp(18px, 5vw, 64px);
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  flex: 0 0 auto;
  font-size: 20px;
  font-weight: 800;
  color: var(--brand-strong);
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 16px;
  font-size: 14px;
  color: var(--muted);
}

.main-nav a {
  padding: 6px 0;
}

.main-nav a:hover,
.article-card a:hover,
.article-list a:hover {
  color: var(--brand);
}

main {
  width: min(1160px, calc(100% - 32px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(280px, 0.8fr);
  gap: 28px;
  align-items: stretch;
  padding: 56px 0 34px;
}

.hero-copy,
.hero-panel,
.category-card,
.article-card,
.toc,
.article-brief,
.category-brief,
.info-panel,
.callout,
.checklist-panel,
.content-page {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero-copy {
  padding: clamp(28px, 5vw, 52px);
}

.hero-copy h1,
.page-title h1 {
  max-width: 780px;
  margin: 10px 0 18px;
  font-size: clamp(34px, 6vw, 58px);
  line-height: 1.12;
  letter-spacing: 0;
}

.hero-copy p,
.page-title p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero-visual {
  display: block;
  width: min(100%, 680px);
  height: auto;
  margin: 28px 0 0;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border-radius: 6px;
  background: var(--brand);
  color: #fff;
  font-weight: 700;
}

.button.secondary {
  background: var(--soft);
  color: var(--brand-strong);
}

.hero-panel {
  padding: 28px;
}

.hero-panel h2 {
  margin-top: 0;
  font-size: 22px;
}

.stat-list {
  display: grid;
  gap: 12px;
  margin: 20px 0;
}

.stat-list div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.stat-list strong {
  color: var(--brand-strong);
  font-size: 34px;
  line-height: 1;
}

.stat-list span {
  color: var(--muted);
}

.hero-panel ul,
.article-brief ul,
.article-content ul,
.content-page ul {
  padding-left: 22px;
}

.eyebrow {
  display: inline-block;
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
}

.section {
  padding: 34px 0;
}

.section.compact {
  padding-top: 12px;
}

.section-heading {
  margin-bottom: 20px;
}

.section-heading h2,
.related h2 {
  margin: 6px 0 0;
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.25;
}

.category-grid,
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.category-card,
.article-card {
  display: block;
  padding: 22px;
}

.category-card span {
  display: inline-block;
  margin-top: 10px;
  color: var(--brand);
  font-weight: 700;
}

.card-topline,
.tag-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.card-topline {
  justify-content: space-between;
}

.card-topline > span:last-child {
  color: var(--muted);
  font-size: 13px;
}

.tag-row {
  margin: 14px 0;
}

.tag-row span {
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--brand-strong);
  font-size: 13px;
  font-weight: 700;
}

.category-card h3,
.article-card h3 {
  margin: 8px 0 10px;
  font-size: 21px;
  line-height: 1.35;
}

.category-card p,
.article-card p,
.card-meta,
.article-meta {
  color: var(--muted);
}

.card-meta {
  margin-top: 14px;
  font-size: 14px;
}

.article-list {
  display: grid;
  gap: 10px;
}

.article-list a {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 16px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.article-list small {
  flex: 0 0 auto;
  color: var(--muted);
}

.feature-band {
  padding: 28px;
  margin: 18px 0;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.path-grid,
.principle-grid,
.category-brief,
.article-brief {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.path-grid a,
.principle-grid div,
.category-brief div,
.article-brief div {
  padding: 18px;
  background: #f9fbfc;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.path-grid strong,
.path-grid span {
  display: block;
}

.path-grid span,
.principle-grid p,
.category-brief p,
.article-brief p,
.article-brief li {
  color: var(--muted);
}

.principle-grid h3,
.category-brief h2 {
  margin: 0 0 8px;
  font-size: 20px;
}

.page-title {
  padding: 54px 0 28px;
}

.category-brief {
  grid-template-columns: 1fr 1fr;
  margin-bottom: 20px;
}

.article-page {
  width: min(920px, 100%);
  margin: 0 auto;
  padding: 44px 0;
}

.article-header {
  padding-bottom: 20px;
}

.article-header h1 {
  margin: 10px 0 14px;
  font-size: clamp(32px, 6vw, 50px);
  line-height: 1.16;
}

.article-header p {
  color: var(--muted);
  font-size: 18px;
}

.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 18px;
  margin: 18px 0 30px;
}

.toc a {
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--brand-strong);
  font-size: 14px;
}

.article-content {
  font-size: 18px;
}

.article-content h2,
.content-page h2 {
  margin: 34px 0 10px;
  font-size: 26px;
  line-height: 1.3;
}

.article-content p,
.article-content li,
.content-page p,
.content-page li {
  color: #2f3b46;
}

.article-content section {
  scroll-margin-top: 110px;
}

.article-brief {
  grid-template-columns: 0.9fr 1.1fr;
  margin: 24px 0 18px;
}

.article-brief strong {
  display: block;
  margin-bottom: 8px;
  color: var(--brand-strong);
}

.info-panel,
.callout,
.checklist-panel {
  padding: 22px;
  margin: 28px 0;
}

.callout {
  border-left: 5px solid var(--brand);
}

.soft-callout {
  background: var(--soft);
}

.warning {
  border-left: 5px solid var(--accent);
}

.step-list {
  display: grid;
  gap: 14px;
}

.step-item {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 16px;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.step-item span {
  display: inline-flex;
  width: 34px;
  height: 34px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--brand);
  color: #ffffff;
  font-weight: 800;
}

.step-item p {
  margin: 0;
}

.checklist-panel ul {
  display: grid;
  gap: 10px;
  padding-left: 0;
  list-style: none;
}

.checklist-panel li {
  padding-left: 28px;
  position: relative;
}

.checklist-panel li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brand);
}

.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin: 38px 0;
}

.post-nav a,
.post-nav .disabled {
  min-height: 84px;
  padding: 16px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--surface);
}

.post-nav span span,
.post-nav a span {
  display: block;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 4px;
}

.disabled {
  color: var(--muted);
}

.related {
  margin-top: 28px;
}

.content-page {
  width: min(860px, 100%);
  margin: 0 auto 48px;
  padding: clamp(22px, 5vw, 42px);
  font-size: 18px;
}

.site-footer {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 0.8fr;
  gap: 28px;
  margin-top: 44px;
  padding: 34px clamp(18px, 5vw, 64px);
  background: #17212b;
  color: #dbe4ee;
}

.site-footer p {
  color: #b7c4d2;
}

.site-footer h2 {
  margin: 0 0 10px;
  font-size: 16px;
}

.site-footer a {
  display: block;
  color: #dbe4ee;
  margin: 6px 0;
}

@media (max-width: 840px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .main-nav {
    justify-content: flex-start;
  }

  .hero,
  .category-grid,
  .article-grid,
  .path-grid,
  .principle-grid,
  .category-brief,
  .article-brief,
  .site-footer {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 30px;
  }

  .article-list a,
  .post-nav {
    grid-template-columns: 1fr;
  }

  .article-list a {
    display: grid;
  }
}

@media (max-width: 520px) {
  main {
    width: min(100% - 24px, 1160px);
  }

  .hero-copy,
  .hero-panel,
  .feature-band,
  .category-card,
  .article-card,
  .article-brief,
  .category-brief,
  .info-panel,
  .callout,
  .checklist-panel,
  .content-page {
    padding: 18px;
  }

  .hero-copy h1,
  .page-title h1,
  .article-header h1 {
    font-size: 32px;
  }

  .hero-copy p,
  .page-title p,
  .article-header p,
  .article-content,
  .content-page {
    font-size: 16px;
  }
}