:root {
  color-scheme: light;
  --page-bg: #f5f5f7;
  --surface: #ffffff;
  --surface-muted: #fafafc;
  --text: #1d1d1f;
  --text-muted: #6e6e73;
  --border: #dcdce1;
  --line: #e5e5ea;
  --link: #0a66cc;
  --shadow: 0 18px 40px rgba(15, 23, 42, 0.06);
  --radius: 22px;
  --content-width: 960px;
  --reading-width: 760px;
}

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

html {
  font-size: 16px;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--page-bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", Helvetica, Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
}

.site-shell {
  min-height: 100vh;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(245, 245, 247, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(220, 220, 225, 0.9);
}

.header-inner,
.main-inner,
.footer-inner {
  width: min(calc(100% - 2rem), var(--content-width));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text);
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.3rem;
  height: 2.3rem;
  border-radius: 999px;
  background: #111827;
  color: #ffffff;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.brand-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-title {
  font-size: 1rem;
  font-weight: 600;
}

.brand-meta {
  font-size: 0.84rem;
  color: var(--text-muted);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.4rem;
}

.site-nav a {
  padding: 0.55rem 0.8rem;
  border-radius: 999px;
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  background: rgba(17, 24, 39, 0.06);
  color: var(--text);
  text-decoration: none;
}

.main-inner {
  padding: 3rem 0 4rem;
}

.hero {
  background: linear-gradient(180deg, #ffffff 0%, #fbfbfc 100%);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 4px);
  box-shadow: var(--shadow);
  padding: clamp(2rem, 6vw, 4rem);
  margin-bottom: 1.5rem;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 1rem;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  background: rgba(10, 102, 204, 0.08);
  color: var(--link);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.15;
  letter-spacing: -0.03em;
}

h1 {
  max-width: 12ch;
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  font-weight: 700;
}

h2 {
  font-size: clamp(1.45rem, 4vw, 2rem);
  font-weight: 650;
}

h3 {
  font-size: 1.05rem;
  font-weight: 650;
}

p {
  margin: 0;
}

.lead {
  max-width: 44rem;
  margin-top: 1rem;
  font-size: clamp(1.06rem, 2vw, 1.26rem);
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.75rem;
}

.button-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.78rem 1.1rem;
  border-radius: 999px;
  border: 1px solid #111827;
  background: #111827;
  color: #ffffff;
  font-weight: 600;
  text-decoration: none;
}

.button-link:hover {
  background: #1f2937;
  text-decoration: none;
}

.button-link.secondary {
  border-color: var(--border);
  background: transparent;
  color: var(--text);
}

.button-link.secondary:hover {
  background: rgba(17, 24, 39, 0.04);
}

.section-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
}

.card h2,
.card h3 {
  margin-bottom: 0.7rem;
}

.card p + p,
.card ul + p,
.card ul + ul,
.card p + ul {
  margin-top: 0.9rem;
}

.span-7 {
  grid-column: span 7;
}

.span-5 {
  grid-column: span 5;
}

.span-6 {
  grid-column: span 6;
}

.span-12 {
  grid-column: span 12;
}

.reading-layout {
  display: grid;
  gap: 1rem;
}

.reading-layout .hero h1 {
  max-width: none;
}

.reading-layout .card {
  width: min(100%, var(--reading-width));
}

.document {
  width: min(100%, var(--reading-width));
  padding: clamp(1.5rem, 4vw, 2.25rem);
}

.document h2 {
  margin-bottom: 0.8rem;
  font-size: clamp(1.25rem, 3vw, 1.6rem);
  letter-spacing: -0.02em;
}

.document h3 {
  margin-bottom: 0.55rem;
  font-size: 1rem;
  letter-spacing: -0.01em;
}

.document p,
.document ul {
  max-width: 42rem;
}

.document p + p,
.document p + ul,
.document ul + p,
.document-section p + p,
.document-section p + ul,
.document-section ul + p {
  margin-top: 0.9rem;
}

.document-section + .document-section {
  margin-top: 1.7rem;
  padding-top: 1.7rem;
  border-top: 1px solid var(--line);
}

.meta {
  margin-bottom: 1rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.detail-list,
.link-list {
  margin: 0;
  padding-left: 1.2rem;
}

.detail-list li,
.link-list li {
  margin-top: 0.55rem;
}

.detail-list li:first-child,
.link-list li:first-child {
  margin-top: 0;
}

.faq-list {
  display: grid;
  gap: 1rem;
}

.faq-item {
  padding: 1rem 0 0;
  border-top: 1px solid var(--line);
}

.faq-item:first-child {
  padding-top: 0;
  border-top: 0;
}

.faq-item p {
  margin-top: 0.45rem;
  color: var(--text-muted);
}

.footer-inner {
  padding: 0 0 3rem;
}

.site-footer {
  color: var(--text-muted);
  font-size: 0.94rem;
}

.footer-card {
  background: var(--surface-muted);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
}

.footer-card p + p {
  margin-top: 0.45rem;
}

@media (max-width: 820px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
  }

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

  .span-7,
  .span-12,
  .span-6,
  .span-5 {
    grid-column: span 12;
  }

  .main-inner {
    padding-top: 2rem;
  }
}

@media (max-width: 520px) {
  .header-inner,
  .main-inner,
  .footer-inner {
    width: min(calc(100% - 1.25rem), var(--content-width));
  }

  .hero,
  .card,
  .footer-card {
    border-radius: 18px;
    padding-left: 1.15rem;
    padding-right: 1.15rem;
  }

  .site-nav {
    gap: 0.2rem;
  }

  .site-nav a {
    padding-left: 0.55rem;
    padding-right: 0.55rem;
  }

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

  .button-link {
    width: 100%;
  }
}