:root {
  color-scheme: light;
  --brand: #0468d7;
  --brand-deep: #0757b8;
  --ink: #142033;
  --muted: #65758b;
  --line: #dce7f5;
  --soft: #f4f8fd;
  --card: rgba(255, 255, 255, 0.94);
  --shadow: 0 18px 60px rgba(20, 68, 126, 0.12);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 5%, rgba(72, 163, 255, 0.18), transparent 24rem),
    radial-gradient(circle at 94% 22%, rgba(91, 86, 214, 0.12), transparent 25rem),
    #f8fbff;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Segoe UI", sans-serif;
  line-height: 1.75;
}

a { color: var(--brand); }

.site-header {
  position: sticky;
  z-index: 10;
  top: 0;
  border-bottom: 1px solid rgba(220, 231, 245, 0.85);
  background: rgba(248, 251, 255, 0.88);
  backdrop-filter: blur(18px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1080px, calc(100% - 40px));
  min-height: 68px;
  margin: 0 auto;
  gap: 22px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-weight: 760;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 10px;
  color: white;
  background: linear-gradient(145deg, #42a5f5, #0468d7 62%, #5a61df);
  box-shadow: 0 8px 20px rgba(4, 104, 215, 0.24);
  font-weight: 850;
}

.nav-links { display: flex; align-items: center; gap: 6px; }

.nav-links a,
.language-switch button {
  border: 0;
  border-radius: 9px;
  padding: 8px 11px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-size: 14px;
  text-decoration: none;
  cursor: pointer;
}

.nav-links a:hover,
.nav-links a[aria-current="page"],
.language-switch button[aria-pressed="true"] {
  color: var(--brand-deep);
  background: #eaf4ff;
}

.language-switch {
  display: flex;
  padding-left: 8px;
  border-left: 1px solid var(--line);
}

.hero {
  width: min(900px, calc(100% - 40px));
  margin: 0 auto;
  padding: 78px 0 34px;
  text-align: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--brand);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(32px, 6vw, 54px);
  line-height: 1.12;
  letter-spacing: -0.035em;
}

.hero .subtitle {
  max-width: 680px;
  margin: 18px auto 0;
  color: var(--muted);
  font-size: 17px;
}

.meta {
  display: inline-flex;
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 12px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.75);
  font-size: 13px;
}

.page-shell {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  width: min(1080px, calc(100% - 40px));
  margin: 0 auto 80px;
  gap: 28px;
  align-items: start;
}

.toc {
  position: sticky;
  top: 94px;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 16px;
  background: rgba(255, 255, 255, 0.72);
}

.toc strong { display: block; margin: 0 0 8px; font-size: 13px; }
.toc a { display: block; padding: 5px 0; color: var(--muted); font-size: 13px; text-decoration: none; }
.toc a:hover { color: var(--brand); }

.document,
.support-card {
  border: 1px solid rgba(220, 231, 245, 0.95);
  border-radius: 22px;
  padding: clamp(24px, 5vw, 54px);
  background: var(--card);
  box-shadow: var(--shadow);
}

.notice {
  margin: 0 0 30px;
  border-left: 4px solid var(--brand);
  border-radius: 10px;
  padding: 15px 18px;
  color: #29405f;
  background: #edf6ff;
}

.document h2 { margin: 38px 0 12px; font-size: 21px; line-height: 1.35; }
.document h2:first-of-type { margin-top: 0; }
.document h3 { margin: 22px 0 8px; font-size: 16px; }
.document p { margin: 9px 0; }
.document ul { margin: 10px 0; padding-left: 22px; }
.document li { margin: 5px 0; }

.data-table { width: 100%; margin: 18px 0; border-collapse: collapse; font-size: 14px; }
.data-table th,
.data-table td { border: 1px solid var(--line); padding: 12px 14px; text-align: left; vertical-align: top; }
.data-table th { background: var(--soft); }

.support-layout {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto 80px;
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin: 24px 0 34px;
  gap: 16px;
}

.contact-item {
  border: 1px solid var(--line);
  border-radius: 15px;
  padding: 20px;
  background: var(--soft);
}

.contact-icon { display: inline-grid; width: 40px; height: 40px; place-items: center; border-radius: 12px; background: #e3f1ff; }
.contact-item h3 { margin: 12px 0 3px; font-size: 16px; }
.contact-item p { margin: 0; color: var(--muted); font-size: 13px; }
.contact-item a { overflow-wrap: anywhere; font-weight: 650; text-decoration: none; }

.faq { border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); padding: 17px 0; }
.faq summary { cursor: pointer; font-weight: 680; }
.faq p { margin: 9px 0 0; color: var(--muted); }

.feature-list { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; padding: 0; list-style: none; }
.feature-list li { border-radius: 10px; padding: 12px 14px; background: var(--soft); }
.feature-list li::before { content: "✓"; margin-right: 9px; color: var(--brand); font-weight: 800; }

.site-footer { padding: 24px 20px 46px; color: var(--muted); text-align: center; font-size: 13px; }
.site-footer a { text-decoration: none; }

[data-lang-content][hidden] { display: none !important; }

@media (max-width: 820px) {
  .nav { align-items: flex-start; padding: 13px 0; }
  .nav-links { flex-wrap: wrap; justify-content: flex-end; }
  .page-shell { grid-template-columns: 1fr; }
  .toc { display: none; }
  .support-grid { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .nav { width: min(100% - 24px, 1080px); }
  .brand span:last-child { display: none; }
  .nav-links a, .language-switch button { padding: 7px 8px; font-size: 12px; }
  .hero { width: min(100% - 28px, 900px); padding-top: 54px; }
  .page-shell, .support-layout { width: min(100% - 24px, 1080px); }
  .document, .support-card { border-radius: 16px; padding: 22px 18px; }
  .data-table { display: block; overflow-x: auto; }
  .feature-list { grid-template-columns: 1fr; }
}