:root {
  --ink: #17213d;
  --muted: #5d6780;
  --paper: #fbfcff;
  --surface: #ffffff;
  --line: #dfe4ef;
  --brand: #3346a8;
  --brand-dark: #24327e;
  --accent: #13806a;
  --soft: #eef1ff;
  --warning: #fff7e6;
  --warning-line: #e3bd68;
  --shadow: 0 18px 50px rgba(31, 43, 91, 0.09);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 0%, rgba(75, 95, 205, 0.11), transparent 28rem),
    linear-gradient(180deg, #f7f8fd 0, var(--paper) 30rem);
  font-family: "Hiragino Sans", "Yu Gothic UI", "Yu Gothic", Meiryo, sans-serif;
  line-height: 1.75;
}

a {
  color: var(--brand);
  text-underline-offset: 0.2em;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  border-bottom: 1px solid rgba(223, 228, 239, 0.9);
  background: rgba(251, 252, 255, 0.92);
  backdrop-filter: blur(16px);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1120px, calc(100% - 40px));
  min-height: 72px;
  margin: 0 auto;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(135deg, var(--brand), #6377dc);
  box-shadow: 0 8px 22px rgba(51, 70, 168, 0.25);
  font-size: 0.82rem;
  letter-spacing: -0.04em;
}

.site-nav {
  display: flex;
  gap: 6px;
}

.site-nav a {
  padding: 9px 12px;
  border-radius: 10px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--brand-dark);
  background: var(--soft);
}

main {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr);
  align-items: center;
  gap: 64px;
  min-height: 620px;
  padding: 88px 0;
}

.eyebrow {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.28;
  letter-spacing: -0.025em;
}

h1 {
  max-width: 12em;
  margin: 0;
  font-size: clamp(2.45rem, 6vw, 4.7rem);
}

.hero-copy {
  max-width: 42rem;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.badge {
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.flow-card {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.86);
  box-shadow: var(--shadow);
}

.flow-label {
  margin: 0 0 22px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.flow-step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: center;
}

.flow-step + .flow-step {
  margin-top: 18px;
}

.flow-icon {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 13px;
  color: var(--brand-dark);
  background: var(--soft);
  font-weight: 900;
}

.flow-step strong,
.flow-step span {
  display: block;
}

.flow-step span {
  color: var(--muted);
  font-size: 0.84rem;
}

.flow-arrow {
  width: 2px;
  height: 22px;
  margin: 4px 0 4px 20px;
  background: linear-gradient(var(--line), var(--brand));
}

.section {
  padding: 84px 0;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 34px;
}

.section-heading h2,
.document h1 {
  margin: 0 0 14px;
  font-size: clamp(2rem, 4vw, 3.25rem);
}

.section-heading p,
.document-lead {
  margin: 0;
  color: var(--muted);
}

.grid-three {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.info-card {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
}

.info-card h3 {
  margin: 0 0 10px;
  font-size: 1.12rem;
}

.info-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.file-list {
  display: grid;
  gap: 10px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.file-list li {
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
  font-family: Consolas, "SFMono-Regular", monospace;
  font-size: 0.9rem;
}

.notice {
  padding: 24px 26px;
  border: 1px solid var(--warning-line);
  border-radius: 18px;
  background: var(--warning);
}

.notice strong {
  display: block;
  margin-bottom: 6px;
}

.notice p {
  margin: 0;
}

.document {
  width: min(800px, 100%);
  padding: 84px 0 100px;
}

.document-header {
  padding-bottom: 38px;
  border-bottom: 1px solid var(--line);
}

.updated {
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.86rem;
}

.document section {
  padding-top: 38px;
}

.document h2 {
  margin: 0 0 14px;
  font-size: 1.45rem;
}

.document p,
.document ul {
  margin-top: 0;
}

.document li + li {
  margin-top: 8px;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #f4f6fb;
}

.footer-wrap {
  display: flex;
  justify-content: space-between;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 30px 0;
  gap: 20px;
  color: var(--muted);
  font-size: 0.86rem;
}

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

@media (max-width: 820px) {
  .nav-wrap {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 0;
    gap: 10px;
  }

  .site-header {
    position: static;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
  }

  .site-nav a {
    white-space: nowrap;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: 64px 0;
    gap: 40px;
  }

  .grid-three {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 64px 0;
  }

  .footer-wrap {
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  .nav-wrap,
  main,
  .footer-wrap {
    width: min(100% - 28px, 1120px);
  }

  .brand {
    font-size: 0.92rem;
  }

  .site-nav a {
    padding: 8px 9px;
    font-size: 0.82rem;
  }

  .flow-card,
  .info-card,
  .notice {
    padding: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}