:root {
  color-scheme: light;
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-soft: #f0f4fa;
  --text: #172033;
  --muted: #5d687d;
  --line: #dfe4ec;
  --accent: #315efb;
  --accent-strong: #2046c7;
  --soft: #edf2ff;
  --success: #0f7a4b;
  --warning: #946200;
  --shadow: 0 18px 48px rgba(32, 49, 82, 0.10);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}
a { color: var(--accent-strong); }
code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: .92em;
  overflow-wrap: anywhere;
}
.wrap { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(246, 248, 251, 0.92);
  border-bottom: 1px solid rgba(223, 228, 236, 0.9);
}
.nav {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  font-weight: 750;
  text-decoration: none;
  color: var(--text);
  flex-shrink: 0;
}
.logo {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: linear-gradient(135deg, #315efb, #6788ff);
  color: white;
  font-size: 16px;
  box-shadow: 0 8px 20px rgba(49, 94, 251, 0.24);
}
.nav-links {
  display: flex;
  gap: 18px;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
}
.nav-links a:hover,
.nav-links a:focus-visible { color: var(--accent-strong); }

.hero { padding: 86px 0 52px; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(290px, .7fr);
  gap: 36px;
  align-items: center;
}
.eyebrow {
  margin: 0 0 12px;
  color: var(--accent-strong);
  font-weight: 760;
  letter-spacing: .05em;
  font-size: .84rem;
  text-transform: uppercase;
}
h1 {
  margin: 0;
  font-size: clamp(2.6rem, 7vw, 5.4rem);
  letter-spacing: -0.05em;
  line-height: 1.02;
}
.lead {
  margin: 24px 0 0;
  max-width: 760px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.22rem);
}
.hero-actions {
  margin-top: 28px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.button {
  min-height: 44px;
  padding: 10px 16px;
  border-radius: 12px;
  border: 1px solid var(--line);
  text-decoration: none;
  font-weight: 720;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.button.primary {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}
.button.primary:hover,
.button.primary:focus-visible { background: var(--accent-strong); }
.button.secondary { background: var(--surface); color: var(--text); }

.hero-card,
.card,
.tech-card,
.status-panel {
  background: var(--surface);
  border: 1px solid var(--line);
}
.hero-card {
  border-radius: 24px;
  padding: 26px;
  box-shadow: var(--shadow);
}
.status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 11px;
  border-radius: 999px;
  background: #eaf7f1;
  color: var(--success);
  font-weight: 720;
  font-size: .9rem;
}
.status::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
}
.kv { margin: 20px 0 0; display: grid; gap: 14px; }
.kv div { padding-top: 14px; border-top: 1px solid var(--line); }
.kv dt { color: var(--muted); font-size: .82rem; }
.kv dd { margin: 3px 0 0; font-weight: 720; }

.section { padding: 56px 0 68px; }
.section-tight { padding-top: 8px; padding-bottom: 34px; }
.alt-section {
  background: var(--surface-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.section h2 {
  margin: 0 0 18px;
  font-size: clamp(1.7rem, 3vw, 2.5rem);
  letter-spacing: -0.03em;
  line-height: 1.18;
}
.section-intro { max-width: 820px; color: var(--muted); }
.inline-link { margin-top: 24px; }

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 28px;
}
.card { border-radius: 20px; padding: 23px; }
.card-tag {
  display: inline-block;
  margin-bottom: 10px;
  color: var(--accent-strong);
  font-size: .78rem;
  font-weight: 780;
  letter-spacing: .04em;
  text-transform: uppercase;
}
.card h3,
.tech-card h3,
.status-panel h3 { margin: 0 0 10px; font-size: 1.06rem; }
.card p,
.tech-card p { margin: 0; color: var(--muted); }

.notice {
  background: var(--soft);
  border: 1px solid #ccd8ff;
  border-radius: 20px;
  padding: 24px;
}
.notice strong { display: block; margin-bottom: 6px; }
.dev-summary {
  border-left: 4px solid var(--accent);
  max-width: 980px;
}

.architecture-flow {
  margin-top: 30px;
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  gap: 12px;
  align-items: stretch;
}
.flow-node {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 20px;
  min-width: 0;
}
.flow-node strong { display: block; }
.flow-node span {
  display: block;
  margin-top: 5px;
  color: var(--muted);
  font-size: .9rem;
}
.flow-arrow {
  display: grid;
  place-items: center;
  color: var(--accent-strong);
  font-size: 1.4rem;
  font-weight: 800;
}
.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 18px;
}
.tech-card {
  border-radius: 18px;
  padding: 22px;
}

.spec-table {
  margin-top: 26px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  overflow: hidden;
}
.spec-row {
  display: grid;
  grid-template-columns: minmax(160px, .65fr) minmax(0, 1.35fr);
  gap: 20px;
  padding: 16px 20px;
  border-top: 1px solid var(--line);
}
.spec-row:first-child { border-top: 0; }
.spec-row span { color: var(--muted); }

.status-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-top: 28px;
}
.status-panel {
  border-radius: 20px;
  padding: 23px;
}
.status-panel ul {
  margin: 14px 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
}
.status-panel li + li { margin-top: 7px; }
.status-label {
  display: inline-flex;
  border-radius: 999px;
  padding: 5px 9px;
  margin-bottom: 12px;
  font-size: .76rem;
  font-weight: 800;
  letter-spacing: .03em;
  text-transform: uppercase;
}
.status-label.done { color: var(--success); background: #eaf7f1; }
.status-label.current { color: var(--accent-strong); background: var(--soft); }
.status-label.next { color: var(--warning); background: #fff5d9; }

.pipeline {
  margin-top: 26px;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.pipeline span {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 9px 12px;
  font-weight: 720;
}
.pipeline b { color: var(--accent-strong); }

.english-copy {
  max-width: 900px;
  color: var(--muted);
}
.english-copy p { margin: 0; }
.english-copy p + p { margin-top: 14px; }

.policy { max-width: 900px; padding: 54px 0 72px; }
.policy h1 { font-size: clamp(2.1rem, 5vw, 3.8rem); }
.policy h2 { margin-top: 40px; font-size: 1.45rem; }
.policy h3 { margin-top: 26px; font-size: 1.12rem; }
.policy p,
.policy li { color: var(--muted); }
.policy ul { padding-left: 1.25rem; }
.meta { color: var(--muted); margin-top: 12px; }
.lang-divider {
  margin: 50px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 26px 0 42px;
  color: var(--muted);
  font-size: .92rem;
}
.footer-row {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-row a { color: var(--muted); }

@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; }
  .cards,
  .status-grid { grid-template-columns: 1fr; }
  .tech-grid { grid-template-columns: 1fr; }
  .architecture-flow {
    grid-template-columns: 1fr;
  }
  .flow-arrow { transform: rotate(90deg); }
}
@media (max-width: 760px) {
  .hero { padding-top: 54px; }
  .nav {
    align-items: flex-start;
    padding: 14px 0;
  }
  .nav-links {
    gap: 10px 12px;
    font-size: .9rem;
  }
  .spec-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}
@media (max-width: 560px) {
  .wrap { width: min(100% - 22px, 1120px); }
  .brand span:last-child { display: none; }
  .nav-links a { font-size: .84rem; }
  .hero-card,
  .card,
  .tech-card,
  .status-panel,
  .notice { border-radius: 16px; }
  .hero-actions .button { width: 100%; }
}