:root{
  --bg: #ffffff;
  --bg2:#ffffff;
  --card:#ffffff;
  --text:#111827;     /* ほぼ黒 */
  --muted:#4b5563;    /* グレー */
  --line: rgba(17,24,39,.14);
  --accent:#2563eb;   /* 青 */
  --accent2:#059669;  /* 緑 */
  --shadow: 0 10px 26px rgba(17,24,39,.10);
  --radius: 18px;
  --max: 1080px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}

*{box-sizing:border-box}
html,body{height:100%}

body{
  margin:0;
  font-family:var(--sans);
  color:var(--text);
  background: #ffffff;
}

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

.container{max-width:var(--max); margin:0 auto; padding:24px}

.nav{
  display:flex; align-items:center; justify-content:space-between;
  gap:16px; padding:14px 18px; border:1px solid var(--line);
  background: rgba(255,255,255,.90);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.brand{display:flex; align-items:center; gap:10px; font-weight:800; letter-spacing:.3px}

.badge{
  font-family:var(--mono);
  font-size:12px;
  padding:4px 10px;
  border:1px solid var(--line);
  border-radius:999px;
  color:var(--muted);
  background: rgba(17,24,39,.03);
}

.navlinks{display:flex; gap:10px; align-items:center; flex-wrap:wrap}

.btn{
  display:inline-flex; align-items:center; gap:8px;
  padding:10px 14px;
  border-radius:12px;
  border:1px solid var(--line);
  background: rgba(17,24,39,.03);
  color:var(--text);
  transition: transform .08s ease, background .12s ease, border-color .12s ease;
}

.btn:hover{
  transform: translateY(-1px);
  background: rgba(17,24,39,.06);
  border-color: rgba(17,24,39,.22);
}

.btn.primary{
  border-color: rgba(37,99,235,.35);
  background: linear-gradient(90deg, rgba(37,99,235,.12), rgba(5,150,105,.10));
}

.hero{
  margin-top:22px;
  padding:28px;
  border:1px solid var(--line);
  border-radius: calc(var(--radius) + 6px);
  background: rgba(255,255,255,.92);
  box-shadow: var(--shadow);
}

.hero h1{
  margin: 0 0 10px 0;
  font-size: 38px;
  line-height:1.15;
  letter-spacing: .2px;
}

.hero p{
  margin:0 0 18px 0;
  color:var(--muted);
  font-size:16px;
  line-height:1.7
}

.kpis{display:flex; gap:10px; flex-wrap:wrap; margin-top:10px}

.kpi{
  padding:8px 12px;
  border:1px solid var(--line);
  border-radius:12px;
  background: rgba(17,24,39,.03);
  font-family:var(--mono);
  font-size:12px;
  color:var(--muted);
}

.grid{
  margin-top:18px;
  display:grid;
  grid-template-columns: repeat(3, 1fr);
  gap:14px;
}

.card{
  padding:18px;
  border:1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(255,255,255,.92);
  box-shadow: 0 10px 22px rgba(17,24,39,.08);
}

.card h3{margin:0 0 8px 0; font-size:16px}

.card p{margin:0; color:var(--muted); line-height:1.7; font-size:14px}

.card code{
  display:inline-block;
  font-family:var(--mono);
  font-size:12px;
  padding:2px 6px;
  border:1px solid var(--line);
  border-radius:8px;
  background: rgba(17,24,39,.03);
}

.footer{
  margin-top:18px;
  padding:12px 14px;
  color:var(--muted);
  font-family:var(--mono);
  font-size:12px;
  border-top:1px solid var(--line);
}

/* 小さめ画面 */
@media (max-width: 900px){
  .grid{grid-template-columns: 1fr}
  .hero h1{font-size:30px}
}