:root{
  --text:#111; --muted:#666; --border:#e5e7eb; --bg:#ffffff; --bg-sub:#f9fafb;
  --accent:#2563eb; --radius:14px; --shadow:0 8px 24px rgba(0,0,0,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;color:var(--text);background:var(--bg);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic UI","YuGothic","Meiryo",sans-serif;line-height:1.65}
img{max-width:100%;height:auto}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:1100px;margin:0 auto;padding:0 16px}
header.header{position:sticky;top:0;background:#fff;box-shadow:0 1px 0 var(--border);z-index:30}
.nav{display:flex;align-items:center;gap:20px;height:64px}
.brand{font-weight:800}
nav ul{display:flex;gap:10px;list-style:none;margin:0;padding:0}
nav a{display:block;padding:10px 14px;border-radius:10px}
nav a.active, nav a:hover{background:var(--bg-sub);text-decoration:none}
main{padding:28px 0 60px}
.hero{padding:40px 0;background:var(--bg-sub);border-bottom:1px solid var(--border)}
.hero h1{margin:0 0 12px;font-size:clamp(20px,4vw,32px)}
.hero p{color:var(--muted);margin:0}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.card{border:1px solid var(--border);border-radius:var(--radius);background:#f6fbfe;box-shadow:var(--shadow);padding:18px} /* light blue unified */
.card h3{margin:0 0 6px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:12px 16px;border-radius:12px;border:1px solid var(--border);background:#fff;text-decoration:none}
.btn.primary{background:var(--accent);border-color:transparent;color:#fff}
footer{border-top:1px solid var(--border);padding:24px 0;color:var(--muted);background:#fff}
.lead{font-size:1.1rem;color:var(--muted)}
.note{font-size:.9rem;color:var(--muted)}
.center{display:flex;justify-content:center;align-items:center}
/* mobile */
.nav-toggle{display:none;border:1px solid var(--border);background:#fff;border-radius:12px;padding:10px 12px;font:inherit}
@media (max-width:960px){
  .grid{grid-template-columns:1fr}
  .nav{gap:10px}
  nav{position:relative}
  .nav-toggle{display:block;margin-left:auto}
  nav ul{position:absolute;right:0;top:56px;min-width:220px;display:none;flex-direction:column;gap:0;background:#fff;border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow);padding:6px}
  nav a{padding:12px 14px;border-radius:10px}
  header.is-open nav ul{display:flex}
}
/* buttons */
.btn{min-height:44px}