:root {
  --bg: #f6f8fc;
  --surface: #ffffff;
  --surface-soft: #f4f6ff;
  --text: #1b2230;
  --muted: #5b6475;
  --line: #dce2ef;
  --primary: #4f46e5;
  --primary-strong: #3730a3;
  --accent: #7c3aed;
  --success: #0ea5a3;
  --shadow: 0 12px 32px rgba(15, 23, 42, 0.08);
  --radius-lg: 20px;
  --radius-md: 14px;
  --space-1: 8px;
  --space-2: 12px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 32px;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: 'Inter', 'Noto Sans JP', sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 15% 10%, #eef1ff 0, transparent 38%),
              radial-gradient(circle at 85% 0%, #f3e8ff 0, transparent 32%), var(--bg);
  line-height: 1.6;
}

a { color: inherit; }
img { max-width: 100%; display: block; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  backdrop-filter: blur(10px);
  background: rgba(246, 248, 252, 0.88);
  border-bottom: 1px solid var(--line);
}

.header-inner,
.page-shell,
.footer-inner {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: var(--space-3);
}

.brand {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}
.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: inset 0 0 0 2px rgba(255,255,255,.25);
}
.brand-sub { color: var(--muted); font-size: .78rem; margin-top: -4px; }

.menu-toggle {
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
  width: 42px;
  height: 42px;
  display: none;
  place-items: center;
  cursor: pointer;
}

.site-nav ul { display: flex; list-style: none; gap: var(--space-1); margin: 0; padding: 0; }
.site-nav a {
  text-decoration: none;
  color: var(--muted);
  padding: 8px 12px;
  border-radius: 999px;
  font-size: .93rem;
  transition: .2s ease;
}
.site-nav a:hover,
.site-nav a[aria-current='page'] { background: var(--surface); color: var(--text); box-shadow: var(--shadow); }

.page-shell { padding: var(--space-5) 0 64px; }
.section + .section { margin-top: var(--space-5); }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  padding: var(--space-4);
}

.page-title { font-size: clamp(1.7rem, 3.2vw, 2.5rem); line-height: 1.2; margin: 0 0 10px; }
.page-lead { color: var(--muted); margin: 0; }

.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-3); }

.btn {
  border: none;
  border-radius: 12px;
  padding: 12px 18px;
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  cursor: pointer;
  transition: transform .2s ease, box-shadow .2s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn:focus-visible { outline: 3px solid rgba(79,70,229,.25); outline-offset: 2px; }
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; box-shadow: 0 10px 24px rgba(79,70,229,.35); }
.btn-secondary { background: var(--surface-soft); border: 1px solid var(--line); color: var(--text); }
.btn-ghost { background: transparent; border: 1px solid var(--line); color: var(--muted); }

.footer {
  border-top: 1px solid var(--line);
  background: rgba(255,255,255,.8);
  padding: 24px 0 36px;
}
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: var(--space-3); flex-wrap: wrap; }
.footer-links { display: flex; gap: var(--space-3); flex-wrap: wrap; }
.footer a { color: var(--muted); text-decoration: none; font-size: .92rem; }

.field-label { display: block; font-weight: 600; margin-bottom: 6px; }
.input,
textarea,
input[type='text'],
input[type='file'] {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 11px 12px;
  background: #fff;
  font: inherit;
}

.modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.48);
  display: grid;
  place-items: center;
  padding: 1rem;
}
.hidden { display: none !important; }
.modal-card { width: min(500px, 100%); }

@media (max-width: 900px) {
  .grid-3 { grid-template-columns: 1fr; }
  .site-nav {
    position: fixed;
    inset: 72px 1rem auto;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 12px;
    box-shadow: var(--shadow);
    display: none;
  }
  .site-nav.is-open { display: block; }
  .site-nav ul { flex-direction: column; }
  .menu-toggle { display: grid; }
}