:root {
  color-scheme: light;
  --ink: #172333;
  --muted: #5f6f7f;
  --line: #d8e1e8;
  --surface: #ffffff;
  --background: #f4f7f9;
  --primary: #087f8c;
  --primary-dark: #075f69;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans JP", sans-serif;
  line-height: 1.75;
}

a { color: var(--primary-dark); }

header {
  background: #071626;
  color: #fff;
  border-bottom: 3px solid #12b8c8;
}

.header-inner,
main,
.footer-inner {
  width: min(900px, calc(100% - 40px));
  margin: 0 auto;
}

.header-inner {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: #fff;
  text-decoration: none;
  font-size: 21px;
  font-weight: 800;
}

nav { display: flex; gap: 20px; }
nav a { color: #d8e7ef; text-decoration: none; font-size: 14px; }
nav a:hover { color: #fff; }

main {
  padding: 56px 0 72px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--primary-dark);
  font-size: 13px;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1.25;
}

.lead {
  max-width: 720px;
  margin: 14px 0 42px;
  color: var(--muted);
}

section {
  padding: 28px 0;
  border-top: 1px solid var(--line);
}

h2 { margin: 0 0 12px; font-size: 21px; }
h3 { margin: 22px 0 8px; font-size: 17px; }
p, ul { margin: 8px 0; }
ul { padding-left: 1.4em; }

.notice {
  margin: 24px 0;
  padding: 16px 18px;
  border-left: 4px solid var(--primary);
  background: #e9f6f7;
}

.contact {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 700;
}

footer {
  border-top: 1px solid var(--line);
  background: var(--surface);
  color: var(--muted);
}

.footer-inner {
  padding: 26px 0;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 13px;
}

.footer-links { display: flex; gap: 16px; flex-wrap: wrap; }

@media (max-width: 640px) {
  .header-inner { align-items: flex-start; flex-direction: column; padding: 15px 0; }
  nav { gap: 14px; flex-wrap: wrap; }
  main { padding-top: 38px; }
  .footer-inner { flex-direction: column; }
}