:root {
  --navy: #0D3B66;
  --blue: #4A90E2;
  --sky: #A8D8F0;
  --ivory: #F6F1E7;
  --ink: #17324d;
  --muted: #5d7183;
  --white: #ffffff;
  --line: #dbe6ee;
  --shadow: 0 18px 45px rgba(13, 59, 102, .10);
  --radius: 22px;
  --max: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Yu Gothic", "Meiryo", sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--navy); }
a:hover { color: var(--blue); }
img { max-width: 100%; height: auto; }
.container { width: min(calc(100% - 40px), var(--max)); margin-inline: auto; }

.site-header {
  border-bottom: 1px solid rgba(13, 59, 102, .08);
  background: rgba(255,255,255,.96);
}
.header-inner {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  display: inline-flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--navy);
  line-height: 1.15;
}
.brand-ja { font-weight: 800; font-size: 1.12rem; letter-spacing: .04em; }
.brand-en { margin-top: 5px; font-size: .72rem; letter-spacing: .16em; color: var(--muted); }
.nav { display: flex; align-items: center; gap: 20px; flex-wrap: wrap; justify-content: flex-end; }
.nav a { text-decoration: none; font-size: .9rem; font-weight: 650; }
.lang-link {
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--white);
}

.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 86% 20%, rgba(168,216,240,.65) 0 120px, transparent 121px),
    linear-gradient(135deg, #fff 0%, #fff 55%, #f3f9fc 100%);
}
.hero::after {
  content: "";
  position: absolute;
  width: 520px;
  height: 520px;
  right: -250px;
  bottom: -320px;
  border-radius: 50%;
  background: var(--ivory);
  opacity: .9;
}
.hero-inner {
  position: relative;
  z-index: 1;
  min-height: 520px;
  display: grid;
  grid-template-columns: 1.25fr .75fr;
  gap: 60px;
  align-items: center;
  padding-block: 74px;
}
.eyebrow {
  margin: 0 0 16px;
  color: var(--blue);
  font-size: .82rem;
  font-weight: 800;
  letter-spacing: .18em;
  text-transform: uppercase;
}
h1, h2, h3 { color: var(--navy); line-height: 1.25; }
h1 {
  margin: 0;
  font-size: clamp(2.35rem, 5vw, 4.5rem);
  letter-spacing: .02em;
}
.hero-lead {
  max-width: 680px;
  margin: 24px 0 0;
  font-size: clamp(1.05rem, 2vw, 1.28rem);
  color: #35536d;
}
.hero-note { margin: 14px 0 0; color: var(--muted); font-size: .92rem; }
.hero-art {
  min-height: 300px;
  position: relative;
}
.hero-art .sun,
.hero-art .sea,
.hero-art .line {
  position: absolute;
  border-radius: 999px;
}
.hero-art .sun {
  width: 170px; height: 170px; right: 18px; top: 18px;
  background: var(--ivory);
  border: 1px solid #eadfca;
}
.hero-art .sea {
  width: 290px; height: 150px; right: 0; bottom: 22px;
  background: linear-gradient(180deg, var(--sky), #dff2fa);
  border-radius: 50% 50% 18px 18px;
}
.hero-art .line {
  width: 230px; height: 4px; right: 30px; bottom: 88px;
  background: var(--navy);
  opacity: .8;
}

.section { padding: 86px 0; }
.section.alt { background: #f8fbfd; }
.section-kicker { margin: 0 0 10px; color: var(--blue); font-weight: 800; letter-spacing: .14em; font-size: .78rem; text-transform: uppercase; }
.section h2 { margin: 0 0 22px; font-size: clamp(1.75rem, 3vw, 2.55rem); }
.section-intro { max-width: 760px; margin: 0; color: var(--muted); }
.about-mascot { display: block; width: 100px; height: auto; margin-top: 16px; }

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-top: 38px;
}
.card {
  padding: 30px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.card .num {
  display: inline-flex;
  width: 34px; height: 34px;
  align-items: center; justify-content: center;
  border-radius: 50%;
  background: var(--ivory);
  color: var(--navy);
  font-size: .8rem;
  font-weight: 800;
}
.card h3 { margin: 18px 0 10px; font-size: 1.25rem; }
.card p { margin: 0; color: var(--muted); }

.channel {
  margin-top: 34px;
  padding: 26px 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: var(--white);
}
.channel strong { display: block; color: var(--navy); font-size: 1.08rem; }
.channel span { display: block; color: var(--muted); margin-top: 4px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border-radius: 999px;
  background: var(--navy);
  color: var(--white);
  text-decoration: none;
  font-weight: 750;
  white-space: nowrap;
}
.button:hover { background: var(--blue); color: var(--white); }

.contact-box {
  padding: 34px;
  border-radius: var(--radius);
  background: var(--ivory);
  border: 1px solid #eadfca;
}
.contact-box p { margin: 0; }
.contact-box p + p { margin-top: 10px; }
.small { color: var(--muted); font-size: .9rem; }

.site-footer {
  padding: 30px 0;
  background: var(--navy);
  color: rgba(255,255,255,.84);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}
.footer-links { display: flex; gap: 16px; flex-wrap: wrap; }
.site-footer a { color: var(--white); text-decoration: none; }
.site-footer p { margin: 0; }

.legal { max-width: 820px; }
.legal h1 { font-size: clamp(2rem, 4vw, 3.2rem); }
.legal h2 { margin-top: 42px; font-size: 1.35rem; }
.legal p, .legal li { color: #405d75; }
.legal ul { padding-left: 1.3em; }

.not-found {
  min-height: calc(100vh - 138px);
  display: grid;
  place-items: center;
  text-align: center;
  padding: 60px 20px;
}
.not-found h1 { font-size: clamp(3rem, 8vw, 6rem); margin-bottom: 8px; }
.not-found p { color: var(--muted); margin: 0 0 24px; }

@media (max-width: 800px) {
  .header-inner { align-items: flex-start; padding-block: 18px; }
  .nav { gap: 12px; }
  .nav .desktop-link { display: none; }
  .hero-inner { grid-template-columns: 1fr; gap: 20px; min-height: auto; padding-block: 58px 70px; }
  .hero-art { min-height: 190px; }
  .hero-art .sun { width: 115px; height: 115px; }
  .hero-art .sea { width: 220px; height: 110px; }
  .hero-art .line { width: 175px; bottom: 66px; }
  .section { padding: 66px 0; }
  .cards { grid-template-columns: 1fr; }
  .channel { align-items: flex-start; flex-direction: column; }
  .button { width: 100%; }
}