* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Noto Sans JP", Arial, sans-serif;
  background: linear-gradient(180deg, #f8fbff 0%, #eef4ff 100%);
  color: #1e2a40;
}

.page-container {
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px;
}

.hero {
  text-align: center;
  padding-bottom: 28px;
}

h1 {
  margin: 0;
  font-size: clamp(2.2rem, 4vw, 3rem);
  letter-spacing: -0.04em;
}

.subtitle {
  margin: 18px auto 0;
  max-width: 640px;
  color: #4b5d79;
  font-size: 1rem;
  line-height: 1.8;
}

.links-panel {
  display: grid;
  gap: 18px;
  margin-top: 32px;
}

.link-card {
  display: block;
  padding: 20px 24px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(30, 42, 64, 0.12);
  color: #1e2a40;
  text-decoration: none;
  font-weight: 700;
  font-size: 1.1rem;
  text-align: center;
  box-shadow: 0 18px 40px rgba(21, 50, 93, 0.08);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.link-card:hover {
  transform: translateY(-2px);
  border-color: rgba(30, 42, 64, 0.2);
  box-shadow: 0 24px 44px rgba(21, 50, 93, 0.12);
}

@media (max-width: 560px) {
  .page-container {
    padding: 28px 16px;
  }

  .link-card {
    padding: 18px 20px;
    font-size: 1rem;
  }
}