:root {
  color-scheme: light;
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "Yu Gothic Medium", "Yu Gothic", Meiryo, sans-serif;
  color: #243242;
  background: #f3f7fa;
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  background:
    linear-gradient(135deg, rgba(16, 91, 145, 0.08), transparent 45%),
    #f3f7fa;
}

.notice {
  display: grid;
  min-height: 100vh;
  padding: 40px 20px;
  place-items: center;
}

.notice__card {
  width: min(100%, 720px);
  padding: 64px 56px;
  text-align: center;
  background: #fff;
  border-top: 5px solid #12639c;
  border-radius: 6px;
  box-shadow: 0 18px 50px rgba(31, 53, 72, 0.12);
}

.notice__label {
  margin: 0 0 16px;
  color: #12639c;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.18em;
}

h1 {
  margin: 0;
  color: #203448;
  font-size: clamp(1.65rem, 5vw, 2.4rem);
  line-height: 1.4;
}

.notice__message {
  margin: 32px 0;
  font-size: 1rem;
  line-height: 2;
}

.notice__button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  min-height: 54px;
  padding: 14px 28px;
  color: #fff;
  font-weight: 700;
  line-height: 1.5;
  text-decoration: none;
  background: #12639c;
  border-radius: 4px;
  box-shadow: 0 8px 20px rgba(18, 99, 156, 0.22);
  transition: background-color 0.2s, transform 0.2s;
}

.notice__button:hover {
  background: #0d4d7a;
  transform: translateY(-2px);
}

.notice__button:focus-visible {
  outline: 3px solid rgba(18, 99, 156, 0.35);
  outline-offset: 4px;
}

.notice__url {
  margin: 24px 0 0;
  overflow-wrap: anywhere;
  color: #586777;
  font-size: 0.9rem;
}

.notice__url a {
  color: #12639c;
}

.notice__help {
  margin: 36px 0 0;
  padding-top: 24px;
  color: #687786;
  font-size: 0.875rem;
  line-height: 1.8;
  border-top: 1px solid #e3e9ee;
}

@media (max-width: 600px) {
  .notice {
    padding: 20px 14px;
  }

  .notice__card {
    padding: 44px 22px;
  }

  .notice__message br {
    display: none;
  }

  .notice__button {
    width: 100%;
    padding-inline: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .notice__button {
    transition: none;
  }
}