:root {
  --text: #222;
  --subtext: #666;
  --border: #e8e8e8;
  --bg: #f2f2f2;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family:
    -apple-system,
    BlinkMacSystemFont,
    "Helvetica Neue",
    "Hiragino Kaku Gothic ProN",
    "Yu Gothic",
    YuGothic,
    Arial,
    sans-serif;

  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  width: 100%;
  max-width: 600px;
  padding: 40px 24px;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 64px 48px;
  text-align: center;
}

h1 {
  margin: 0 0 32px;
  font-size: 32px;
  font-weight: 600;
  letter-spacing: 0.05em;
}

.message {
  margin: 0 0 28px;
  color: var(--subtext);
  line-height: 1.8;
  font-size: 15px;
}

footer {
  text-align: center;
  margin-top: 32px;
  color: #999;
  font-size: 13px;
}


/* スマートフォン */
@media (max-width: 600px) {

  .container {
    padding: 48px 32px;
  }

  .card {
    padding: 48px 24px;
    border-radius: 12px;
  }

  h1 {
    font-size: 24px;
    margin-bottom: 24px;
  }

  .message {
    font-size: 14px;
  }
}