body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  background: #009297;
  color: #fff;
}

.container {
  max-width: 100%;
  padding: 20px;
  box-sizing: border-box;
  text-align: center;
}

.subtitle {
  font-size: 16px;
  margin-bottom: 10px;
  color: #e0f7f7;
}

h1 {
  font-size: 22px;
  margin-bottom: 20px;
  color: #fff;
}

.form-group {
  background: #ffffff;
  color: #333;
  padding: 20px;
  border-radius: 10px;
  margin: 0 auto;
  max-width: 100%;
  box-sizing: border-box;
  text-align: center;
}

.form-group div {
  margin-bottom: 15px;
}

select, input {
  padding: 10px;
  font-size: 16px;
  width: 90%;
  max-width: 300px;
  box-sizing: border-box;
}

button {
  margin-top: 10px;
  padding: 12px 20px;
  font-size: 16px;
  background: #009297;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

.result-box {
  margin-top: 30px;
  padding: 20px;
  border-radius: 10px;
  text-align: center;
  background: #ffffff;
  color: #333;
  box-sizing: border-box;
}

.hidden {
  display: none;
}

.rank-box {
  margin-top: 10px;
  font-size: 22px;
  font-weight: bold;
  padding: 15px;
  border-radius: 10px;
  color: white;
}

.rank-note {
  margin-top: 8px;
  font-size: 14px; /* 少し小さめ */
  line-height: 1.6;
  color: #333;
  white-space: pre-line; /* \nで改行表示 */
}

/* ランク色 */
.rank-a { background-color: #2e7d32; }  /* 濃い緑 */
.rank-b { background-color: #fdd835; color: #333; } /* 黄 */
.rank-c { background-color: #fb8c00; }  /* 橙 */
.rank-d { background-color: #e53935; }  /* 赤 */