body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  margin: 0;
  padding: 20px;
  background-color: #f9f9f9;
  color: #222;
  max-width: 390px;
  margin-left: auto;
  margin-right: auto;
}

header h1 {
  font-size: 1.5rem;
  text-align: center;
  margin-bottom: 1.5rem;
}

/* --- ここから修正 --- */
label {
  display: block;
  margin-bottom: 8px;
  font-weight: bold;
  font-size: 1rem;          /* 文字サイズを1remに統一 */
  color: #333;
}

/* セレクトボックスのデザイン追加 */
#stage-select {
  display: block;
  width: 100%;
  font-size: 1rem;          /* ラベルと同じサイズ */
  padding: 8px 10px;
  margin-bottom: 20px;      /* 下に十分な余白 */
  border-radius: 6px;
  border: 1px solid #ccc;
  box-sizing: border-box;
  background-color: white;
}
/* --- 修正ここまで --- */

textarea {
  width: 100%;
  max-width: 100%;
  font-size: 1rem;
  padding: 14px;
  border-radius: 6px;
  border: 1px solid #ccc;
  margin-bottom: 12px;
  height: 180px;
  box-sizing: border-box;
  resize: vertical;
}

@media screen and (max-width: 430px) {
  textarea {
    font-size: 1rem;
    height: 100px;
  }
}

button#assign-btn {
  display: block;
  width: 100%;
  padding: 15px;
  font-size: 1.2rem;
  background-color: #007aff;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

button#assign-btn:hover {
  background-color: #005bb5;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid #ccc;
  padding: 8px;
  text-align: left;
}

thead {
  background-color: #f2f2f2;
}