.nav-button{
  background-color: #0078D4;
  color: white;
  font-size: 16px;              /* ✅ 大きな文字 */
  font-weight: bold;            /* ✅ 太文字を追加 */
  padding: 8px 8px;
  margin: 1px 1px;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s;
}

.nav-button:hover{
  background-color: #005A9E;
}

  .big-input {
    font-size: 20px;
    padding: 8px 8px;
    width: 200px;
    border: 2px solid #0078D4;
    border-radius: 6px;
    margin: 6px 4px;
  }

  .big-input::placeholder {
    font-size: 20px;
    color: #888;
  }