/* bodyを追加して全体を中央寄せ */
body {
  display: flex;
  justify-content: center;
  margin: 0;
  width: 100%;
}

h1 {
  font-size:32px;
}
#setBox {
  font-size: 24px;
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding-left: 0; 
  width: 480px;
}

.btn-container {
  display: flex;
  justify-content: flex-start;
  gap: 40px;
  margin-bottom: 20px;
}

.input-container {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  width: 480px;
}

#inpStr {
  flex-grow: 1;
  height: 48px;
  font-size: 24px;
}

.Btn-add {
  font-size: 24px;
  height: 52px;
  padding: 0 10px;
  white-space: nowrap;
}

#txtdata { 
  margin-top: 0px;
  font-size: 18px;
  height: 400px;
  width: 480px;
}

.Btn {
  font-size: 24px;
  height: 48px;
  width: 120px;
  margin-top: 0;
}