body {
  font-family: Arial, sans-serif;
  margin: 20px;
}
.container {
  background-color: #f4f4f4;
  padding: 20px;
  box-shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
  text-align: center;
}
.input-container {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 20px;
}

.input-labels {
  display: flex;
  flex-direction: column;
}
.input-box {
  margin: 10px;
  padding: 10px;
  font-size: 18px;
}
.input-box.invalid {
  color: red;
}

input::placeholder,
input:invalid::placeholder {
  color: grey;
}

.output-header,
.output-row {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: 20px;
}
.column {
  flex: 1;
  text-align: center;
}
.output-container {
  max-height: 200px;
  overflow-y: auto;
}
.hidden {
  display: none;
}
.calculate-btn {
  margin-right: 12px;
}

.action-container {
  margin-top: 10px;
}