body {
  margin: 40px auto;
  max-width: 700px;
  line-height: 1.6;
  font-size: 18px;
  color: #444;
  padding: 0;
}
h1,
h2,
h3 {
  line-height: 1.2;
}
img {
  max-height: 600px;
}
.row {
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}

.column {
  display: flex;
  flex-direction: column;
}

.calc {
  max-width: fit-content;
}

button {
  max-width: fit-content;
  margin-top: 1em;
}

input {
  width: 100%;
  max-width: 100%;
}