body {
  margin: 0;
  padding: 0;
  box-sizing: border-box;

  height: 100dvh;
  display: flex;
  flex-direction: column;
}

main {
  flex-grow: 1;
}

#downRow {
  margin-left: 20px;
}

button {
  width: 50px;
  height: 50px;
}