* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  background-color: brown;
}
.box {
  display: flex;
}
.box > * {
  flex: 1;
}
.container {
  display: flex;
  flex-direction: column;
  background-color: black;
  padding: 3rem;
  align-items: center;
  height: 50rem;
  width: 50rem;
}

.showborder {
  gap: 0.07rem;
}