styles.css

#calc {
  display: grid;
  grid-template-rows: repeat(18, 1fr);
  grid-template-columns: repeat(8, 1fr);
  height: 800px;
  width: 600px;
  margin: auto;
  border: 1px solid black;
  border-radius: 25px;
  background-color: #bebebe;
}

/* Screen */
.screen {
  grid-area: 2 / 2 / span 2 / span 6;
  background-color: white;
  display: flex;
  justify-content: right;
  align-items: flex-end;
  font-size: 36px;
}

/* Big buttons */
.clear {
  grid-area: 5 / 2 / span 1 / span 2;
  background-color: #faa;
}

.backspace {
  grid-area: 5 / 6 / span 1 / span 2;
  background-color: #aaaafe;
}

.big-button-style {
  display: flex;
  border: 1px solid black;
  border-radius: 25px;
  font-size: 30px;
  font-weight: bold;
  padding: 20%;
  justify-content: center;
  align-items: center;
}

/* Little Buttons */

.button {
  grid-area: 7 / 2 / 18 / 8;
  /* This creates a subgrid! */
  display: grid;
  grid-template-rows: repeat(4, 1fr);
  grid-template-columns: repeat(4, 1fr);
}

.button-design {
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: x-large;
  border: 1px solid black;
}