*,
*::before,
*::after {
  padding: 0px;
  margin: 0px;
  box-sizing: border-box;
}

h1 {
  text-align: center;
  color: #4d4b4b;
  margin-top: 1rem;
  font-size: 2rem;
  font-family: Verdana, Geneva, Tahoma, sans-serif;
  font-weight: 600;
}

.calcBtn {
  width: 2.8rem;
  height: 2.8rem;
  background-color: #faffff;
  border: 1px solid #7bf3f3;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  font-size: 1.7rem;
  margin: 0.6rem;
  color: #302b2b;
  border-radius: 6px;
}

.calcBtn:hover {
  background-color: #dcfafa;
  cursor: pointer;
}

#outerBox {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(6, 1fr);
  width: fit-content;
  height: fit-content;
  margin: 6vh auto;
  padding: 1.2rem;
  background-color: #4d4b4b;
  border: 1px solid #dbdbdb;
  border-radius: 9px;
  box-shadow: 0px 1px 10px 8px #f1f1f1;
}

#displayBox {
  grid-column: 1/5;
  grid-row: 1/2;
  height: 3.2rem;
  width: 96%;
  background-color: #eefcfc;
  border: 1px solid #686464;
  padding: 0.4rem;
  font-size: 2.8rem;
  color: #0c0b0b;
  align-self: center;
  justify-self: center;
  border-radius: 2px;
  text-align: end;
  font-family: Arial, Helvetica, sans-serif;
}

.cancel {
  grid-column: 4/5;
  grid-row: 2/4;
  height: 7rem;
}

.equalToSign {
  grid-column: 3/5;
  grid-row: 6/7;
  width: 7.2rem;
}

@media (min-width: 992px) {
  .calcBtn {
    width: 4.5rem;
    height: 3.2rem;
    align-self: center;
    justify-self: center;
  }
  .cancel {
    grid-column: 4/5;
    grid-row: 2/4;
    height: 7.6rem;
  }

  .equalToSign {
    grid-column: 3/5;
    grid-row: 6/7;
    width: 11rem;
  }
  #displayBox {
    height: 3.4rem;
  }

  #outerBox {
    width: 490px;
    padding-top: 2rem;
  }
}