* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 62.4%;
}

body {
  background-color: rgba(198, 197, 197, 0.492);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.calculator {
  width: 40rem;
  height: 50rem;
  background-color: #e99f86;
  padding: 4rem;
  border-top-left-radius: 80% 20px;
  border-top-right-radius: 80% 20px;
  border-bottom-left-radius: 80% 20px;
  border-bottom-right-radius: 80% 20px;
  box-shadow: inset 5px 0 10px -5px #555, inset -5px 0 10px -5px #555,
    inset 0px -5px 10px -2px #555, 0 0 1px 2px #333, 0 10px 20px 0 #333;
}
.calculator p {
  text-align: center;
  font-size: 3rem;
  font-weight: bold;
  margin-bottom: 1.5rem;
}
.calculator input {
  width: 100%;
  height: 4rem;
  border: 1.5px solid #333;
  background-color: antiquewhite;
  text-align: right;
  padding: 0 1rem;
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}
.button-container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-template-rows: repeat(5, 1fr);
  min-height: 32rem;
}
.button {
  display: inline-block;
  border-top-left-radius: 80% 10px;
  border-top-right-radius: 80% 10px;
  border-bottom-left-radius: 80% 10px;
  border-bottom-right-radius: 80% 10px;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.08),
    inset 0 1px 6px rgba(255, 255, 255, 0.67),
    inset 0 -1px 0 rgba(0, 0, 0, 0.14);
  border: none;
  margin: 0.75rem;
  font-size: 2rem;
  font-weight: bold;
  background-color: #333;
  color: #fff;
}

.button.plus {
  grid-column: 4/5;
  grid-row: -3/-1;
}

.button.red {
  background-color: rgb(171, 1, 1);
}