* {
  box-sizing: border-box;
}

body {
  background-color: rgb(23, 23, 23);
  display: grid;
  grid-template-columns: 1fr;
  justify-items: center;
  color: white;
  padding-top: 3rem;
}
.calculator {
  border-radius: 1rem;
  background-color: black;
  display: grid;
  grid-template-columns: 1;
  overflow: hidden;
}
.screen {
  background-color: rgb(40, 39, 39);
  display: grid;
  justify-items: end;
  font-family: arial;
  align-items: center;
  padding: 1rem;
  height: 5rem;
}
.input {
  color: greenyellow;
}
.output {
  color: white;
  font-size: 1.5rem;
}
.functions {
  padding: 1rem;
  background-color: rgb(33, 33, 34);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  box-shadow: inset 0.5rem 0 2rem rgba(6, 6, 6, 0.5);
}
button {
  font-size: 1.2rem;
  border: none;
  padding: 1rem;
  color: white;
  background-color: rgb(33, 33, 34);
  box-shadow: inset 0.5rem 0 2rem rgba(6, 6, 6, 0.5);
  transition: all 0.4s;
  border-radius: 0.5rem;
  &:hover {
    outline: 1px solid greenyellow;
  }
  &:focus {
    background-color: rgb(38, 38, 38);
    transform: translateY(-1px);
  }
}
.calculator-operator {
  color: greenyellow;
}