@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono&family=Quantico&display=swap');

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background-color: cornflowerblue;
}

.wrapper {
  height: 100vh;
  display: grid;
  place-items: center;
}

.calculator {
  background-color: #353539;
  padding: 1em;
  border-radius: 0.3em;
  box-shadow: 0 1px 0px #7f878d inset, 0 -1px 2px #202224 inset,
    -2px 0 1px #676d73 inset, 1px 0 1px #646b71 inset, 0 0 1px 2px #100f1055,
    0 1px 3px 5px #100f1033, 0 3px 3px #111;
}

.output {
  padding: 0 0.2em;
  font-size: 2rem;
  width: 100%;
  font-family: 'Quantico', sans-serif;
  text-align: right;
  background-color: #d9ed92;
  color: #343a40;
  box-shadow: rgba(50, 50, 93, 0.25) 0px 30px 60px -12px inset,
    rgba(0, 0, 0, 0.3) 0px 18px 36px -18px inset;
}

.prevous-output {
  display: block;
  font-size: 1rem;
}

.input {
  margin-top: 0.2em;
  display: grid;
  grid-template-rows: repeat(5, 1fr);
  grid-template-columns: repeat(4, 1fr);
}

button {
  font-size: 2rem;
  font-family: 'IBM Plex Mono', monospace;
  color: white;
  background-color: #535c61;
  text-shadow: 0 0 4px #0004;
  border-radius: 5px;
  margin: 0.2em;
  border: none;
  box-shadow: 0 1px 0px #7f878d inset, 0 -1px 2px #202224 inset,
    -2px 0 1px #676d73 inset, 1px 0 1px #646b71 inset, 0 0 1px 2px #100f1055,
    0 1px 3px 5px #100f1033, 0 3px 3px #111;
  transition: all 0.15s;
  cursor: pointer;
}

.input > button:first-of-type {
  grid-column-start: 1;
  grid-column-end: 3;
}

.input > button:last-of-type {
  grid-column-start: 3;
  grid-column-end: 5;
}

button:active {
  box-shadow: 0 1px 0px #7f878d inset, 0 -1px 2px #202224 inset,
    -2px 0 1px #676d73 inset, 1px 0 1px #646b71 inset, 0 0 1px 2px #100f1055;
  transform: translateY(2px);
}