style.css

body {
    background: #FF6F61;
    font-family: 'Montserrat', sans-serif;
}
.container {
  background: #EEEEEE;
  width: 320px;
  height: 600px;
  border-radius: .5em;
  box-shadow: 4px 4px 10px 0 rgba(0,0,2,.3);
  margin: 0 auto;
  padding: 32px 16px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  margin-top: 10%;
}
.container .result {
  width: 100%;
  height: 150px;
}
.container .result p {
  font-size: 45pt;
  overflow-y: auto;
  text-align: right;
}

.container .buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 1em;
}
.container .buttons .button, .container .buttons .num-button  {
  cursor: grab;
  text-align: center;
  width: 60px;
  height: 60px;
  display: grid;
  place-content: center;
  border-radius: 50%;
  box-shadow: 6px 6px 16px 0 rgba(209, 205, 199, .5),
    -6px -6px 16px 0 rgba(255, 255, 255, .5);
}

.container .buttons .zero {
  grid-column: 1/ 3;
  width: 100%;
  border-radius: 10px;
  box-shadow:  6px 6px 16px 0 rgba(209, 205, 199, .5),
  -6px -6px 16px 0 rgba(255, 255, 255, .5);
}
.action-btn {
  color: grey;
  font-weight: bold;
}
.calc-action-btn{
  color: orange;
  font-weight: bold;
}

button{
  outline: none;
  border: none;
}


input {
  background-color: transparent;
  border-radius: 5px;
  border: 3px solid #ffffff;
  color: #553939;
  display: block;
  font-size: 25px;
  font-weight: bold;
  height: 50px;
  margin: 10px auto;
  outline: 1px solid transparent;
  text-align: center;
  text-transform: uppercase;
  transition: .3s ease;
  width: 100%;
}