.container{
    max-width: 400px;
    margin: 10vh auto 0 auto;
    box-shadow: 0px 0px 43px 17px rgba(153, 153,153, 1);
}
#display{
    text-align: right;
    height: 70px;
    line-height: 70px;
    padding: 16px 8px;
    font-size: 25px;
}

.buttons{
    display: grid;
    border-bottom: 1px solid #999;
    border-left: 1px solid #999;
    grid-template-columns: 1fr 1fr 1fr 1fr;
}
.button > div{
    border-top: 1px solid #999;
    border-right:1px solid #999;
}
.button{
  border: 0.5px solid #999;
  line-height: 100px;
  text-align: center;
  font-size: 25px;
  cursor: pointer;
}
#equal{
    background-color: #5555ff;
    color: #fff;
}
.button:hover{
   background-color:rgb(226, 156, 25);
   color: #fff;
   transition: 0.5s ease-in-out;
}