*{
    margin: 0;
    padding: 0;
}
body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background-color: rgb(222, 220, 224);
}
.content{
     width: 35%;
     height: 45vh;
     padding: 10px;
     border-radius: 8px;
     box-shadow: 12px 12px 20px gray,
                 -12px -12px 20px gray;
                 
}
.display #screen{
    width: 97%;
    height: 70px;
    font-size: 35px;
    outline: none;
    border: none;
    text-align: right;
    padding-right: .5em;
    background-color: yellow ;
    border-radius: 6px;
    box-shadow: inset 8px 8px 8px gray,
                inset -8px 8px 8px gray;
}
.btns{
    width: 100%;
    margin-top: 1.7em;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}
.btns .row button{
    width: 80px;
    height: 30px;
    font-size: 16px;
    border: none;
    outline: none;
    margin: 5px;
    border-radius: 4px;
    box-shadow: 5px 5px 8px gray,
              -5px -5px 8px gray;
              background-color: aquamarine;
}