.calculator{
    text-align: center;
    margin: auto;
    width: 350px;
    height: 515px;
    padding: 2px;
    border-radius: 10px;
    background-color:#000000;
    border: 2px solid #334240;
    margin-top: 50px;
}

.calculator-screen{
    width: 100%;
    height: 100px;
    background-color: #bdcfdf;
    color: rgb(17, 17, 17);
    text-align: right;
    padding-right: 10px;
    font-size: 36px;
    border: 8px solid #a2bbcf;
    box-sizing: border-box;
    border-radius: 5px;
}

.calculator-keys{
    width: 100%;
}

.row{
    display: flex;
}

button{
    height: 80px;
    margin: 1.5px 1.5px 1.5px 1.5px;
    background-color: #002533;
    border: 2px solid #0e96b8;
    font-size: 32px;
    font-style:oblique;
    color: #fff;
    width: 25%;
    outline: none;
    border-radius: 7px;
}

button:hover{
    background-color: #00506d;
}

.all-clear, .zero-btn{
    width: 50%;
}

.operator, .equal-sign{
    background-color: #073d00;
}

.operator:hover, .equal-sign:hover{
    background-color: #0d7400;
}