body {
    text-align: center;
    background-color: aliceblue;
}   

.container {
    max-width: 650px;
    margin: 0 auto;
    padding: 0 15px;
}


#equation {
    display: block;
    margin: 0 auto;
    margin-top: 50px;
    width: 345px;
    height: 30px;
    font-size: x-large;
    text-align: right;
    border: 1px solid #2375d4;
}

.calcbody table {
    margin: 0 auto;
    display: inline-block;
    padding: 10px;
}

.calc-button {
    font-size: large;
    background-color: transparent;
    width: 85px;
    height: 85px;
    cursor: pointer;
    border: 1px solid #2375d4;
    transition-duration: 0.7s;
}

.backspace {
    width: 173px;
}

.calc-button:hover {
    background-color: #2375d4;
    color: white;
}
.operation, #equals {
    font-size: x-large;
}