body {
    margin: 0;
    padding: 0;
    background-color: rgb(118, 159, 165);
}

#calculator {
    height: 480px;
    width: 360px;
    position: absolute;
    transform: translate(-50%, -50%);
    top: 50%;
    left: 50%;
    box-shadow: 10px 10px 10px rgb(95, 130, 135);
    overflow: hidden;
}

#result-box {
    height: 120px;
    background-color: #333;
    overflow: hidden;
    position: relative;
}

.result {
    font-family: 'Roboto', sans-serif;
    position: absolute;
    right: 15px;
    text-align: right;
}

#calculation {
    color: rgb(95, 130, 135);
    font-size: 100%;
    font-weight: 400;
    top: 50px;
}

#result {
    color: white;
    font-size: 200%;
    font-weight: 300;
    top: 75px;
}

#reset {
    color: white;
    font-size: 150%;
    position: absolute;
    top: 50px;
    left: 15px;
    cursor: pointer;
    display: none;
}

.btn {
    width: 90px;
    height: 90px;
    float: left;
    background-color: rgb(134, 181, 189);
    border: 1px solid rgb(95, 130, 135);
    color: white;
    font-family: 'Roboto', sans-serif;
    font-size: 175%;
    cursor: pointer;
}

.operator {
    background-color: rgb(125, 204, 218);
}

button:focus {
    outline: none;
}

#end {
    transition: .3s;
}