* {
    box-sizing: border-box;
}

html {
    height: 100%;
    width: 100%;
    -webkit-user-select: none;
    /* Chrome all / Safari all */
    -moz-user-select: none;
    /* Firefox all */
    -ms-user-select: none;
    /* IE 10+ */
    user-select: none;
    /* Likely future */
}

/* Calculator Start */

.calculator {
    text-align: center;
    width: 400px;
    height: auto;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

/* Calculator Heading Start */

.calculator h1 {
    margin-top: 0;
    font-family: 'Courier New', Courier, monospace;
}

/* Calculator Heading End */

/* Calculator Screen Start */

.calculatorScreen {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    width: 100%;
    height: 100px;
    background-color: rgb(19, 43, 24);
    border: 5px solid rgb(1, 19, 4);
    color: rgb(255, 255, 255);
    text-align: right;
    font-size: 36px;
    padding: 0 20px;
    user-select: none;
    border-top-right-radius: 50px;
    border-top-left-radius: 50px;
    display: flex;
    align-items: center;
    overflow: auto;
    white-space: nowrap;
}

/* Calculator Screen End */

.row {
    display: flex;
}

/* Button Start */

.calculator-keys {
    width: 100%;
}

button {
    outline: none;
    height: 80px;
    background-color: rgb(255, 80, 95);
    border: 1px solid rgb(0, 0, 0);
    font-size: 32px;
    color: rgb(19, 43, 24);
    width: 25%;
    border-radius: 0px;
}

button:hover {
    background-color: rgb(209, 58, 58);
}

.zeroBtn {
    width: 50%;
    cursor: pointer;
    border-bottom-left-radius: 50px;
}

.operator, .equalSign {
    background-color: rgb(16, 133, 201);
    cursor: pointer;
}

.operator:hover, .equal-sign:hover {
    background-color: rgb(82, 228, 143);
}

.allClear, .delete {
    background-color: rgb(141, 128, 53);
    cursor: pointer;
}

.allClear:hover, .delete:hover {
    background-color: rgb(208, 211, 134);
}

.number, .percentage, .decimal {
    cursor: pointer;
}

.equalSign {
    border-bottom-right-radius: 50px;
}

/* Button End */

/* Calculator End */

/*
    MEDIA QUERIES START
*/

@media only screen and (max-width: 400px) {
    .calculator {
        width: 300px;
    }
    button {
        height: 57.405281285878px;
    }
    .equalSign {
        border-bottom-right-radius: 0;
    }
}

@media only screen and (max-width: 300px) {
    .calculator {
        width: 280px;
    }
    button {
        height: 53.578262533486px;
    }
}

@media only screen and (max-height: 560px) {
    .calculator h1 {
        margin-bottom: 0;
    }
}

/*
    MEDIA QUERIES END
*/