style.css

body {
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    border: none;

}

#display {
    width: 100%;
    height: 45px;
    padding: 20px;
    background-color: hsl(0, 0%, 25%);
    border-radius: 15px;
    border: none;
    font-size: 24px;
    font-weight: bold;
    color: white;


    text-align: left;
    overflow: hidden;





}

#calculator {
    font-family: Arial, Helvetica, sans-serif;
    background-color: hsl(0, 0%, 15%);
    border-radius: 15px;
    max-width: 500px;
    /* margin: 50px auto; */
    overflow: hidden;

}


#keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 25px;
    border: none;

}



button {
    width: 70px;
    height: 70px;
    border-radius: 50px;
    border: none;
    background-color: hsl(0, 0%, 30%);
    color: white;
    font-size: 3rem;
    cursor: pointer;
    font-weight: bold;



}

button:hover {
    background-color: hsl(0, 0%, 40%);
}

button:active {
    background-color: hsl(0, 0%, 50%);
}

.operator {
    background-color: hsl(0, 100%, 55%);

}

.operator:hover {
    background-color: hsl(0, 100%, 65%);
}

.operator:active {
    background-color: hsl(0, 100%, 75%);
}