*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 5rem;
    background-color:#222
}


/* button styling */
button{
    width: 100px;
    height: 100px;
    border-radius: 50px;
    border: none;
    color: #fff;
    background-color: #2C2C2C;
    font-weight: bold;
    font-size: 1.5rem;
    cursor: pointer;
}


.buttons{
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 8px;
    padding: 25px;

}

/* clear button styles */
.clear-button{
    background-color: #FF4136;
}


/* equals button styles */
.equals-button{
    background-color: #2ECC40;
}


/* container */
.calculator{
    font-family: sans-serif;
    background-color: black;
    border-radius: 10px;
    max-width: 600px;

}


/* output styling */

#output-screen{
    width: 100%;
    padding: 25px;
    font-size: 5.2rem;
    font-weight: bold;
    text-align: left;
    border: none;
    background-color: rgb(82, 80, 80);
    color:#ffffff;
    
}

/* operator styling */
 .operator{
    background-color:#FF9500;
 }

.operator:hover{
    background-color:#E07E00;
}