body {
    font-family: Arial, sans-serif;
    margin: 0%;
}

.calculator {
    width: 350px;
    margin: 60px auto;
    padding: 20px;
    height: 400px;
    background-color: #070202;
    border: 2px solid #373535;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.4);
}
@media(max-width:590px) {
    .calculator{
        height: 380px;
        width: 300px;
    }
    
}
@media(max-width:400px) {
    .calculator{
        height: 350px;
        width: 200px;
    }
    
}
#display {
    width: 95%;
    height: 30px;
    margin-bottom: 25px;
    padding: 10px;
    font-size: 20px;
    background-color: #ddd;
    text-align: right;
    border: 1px solid #2f2727;
    border-radius:4PX;
    color:#070202;
}

.keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

button {
    height: 45px;
    font-size: 20px;
    cursor: pointer;
    border-radius: 5px;
}
@media(max-width:590px){
    button{
        height: 35px;
        font-size: 17px;
    }
}
@media(max-width:400px){
    button{
        height: 20px;
        font-size: 12px;
    }
}

#equals {
    background-color: #007bff;
    color: white;
    grid-column: 1/5;
}