#calculator{
    width: 400px;
    max-width: 400px;
    margin: 50px auto;
    padding: 50px 5px 0 5px;
    border-radius: 10px;
    background-color: #1c1c1c;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

#display{
    width: 100%;
    height: 80px;
    margin-bottom: 20px;    
    padding: 10px;
    font-size: 36px;
    color: white;
    background-color: #1c1c1c;
    border: none;
    outline: none;
    text-align: right;
    box-sizing: border-box;
}

#buttons{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 8px;
}
#buttons button{
    width: 80px;
    height: 80px;
    padding: 10px;
    font-size: 30px;
    border: none;
    text-align: center;
    border-radius: 40px;
    border: none;
    background-color: #505050;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

#buttons button:hover{
    opacity: 0.7;
}
#buttons button:active{
    opacity: 0.9;
}