body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #121212; /* Dark background for the body */
    margin: 0;
    font-family: Arial, sans-serif;
}

.calculator {
    width: 280px;
    border-radius: 20px; /* Rounded corners for the calculator */
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    background-color: #1e1e1e; /* Dark background for the calculator */
}

.display {
    background-color: #333; /* Darker display background */
    color: #e0e0e0; /* Lighter text color */
    padding: 20px;
    text-align: right;
    font-size: 2em;
    border-radius: 20px 20px 0 0; /* Rounded top corners */
    overflow: hidden;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
}

button {
    border: none;
    background-color: #2c2c2c; /* Dark button background */
    color: #e0e0e0; /* Light text color */
    font-size: 1.5em;
    padding: 20px;
    cursor: pointer;
    transition: background-color 0.3s;
    border-radius: 50%; /* Fully rounded buttons */
}

button:hover {
    background-color: #5d5d5d; /* Slightly lighter on hover */
}

button:active {
    background-color: #c1c1c1; /* Even lighter on active */
}

.clear {
    background-color: #ad3838; /* Light red for clear button */
    color: #fff;
    border-radius: 50%; /* Fully rounded button */
}

.clear:hover {
    background-color: #b22320; /* Slightly darker on hover */
}

.operator {
    background-color: #cb9a44; /* Light orange for operator buttons */
    color: #fff;
    border-radius: 50%; /* Fully rounded button */
}

.operator:hover {
    background-color: #ffac2f; /* Slightly darker on hover */
}