body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    user-select:none;
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #e0e0e0;
}

.calculator {
    background-color: #f7f7f7;
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0px 0px 20px rgba(0, 0, 0, 0.1);
}

.display {
    width: 100%;
    height: 60px;
    background-color: #eef3fa;
    border: none;
    font-size: 2rem;
    text-align: right;
    padding: 10px;
    border-radius: 10px;
    box-shadow: inset 0px 0px 10px rgba(0, 0, 0, 0.1);
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-top: 20px;
}

.button {
    background-color: white;
    border: none;
    padding: 20px;
    font-size: 1.5rem;
    border-radius: 50px;
    box-shadow: 0px 5px 10px rgba(0, 0, 0, 0.1);
    transition: background-color 0.3s ease, transform 0.1s ease;
}

.button:hover {
    background-color: #d8e6ff;
}

.button:active {
    transform: scale(0.95);
}