body {
    font-family: Poppins, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(  to top, #007bff83, #0057b383);
    margin: 0;
}

.calculator {
    background: rgb(38, 38, 80);
    border-radius: 12px;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    padding: 20px;
    width: 280px;
}

.display {
    width: 90%;
    height: 50px;
    font-size: 24px;
    text-align: right;
    margin-bottom: 10px;
    padding: 10px;
    border: none;
    border-radius: 6px;
    background: #eee;
    font-weight: bold;
}

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

button {
    padding: 15px;
    font-size: 18px;
    border: none;
    border-radius: 8px;
    background: #007bff;
    color: #ddd;
    font-weight:bold;
    cursor: pointer;
    transition: background 0.3s;
}

button:hover {
    background: #0056b3;
}

button.operator {
    background: #ff9800;
}

button.operator:hover {
    background: #e68900;
}

button.clear {
    background: #f44336;
}

button.clear:hover {
    background: #d32f2f;
}