body {
    font-family: Arial, sans-serif;
    background: linear-gradient(135deg, #74ebd5, #ACB6E5);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.calculator {
    background: white;
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0px 4px 12px rgba(0,0,0,0.2);
    text-align: center;
    width: 300px;
}

.calculator h2 {
    margin-bottom: 20px;
    color: #333;
}

.calculator input {
    width: 85%;
    padding: 10px;
    margin: 8px 0;
    border: 2px solid #ccc;
    border-radius: 8px;
    font-size: 16px;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-top: 15px;
}

button {
    padding: 12px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    background: #4CAF50;
    color: white;
    transition: 0.3s;
}

button:hover {
    background: #45a049;
}

#result {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
    color: #444;
}