/* Calculator Styling */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.calculator {
    background-color: #fff;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
}

.display {
    padding: 20px;
    text-align: right;
}

.display input {
    width: 100%;
    font-size: 2.5rem;
    border: none;
    background: none;
    text-align: right;
    padding: 10px;
    color: #333;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    padding: 20px;
}

.btn {
    background-color: #f0f0f0;
    border: none;
    border-radius: 10px;
    font-size: 1.5rem;
    padding: 20px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-weight: 600;
}

.btn:hover {
    background-color: #e0e0e0;
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
}

.operator {
    background-color: #ff9500;
    color: white;
}

.operator:hover {
    background-color: #e68900;
}

.equals {
    background-color: #ff9500;
    color: white;
    grid-column: span 2;
}

.equals:hover {
    background-color: #e68900;
}

.zero {
    grid-column: span 2;
}

/* Responsive adjustments */
@media (max-width: 480px) {
    .calculator {
        width: 100%;
        max-width: none;
        border-radius: 0;
    }
    
    .display input {
        font-size: 2rem;
    }
    
    .btn {
        font-size: 1.25rem;
        padding: 15px;
    }
}