* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}
h1{
    display: flex;
    justify-content: center;
    color: #00ffee;
    
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #c5c4da;
}

.calculator {
    width: 90%;
    max-width: 350px;
    background: #2c2c3e;
    padding: 15px;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
}

#display {
    width: 100%;
    height: 60px;
    font-size: 1.8rem;
    text-align: right;
    padding: 10px;
    border: none;
    border-radius: 10px;
    margin-bottom: 10px;
    background: #111;
    color: #fff;
}

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

button {
    padding: 15px;
    font-size: 1.2rem;
    border: none;
    border-radius: 10px;
    background: #3b3b5c;
    color: white;
    cursor: pointer;
    transition: 0.2s;
}

button:hover {
    background: #57577a;
}

.equal {
    background: #ff9500;
}

.equal:hover {
    background: #e08900;
}

.zero {
    grid-column: span 2;
}

/* 📱 Mobile */
@media (max-width: 480px) {
    #display {
        height: 50px;
        font-size: 1.5rem;
    }

    button {
        padding: 12px;
        font-size: 1rem;
    }
}