body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
}

.calculadora {
    background-color: #333;
    border-radius: 10px;
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: auto repeat(5, 1fr);
    gap: 10px;
    max-width: 300px;
    width: 100%;
}

.tela {
    grid-column: span 4;
    background-color: #222;
    color: white;
    font-size: 2em;
    padding: 10px;
    text-align: right;
    border-radius: 5px;
    margin-bottom: 10px;
}

button {
    font-size: 1.6em;
    padding: 15px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.numero, .ponto {
    background-color: #555;
    color: white;
}

.operador {
    background-color: #ff9800;
    color: white;
}

.igual {
    background-color: #4caf50;
    color: white;
    grid-row: span 2;
}

.limpar {
    background-color: #f44336;
    color: white;
}

.zero {
    grid-column: span 3;
}

button:hover {
    opacity: 0.8;
}