body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f4f4f9;
    font-family: Arial, sans-serif;
}

.calculator {
    width: 250px;
    background: #131313;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}

#display {
    width: 100%;
    height: 50px;
    font-size: 24px;
    text-align: right;
    border: none;
    padding: 10px;
    background: #000;
    color: #5cbdb4;
    margin-bottom: 10px;
    border-radius: 5px;
}

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

button {
    width: 100%;
    height: 50px;
    font-size: 20px;
    border: none;
    border-radius: 5px;
    color: #fff;
    cursor: pointer;
}

/* Estilo dos botões operacionais */
button:nth-child(1) { background: #f44336; } /* Botão Limpar "C" */
button:nth-child(2), button:nth-child(3), button:nth-child(4), button:nth-child(8) {
    background: #5cbdb4;
}

/* Estilo dos botões numéricos e ponto */
button:not(:nth-child(1)):not(:nth-child(2)):not(:nth-child(3)):not(:nth-child(4)):not(:nth-child(8)):not(:nth-child(18)) {
    background: #333;
}

/* Estilo do botão igual */
button:nth-last-child(1) {
    grid-column: span 2;
    background: #5cbdb4;
}

button:hover {
    opacity: 0.9;
}