body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: #f2f2f2;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.calculadora {
    background-color: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
    text-align: center;
    width: 260px;
}

input {
    width: 90%;
    height: 30px;
    font-size: 1rem;
    margin: 5px 0;
    text-align: center;
}

.operaciones {
    display: flex;
    justify-content: space-between;
    margin: 10px 0;
}

button {
    height: 40px;
    width: 45px;
    font-size: 1.2rem;
    font-weight: bold;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    background-color: #4caf50;
    color: white;
}

.triple {
    display: flex;
    justify-content: space-between;
    margin-top: 10px;
}

.doble {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    margin-top: 10px;
}

.doble button {
    width: 100%;
    padding: 8px 4px;
    background-color: #2196f3;
    font-size: 0.85rem;
    white-space: nowrap;
    text-align: center;
}

.triple button {
    width: 70px;
    background-color: #ff9800;
    font-size: 0.9rem;
}

#resultado {
    font-weight: bold;
}