body {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f4f4f4;
    font-family: 'consola', Arial, sans-serif;
}

.calculadora {
    background-color: #fff;
    border-radius: 15px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: 40px;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

.label {
    width: 250px;
    height: 30px;
    background-color: #222;
    color: #fff;
    border-radius: 10px;
    text-align: right;
    padding: 15px;
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.btn {
    padding: 20px;
    background-color: #f0f0f0;
    border: 1px solid #ddd;
    border-radius: 10px;    
    text-align: center;
    font-size: 1.2rem;
    color: #333;
    transition: all 0.3s ease;
}

.btn:hover {
    background-color: #ecd9d1;
}

.firma {
    position: absolute;
    bottom: 10px;
    left: 10px;
    color:#d8d8d8;
    text-align: start;
}

.btnEqual {
    padding: 20px;
    background-color: #f07d1f;
    border: 1px solid #f07d1f;
    border-radius: 10px;    
    text-align: center;
    font-size: 1.2rem;
    color: #ffffff;
    transition: all 0.3s ease;    
}

.botones {
    display: grid;
    gap: 1px;
    grid-template-columns: repeat(4, 1fr);
    gap: 2px;
    width: 300px;
    height: 300px;
}


.nbtn {
    opacity: 0;
    pointer-events: none;
}