.calculadora-body {
    background-color: #0b0b0b;
    color: white;
    font-family: 'Segoe UI', sans-serif;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 40px 20px;
}

.container-calculadora {
    max-width: 600px;
    width: 100%;
    text-align: center;
}

.calculadora {
    background: #111111;
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 0 20px rgba(0,0,0,0.6);
}

.calculadora input {
    width: 100%;
    padding: 25px 30px 25px 20px;
    font-size: 32px;
    border: none;
    border-radius: 16px;
    margin-bottom: 25px;
    background-color: #1c1c1c;
    color: #00f0ff;
    text-align: right;
    box-shadow: inset 0 0 8px #050505;
    box-sizing: border-box;
}



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

.teclado button {
    padding: 20px;
    font-size: 18px;
    border: none;
    border-radius: 12px;
    background-color: #1f1f1f;
    color: #ffffff;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.teclado button:hover {
    background-color: #007bff;
    transform:scale(1.05);
}

.teclado button.doble {
    grid-column: span 2;
}

.volver-btn {
    display: inline-block;
    margin-top: 30px;
    text-decoration: none;
    color: #007bff;
    font-weight: bold;
    font-size: 16px;
    transition: color 0.3s;
}

.volver-btn:hover {
    color: #00bfff;
}