body {
    margin: 0;
    padding: 0;
    background: #111;
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    color: #eee;
}

.contenedor {
    background: #1b1b1b;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 0 20px rgba(0,0,0,0.4);
    text-align: center;
    width: 90%;
    max-width: 400px;
}

h1 {
    margin-bottom: 25px;
    color: #fff;
}

.formulario input[type="date"] {
    padding: 12px;
    border: none;
    border-radius: 8px;
    width: 100%;
    font-size: 16px;
    margin-bottom: 15px;
}

.formulario button {
    padding: 12px;
    width: 100%;
    font-size: 16px;
    background: #4CAF50;
    border: none;
    color: white;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s;
}

.formulario button:hover {
    background: #3e8e41;
}

.resultado {
    background: #222;
    margin-top: 20px;
    padding: 20px;
    border-radius: 10px;
    font-size: 20px;
}

.resultado span {
    font-weight: bold;
    color: #4CAF50;
    font-size: 26px;
}