body {
    background-color: #0f172a;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.card {
    background-color: #1e293b;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
    width: 380px;
}

h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #38bdf8;
    margin-top: 0;
}

hr {
    border: 0;
    border-top: 1px solid #334155;
    margin: 20px 0;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-size: 0.85rem;
    color: #94a3b8;
    font-weight: 600;
}

input[type="text"] {
    width: 100%;
    padding: 10px;
    background-color: #0f172a;
    border: 1px solid #334155;
    border-radius: 6px;
    color: #fff;
    font-size: 0.95rem;
    box-sizing: border-box;
}

.result-container input {
    color: #22c55e; /* Color verde para la clave final */
    font-size: 1.2rem;
    font-family: 'Courier New', Courier, monospace;
    text-align: center;
    font-weight: bold;
}

.settings {
    margin: 20px 0;
}

.setting {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

input[type="range"] {
    width: 40%;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #38bdf8;
    color: #0f172a;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s;
}

button:hover {
    background-color: #0ea5e9;
}

.btn-secondary {
    background-color: #334155;
    color: #f8fafc;
    padding: 8px;
    font-size: 0.85rem;
}

.btn-secondary:hover {
    background-color: #475569;
}