:root {
    --color-bg: #0f172a;
    --color-surface: #1e293b;
    --color-border: #334155;
    --color-text: #e2e8f0;
    --color-muted: #94a3b8;
    --color-accent: #38bdf8;
    --color-accent-hover: #0ea5e9;
    --color-success: #4ade80;
    --color-danger: #f87171;
    --radius: 10px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.app {
    width: 100%;
    max-width: 720px;
    padding: 2.5rem 2rem;
}

h1 {
    margin: 0 0 0.5rem;
    font-size: 1.5rem;
    text-align: center;
}

.subtitle {
    margin: 0 0 2rem;
    text-align: center;
    color: var(--color-muted);
    font-size: 0.95rem;
}

.key-types {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.75rem;
    margin-bottom: 2rem;
}

.key-type-button {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
    padding: 0.75rem 1rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background-color: var(--color-surface);
    color: var(--color-text);
    font-size: 0.95rem;
    cursor: pointer;
    transition: border-color 0.15s ease, background-color 0.15s ease;
}

.key-type-button:hover,
.key-type-button:focus-visible {
    border-color: var(--color-accent);
    background-color: #24314a;
}

.key-type-button:last-child {
    grid-column: 1 / -1;
}

.key-type-icon {
    width: 22px;
    height: 22px;
    color: var(--color-muted);
}

.key-type-button:hover .key-type-icon,
.key-type-button:focus-visible .key-type-icon {
    color: var(--color-accent);
}

.options {
    margin-bottom: 1.5rem;
    padding: 1rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
}

.options-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    transition: opacity 0.15s ease;
}

/*
 * Se deshabilita solo la fila de longitud cuando el tipo no la admite
 * (API key, Mifare A/B) — a diferencia del resto de opciones (como el
 * prefijo de API key), que deben seguir siendo usables aunque la
 * longitud esté fija.
 */
.options-row.is-disabled {
    opacity: 0.4;
    pointer-events: none;
}

.options-row label {
    font-size: 0.9rem;
    color: var(--color-muted);
    white-space: nowrap;
}

.options-row input[type="range"] {
    flex: 1;
    accent-color: var(--color-accent);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--color-muted);
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    accent-color: var(--color-accent);
}

.prefix-option {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    margin-top: 0.75rem;
    font-size: 0.9rem;
    color: var(--color-muted);
}

.prefix-option input[type="text"] {
    padding: 0.5rem 0.6rem;
    border: 1px solid var(--color-border);
    border-radius: calc(var(--radius) / 2);
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: "Cascadia Code", "Consolas", monospace;
    font-size: 0.9rem;
}

.prefix-option input[type="text"]:focus-visible {
    outline: none;
    border-color: var(--color-accent);
}

.result {
    text-align: center;
}

.key-output {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    width: 100%;
    padding: 1.1rem 1rem;
    border: 1px dashed var(--color-border);
    border-radius: var(--radius);
    background-color: var(--color-surface);
    color: var(--color-text);
    font-family: "Cascadia Code", "Consolas", monospace;
    font-size: 0.95rem;
    letter-spacing: 0.03em;
    cursor: pointer;
    transition: border-color 0.15s ease, transform 0.1s ease;
}

.key-output:disabled {
    color: var(--color-muted);
    cursor: default;
    font-family: inherit;
    letter-spacing: normal;
}

/*
 * En vez de partir la clave en varias líneas (rompía la lectura y el
 * copiado visual), se deja en una sola línea con scroll horizontal
 * propio si no cabe entera (p. ej. con un prefijo de API key largo).
 */
#key-output-text {
    overflow-x: auto;
    white-space: nowrap;
    max-width: 100%;
}

.copy-icon {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
    color: var(--color-muted);
}

.key-output:disabled .copy-icon {
    display: none;
}

.key-output:not(:disabled):hover {
    border-color: var(--color-accent);
}

.key-output:not(:disabled):active {
    transform: scale(0.99);
}

.entropy {
    min-height: 1.2rem;
    margin: 0.6rem 0 0;
    color: var(--color-muted);
    font-size: 0.85rem;
}

.copy-feedback {
    min-height: 1.4rem;
    margin: 0.4rem 0 0;
    color: var(--color-success);
    font-size: 0.9rem;
}

.copy-feedback.copy-feedback--error {
    color: var(--color-danger);
}