:root {
            --bg: #0f172a;
            --panel: #1e293b;
            --text: #f8fafc;
            --muted: #94a3b8;
            --border: #334155;
            --accent: #3b82f6;
            --accent-hover: #2563eb;
            --button-bg: #475569;
            --button-hover: #334155;
            --success: #10b981;
            --warning: #facc15;
            --warning-orange: #f97316;
            --error: #ef4444;
            --danger: #ef4444;
        }

        * { box-sizing: border-box; }

        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
            background-color: var(--bg);
            color: var(--text);
            margin: 0;
            padding: 20px;
            display: flex;
            justify-content: center;
        }

        .container {
            background-color: var(--panel);
            max-width: 900px;
            width: 100%;
            padding: 30px;
            border-radius: 4px;
            border: 1px solid var(--border);
            box-shadow: 0 4px 6px rgba(0,0,0,0.3);
        }

        h1 {
            font-size: 1.4rem;
            margin: 0 0 20px 0;
            padding-bottom: 15px;
            border-bottom: 1px solid var(--border);
            font-weight: 600;
        }

        h2 {
            font-size: 1.2rem;
            margin-top: 0;
            font-weight: 600;
        }

        h3 {
            font-size: 1rem;
            margin-top: 20px;
            margin-bottom: 8px;
            color: var(--text);
            font-weight: 600;
        }

        /* --- Pestañas --- */
        .tabs {
            display: flex;
            flex-wrap: wrap;
            gap: 4px;
            border-bottom: 1px solid var(--border);
            margin-bottom: 25px;
        }

        .tabs button {
            padding: 10px 16px;
            background: transparent;
            color: var(--muted);
            border: none;
            border-bottom: 2px solid transparent;
            cursor: pointer;
            font-size: 0.95rem;
            font-weight: 500;
            transition: color 0.15s, border-color 0.15s;
            margin-bottom: -1px;
        }

        .tabs button:hover { color: var(--text); }
        .tabs button[aria-selected="true"] {
            color: var(--text);
            border-bottom-color: var(--accent);
        }

        /* --- Formularios --- */
        .form-group { margin-bottom: 15px; }

        label, .pseudo-label {
            display: block;
            margin-bottom: 6px;
            font-weight: 500;
            font-size: 0.85rem;
            color: var(--muted);
        }

        input[type="text"], input[type="number"], input[type="password"], select, textarea {
            width: 100%;
            padding: 8px 10px;
            background-color: var(--bg);
            border: 1px solid var(--border);
            color: var(--text);
            border-radius: 3px;
            font-size: 0.95rem;
            font-family: inherit;
        }

        input:focus, select:focus, textarea:focus {
            outline: none;
            border-color: var(--accent);
        }

        input.warning-border {
            border-color: var(--warning-orange);
            box-shadow: 0 0 5px rgba(249, 115, 22, 0.3);
        }

        input.error-border {
            border-color: var(--error);
            box-shadow: 0 0 5px rgba(239, 68, 68, 0.3);
        }

        /* --- Botones --- */
        button {
            padding: 8px 12px;
            background-color: var(--button-bg);
            color: var(--text);
            border: 1px solid var(--border);
            border-radius: 3px;
            cursor: pointer;
            transition: all 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
            font-family: inherit;
        }

        button:disabled { cursor: default; opacity: 0.8; }
        button:hover:not(:disabled) { background-color: var(--button-hover); }

        button.primary {
            background-color: var(--accent);
            color: #ffffff;
            border-color: var(--accent);
        }
        button.primary:hover:not(:disabled) { background-color: var(--accent-hover); }

        button svg { width: 18px; height: 18px; stroke: currentColor; }

        .toggle-btn {
            position: absolute;
            right: 8px;
            top: 50%;
            transform: translateY(-50%);
            background: none;
            border: none;
            color: var(--muted);
            padding: 5px;
            cursor: pointer;
        }
        .toggle-btn:hover { color: var(--text); background: none; }

        /* --- Rows / grids / layouts comunes --- */
        .input-row { display: flex; gap: 8px; }
        .input-row input { flex-grow: 1; }

        .input-wrapper {
            position: relative;
            display: flex;
            align-items: center;
        }

        .generator-box {
            background-color: rgba(59, 130, 246, 0.05);
            border: 1px solid var(--border);
            padding: 15px;
            margin-bottom: 20px;
            border-radius: 3px;
        }

        .controls-grid {
            display: grid;
            grid-template-columns: 1fr 2fr;
            gap: 15px;
        }

        .controls-box {
            background-color: rgba(15, 23, 42, 0.5);
            padding: 20px;
            border-radius: 3px;
            border: 1px solid var(--border);
            margin-bottom: 20px;
        }

        .controls-box h2 {
            font-size: 1rem;
            margin: 0 0 15px 0;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 15px;
            margin-bottom: 15px;
        }
        .row.single { grid-template-columns: 1fr; }
        .row:last-child { margin-bottom: 0; }

        /* --- Output / stats --- */
        .output-section {
            margin-top: 25px;
            padding-top: 20px;
            border-top: 1px solid var(--border);
        }

        textarea.result-box {
            width: 100%;
            background-color: var(--bg);
            border: 1px solid var(--accent);
            padding: 12px;
            border-radius: 3px;
            font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
            font-size: 1.05rem;
            color: var(--text);
            resize: vertical;
            min-height: 60px;
            word-break: break-all;
            letter-spacing: 1px;
        }
        textarea.result-box.is-status { color: var(--muted); letter-spacing: normal; font-size: 1rem; }
        textarea.result-box.is-error  { color: var(--error); letter-spacing: normal; font-size: 1rem; border-color: var(--error); }

        .stats-container {
            margin-top: 15px;
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 10px;
            background: rgba(0,0,0,0.2);
            border: 1px solid var(--border);
            padding: 15px;
            border-radius: 3px;
        }

        .stat-card { font-size: 0.85rem; color: var(--muted); }
        .stat-card div { margin-bottom: 4px; }
        .stat-val { font-weight: 600; color: var(--text); }

        /* --- Ayuda inline --- */
        .help-section {
            margin-top: 30px;
            background-color: rgba(15, 23, 42, 0.5);
            padding: 20px;
            border-radius: 3px;
            border: 1px solid var(--border);
            font-size: 0.9rem;
            line-height: 1.6;
        }

        .help-section h2 {
            font-size: 1.1rem;
            margin: 0 0 10px 0;
            padding: 0;
            border: none;
        }

        .help-section h3 {
            font-size: 1rem;
            margin-top: 20px;
            margin-bottom: 8px;
            border-left: 2px solid var(--accent);
            padding-left: 10px;
        }

        .help-section p, .help-section ul, .help-section li {
            color: var(--muted);
            margin-top: 0;
        }

        .help-section p { margin-bottom: 10px; }
        .help-section strong { color: var(--text); font-weight: 600; }

        .help-section code {
            background: var(--bg);
            padding: 2px 4px;
            border-radius: 3px;
            font-family: monospace;
            color: var(--accent);
            border: 1px solid var(--border);
        }

        .help-section .formula-box {
            background: var(--bg);
            padding: 12px 15px;
            border-radius: 3px;
            font-family: ui-monospace, monospace;
            border: 1px solid var(--border);
            color: var(--accent);
            margin: 12px 0;
            text-align: center;
            font-size: 0.95rem;
        }

        .help-section table {
            width: 100%;
            border-collapse: collapse;
            text-align: left;
            font-size: 0.85rem;
            color: var(--muted);
            border: 1px solid var(--border);
            margin: 12px 0;
        }
        .help-section th, .help-section td {
            padding: 8px 10px;
            border-bottom: 1px solid var(--border);
        }
        .help-section th { background: rgba(0,0,0,0.2); color: var(--text); }

        /* --- Determinista: matriz y restricciones --- */
        .det-layout-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 25px;
        }

        @media (min-width: 768px) {
            .det-layout-grid { grid-template-columns: 1fr 1fr; }
        }

        .header-row {
            display: flex;
            justify-content: space-between;
            align-items: baseline;
            margin-bottom: 6px;
        }

        .checksum-label {
            font-family: monospace;
            color: var(--accent);
            font-size: 0.8rem;
            letter-spacing: 1px;
        }

        .version-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 15px;
        }

        .req-section {
            padding: 15px;
            border-radius: 3px;
            border: 1px solid var(--border);
            margin-bottom: 15px;
        }

        .req-section h3 {
            margin: 0 0 12px 0;
            font-size: 0.8rem;
            color: var(--muted);
            text-transform: uppercase;
            letter-spacing: 1px;
            border: none;
            padding: 0;
            display: flex;
            justify-content: space-between;
            font-weight: 600;
        }

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

        .req-grid label {
            font-size: 0.75rem;
            text-align: center;
        }

        .req-grid input {
            padding: 8px;
            text-align: center;
        }

        .req-grid input::placeholder { color: #475569; }

        #det-warningMsg {
            color: var(--warning);
            font-size: 0.75rem;
            display: none;
        }

        .matrix-wrapper {
            display: flex;
            flex-direction: column;
            align-items: center;
            padding-top: 10px;
        }

        .byte-matrix {
            display: grid;
            grid-template-columns: repeat(8, 34px);
            gap: 5px;
            background-color: var(--bg);
            padding: 12px;
            border-radius: 3px;
            border: 1px solid var(--border);
        }

        .cell {
            display: flex;
            align-items: center;
            justify-content: center;
            background-color: var(--panel);
            border-radius: 3px;
            height: 34px;
            font-size: 0.8rem;
            font-family: monospace;
            color: var(--text);
            border: 1px solid var(--border);
            transition: background-color 0.2s;
        }
        .cell.filled {
            background-color: var(--button-bg);
            border-color: var(--accent);
        }

        .matrix-caption {
            font-size: 0.75rem;
            color: var(--muted);
            text-align: center;
            margin-top: 12px;
        }

        #det-master { padding-right: 40px; }

        /* --- Toggle de ojo --- */
        .icon-eye { display: block; }
        .icon-eye-off { display: none; }
        .toggle-btn.show-text .icon-eye { display: none; }
        .toggle-btn.show-text .icon-eye-off { display: block; }

        /* --- Aviso inline en frase --- */
        .info-icon {
            position: relative;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 18px;
            height: 18px;
            border-radius: 50%;
            border: 1px solid var(--muted);
            color: var(--muted);
            font-size: 0.7rem;
            font-weight: 700;
            font-style: italic;
            font-family: Georgia, serif;
            cursor: help;
            background: transparent;
            padding: 0;
        }

        .info-icon:hover, .info-icon:focus-visible {
            color: var(--text);
            border-color: var(--text);
            outline: none;
        }

        .info-tooltip {
            position: absolute;
            top: calc(100% + 8px);
            left: 0;
            width: max-content;
            max-width: min(360px, calc(100vw - 40px));
            background: rgba(234, 179, 8, 0.08);
            border: 1px solid rgba(8, 46, 234, 0.4);
            color: #dae3ff;
            padding: 10px 12px;
            border-radius: 3px;
            font-size: 0.82rem;
            font-weight: 400;
            font-style: normal;
            font-family: inherit;
            line-height: 1.5;
            text-align: left;
            z-index: 10;
            box-shadow: 0 4px 8px rgba(0,0,0,0.3);
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.15s, visibility 0.15s;
            pointer-events: none;
        }

        .info-icon:hover .info-tooltip,
        .info-icon:focus-visible .info-tooltip {
            opacity: 1;
            visibility: visible;
        }

        /* --- Footer --- */
        footer {
            margin-top: 30px;
            padding-top: 15px;
            border-top: 1px solid var(--border);
            font-size: 12px;
            color: var(--muted);
            text-align: center;
        }
        footer a { color: var(--muted); text-decoration: none; }
        footer a:hover { text-decoration: underline; }

        /* --- Responsive --- */
        @media (max-width: 600px) {
            body { padding: 10px; }
            .container { padding: 15px; }
            .controls-grid { grid-template-columns: 1fr; }
            .stats-container { grid-template-columns: 1fr; }
            .row { grid-template-columns: 1fr; }
            .byte-matrix { grid-template-columns: repeat(8, 30px); }
            .cell { height: 30px; font-size: 0.7rem; }
            .tabs button { padding: 8px 12px; font-size: 0.9rem; }
        }