/* =====================================================================
   StudyAPI — sistema de diseño
   Tokens, modo claro/oscuro, layout, contenido, exámenes y vistas.
   ===================================================================== */

/* ---------- Tokens ---------- */
:root {
    --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

    --bg: #f3f5f9;
    --surface: #ffffff;
    --surface-2: #f7f9fc;
    --surface-3: #eef2f7;
    --border: #e3e8ef;
    --border-strong: #cbd5e1;

    --text: #0f172a;
    --text-2: #334155;
    --text-3: #64748b;

    --primary: #2457d6;
    --primary-hover: #1b47b3;
    --primary-soft: #e8efff;
    --primary-soft-text: #1b47b3;
    --on-primary: #ffffff;

    --accent: #f59e0b;
    --accent-soft: #fef3c7;
    --accent-soft-text: #92400e;

    --success: #16a34a;
    --success-soft: #dcfce7;
    --success-soft-text: #166534;
    --danger: #dc2626;
    --danger-soft: #fee2e2;
    --danger-soft-text: #991b1b;
    --info-soft: #e0f2fe;
    --info-soft-text: #075985;

    --sidebar-bg: #0f1b2d;
    --sidebar-bg-2: #16243a;
    --sidebar-text: #c3cedf;
    --sidebar-text-strong: #ffffff;
    --sidebar-muted: #7f90aa;
    --sidebar-border: rgba(255, 255, 255, 0.08);
    --sidebar-hover: rgba(255, 255, 255, 0.06);
    --sidebar-active: #2457d6;

    --radius-sm: 8px;
    --radius: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
    --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 16px 48px rgba(15, 23, 42, 0.16);

    --sidebar-width: 300px;
    --topbar-height: 60px;
    --content-max: 1080px;

    --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
    color-scheme: light;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg: #0b1220;
        --surface: #121c2e;
        --surface-2: #172338;
        --surface-3: #1e2c45;
        --border: #243349;
        --border-strong: #35486a;
        --text: #e6ebf4;
        --text-2: #b8c4d8;
        --text-3: #8696b1;
        --primary: #5b8cff;
        --primary-hover: #78a0ff;
        --primary-soft: rgba(91, 140, 255, 0.16);
        --primary-soft-text: #a9c2ff;
        --on-primary: #0b1220;
        --accent: #fbbf24;
        --accent-soft: rgba(251, 191, 36, 0.16);
        --accent-soft-text: #fde68a;
        --success: #4ade80;
        --success-soft: rgba(74, 222, 128, 0.16);
        --success-soft-text: #bbf7d0;
        --danger: #f87171;
        --danger-soft: rgba(248, 113, 113, 0.16);
        --danger-soft-text: #fecaca;
        --info-soft: rgba(56, 189, 248, 0.14);
        --info-soft-text: #bae6fd;
        --sidebar-bg: #0a1120;
        --sidebar-bg-2: #111b2e;
        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
        --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.35);
        --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
        color-scheme: dark;
    }
}

:root[data-theme="dark"] {
    --bg: #0b1220;
    --surface: #121c2e;
    --surface-2: #172338;
    --surface-3: #1e2c45;
    --border: #243349;
    --border-strong: #35486a;
    --text: #e6ebf4;
    --text-2: #b8c4d8;
    --text-3: #8696b1;
    --primary: #5b8cff;
    --primary-hover: #78a0ff;
    --primary-soft: rgba(91, 140, 255, 0.16);
    --primary-soft-text: #a9c2ff;
    --on-primary: #0b1220;
    --accent: #fbbf24;
    --accent-soft: rgba(251, 191, 36, 0.16);
    --accent-soft-text: #fde68a;
    --success: #4ade80;
    --success-soft: rgba(74, 222, 128, 0.16);
    --success-soft-text: #bbf7d0;
    --danger: #f87171;
    --danger-soft: rgba(248, 113, 113, 0.16);
    --danger-soft-text: #fecaca;
    --info-soft: rgba(56, 189, 248, 0.14);
    --info-soft-text: #bae6fd;
    --sidebar-bg: #0a1120;
    --sidebar-bg-2: #111b2e;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
    color-scheme: dark;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; }
button, input, select { font: inherit; color: inherit; }
button { cursor: pointer; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    border-radius: 4px;
}

.hidden { display: none !important; }
.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
    html { scroll-behavior: auto; }
}

/* ---------- Layout ---------- */
.app {
    display: grid;
    grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
    min-height: 100vh;
}

/* ---------- Sidebar ---------- */
.sidebar {
    position: sticky;
    top: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    border-right: 1px solid var(--sidebar-border);
    overflow: hidden;
    z-index: 40;
}

.sidebar ul { list-style: none; margin: 0; padding: 0; }

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 18px 18px 16px;
    border-bottom: 1px solid var(--sidebar-border);
}

.brand-mark {
    flex: none;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #2457d6, #5b8cff);
    color: #fff;
    font-weight: 800;
    font-size: 13px;
    letter-spacing: 0.02em;
    box-shadow: 0 6px 16px rgba(36, 87, 214, 0.35);
}

.brand-text { min-width: 0; }
.brand-title {
    display: block;
    color: var(--sidebar-text-strong);
    font-weight: 700;
    font-size: 15px;
    line-height: 1.25;
}
.brand-subtitle {
    display: block;
    color: var(--sidebar-muted);
    font-size: 12px;
    margin-top: 2px;
}

.sidebar-scroll {
    flex: 1;
    overflow-y: auto;
    padding: 14px 12px 20px;
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.18) transparent;
}
.sidebar-scroll::-webkit-scrollbar { width: 6px; }
.sidebar-scroll::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.18); border-radius: 3px; }

.sidebar-section-label {
    margin: 14px 10px 6px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--sidebar-muted);
}

/* Navegación principal */
.sidebar-nav .nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 12px;
    margin-bottom: 2px;
    border-radius: var(--radius-sm);
    color: var(--sidebar-text);
    font-weight: 500;
    font-size: 14.5px;
    cursor: pointer;
    transition: background 0.15s var(--ease), color 0.15s var(--ease);
    user-select: none;
}
.sidebar-nav .nav-item:hover { background: var(--sidebar-hover); color: var(--sidebar-text-strong); }
.sidebar-nav .nav-item.active {
    background: var(--sidebar-active);
    color: #fff;
    box-shadow: 0 4px 12px rgba(36, 87, 214, 0.35);
}
.sidebar-nav .nav-item svg { flex: none; width: 18px; height: 18px; opacity: 0.85; }
.sidebar-nav .nav-item.active svg { opacity: 1; }
.sidebar-nav .nav-label { flex: 1; }

.sidebar-divider {
    border: 0;
    border-top: 1px solid var(--sidebar-border);
    margin: 10px 4px;
}

/* Selector de código */
.code-selector { padding: 0 2px; margin-bottom: 6px; }
.code-selector select {
    width: 100%;
    padding: 10px 36px 10px 12px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-sm);
    background-color: var(--sidebar-bg-2);
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='none' stroke='%23c3cedf' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m4 6 4 4 4-4'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    color: var(--sidebar-text-strong);
    font-size: 14px;
    font-weight: 500;
    appearance: none;
    -webkit-appearance: none;
    cursor: pointer;
    transition: border-color 0.15s;
}
.code-selector select:hover { border-color: rgba(255, 255, 255, 0.25); }
.code-selector select:focus-visible { outline-color: #5b8cff; }

/* Lista de capítulos */
#chapter-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 9px 12px;
    margin-bottom: 2px;
    border-radius: var(--radius-sm);
    color: var(--sidebar-text);
    font-size: 13.5px;
    line-height: 1.4;
    cursor: pointer;
    transition: background 0.15s var(--ease), color 0.15s var(--ease);
}
#chapter-list li:hover { background: var(--sidebar-hover); color: var(--sidebar-text-strong); }
#chapter-list li.active { background: var(--sidebar-active); color: #fff; }
#chapter-list li.placeholder,
#chapter-list li.placeholder:hover {
    cursor: default;
    background: transparent;
    color: var(--sidebar-muted);
    font-size: 13px;
    padding: 10px 12px;
}
#chapter-list li.loading::before {
    content: '';
    width: 14px; height: 14px;
    border: 2px solid rgba(255, 255, 255, 0.25);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-top: 2px;
}
.chapter-id {
    flex: none;
    min-width: 28px;
    padding: 1px 6px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.08);
    color: var(--sidebar-text-strong);
    font-size: 11.5px;
    font-weight: 700;
    text-align: center;
    font-variant-numeric: tabular-nums;
    margin-top: 1px;
}
#chapter-list li.active .chapter-id { background: rgba(255, 255, 255, 0.22); }

.sidebar-footer {
    padding: 12px 16px;
    border-top: 1px solid var(--sidebar-border);
    font-size: 12px;
    color: var(--sidebar-muted);
}

.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(2, 6, 23, 0.55);
    backdrop-filter: blur(2px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
    z-index: 35;
}
.sidebar-overlay.active { opacity: 1; pointer-events: auto; }

/* ---------- Área principal ---------- */
.content { min-width: 0; display: flex; flex-direction: column; }

.topbar {
    position: sticky;
    top: 0;
    z-index: 30;
    display: flex;
    align-items: center;
    gap: 10px;
    height: var(--topbar-height);
    padding: 0 20px;
    background: color-mix(in srgb, var(--bg) 82%, transparent);
    backdrop-filter: saturate(160%) blur(10px);
    -webkit-backdrop-filter: saturate(160%) blur(10px);
    border-bottom: 1px solid var(--border);
}
.topbar-title {
    flex: 1;
    min-width: 0;
    font-weight: 600;
    font-size: 14px;
    color: var(--text-2);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.topbar-title .crumb-sep { margin: 0 6px; color: var(--text-3); }
.topbar-actions { display: flex; align-items: center; gap: 6px; }

.icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 38px;
    min-width: 38px;
    padding: 0 10px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--surface);
    color: var(--text-2);
    font-size: 13.5px;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.1s;
}
.icon-btn:hover { background: var(--surface-2); border-color: var(--border-strong); color: var(--text); }
.icon-btn:active { transform: translateY(1px); }
.icon-btn svg { width: 18px; height: 18px; flex: none; }
.icon-btn .btn-text { white-space: nowrap; }

.toggle-sidebar { display: none; }

.lang-toggle { font-variant: all-small-caps; letter-spacing: 0.04em; font-size: 15px; }
.lang-toggle .lang-active { color: var(--primary); }
.lang-toggle .lang-sep { color: var(--text-3); margin: 0 2px; }

.read-aloud-btn.reading { background: var(--primary-soft); border-color: var(--primary); color: var(--primary-soft-text); }

.theme-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: block; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .theme-toggle .icon-sun { display: block; }
    :root:not([data-theme="light"]) .theme-toggle .icon-moon { display: none; }
}

.page {
    flex: 1;
    width: 100%;
    max-width: var(--content-max);
    margin: 0 auto;
    padding: 28px 24px 48px;
}

/* Tarjetas de contenido */
#chapter-content,
#exam-container.active {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 40px 44px;
    animation: fadeIn 0.25s var(--ease);
}
#chapter-content:empty { display: none; }
body.exam-mode #chapter-content { display: none; }
#exam-container { display: none; }
#exam-container.active { display: block; }

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(6px); }
    to { opacity: 1; transform: translateY(0); }
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------- Tipografía del contenido ---------- */
#chapter-content h1,
.view-container h1 {
    margin: 0 0 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
    font-size: clamp(1.5rem, 1.2rem + 1.2vw, 2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.2;
    color: var(--text);
}
#chapter-content h2, .chapter-body h2, .subsection h2 {
    margin: 32px 0 14px;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--text);
}
.chapter-body h3, #chapter-content h3 {
    margin: 28px 0 12px;
    font-size: 1.18rem;
    font-weight: 700;
    color: var(--text);
}
.chapter-body h4, #chapter-content h4 {
    margin: 22px 0 8px;
    font-size: 1.02rem;
    font-weight: 650;
    color: var(--text);
}
.chapter-body h5 { margin: 18px 0 6px; font-size: 0.95rem; font-weight: 650; color: var(--text-2); }

.chapter-body { color: var(--text-2); font-size: 16px; line-height: 1.7; }
.chapter-body p, .view-container p { margin: 0 0 14px; }
.chapter-body ul, .chapter-body ol { margin: 0 0 14px; padding-left: 24px; }
.chapter-body li { margin-bottom: 6px; }
.chapter-body strong { color: var(--text); font-weight: 600; }
.chapter-body sup, .chapter-body sub { line-height: 0; }

.chapter-body .subsection { margin: 0 0 18px; }
.chapter-body .subsection .subsection {
    margin-left: 0;
    padding-left: 16px;
    border-left: 2px solid var(--border);
}
.chapter-body .subsection .subsection .subsection { border-left-color: transparent; padding-left: 12px; }

hr {
    border: 0;
    border-top: 1px solid var(--border);
    margin: 28px 0;
}

/* Figuras */
.figure-container {
    margin: 24px auto;
    padding: 14px;
    max-width: 92%;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: center;
}
.figure-image {
    display: inline-block;
    max-width: 100%;
    height: auto;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: zoom-in;
    transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.figure-image:hover { transform: translateY(-1px); box-shadow: var(--shadow-md); }
.figure-caption {
    margin: 10px 4px 0;
    font-size: 0.88rem;
    font-style: italic;
    color: var(--text-3);
}
.figure-caption-sub, .figure-note { font-size: 0.82rem; color: var(--text-3); margin-top: 6px; }

/* Tablas */
.table-container, .table-wrapper, .table-responsive {
    margin: 22px 0;
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
}
.api-table, .progress-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.93rem;
    line-height: 1.5;
    color: var(--text-2);
}
.api-table caption {
    caption-side: top;
    padding: 12px 14px;
    font-weight: 700;
    color: var(--text);
    text-align: left;
    border-bottom: 2px solid var(--primary);
}
.api-table thead th, .progress-table thead th {
    position: sticky;
    top: 0;
    padding: 11px 14px;
    background: var(--surface-2);
    color: var(--text);
    font-weight: 650;
    font-size: 0.85rem;
    text-align: left;
    letter-spacing: 0.01em;
    border-bottom: 1px solid var(--border-strong);
    white-space: nowrap;
}
.api-table td, .progress-table td {
    padding: 10px 14px;
    vertical-align: top;
    border-bottom: 1px solid var(--border);
}
.api-table tbody tr:last-child td, .progress-table tbody tr:last-child td { border-bottom: 0; }
.api-table tbody tr:nth-child(even) { background: color-mix(in srgb, var(--surface-2) 60%, transparent); }
.api-table tbody tr:hover, .progress-table tbody tr:hover { background: var(--primary-soft); }
.api-table td[rowspan] { border-right: 1px solid var(--border); font-weight: 500; color: var(--text); }
.api-table .section-header td {
    background: var(--surface-3);
    color: var(--text);
    font-weight: 700;
    border-bottom: 2px solid var(--primary);
}
.table-note, .api-table .note, .table-reference {
    margin: 8px 0 0;
    padding: 6px 14px 10px;
    font-size: 0.84rem;
    color: var(--text-3);
    font-style: italic;
}
.table-reference { font-style: normal; }

/* Notas y llamadas de atención */
.chapter-body .note, .note {
    margin: 16px 0;
    padding: 12px 16px;
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: var(--primary-soft);
    color: var(--primary-soft-text);
    font-size: 0.93rem;
}
.footnotes { margin-top: 20px; padding-top: 12px; border-top: 1px dashed var(--border); font-size: 0.86rem; color: var(--text-3); }
.alert-info {
    margin: 16px 0 24px;
    padding: 12px 16px;
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: var(--info-soft);
    color: var(--info-soft-text);
}
.alert-info a { font-weight: 600; color: inherit; text-decoration: underline; }
.library-note {
    margin-top: 24px;
    padding: 12px 16px;
    border-left: 4px solid var(--accent);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: var(--accent-soft);
    color: var(--accent-soft-text);
    font-size: 0.92rem;
}
.library-note a { color: inherit; font-weight: 600; text-decoration: underline; }

/* Definiciones (glosarios) */
.definition-item {
    margin: 0 0 12px;
    padding: 12px 14px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}
.definition-item h4, .definition-item strong:first-child { margin-top: 0; }
.term-definition { color: var(--text-2); }

/* Listas de la vista Home */
.main-list { margin: 0 0 18px; padding-left: 22px; overflow: hidden; }
.main-list > li { margin-bottom: 10px; line-height: 1.6; }
.list-title { font-weight: 650; color: var(--text); }
.sub-list { list-style: circle; margin-top: 6px; padding-left: 20px; }
.sub-list > li { margin-bottom: 6px; }
.main-list em, .sub-list em { color: var(--text-3); }
.img-float-left { margin: 0 0 16px; border-radius: var(--radius-sm); background: #fff; padding: 6px; border: 1px solid var(--border); }
@media (min-width: 560px) {
    .img-float-left { float: left; width: 190px; margin: 4px 20px 10px 0; }
}
.view-container::after { content: ''; display: block; clear: both; }
.link-pdf, .external-link { font-weight: 500; }

/* Botón de examen al final del capítulo */
.exam-button-container {
    margin-top: 36px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: center;
}

/* ---------- Botones ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 11px 20px;
    border: 1px solid transparent;
    border-radius: 10px;
    background: var(--primary);
    color: var(--on-primary);
    font-weight: 600;
    font-size: 14.5px;
    line-height: 1.2;
    box-shadow: 0 2px 8px rgba(36, 87, 214, 0.25);
    transition: background 0.15s, transform 0.1s, box-shadow 0.15s, opacity 0.15s;
}
.btn:hover { background: var(--primary-hover); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; box-shadow: none; transform: none; }
.btn-back, .btn.btn-back {
    background: var(--surface);
    color: var(--text-2);
    border-color: var(--border-strong);
    box-shadow: none;
}
.btn-back:hover, .btn.btn-back:hover { background: var(--surface-2); color: var(--text); }
.btn-nav {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 999px;
    background: var(--surface-2);
    color: var(--text-2);
    font-size: 13.5px;
    font-weight: 600;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.btn-nav:hover { background: var(--primary-soft); border-color: var(--primary); color: var(--primary-soft-text); }
.btn-nav.is-on { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-soft-text); }
.back-to-chapter {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    border: 0;
    border-radius: 8px;
    background: transparent;
    color: var(--text-3);
    font-weight: 600;
    font-size: 14px;
}
.back-to-chapter:hover { color: var(--primary); background: var(--primary-soft); }

/* ---------- Examen ---------- */
.exam-wrapper .exam-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
    padding-bottom: 16px;
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border);
}
.exam-title { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.01em; color: var(--text); }
.exam-info { display: flex; align-items: center; gap: 10px; }
.user-name {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border-radius: 999px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    color: var(--text-2);
    font-size: 13.5px;
    font-weight: 600;
}
.user-name::before {
    content: '';
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--success);
}
.timer {
    padding: 6px 14px;
    border-radius: 999px;
    background: var(--text);
    color: var(--bg);
    font-family: var(--font-mono);
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.04em;
    font-variant-numeric: tabular-nums;
}
.progress-container {
    height: 8px;
    background: var(--surface-3);
    border-radius: 999px;
    overflow: hidden;
}
.progress-bar {
    height: 100%;
    width: 0;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--primary), #5b8cff);
    transition: width 0.3s var(--ease);
}
.progress-text { margin: 8px 0 18px; font-size: 13px; font-weight: 600; color: var(--text-3); }

.exam-navigation { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }

.question-container { margin-bottom: 8px; }
.question {
    font-size: 1.12rem;
    font-weight: 600;
    line-height: 1.55;
    color: var(--text);
    margin-bottom: 18px;
}
.options { display: grid; gap: 10px; }
.option {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s, box-shadow 0.15s, transform 0.1s;
}
.option:hover { border-color: var(--border-strong); background: var(--surface-2); }
.option.selected {
    border-color: var(--primary);
    background: var(--primary-soft);
    box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 18%, transparent);
}
.option input[type="radio"] {
    flex: none;
    width: 18px; height: 18px;
    margin: 3px 0 0;
    accent-color: var(--primary);
    cursor: pointer;
}
.option label { flex: 1; cursor: pointer; color: var(--text-2); line-height: 1.5; }
.option.selected label { color: var(--text); font-weight: 500; }

#question-annex { margin-top: 20px; }
.annex-box {
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-left: 4px solid var(--accent);
    border-radius: var(--radius-sm);
    background: var(--surface-2);
    font-size: 0.93rem;
    color: var(--text-2);
}

.exam-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
}
.exam-actions-secondary { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 14px; }

/* Visor PDF */
#pdf-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(2, 6, 23, 0.88);
    z-index: 100;
}
#pdf-overlay .pdf-close { position: absolute; top: 16px; right: 16px; z-index: 2; }
#pdf-overlay iframe {
    position: absolute; top: 64px; left: 4%; width: 92%; height: calc(100% - 80px);
    border: 0; border-radius: var(--radius); background: #fff;
}
#pdf-error {
    display: none;
    position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
    color: #fff; text-align: center; font-size: 18px;
}

/* Índice de preguntas */
.index-header { margin-bottom: 18px; }
.index-header h2 { margin: 0 0 12px; font-size: 1.3rem; }
.index-legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 13px; color: var(--text-3); }
.legend-item { display: inline-flex; align-items: center; gap: 6px; }
.legend-color { width: 14px; height: 14px; border-radius: 4px; border: 1.5px solid var(--border-strong); background: var(--surface); }
.legend-color.answered { background: var(--success-soft); border-color: var(--success); }
.legend-color.marked { background: var(--accent-soft); border-color: var(--accent); }
.index-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(56px, 1fr));
    gap: 8px;
    margin-bottom: 22px;
}
.index-question {
    display: grid;
    place-items: center;
    height: 48px;
    border: 1.5px solid var(--border-strong);
    border-radius: 10px;
    background: var(--surface);
    color: var(--text-2);
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.15s;
}
.index-question:hover { transform: translateY(-1px); box-shadow: var(--shadow-md); }
.index-question.answered { background: var(--success-soft); border-color: var(--success); color: var(--success-soft-text); }
.index-question.marked { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-soft-text); }
.index-question.current { box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 35%, transparent); border-color: var(--primary); }
.index-actions { display: flex; flex-wrap: wrap; gap: 8px; }

/* Resultados */
#result-view h2, #review-view h2 { margin: 0 0 20px; font-size: 1.4rem; font-weight: 800; letter-spacing: -0.01em; }
.result-container { text-align: center; }
.result-score {
    font-size: clamp(3rem, 8vw, 4.5rem);
    font-weight: 900;
    letter-spacing: -0.04em;
    line-height: 1;
    background: linear-gradient(135deg, var(--primary), #5b8cff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    margin: 10px 0 6px;
}
.result-message { font-size: 1.05rem; color: var(--text-2); margin-bottom: 26px; }
.result-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 12px;
    margin-bottom: 26px;
}
.result-item {
    padding: 18px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface-2);
}
.result-value { font-size: 1.7rem; font-weight: 800; color: var(--text); font-variant-numeric: tabular-nums; }
.result-label { margin-top: 4px; font-size: 12.5px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; color: var(--text-3); }
.result-container .btn { margin: 4px; }

/* Revisión */
.review-question {
    margin-bottom: 16px;
    padding: 18px 20px;
    border: 1px solid var(--border);
    border-left: 5px solid var(--border-strong);
    border-radius: var(--radius);
    background: var(--surface);
}
.review-question.correct { border-left-color: var(--success); }
.review-question.incorrect { border-left-color: var(--danger); }
.review-question h3 {
    margin: 0 0 8px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-3);
}
.review-question > p { color: var(--text); font-weight: 500; }
.review-options { display: grid; gap: 8px; margin: 12px 0; }
.review-option {
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface-2);
    color: var(--text-2);
    font-size: 0.95rem;
}
.review-option.correct-answer { background: var(--success-soft); border-color: var(--success); color: var(--success-soft-text); font-weight: 600; }
.review-option.user-selected:not(.correct-answer) { background: var(--danger-soft); border-color: var(--danger); color: var(--danger-soft-text); text-decoration: line-through; }
.review-reference { font-size: 0.86rem; color: var(--text-3); }
.solution-box {
    margin-top: 10px;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    background: var(--info-soft);
    color: var(--info-soft-text);
    font-size: 0.92rem;
}

/* ---------- Vistas ---------- */
.view-container { animation: fadeIn 0.25s var(--ease); }
.view-container > .lang-content > p:first-of-type { color: var(--text-2); }

/* Exámenes de práctica */
.exam-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 18px;
    margin-bottom: 18px;
}
.exam-card {
    position: relative;
    display: flex;
    flex-direction: column;
    padding: 24px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--surface);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.exam-card::before {
    content: '';
    position: absolute; top: 0; left: 0; right: 0; height: 4px;
    background: linear-gradient(90deg, var(--accent), #fb923c);
}
.exam-card.closed::before { background: linear-gradient(90deg, var(--primary), #5b8cff); }
.exam-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.exam-card .exam-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 10px; }
.exam-card .exam-header h2 { margin: 0; font-size: 1.1rem; font-weight: 700; color: var(--text); }
.exam-badge {
    flex: none;
    padding: 3px 10px;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent-soft-text);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}
.exam-card.closed .exam-badge { background: var(--primary-soft); color: var(--primary-soft-text); }
.exam-description { color: var(--text-2); font-size: 0.95rem; margin-bottom: 14px; }
.exam-details { list-style: none; margin: 0 0 20px; padding: 0; flex: 1; }
.exam-details li {
    display: flex; align-items: center; gap: 8px;
    padding: 7px 0;
    border-bottom: 1px dashed var(--border);
    font-size: 0.9rem;
    color: var(--text-2);
}
.exam-details li:last-child { border-bottom: 0; }
.btn-exam {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 11px 20px;
    border: 0; border-radius: 10px;
    background: var(--accent);
    color: #1f1300;
    font-weight: 700; font-size: 14.5px;
    transition: filter 0.15s, transform 0.1s, box-shadow 0.15s;
}
.exam-card.closed .btn-exam { background: var(--primary); color: var(--on-primary); }
.btn-exam:hover { filter: brightness(1.06); box-shadow: var(--shadow-md); }
.btn-exam:active { transform: translateY(1px); }

/* Biblioteca */
.library-filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 6px 0 20px; }
.filter-btn {
    padding: 7px 14px;
    border: 1px solid var(--border-strong);
    border-radius: 999px;
    background: var(--surface);
    color: var(--text-2);
    font-size: 13.5px;
    font-weight: 600;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.filter-btn:hover { background: var(--surface-2); color: var(--text); }
.filter-btn.active { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
.resources-table td:first-child { min-width: 260px; color: var(--text); }
.resources-table strong { color: var(--text); }
.text-muted { display: block; margin-top: 2px; font-size: 0.84rem; color: var(--text-3); }
.badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 999px;
    font-size: 0.74rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    white-space: nowrap;
}
.badge-api { background: var(--primary-soft); color: var(--primary-soft-text); }
.badge-asme { background: var(--accent-soft); color: var(--accent-soft-text); }
.badge-exam { background: var(--success-soft); color: var(--success-soft-text); }
.btn-download {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 7px 12px;
    border-radius: 8px;
    background: var(--success);
    color: #fff;
    font-size: 0.84rem;
    font-weight: 700;
    white-space: nowrap;
    transition: filter 0.15s, transform 0.1s;
}
.btn-download:hover { filter: brightness(1.08); text-decoration: none; transform: translateY(-1px); }
:root[data-theme="dark"] .btn-download { color: #052e16; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .btn-download { color: #052e16; } }

/* Calendarios */
.schedule-table th, .schedule-table td { white-space: nowrap; }
#schedules-view h2, #library-view h2, #exams-view h2:not(.exam-card h2) {
    margin: 30px 0 14px;
    padding-left: 12px;
    border-left: 4px solid var(--primary);
    font-size: 1.25rem;
}
.note.schedule-note, #schedules-view .note { background: var(--surface-2); color: var(--text-3); border-left-color: var(--border-strong); font-style: italic; font-size: 0.86rem; }

/* Progreso */
.student-name { margin-bottom: 14px; }
.student-name-card {
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-left: 4px solid var(--primary);
    border-radius: var(--radius-sm);
    background: var(--surface-2);
    color: var(--text-2);
}
.student-name-card strong { color: var(--text); }
.progress-summary { margin-bottom: 20px; }
.summary-card {
    padding: 18px 22px;
    border-radius: var(--radius);
    background: linear-gradient(135deg, #16244a 0%, #2457d6 100%);
    color: #fff;
    font-weight: 600;
    text-align: center;
    box-shadow: 0 8px 24px rgba(36, 87, 214, 0.3);
}
.progress-details {
    margin-bottom: 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    overflow: hidden;
}
.progress-details summary {
    display: flex; align-items: center; gap: 10px;
    padding: 14px 18px;
    background: var(--surface-2);
    color: var(--text);
    font-weight: 650;
    cursor: pointer;
    list-style: none;
    user-select: none;
}
.progress-details summary::-webkit-details-marker { display: none; }
.progress-details summary::before {
    content: '';
    width: 8px; height: 8px;
    border-right: 2px solid var(--text-3);
    border-bottom: 2px solid var(--text-3);
    transform: rotate(-45deg);
    transition: transform 0.2s;
    margin-right: 4px;
}
.progress-details[open] summary::before { transform: rotate(45deg); }
.progress-details summary:hover { background: var(--surface-3); }
.progress-details .table-responsive { margin: 0; border: 0; border-radius: 0; }
.progress-bar-container { width: 100%; max-width: 160px; height: 8px; border-radius: 999px; background: var(--surface-3); overflow: hidden; }
.progress-bar-fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--primary), var(--success)); transition: width 0.3s; }
.sync-btn { margin: 16px auto 0; display: block; }

/* ---------- Modales ---------- */
.name-modal {
    display: none;
    position: fixed; inset: 0;
    align-items: center; justify-content: center;
    padding: 20px;
    background: rgba(2, 6, 23, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 200;
}
.name-modal-content {
    width: 100%;
    max-width: 460px;
    padding: 32px 30px;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--surface);
    box-shadow: var(--shadow-lg);
    text-align: center;
    animation: popIn 0.25s var(--ease);
}
@keyframes popIn { from { opacity: 0; transform: translateY(10px) scale(0.98); } to { opacity: 1; transform: none; } }
.name-modal-content .brand-mark { margin: 0 auto 14px; width: 52px; height: 52px; font-size: 15px; }
.name-modal-content h2 { margin: 0 0 6px; font-size: 1.3rem; font-weight: 800; letter-spacing: -0.01em; }
.name-modal-content p { margin: 0 0 20px; color: var(--text-3); font-size: 0.95rem; }
#user-buttons { display: grid; gap: 8px; }
.user-btn {
    display: flex; align-items: center; gap: 12px;
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface-2);
    color: var(--text);
    font-weight: 600;
    text-align: left;
    transition: border-color 0.15s, background 0.15s, transform 0.1s;
}
.user-btn:hover { border-color: var(--primary); background: var(--primary-soft); transform: translateY(-1px); }
.user-avatar {
    flex: none;
    width: 34px; height: 34px;
    border-radius: 50%;
    display: grid; place-items: center;
    background: linear-gradient(135deg, var(--primary), #5b8cff);
    color: #fff;
    font-size: 12.5px;
    font-weight: 800;
    letter-spacing: 0.02em;
}

/* Visor de imágenes */
.modal {
    display: none;
    position: fixed; inset: 0;
    background: rgba(2, 6, 23, 0.92);
    z-index: 300;
}
.zoom-container {
    position: absolute; inset: 0;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden;
}
.modal-content {
    max-width: none;
    user-select: none;
    -webkit-user-drag: none;
    touch-action: none;
    will-change: transform;
    transform-origin: center center;
    cursor: grab;
    background: #fff;
    border-radius: 6px;
}
.zoom-controls {
    position: absolute;
    bottom: 24px; left: 50%;
    transform: translateX(-50%);
    display: flex; gap: 6px;
    padding: 6px;
    border-radius: 999px;
    background: rgba(15, 23, 42, 0.85);
    border: 1px solid rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(8px);
    z-index: 2;
}
.zoom-controls button {
    min-width: 40px; height: 36px;
    padding: 0 12px;
    border: 0; border-radius: 999px;
    background: transparent;
    color: #fff;
    font-weight: 700;
    font-size: 15px;
}
.zoom-controls button:hover { background: rgba(255, 255, 255, 0.12); }
.close {
    position: absolute; top: 16px; right: 16px;
    width: 42px; height: 42px;
    display: grid; place-items: center;
    border-radius: 50%;
    background: rgba(15, 23, 42, 0.85);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: #fff;
    font-size: 26px;
    line-height: 1;
    cursor: pointer;
    z-index: 2;
}
.close:hover { background: rgba(255, 255, 255, 0.16); }

/* Volver arriba */
#scroll-to-top {
    position: fixed;
    right: 22px; bottom: 22px;
    width: 44px; height: 44px;
    display: grid; place-items: center;
    border: 1px solid var(--border);
    border-radius: 50%;
    background: var(--surface);
    color: var(--text-2);
    box-shadow: var(--shadow-md);
    opacity: 0;
    transform: translateY(10px);
    pointer-events: none;
    transition: opacity 0.2s, transform 0.2s, background 0.15s;
    z-index: 50;
}
#scroll-to-top.visible { opacity: 1; transform: none; pointer-events: auto; }
#scroll-to-top:hover { background: var(--primary); border-color: var(--primary); color: var(--on-primary); }
#scroll-to-top svg { width: 20px; height: 20px; }

/* Pie */
.footer {
    padding: 18px 24px;
    border-top: 1px solid var(--border);
    color: var(--text-3);
    font-size: 12.5px;
    text-align: center;
}
.footer p { margin: 0; }

/* Mensaje de error de carga */
.load-error {
    padding: 14px 16px;
    border-left: 4px solid var(--danger);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    background: var(--danger-soft);
    color: var(--danger-soft-text);
}

/* ---------- Responsive ---------- */
@media (max-width: 1100px) {
    :root { --sidebar-width: 272px; }
    #chapter-content, #exam-container.active { padding: 32px 30px; }
}

@media (max-width: 900px) {
    .app { grid-template-columns: 1fr; }
    .sidebar {
        position: fixed;
        top: 0; left: 0; bottom: 0;
        width: min(86vw, 320px);
        transform: translateX(-100%);
        transition: transform 0.25s var(--ease);
        box-shadow: none;
    }
    .sidebar.active { transform: none; box-shadow: var(--shadow-lg); }
    .toggle-sidebar { display: inline-flex; }
    .icon-btn .btn-text { display: none; }
    .lang-toggle .btn-text { display: inline; }
    .topbar { padding: 0 14px; }
    .page { padding: 18px 14px 40px; }
    #chapter-content, #exam-container.active { padding: 24px 20px; border-radius: var(--radius); }
    .figure-container { max-width: 100%; padding: 10px; }
    .chapter-body .subsection .subsection { padding-left: 12px; }
    .exam-wrapper .exam-header { flex-direction: column; align-items: flex-start; }
    .exam-actions .btn { flex: 1; }
    .index-container { grid-template-columns: repeat(auto-fill, minmax(48px, 1fr)); }
}

@media (max-width: 560px) {
    body { font-size: 15.5px; }
    #chapter-content, #exam-container.active { padding: 20px 16px; }
    .result-details { grid-template-columns: 1fr 1fr; }
    .btn, .btn-exam { width: 100%; }
    .exam-actions { flex-direction: column-reverse; }
    .exam-actions > * { width: 100%; }

    /* Tablas de recursos y progreso como tarjetas */
    .resources-table thead, .progress-table thead { display: none; }
    .resources-table tbody tr, .progress-table tbody tr {
        display: block;
        margin: 10px;
        padding: 6px 12px;
        border: 1px solid var(--border);
        border-radius: var(--radius-sm);
        background: var(--surface-2);
    }
    .resources-table td, .progress-table td {
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: 12px;
        padding: 8px 0;
        border-bottom: 1px dashed var(--border);
    }
    .resources-table td:last-child, .progress-table td:last-child { border-bottom: 0; }
    .resources-table td::before, .progress-table td::before {
        content: attr(data-label);
        flex: none;
        font-size: 0.78rem;
        font-weight: 700;
        letter-spacing: 0.04em;
        text-transform: uppercase;
        color: var(--text-3);
    }
    .resources-table td:first-child { min-width: 0; display: block; }
    .resources-table td:first-child::before { display: block; margin-bottom: 4px; }
}

/* ---------- Impresión ---------- */
@media print {
    .sidebar, .topbar, #scroll-to-top, .footer, .exam-button-container { display: none !important; }
    .app { display: block; }
    #chapter-content { border: 0; box-shadow: none; padding: 0; }
}

/* =====================================================================
   Examen de certificación: interfaz tipo Prometric (API ICP)
   ===================================================================== */
#pm-root {
    --pm-green: #8dc63f;
    --pm-green-dark: #5d8f1f;
    --pm-green-darker: #3f6a12;
    --pm-bar: #3c3c3c;
    --pm-bar-text: #ffffff;
    --pm-bg: #d4d6d8;
    --pm-panel: #ffffff;
    --pm-text: #222222;
    --pm-text-2: #555555;
    --pm-line: #9a9a9a;
    --pm-opt-border: #5b5b5b;
    --pm-opt-hover: #f1f6e8;
    --pm-opt-selected: #e2f0c8;
    --pm-finish: #8a8a8a;
    --pm-alert: #e4572e;
    --pm-font: 'Open Sans', 'Segoe UI', 'Inter', system-ui, sans-serif;

    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    background: var(--pm-bg);
    color: var(--pm-text);
    font-family: var(--pm-font);
    font-size: 15px;
    line-height: 1.5;
    user-select: none;
}
#pm-root[data-scheme="dark"] {
    --pm-bg: #1b1d1f; --pm-panel: #26292c; --pm-text: #eef0f2; --pm-text-2: #b7bcc2; --pm-line: #4a4f55;
    --pm-opt-border: #8a9099; --pm-opt-hover: #2f3338; --pm-opt-selected: #3b5220; --pm-bar: #121314;
}
#pm-root[data-scheme="contrast"] {
    --pm-bg: #000; --pm-panel: #000; --pm-text: #ffff66; --pm-text-2: #ffff99; --pm-line: #ffff66;
    --pm-opt-border: #ffff66; --pm-opt-hover: #222; --pm-opt-selected: #444400; --pm-bar: #000; --pm-green: #ffff00;
    --pm-green-dark: #cccc00; --pm-green-darker: #999900; --pm-finish: #666;
}
#pm-root[data-scheme="contrast"] .pm-band, #pm-root[data-scheme="contrast"] .pm-nav, #pm-root[data-scheme="contrast"] .pm-num { color: #000; }
body.pm-open { overflow: hidden; }
#pm-root * { box-sizing: border-box; }
#pm-root button { font: inherit; cursor: pointer; }
#pm-root [hidden] { display: none !important; }
#pm-root svg { width: 18px; height: 18px; flex: none; }

/* Barra superior */
.pm-top {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 12px;
    padding: 6px 14px;
    background: var(--pm-bar);
    color: var(--pm-bar-text);
    font-size: 13px;
    line-height: 1.35;
}
.pm-top-left strong, .pm-band strong { font-weight: 700; }
.pm-top-center { display: flex; align-items: center; gap: 22px; }
.pm-clock {
    display: flex; align-items: center; gap: 8px;
    padding: 4px 10px;
    border: 1px solid transparent; border-radius: 4px;
    background: transparent; color: inherit;
    text-align: left;
}
.pm-clock:hover { border-color: rgba(255, 255, 255, 0.25); }
.pm-clock svg { width: 22px; height: 22px; }
.pm-clock small { display: block; font-size: 11.5px; opacity: 0.9; }
.pm-clock b { display: block; font-size: 15px; font-variant-numeric: tabular-nums; letter-spacing: 0.03em; }
.pm-clock.pm-warning b { color: #ffb347; animation: pmBlink 1s steps(2) infinite; }
@keyframes pmBlink { 50% { opacity: 0.4; } }
.pm-attempted { text-align: center; }
.pm-attempted b { display: block; font-size: 13px; }
.pm-attempted small { font-size: 11px; opacity: 0.9; }
.pm-top-right { text-align: right; }
.pm-finish {
    padding: 8px 18px;
    border: 0; border-radius: 3px;
    background: var(--pm-finish); color: #fff;
    font-weight: 700; font-size: 13px;
}
.pm-finish:hover { filter: brightness(1.12); }

/* Franja verde */
.pm-band {
    display: flex; justify-content: space-between; gap: 16px;
    padding: 3px 14px;
    background: var(--pm-green); color: #fff;
    font-size: 12.5px;
}
.pm-band span { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.pm-alert {
    margin: 8px 16px 0;
    padding: 8px 14px;
    border-radius: 4px;
    background: var(--pm-alert); color: #fff;
    font-weight: 600; font-size: 14px;
    animation: fadeIn 0.2s;
}

/* Cuerpo */
.pm-body { flex: 1; min-height: 0; display: flex; gap: 10px; padding: 10px 14px; }
.pm-rail {
    width: 46px; flex: none;
    overflow-y: auto; overflow-x: hidden;
    padding: 2px 6px 2px 0;
    scrollbar-width: thin;
}
.pm-num {
    position: relative;
    display: flex; align-items: center; justify-content: center;
    width: 36px; height: 20px;
    margin: 0 0 5px;
    border: 0; border-radius: 2px;
    background: var(--pm-green); color: #fff;
    font-size: 11px; font-weight: 700;
    transition: filter 0.1s;
}
.pm-num:hover { filter: brightness(1.08); }
.pm-num.pm-attempted { background: var(--pm-green-dark); }
.pm-num.pm-current {
    width: 40px;
    clip-path: polygon(0 0, 82% 0, 100% 50%, 82% 100%, 0 100%);
    background: var(--pm-green-darker);
}
.pm-num .pm-num-flag { display: none; position: absolute; left: 2px; top: 3px; width: 11px; height: 11px; }
.pm-num .pm-num-flag svg { width: 11px; height: 11px; }
.pm-num.pm-flagged .pm-num-flag { display: block; }
.pm-num.pm-flagged span { padding-left: 8px; }

.pm-panel {
    position: relative;
    flex: 1; min-width: 0;
    overflow-y: auto;
    padding: 26px 32px 60px;
    border: 1px solid #b9bcbf;
    border-radius: 6px;
    background: var(--pm-panel);
    box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.4);
}
.pm-qtext { font-size: 16px; line-height: 1.6; margin-bottom: 18px; }
.pm-qtext img { max-width: 100%; height: auto; }
.pm-tools { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; margin: 0 0 20px; }
.pm-tool {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 4px 8px;
    border: 1px solid transparent; border-radius: 3px;
    background: transparent; color: var(--pm-text);
    font-size: 14px;
}
.pm-tool svg { color: var(--pm-green-dark); }
.pm-tool:hover { border-color: var(--pm-line); background: var(--pm-opt-hover); }
.pm-options { display: grid; gap: 10px; max-width: 860px; }
.pm-opt { display: grid; grid-template-columns: 22px 1fr; align-items: center; gap: 8px; }
.pm-letter { font-size: 14px; font-weight: 600; color: var(--pm-text-2); text-align: center; }
.pm-opt-box {
    width: 100%;
    min-height: 40px;
    padding: 8px 14px;
    border: 1.5px solid var(--pm-opt-border);
    border-radius: 2px;
    background: var(--pm-panel); color: var(--pm-text);
    text-align: left;
    line-height: 1.45;
    transition: background 0.1s, box-shadow 0.1s;
}
.pm-opt-box:hover { background: var(--pm-opt-hover); }
.pm-opt.pm-selected .pm-opt-box { background: var(--pm-opt-selected); border-color: var(--pm-green-dark); box-shadow: inset 0 0 0 1px var(--pm-green-dark); }
.pm-opt.pm-selected .pm-letter { color: var(--pm-green-darker); }
.pm-opt.pm-struck .pm-opt-box, .pm-opt.pm-struck .pm-letter { text-decoration: line-through; color: var(--pm-text-2); opacity: 0.75; }
.pm-scroll-hint {
    position: sticky; bottom: 0; float: right;
    margin: 12px -8px -40px 0;
    padding: 6px 14px;
    border-radius: 3px;
    background: var(--pm-green); color: #fff;
    font-size: 12.5px; font-weight: 600;
    clip-path: polygon(0 0, 92% 0, 100% 50%, 92% 100%, 0 100%);
    padding-right: 22px;
}

/* Barra inferior */
.pm-bottom {
    display: flex; justify-content: space-between; align-items: center; gap: 10px;
    padding: 6px 14px;
    background: var(--pm-bar);
}
.pm-bottom-left, .pm-bottom-right { display: flex; align-items: center; gap: 6px; }
.pm-icon {
    display: grid; place-items: center;
    width: 34px; height: 30px;
    border: 0; border-radius: 3px;
    background: transparent; color: #fff;
}
.pm-icon svg { width: 20px; height: 20px; }
.pm-icon:hover { background: rgba(255, 255, 255, 0.14); }
.pm-icon.pm-on { color: var(--pm-green); }
.pm-nav {
    display: inline-flex; align-items: center; gap: 4px;
    min-width: 88px; height: 30px;
    padding: 0 10px;
    border: 0; border-radius: 3px;
    background: var(--pm-green); color: #fff;
    font-weight: 700; font-size: 13px;
}
.pm-nav svg { width: 16px; height: 16px; }
.pm-nav:hover { filter: brightness(1.08); }
.pm-nav:disabled { opacity: 0.45; cursor: not-allowed; filter: none; }

/* Capas */
.pm-layer { position: absolute; inset: 0; z-index: 5; display: flex; align-items: center; justify-content: center; padding: 16px; }
.pm-layer-dim { background: rgba(0, 0, 0, 0.45); }
.pm-layer-float { pointer-events: none; align-items: flex-end; justify-content: flex-end; padding: 0 40px 60px 0; }
.pm-layer-float > * { pointer-events: auto; }
.pm-layer:not(.pm-layer-dim):not(.pm-layer-float) { background: rgba(0, 0, 0, 0.55); }
.pm-btn {
    padding: 8px 16px;
    border: 1px solid #6c6c6c; border-radius: 3px;
    background: #f2f2f2; color: #222;
    font-weight: 600; font-size: 13.5px;
}
.pm-btn:hover { filter: brightness(0.96); }
.pm-btn-primary { background: var(--pm-green); border-color: var(--pm-green-dark); color: #fff; }
.pm-dialog {
    width: min(520px, 100%);
    padding: 22px 24px;
    border-radius: 6px;
    background: #fff; color: #222;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
    font-family: var(--pm-font);
}
.pm-dialog h3 { margin: 0 0 12px; font-size: 17px; }
.pm-dialog-wide { width: min(680px, 100%); }
.pm-dialog-body { font-size: 15px; line-height: 1.55; }
.pm-dialog-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 18px; flex-wrap: wrap; }
.pm-dialog textarea { width: 100%; padding: 8px; border: 1px solid #999; border-radius: 3px; font: inherit; resize: vertical; }
.pm-dialog small { display: block; margin-top: 6px; color: #666; }
.pm-help-list { margin: 0; padding-left: 20px; line-height: 1.6; }
.pm-help-list li { margin-bottom: 8px; }
.pm-schemes { display: flex; gap: 8px; flex-wrap: wrap; }

/* Visor PDF / anexos */
.pm-viewer { display: flex; flex-direction: column; width: 100%; height: 100%; border-radius: 6px; background: #fff; overflow: hidden; }
.pm-viewer-bar {
    display: flex; justify-content: space-between; align-items: center; gap: 10px;
    padding: 8px 12px;
    background: var(--pm-bar); color: #fff;
    font-weight: 600; font-size: 14px;
}
.pm-viewer-bar span, .pm-viewer-bar label { display: inline-flex; align-items: center; gap: 8px; }
.pm-viewer-bar select { padding: 5px 8px; border-radius: 3px; border: 1px solid #777; font: inherit; }
.pm-viewer-bar div { display: flex; gap: 6px; }
.pm-viewer iframe { flex: 1; width: 100%; border: 0; background: #fff; }
.pm-viewer-html { width: min(900px, 100%); height: auto; max-height: 100%; }
.pm-exhibit-body { overflow: auto; padding: 18px 22px; color: #222; }
.pm-exhibit-body img { max-width: 100%; height: auto; }
.pm-exhibit-body .figure-container { background: #f5f5f5; border-color: #ddd; }
.pm-exhibit-body .figure-caption { color: #555; }

/* Pantalla de revisión */
.pm-review { display: flex; flex-direction: column; width: min(960px, 100%); max-height: 100%; border-radius: 6px; background: #fff; color: #222; overflow: hidden; }
.pm-review-summary { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; padding: 12px 16px; border-bottom: 1px solid #ddd; font-size: 13.5px; }
.pm-review-summary small { color: #666; margin-left: auto; }
.pm-legend::before { content: ''; display: inline-block; width: 14px; height: 14px; margin-right: 6px; vertical-align: -2px; border-radius: 2px; background: var(--pm-green); }
.pm-legend.pm-attempted::before { background: var(--pm-green-dark); }
.pm-legend.pm-flagged::before { background: var(--pm-green); box-shadow: inset 0 0 0 2px #fff, inset 0 0 0 4px var(--pm-green-darker); }
.pm-review-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(52px, 1fr)); gap: 6px; padding: 14px 16px; overflow-y: auto; }
.pm-rv-cell {
    position: relative; height: 34px;
    border: 0; border-radius: 2px;
    background: var(--pm-green); color: #fff;
    font-weight: 700; font-size: 13px;
}
.pm-rv-cell.pm-attempted { background: var(--pm-green-dark); }
.pm-rv-cell.pm-current { outline: 3px solid var(--pm-green-darker); outline-offset: 1px; }
.pm-rv-cell i { position: absolute; left: 4px; top: 4px; }
.pm-rv-cell i svg { width: 11px; height: 11px; }

/* Resultados */
.pm-results { width: min(640px, 100%); }
.pm-results-card { padding: 28px 30px; border-radius: 8px; background: #fff; color: #222; text-align: center; box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4); }
.pm-results-card h2 { margin: 0 0 8px; font-size: 20px; }
.pm-score { font-size: 56px; font-weight: 800; line-height: 1; margin: 8px 0 18px; }
.pm-score.pm-pass { color: var(--pm-green-dark); }
.pm-score.pm-fail { color: #c0392b; }
.pm-results-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(110px, 1fr)); gap: 10px; }
.pm-results-grid div { padding: 12px 8px; border: 1px solid #ddd; border-radius: 6px; background: #f7f7f7; }
.pm-results-grid b { display: block; font-size: 22px; }
.pm-results-grid span { font-size: 12px; color: #666; text-transform: uppercase; letter-spacing: 0.04em; }
.pm-pass-hint { margin: 16px 0 0; font-size: 13.5px; color: #666; }
.pm-results .pm-dialog-actions { justify-content: center; }

/* Revisión de respuestas */
.pm-answer-review { width: min(1000px, 100%); height: 100%; }
.pm-review-list { overflow-y: auto; padding: 16px; user-select: text; }
.pm-rv-item { margin-bottom: 14px; padding: 14px 18px; border: 1px solid #ddd; border-left: 5px solid #bbb; border-radius: 6px; background: #fff; }
.pm-rv-item.pm-ok { border-left-color: var(--pm-green-dark); }
.pm-rv-item.pm-bad { border-left-color: #c0392b; }
.pm-rv-item header { display: flex; justify-content: space-between; margin-bottom: 8px; font-size: 12.5px; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; color: #666; }
.pm-rv-item .pm-qtext { font-size: 15px; margin-bottom: 12px; }
.pm-rv-opts { display: grid; gap: 6px; }
.pm-rv-opt { display: grid; grid-template-columns: 22px 1fr; gap: 8px; align-items: center; padding: 7px 12px; border: 1px solid #ddd; border-radius: 3px; font-size: 14px; }
.pm-rv-opt.pm-rv-correct { background: #e2f0c8; border-color: var(--pm-green-dark); font-weight: 600; }
.pm-rv-opt.pm-rv-wrong { background: #fbe3e0; border-color: #c0392b; text-decoration: line-through; }
.pm-rv-ref { margin-top: 8px; font-size: 13px; color: #666; }
.pm-rv-sol, .pm-rv-comment { margin-top: 8px; padding: 8px 12px; border-radius: 4px; background: #eef5ff; font-size: 13.5px; }
.pm-rv-comment { background: #fff8e1; }

/* Calculadora */
.pm-calc {
    width: 300px;
    border-radius: 6px;
    background: #f0f0f0; color: #222;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
    overflow: hidden;
    font-family: 'Segoe UI', system-ui, sans-serif;
}
.pm-calc-title { display: flex; justify-content: space-between; align-items: center; padding: 6px 10px; background: var(--pm-bar); color: #fff; font-size: 13px; font-weight: 600; }
.pm-calc-title button { border: 0; background: transparent; color: #fff; font-size: 14px; }
.pm-calc-display { margin: 10px; padding: 10px 12px; border: 1px solid #bbb; border-radius: 3px; background: #fff; text-align: right; font-size: 22px; font-variant-numeric: tabular-nums; overflow: hidden; white-space: nowrap; }
.pm-calc-keys { display: grid; grid-template-columns: repeat(6, 1fr); gap: 5px; padding: 0 10px 10px; }
.pm-calc-keys button { height: 36px; border: 1px solid #c9c9c9; border-radius: 3px; background: #fff; font-size: 14px; font-weight: 600; }
.pm-calc-keys button:hover { background: #e8e8e8; }
.pm-calc-keys button[data-k="BS"] { grid-column: span 2; }
.pm-calc-keys button[data-k="CE"] { grid-column: span 2; }
.pm-k-red { background: #c0392b !important; border-color: #a93226 !important; color: #fff; }
.pm-k-mem { background: #e4e4e4 !important; color: #555; }
.pm-k-op { background: #27ae60 !important; border-color: #1e8449 !important; color: #fff; font-size: 17px !important; }
.pm-k-eq { background: #2a6db5 !important; border-color: #1f5590 !important; color: #fff; }

/* Responsive */
@media (max-width: 760px) {
    .pm-top { grid-template-columns: 1fr auto; font-size: 12px; }
    .pm-top-center { grid-column: 1 / -1; order: 3; justify-content: space-between; }
    .pm-top-right { text-align: right; }
    .pm-band { font-size: 11.5px; }
    .pm-body { padding: 8px; gap: 6px; }
    .pm-rail { width: 40px; }
    .pm-num { width: 32px; }
    .pm-panel { padding: 16px 14px 60px; }
    .pm-nav { min-width: 0; }
    .pm-nav span { display: none; }
    .pm-layer-float { padding: 0 8px 50px 0; }
    .pm-calc { width: min(300px, 100%); }
}