/* ============================================================
   edoo · landing-demo.css — la demo interactiva de la landing
   (templates/components/landing-demo.html: sección #demo y, fuera de
   ella, el visor de documento #demo-doc-overlay al final del body).
   Se carga ANTES que landing-institucional.css: todo va bajo #demo o
   con clases .demo-* para no depender del orden.

   Referencias (síntesis, no copia)
   - Brightspace, asistente de IA: pasos en la cabecera de la tarjeta
     (✓ hecho en verde · ● actual · ○ siguiente), banda tenue con ⓘ que
     dice qué hace la IA, tarjetas de tipo con icono de línea, nombre y
     una frase. Es el mismo asistente que Crear en la app.
   - Canvas / Blackboard: material como fichas con franja de vista
     previa gris, icono por tipo de archivo, nombre en azul de enlace y
     tipo en gris; video con póster oscuro, botón de reproducir y
     duración.
   - D2L: el cambio de modo son pestañas con texto gris y subrayado de
     2 px en la activa.
   - Brightspace / Canvas, contenido del curso: lección con índice de
     módulos a la izquierda (fila actual con fondo tenue y barra de
     3 px, completados con marca verde) y el elemento a la derecha con
     su barra de acciones gris abajo (Anterior · Siguiente).
   - Canvas New Quizzes: el reproductor real va en un iframe dentro de
     la tarjeta, con una barra superior (volver · tipo) y un pie gris.

   Decisiones de estructura
   1. Una sola tarjeta blanca para el modo "Actividad individual": los
      pasos arriba (rejilla de 6 columnas: cada paso ocupa dos y cada
      línea une los centros de dos pasos) y un solo paso visible debajo.
   2. Cada paso abre con título de 22 px en peso 400 y una frase gris;
      el regreso es un enlace con flecha, siempre arriba a la izquierda.
   3. "Generando" es texto + barra fina de 4 px; sin cerebro, anillos,
      partículas ni confeti (se ocultan: el script los sigue creando).
   4. Correcto/incorrecto solo con --success/--danger; un único color
      de acción (--primary) en botones de 36 px y radio de 4 px, como
      en la app; nada de pastillas, degradados ni sombras de color.
   5. En teléfono (≤ 600 px) un solo margen de 16 px: las tarjetas van de
      borde a borde y el iframe del reproductor ocupa todo el ancho; la
      lección apila índice y contenido (≤ 760 px) y el visor de documento
      sube desde abajo a pantalla completa.
   El póster del video de fracciones es un gráfico de pastel 3/4 dibujado
   con conic-gradient de cortes duros (es una ilustración del contenido,
   no un degradado decorativo).

   Clases de estado: active, done (pasos y elementos de la lección),
   show (visor, puntaje), hide (generando), on (puntos de diapositiva),
   [hidden] en los paneles de modo.
   Sin estilo propio (código muerto: renderMC … renderOpenQ, showScore y
   checkBtn ya no se llaman; renderActivity usa el reproductor real en
   /preview-activity/inline): demo-mc*, demo-q-*, demo-opt-*, demo-tf*,
   demo-fb*, demo-blank-*, demo-pair*, demo-seq*, demo-flash*, demo-dd*,
   demo-cw*, demo-timeline, demo-tl-*, demo-mw*, demo-reading*,
   demo-openq*, y sus estados selected, correct, wrong, missed, flipped,
   knew, didnt, dragging, drag-over, dd-selected, empty. El puntaje
   propio (.demo-score-overlay) tampoco se muestra, pero conserva una
   regla mínima por si vuelve. demo-section y demo-play-wrap no pintan.
   ============================================================ */

/* ---------- 1. Marco de la sección ---------- */
#demo .section-container { font-size: var(--fs-body); line-height: 1.5; color: var(--text); }
#demo .demo-mode-panel[hidden] { display: none; }
/* placa teñida tras la tarjeta, como tras las interfaces de la landing; la
   tarjeta recorta su overflow, así que la placa cuelga del panel que la envuelve */
#demo .demo-mode-panel { position: relative; isolation: isolate; }
#demo .demo-mode-panel::before { content: ""; position: absolute; inset: 16px -16px -16px 16px; z-index: -1; border-radius: var(--radius-lg); background: var(--primary-tint-strong); opacity: .5; }
#demo :focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }

/* ---------- 2. Pestañas de modo ---------- */
#demo .demo-mode-toggle {
    display: flex; gap: 28px; margin: 0 0 24px;
    border-bottom: 1px solid var(--border);
}
#demo .demo-mode-btn {
    display: inline-flex; align-items: center; min-height: 44px; margin-bottom: -1px;
    border-bottom: 2px solid transparent;
    font-family: var(--font-body); font-size: 15px; font-weight: 700; color: var(--muted);
    white-space: nowrap; transition: color .12s, border-color .12s;
}
#demo .demo-mode-btn { flex: 0 1 auto; min-width: 0; }
#demo .demo-mode-btn span { overflow: hidden; text-overflow: ellipsis; }
#demo .demo-mode-btn:hover { color: var(--text); }
#demo .demo-mode-btn.active { color: var(--text); border-bottom-color: var(--primary); }

/* ---------- 3. Tarjeta del asistente y pasos ---------- */
#demo .demo-container {
    position: relative; overflow: hidden;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
}
#demo .demo-steps-indicator {
    display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); align-items: start;
    margin: 0; padding: 24px max(var(--card-pad), calc((100% - 720px) / 2)) 20px;
    list-style: none;
}
#demo .demo-stepper-item {
    grid-row: 1; position: relative; z-index: 1; min-width: 0;
    display: flex; flex-direction: column; align-items: center; gap: 8px; text-align: center;
}
#demo .demo-stepper-item:nth-child(1) { grid-column: 1 / 3; }
#demo .demo-stepper-item:nth-child(3) { grid-column: 3 / 5; }
#demo .demo-stepper-item:nth-child(5) { grid-column: 5 / 7; }
#demo .demo-step-line { grid-row: 1; display: block; height: 2px; margin-top: 13px; background: var(--border); overflow: hidden; }
#demo .demo-step-line:nth-child(2) { grid-column: 2 / 4; }
#demo .demo-step-line:nth-child(4) { grid-column: 4 / 6; }
#demo .demo-step-line-fill { display: block; width: 0; height: 100%; background: var(--accent); transition: width .3s ease; }
#demo .demo-step-dot {
    display: inline-flex; align-items: center; justify-content: center;
    width: 28px; height: 28px; border-radius: 50%;
    border: 2px solid var(--border); background: var(--surface);
    font-size: 12px; font-weight: 700; color: var(--muted); font-variant-numeric: tabular-nums;
}
#demo .demo-step-dot i { display: none; font-size: 11px; }
#demo .demo-step-dot.active { border-color: var(--primary); background: var(--primary); color: var(--on-primary); }
#demo .demo-step-dot.done { border-color: var(--accent); color: var(--accent); }
#demo .demo-step-dot.done > span { display: none; }
#demo .demo-step-dot.done i { display: inline; }
#demo .demo-step-label { font-size: 13px; line-height: 1.35; color: var(--muted); }
#demo .demo-step-label.active { color: var(--primary); font-weight: 700; }
#demo .demo-step-label.done { color: var(--text-secondary); }

/* un paso visible a la vez */
#demo .demo-panel { display: none; padding: var(--card-pad); border-top: 1px solid var(--border-light); }
#demo .demo-panel.active { display: block; }
#demo .demo-panel-head { margin-bottom: 16px; }
#demo .demo-grid-title {
    margin: 0; font-family: var(--font-body); font-size: var(--fs-h2); font-weight: 400;
    line-height: 1.25; letter-spacing: 0; color: var(--text);
}
#demo .demo-panel-sub { margin-top: 4px; font-size: 14px; color: var(--muted); }
#demo .demo-back-link, #demo .demo-back-btn {
    display: inline-flex; align-items: center; gap: 8px; min-height: 32px;
    font-family: var(--font-body); font-size: 14px; font-weight: 700; color: var(--primary); white-space: nowrap;
}
#demo .demo-back-link:hover, #demo .demo-back-btn:hover { color: var(--primary-dark); text-decoration: underline; }
#demo .demo-back-link i, #demo .demo-back-btn i { font-size: 12px; }
#demo .demo-back-link { margin: -4px 0 12px; }

/* aviso de IA (misma banda que .ai-note en Crear) */
#demo .demo-resource-hint {
    display: flex; gap: 12px; align-items: flex-start; margin: 0 0 16px; padding: 12px 16px;
    border-radius: var(--radius-lg); background: var(--primary-tint);
    font-size: 14px; line-height: 1.5; color: var(--text);
}
#demo .demo-resource-hint i { margin-top: 3px; color: var(--primary); }

/* ---------- 4. Paso 1: material de muestra ---------- */
#demo .demo-resource-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
#demo .demo-resource-card {
    display: flex; flex-direction: column; min-width: 0; overflow: hidden; cursor: pointer;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
    transition: border-color .12s, box-shadow .12s;
}
#demo .demo-resource-card:hover { border-color: var(--border-strong); box-shadow: var(--shadow-sm); }
#demo .demo-resource-card:hover .demo-resource-label { text-decoration: underline; }
#demo .demo-resource-preview {
    position: relative; display: flex; align-items: center; justify-content: center; aspect-ratio: 16 / 9;
    background: var(--surface-2); border-bottom: 1px solid var(--border-light);
}
#demo .demo-resource-preview > i { font-size: 34px; color: var(--muted); }
#demo .demo-resource-preview.pdf > i { color: var(--danger); }
#demo .demo-resource-preview.ppt > i { color: var(--warning); }
#demo .demo-resource-preview.word > i { color: var(--info); }
#demo .demo-resource-preview.video { background: var(--primary-deep); border-bottom-color: var(--primary-deep); }
#demo .demo-resource-preview.video > i { display: none; }
#demo .demo-resource-play {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; border-radius: 50%; background: var(--surface); color: var(--primary-deep); font-size: 14px;
}
#demo .demo-resource-play i { margin-left: 2px; }
#demo .demo-resource-duration {
    position: absolute; right: 8px; bottom: 8px; padding: 1px 6px; border-radius: var(--radius-sm);
    background: var(--text); color: var(--on-primary); font-size: 12px; font-weight: 700; font-variant-numeric: tabular-nums;
}
#demo .demo-resource-info { display: flex; flex-direction: column; gap: 4px; padding: 12px 16px 16px; min-width: 0; }
#demo .demo-resource-label { font-size: 15px; font-weight: 700; line-height: 1.35; color: var(--primary); overflow-wrap: anywhere; }
#demo .demo-resource-type { font-size: 13px; color: var(--muted); }

/* ---------- 5. Paso 2: tipo de actividad ---------- */
#demo .demo-grid-cards { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
#demo .demo-act-card {
    display: grid; grid-template-columns: 24px minmax(0, 1fr); column-gap: 12px; row-gap: 2px; align-items: start;
    padding: 12px 16px; cursor: pointer;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
    transition: border-color .12s, background-color .12s;
}
#demo .demo-act-card:hover { border-color: var(--primary); }
#demo .demo-act-card:hover > span { color: var(--primary-dark); text-decoration: underline; }
#demo .demo-act-icon { grid-row: 1 / 3; margin-top: 3px; text-align: center; font-size: 18px; line-height: 1; color: var(--primary); }
#demo .demo-act-card > span { font-size: 15px; font-weight: 700; line-height: 1.3; color: var(--text); }
#demo .demo-act-desc { font-size: 13px; line-height: 1.4; color: var(--muted); }

/* ---------- 6. Paso 3: generar y resolver ---------- */
#demo .demo-step-3.demo-panel { padding: 0; }
#demo .demo-ai-container {
    display: flex; align-items: center; justify-content: center;
    min-height: 320px; padding: 40px var(--card-pad);
}
#demo .demo-ai-container.hide { display: none; }
#demo .demo-ai-brain, #demo .demo-ai-ring, #demo .demo-ai-particles, #demo .demo-particle { display: none; }
#demo .demo-ai-status { display: flex; flex-direction: column; gap: 12px; width: 100%; max-width: 440px; }
#demo .demo-ai-eyebrow { font-size: var(--fs-label); font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); }
#demo .demo-ai-status h3 {
    margin: 0; min-height: 1.35em; font-family: var(--font-body); font-size: var(--fs-h3); font-weight: 700;
    line-height: 1.35; letter-spacing: 0; color: var(--text);
}
#demo .demo-ai-progress { height: 4px; border-radius: 2px; background: var(--border-light); overflow: hidden; }
#demo .demo-ai-progress-fill { width: 0; height: 100%; border-radius: 2px; background: var(--primary); }

#demo .demo-play-header {
    display: flex; align-items: center; gap: 16px; min-height: 56px; padding: 8px var(--card-pad);
    border-bottom: 1px solid var(--border-light);
}
#demo .demo-play-title {
    display: flex; align-items: center; gap: 8px; min-width: 0; padding-left: 16px; border-left: 1px solid var(--border);
    font-size: var(--fs-h3); font-weight: 700; line-height: 1.3; color: var(--text);
}
#demo .demo-play-title i { font-size: 15px; color: var(--primary); }
#demo .demo-play-area { background: var(--surface); }
#demo .demo-iframe { display: block; width: 100%; height: 520px; min-height: 520px; border: 0; background: var(--surface); }
#demo .demo-after {
    display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px 16px;
    padding: 16px var(--card-pad); border-top: 1px solid var(--border); background: var(--surface-2);
}
#demo .demo-after-txt { font-size: 14px; font-weight: 700; color: var(--text); }
#demo .demo-after-actions { display: flex; flex-wrap: wrap; gap: 8px; }

/* ---------- 7. Botones (los de la app: 36 px, radio 4, un solo color de acción) ---------- */
#demo .demo-score-btn, #demo .demo-lesson-next, #demo .demo-slide-btn, #demo .demo-check-btn, .demo-doc-cta {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    min-height: 36px; padding: 0 14px; border: 1px solid var(--border); border-radius: var(--radius);
    background: var(--surface); color: var(--text);
    font-family: var(--font-body); font-size: 14px; font-weight: 700; line-height: 1.2; white-space: nowrap;
    cursor: pointer; transition: background-color .12s, border-color .12s, color .12s;
}
#demo .demo-score-btn:hover, #demo .demo-slide-btn:hover { background: var(--surface-2); border-color: var(--border-strong); }
#demo .demo-score-btn i, #demo .demo-lesson-next i, #demo .demo-slide-btn i, .demo-doc-cta i { font-size: 13px; }
#demo .demo-score-btn.primary, #demo .demo-lesson-next, #demo .demo-slide-btn.primary, #demo .demo-check-btn, .demo-doc-cta {
    background: var(--primary); border-color: var(--primary); color: var(--on-primary);
}
#demo .demo-score-btn.primary:hover, #demo .demo-lesson-next:hover, #demo .demo-slide-btn.primary:hover, #demo .demo-check-btn:hover, .demo-doc-cta:hover {
    background: var(--primary-dark); border-color: var(--primary-dark);
}
#demo .demo-slide-btn:disabled { opacity: .5; cursor: default; pointer-events: none; }

/* ---------- 8. Puntaje propio (sin uso hoy: el reproductor trae el suyo) ---------- */
#demo .demo-score-overlay {
    position: absolute; inset: 0; z-index: 5; display: none; align-items: center; justify-content: center;
    padding: 24px; background: rgba(var(--primary-deep-rgb), .5);
}
#demo .demo-score-overlay.show { display: flex; }
#demo .demo-score-card {
    width: 100%; max-width: 400px; padding: var(--card-pad); text-align: center;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
}
#demo .demo-score-confetti, #demo .confetti-piece { display: none; }
#demo .demo-score-circle { position: relative; width: 112px; height: 112px; margin: 0 auto 16px; }
#demo .demo-score-circle svg { display: block; width: 100%; height: 100%; }
#demo .demo-score-value { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; font-size: 26px; font-weight: 700; font-variant-numeric: tabular-nums; }
#demo .demo-score-card h3 { margin: 0; font-family: var(--font-body); font-size: var(--fs-h3); font-weight: 700; letter-spacing: 0; line-height: 1.35; }
#demo .demo-score-sub { margin-top: 4px; font-size: 14px; color: var(--muted); }
#demo .demo-score-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin-top: 24px; }

/* ---------- 9. Video (lección y visor de documento) ---------- */
.demo-video-frame {
    position: relative; aspect-ratio: 16 / 9; margin: 0 0 24px; overflow: hidden;
    border-radius: var(--radius-lg); background: var(--primary-deep);
}
.demo-video-poster { position: absolute; inset: 0; display: grid; place-items: center; }
.demo-video-poster.pie .demo-video-stamp {
    width: 34%; aspect-ratio: 1; border-radius: 50%;
    background: conic-gradient(var(--primary-light) 0 270deg, var(--primary-dark) 270deg 360deg);
}
.demo-video-poster.space .demo-video-stamp {
    width: 14%; aspect-ratio: 1; border-radius: 50%; background: var(--accent-warm);
    box-shadow: 0 0 0 36px var(--primary-deep), 0 0 0 37px var(--primary-dark);
}
.demo-video-play {
    position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
    display: grid; place-items: center; width: 56px; height: 56px; padding-left: 3px; border-radius: 50%;
    background: var(--surface); color: var(--primary-deep); font-size: 18px; box-shadow: var(--shadow);
}
.demo-video-duration {
    position: absolute; right: 12px; bottom: 22px; padding: 1px 6px; border-radius: var(--radius-sm);
    background: var(--text); color: var(--on-primary);
    font-family: var(--font-body); font-size: 12px; font-weight: 700; font-variant-numeric: tabular-nums;
}
.demo-video-bar { position: absolute; left: 12px; right: 12px; bottom: 12px; height: 4px; border-radius: 2px; background: var(--muted); }
.demo-video-bar span { position: relative; display: block; width: 32%; height: 100%; border-radius: 2px; background: var(--primary-light); }
.demo-video-bar span::after { content: ""; position: absolute; right: -5px; top: -3px; width: 10px; height: 10px; border-radius: 50%; background: var(--on-primary); }
.demo-doc-badge {
    display: inline-flex; align-items: center; gap: 6px; min-height: 22px; margin-left: 8px; padding: 0 8px;
    border-radius: var(--radius-sm); background: var(--success-bg); color: var(--success);
    font-family: var(--font-body); font-size: 12px; font-weight: 700; letter-spacing: 0; line-height: 1; vertical-align: middle;
}
.demo-doc-badge i { font-size: 11px; }

/* ---------- 10. Lección completa ---------- */
#demo .demo-lesson {
    display: grid; grid-template-columns: 300px minmax(0, 1fr); min-height: 600px; overflow: hidden;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
}
#demo .demo-lesson-side { display: flex; flex-direction: column; min-width: 0; border-right: 1px solid var(--border); }
#demo .demo-lesson-side-head { padding: 20px 20px 16px; border-bottom: 1px solid var(--border-light); }
#demo .demo-lesson-badge { display: block; margin-bottom: 4px; font-size: var(--fs-label); font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); }
#demo .demo-lesson-side-head h3 { margin: 0; font-family: var(--font-body); font-size: 20px; font-weight: 700; line-height: 1.3; letter-spacing: 0; color: var(--text); }
#demo .demo-lesson-progress { display: flex; justify-content: space-between; gap: 8px; margin-top: 16px; font-size: 13px; color: var(--muted); }
#demo .demo-lesson-count { font-weight: 700; color: var(--text); font-variant-numeric: tabular-nums; }
#demo .demo-lesson-bar { height: 6px; margin-top: 6px; border-radius: 3px; background: var(--border-light); overflow: hidden; }
#demo .demo-lesson-bar-fill { width: 0; height: 100%; border-radius: 3px; background: var(--accent); transition: width .3s; }
#demo .demo-lesson-modules { padding: 8px 0 16px; }
#demo .demo-lesson-mod { padding-bottom: 8px; }
#demo .demo-lesson-mod + .demo-lesson-mod { border-top: 1px solid var(--border-light); padding-top: 4px; }
#demo .demo-lesson-mod-title { display: flex; align-items: center; min-height: 40px; padding: 0 20px; font-size: 14px; font-weight: 700; color: var(--text); }
#demo .demo-lesson-item {
    display: flex; align-items: center; gap: 12px; width: 100%; min-height: 40px; padding: 6px 16px 6px 17px;
    border-left: 3px solid transparent; text-align: left;
    font-family: var(--font-body); font-size: 14px; line-height: 1.35; color: var(--text);
    transition: background-color .12s;
}
#demo .demo-lesson-item:hover { background: var(--bg); }
#demo .demo-lesson-item.active { background: var(--primary-tint); border-left-color: var(--primary); }
#demo .demo-lesson-item-ic { flex: 0 0 16px; text-align: center; font-size: 13px; color: var(--muted); }
#demo .demo-lesson-item.active .demo-lesson-item-ic { color: var(--primary); }
#demo .demo-lesson-item.done .demo-lesson-item-ic { color: var(--success); }
#demo .demo-lesson-item-tt { flex: 1; min-width: 0; overflow-wrap: anywhere; }
#demo .demo-lesson-item.active .demo-lesson-item-tt { font-weight: 700; color: var(--primary-dark); }
#demo .demo-lesson-item-kind { flex: 0 0 auto; font-size: var(--fs-label); color: var(--muted); }

#demo .demo-lesson-main { display: flex; flex-direction: column; min-width: 0; }
/* barra de acciones del elemento: gris, abajo (como .action-bar) */
#demo .demo-lesson-reading-foot, #demo .demo-lesson-activity-foot, #demo .demo-slide-nav {
    display: flex; align-items: center; justify-content: flex-end; gap: 12px;
    padding: 12px var(--card-pad); border-top: 1px solid var(--border); background: var(--surface-2);
}
/* lectura y video */
#demo .demo-lesson-reading { display: flex; flex-direction: column; flex: 1; }
#demo .demo-lesson-reading-body { flex: 1; padding: 28px 40px 32px; }
#demo .demo-lesson-reading-body h2 {
    margin: 0; max-width: 70ch; font-family: var(--font-body); font-size: var(--fs-h2); font-weight: 400;
    line-height: 1.3; letter-spacing: 0; color: var(--text);
}
#demo .demo-lesson-reading-body .demo-lesson-reading-sub { margin: 6px 0 0; font-size: 15px; color: var(--muted); }
#demo .demo-lesson-reading-body h3 {
    margin: 24px 0 8px; font-family: var(--font-body); font-size: var(--fs-h3); font-weight: 700;
    line-height: 1.35; letter-spacing: 0; color: var(--text);
}
#demo .demo-lesson-reading-body p { max-width: 70ch; margin: 0 0 12px; font-size: 15px; line-height: 1.65; color: var(--text-secondary); }
#demo .demo-lesson-video .demo-video-frame { margin-bottom: 24px; }
/* presentación: la diapositiva como página sobre fondo gris */
#demo .demo-slide-wrap { display: flex; flex-direction: column; flex: 1; background: var(--bg); }
#demo .demo-slide-wrap > .demo-slide { flex: 0 0 auto; }
#demo .demo-slide-wrap::before, #demo .demo-slide-wrap::after { content: ""; flex: 1 1 0; }
#demo .demo-slide-wrap > .demo-slide-nav { order: 3; }
#demo .demo-slide-wrap::after { order: 2; }
#demo .demo-slide {
    display: flex; flex-direction: column; justify-content: center; gap: 16px;
    width: calc(100% - 56px); max-width: 720px; aspect-ratio: 16 / 9; margin: 28px auto; padding: 40px 48px;
    background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow-sm);
}
#demo .demo-slide-icon { font-size: 24px; line-height: 1; color: var(--primary); }
#demo .demo-slide-title { margin: 0; font-family: var(--font-body); font-size: 28px; font-weight: 300; line-height: 1.2; letter-spacing: 0; color: var(--text); }
#demo .demo-slide-bullets { display: flex; flex-direction: column; gap: 8px; margin: 0; padding: 0; }
#demo .demo-slide-bullets li { position: relative; padding-left: 20px; font-size: 16px; line-height: 1.5; color: var(--text-secondary); list-style: none; }
#demo .demo-slide-bullets li::before { content: ""; position: absolute; left: 2px; top: .62em; width: 6px; height: 6px; background: var(--primary); }
#demo .demo-slide-nav { justify-content: space-between; }
#demo .demo-slide-dots { display: flex; align-items: center; gap: 8px; min-width: 0; }
#demo .demo-slide-dots span { width: 8px; height: 8px; border-radius: 50%; background: var(--border-strong); }
#demo .demo-slide-dots span.on { background: var(--primary); }
/* actividad dentro de la lección */
#demo .demo-lesson-activity { display: flex; flex-direction: column; flex: 1; }
#demo .demo-lesson-activity-head {
    display: flex; align-items: center; gap: 8px; min-height: 56px; padding: 8px var(--card-pad);
    border-bottom: 1px solid var(--border-light); font-size: var(--fs-h3); font-weight: 700; line-height: 1.3; color: var(--text);
}
#demo .demo-lesson-activity-head i { font-size: 15px; color: var(--primary); }
#demo .demo-lesson-player { flex: 1; background: var(--surface); }
#demo .demo-lesson-player .demo-iframe { height: 560px; min-height: 560px; }
/* lección terminada */
#demo .demo-lesson-complete {
    flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px;
    padding: 56px var(--card-pad); text-align: center;
}
#demo .demo-lesson-complete-ic { font-size: 40px; line-height: 1; color: var(--success); }
#demo .demo-lesson-complete h3 { margin: 4px 0 0; font-family: var(--font-body); font-size: var(--fs-h2); font-weight: 400; line-height: 1.3; letter-spacing: 0; color: var(--text); }
#demo .demo-lesson-complete p { max-width: 46ch; font-size: 15px; color: var(--text-secondary); }
#demo .demo-lesson-complete .demo-score-btn { margin-top: 12px; }

/* ---------- 11. Visor de documento (fuera de #demo, al final del body) ---------- */
.demo-doc-overlay {
    position: fixed; inset: 0; z-index: 300; display: none; align-items: center; justify-content: center;
    padding: 24px; background: rgba(var(--primary-deep-rgb), .6);
}
.demo-doc-overlay.show { display: flex; }
.demo-doc-modal {
    display: flex; flex-direction: column; width: 100%; max-width: 760px; max-height: calc(100vh - 48px); overflow: hidden;
    background: var(--surface-2); border-radius: var(--radius-lg); box-shadow: var(--shadow-lg);
    font-family: var(--font-body); font-size: var(--fs-body); line-height: 1.5; color: var(--text);
}
.demo-doc-bar {
    flex: 0 0 auto; display: flex; align-items: center; gap: 12px; min-height: 56px; padding: 8px 12px 8px 24px;
    background: var(--surface); border-bottom: 1px solid var(--border);
}
.demo-doc-filename { display: flex; align-items: center; gap: 8px; min-width: 0; font-size: 15px; font-weight: 700; }
.demo-doc-filename > i { flex: 0 0 auto; font-size: 16px; color: var(--muted); }
.demo-doc-filename > i.fa-file-pdf { color: var(--danger); }
.demo-doc-filename > i.fa-file-powerpoint { color: var(--warning); }
.demo-doc-filename > i.fa-file-word { color: var(--info); }
.demo-doc-filename > i.fa-video { color: var(--primary); }
#demo-doc-fname { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.demo-doc-meta { font-size: 13px; color: var(--muted); white-space: nowrap; }
.demo-doc-close {
    flex: 0 0 auto; display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; margin-left: auto;
    border-radius: var(--radius); color: var(--muted); font-size: 16px;
}
.demo-doc-close:hover { background: var(--surface-2); color: var(--text); }
/* la página: blanca, con borde, sobre el gris del visor */
.demo-doc-sheet {
    flex: 1 1 auto; min-height: 0; overflow: auto; margin: 16px 16px 0; padding: 40px 48px;
    background: var(--surface); border: 1px solid var(--border); border-bottom: 0; border-radius: var(--radius) var(--radius) 0 0;
}
.demo-doc-sheet .demo-doc-title { margin: 0; font-family: var(--font-body); font-size: 26px; font-weight: 700; line-height: 1.25; letter-spacing: 0; color: var(--text); }
.demo-doc-sheet .demo-doc-subtitle { margin: 6px 0 0; font-size: 16px; line-height: 1.45; color: var(--muted); }
.demo-doc-sheet .demo-doc-h { margin: 28px 0 8px; font-family: var(--font-body); font-size: 18px; font-weight: 700; line-height: 1.35; letter-spacing: 0; color: var(--text); }
.demo-doc-sheet .demo-doc-p { margin: 0 0 12px; font-size: 15px; line-height: 1.65; color: var(--text-secondary); }
.demo-doc-sheet .demo-video-frame { margin-bottom: 24px; }
.demo-doc-figure {
    display: flex; align-items: flex-start; gap: 12px; margin-top: 24px; padding: 16px;
    border: 1px dashed var(--border-strong); border-radius: var(--radius); background: var(--bg);
    font-size: 14px; line-height: 1.5; color: var(--text-secondary);
}
.demo-doc-figure i { margin-top: 2px; font-size: 18px; color: var(--muted); }
.demo-doc-footer {
    flex: 0 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 12px 24px;
    background: var(--surface); border-top: 1px solid var(--border);
}
.demo-doc-hint { display: flex; align-items: flex-start; gap: 8px; min-width: 0; font-size: 13px; line-height: 1.45; color: var(--text-secondary); }
.demo-doc-hint i { margin-top: 2px; color: var(--primary); }

/* ---------- 12. Pantallas medianas y teléfono ---------- */
@media (max-width: 1023px) {
    #demo .demo-grid-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    #demo .demo-lesson { grid-template-columns: 260px minmax(0, 1fr); }
    #demo .demo-lesson-reading-body { padding: 24px 28px 28px; }
}
@media (max-width: 760px) {
    #demo .demo-resource-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
    /* lección: el índice arriba y el contenido debajo, a todo el ancho */
    #demo .demo-lesson { grid-template-columns: minmax(0, 1fr); min-height: 0; }
    #demo .demo-lesson-side { border-right: 0; border-bottom: 1px solid var(--border); }
    #demo .demo-lesson-modules { padding-bottom: 8px; }
}
@media (max-width: 600px) {
    /* Un solo margen de 16 px en toda la sección: la tarjeta del asistente y
       la de la lección van de borde a borde (sin bordes laterales ni radio),
       así el reproductor del iframe ocupa todo el ancho y no se suman
       rellenos alrededor de su propia columna. */
    #demo { --card-pad: 16px; }
    #demo .ln-wrap { padding-left: 16px; padding-right: 16px; }
    #demo .demo-container, #demo .demo-lesson { margin-left: -16px; margin-right: -16px; border-left: 0; border-right: 0; border-radius: 0; }
    #demo .demo-mode-panel::before { display: none; }
    #demo .demo-mode-toggle { gap: 20px; }
    #demo .demo-mode-btn { font-size: 14px; }
    #demo .demo-steps-indicator { padding-top: 20px; padding-bottom: 16px; }
    #demo .demo-step-label { font-size: var(--fs-label); }
    #demo .demo-grid-title { font-size: 20px; }
    #demo .demo-resource-info { padding: 12px; }
    #demo .demo-resource-label { font-size: 14px; }
    #demo .demo-grid-cards { grid-template-columns: minmax(0, 1fr); gap: 8px; }
    #demo .demo-ai-container { min-height: 260px; padding: 28px var(--card-pad); }
    #demo .demo-play-header { gap: 12px; }
    #demo .demo-play-title { padding-left: 12px; font-size: 15px; }
    #demo .demo-iframe { height: 560px; min-height: 560px; }
    #demo .demo-after { flex-direction: column; align-items: stretch; }
    #demo .demo-after-actions { flex-direction: column; }
    #demo .demo-after .demo-score-btn { width: 100%; }
    #demo .demo-lesson-side-head { padding: 16px; }
    #demo .demo-lesson-mod-title { padding: 0 16px; }
    #demo .demo-lesson-item { padding-left: 13px; padding-right: 16px; }
    #demo .demo-lesson-reading-body { padding: 20px 16px 24px; }
    #demo .demo-lesson-reading-body h2 { font-size: 20px; }
    #demo .demo-lesson-video .demo-video-frame { margin: -4px 0 20px; }
    #demo .demo-slide { width: calc(100% - 32px); margin: 16px auto; padding: 24px 20px; gap: 12px; aspect-ratio: auto; min-height: 220px; }
    #demo .demo-slide-title { font-size: 22px; }
    #demo .demo-slide-bullets li { font-size: 15px; }
    #demo .demo-slide-nav { gap: 8px; }
    #demo #demo-slide-prev { width: 36px; padding: 0; }
    #demo #demo-slide-prev .demo-slide-btn-txt { display: none; }
    #demo .demo-lesson-complete { padding: 40px var(--card-pad); }
    .demo-video-play { width: 48px; height: 48px; font-size: 16px; }
    /* visor de documento: sube desde abajo, a todo el ancho */
    .demo-doc-overlay { padding: 0; align-items: flex-end; }
    .demo-doc-modal { max-width: none; max-height: 92vh; border-radius: var(--radius-lg) var(--radius-lg) 0 0; }
    .demo-doc-bar { flex-wrap: wrap; row-gap: 0; padding: 8px 8px 8px 16px; }
    .demo-doc-filename { flex: 1 1 0; }
    .demo-doc-meta { order: 3; flex-basis: 100%; padding: 0 0 4px 24px; }
    .demo-doc-sheet { margin: 0; padding: 24px 16px; border: 0; border-radius: 0; }
    .demo-doc-sheet .demo-doc-title { font-size: 22px; }
    .demo-doc-footer { flex-direction: column; align-items: stretch; gap: 12px; padding: 12px 16px 16px; }
    .demo-doc-cta { width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
    #demo .demo-step-line-fill, #demo .demo-lesson-bar-fill { transition: none; }
}