:root{
  --primary:#1f5f8b; --primary-d:#184a6c; --secondary:#15435f;
  --ink:#1f2430; --muted:#5b6b86; --line:#e6ecf3; --bg:#f4f7fb; --ok:#15803d; --bad:#b91c1c;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{font-family:'Segoe UI',system-ui,-apple-system,Roboto,Arial,sans-serif;color:var(--ink);background:var(--bg);line-height:1.65}
button{font-family:inherit}
/* header */
.vn-top{position:sticky;top:0;z-index:30;background:linear-gradient(135deg,var(--primary),var(--primary-d));color:#fff}
.vn-top .bar{display:flex;align-items:center;gap:14px;padding:12px 18px}
.vn-top .burger{display:none;background:rgba(255,255,255,.18);border:0;color:#fff;font-size:20px;border-radius:8px;width:40px;height:40px;cursor:pointer}
.vn-top .ttl{flex:1;min-width:0}
.vn-top .ttl b{display:block;font-size:1.02rem;font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.vn-top .ttl span{font-size:.8rem;opacity:.9}
.vn-top .dl{display:inline-flex;align-items:center;gap:7px;background:#fff;color:var(--primary-d);font-weight:700;font-size:.85rem;padding:9px 14px;border-radius:999px;text-decoration:none;white-space:nowrap}
.vn-top .vn-fs{display:inline-grid;place-items:center;background:rgba(255,255,255,.18);border:0;color:#fff;font-size:18px;line-height:1;border-radius:8px;width:40px;height:40px;cursor:pointer;flex-shrink:0}
.vn-top .vn-fs:hover{background:rgba(255,255,255,.30)}
.vn-top .dl:hover{background:#f0f4ff}
.vn-prog{height:6px;background:rgba(255,255,255,.25)}
.vn-prog>i{display:block;height:100%;width:0;background:#fff;transition:width .35s ease}
/* layout */
.vn-wrap{display:flex;min-height:calc(100vh - 60px)}
.vn-toc{width:300px;flex-shrink:0;background:#fff;border-right:1px solid var(--line);padding:16px 0;overflow-y:auto}
.vn-toc h4{margin:0 0 8px;padding:0 18px;font-size:.72rem;text-transform:uppercase;letter-spacing:.5px;color:var(--muted)}
.vn-toc-pct{padding:2px 18px 12px;margin-bottom:6px;border-bottom:1px solid var(--line)}
.vn-toc-pct-bar{height:7px;background:var(--line);border-radius:999px;overflow:hidden;margin-bottom:5px}
.vn-toc-pct-bar>i{display:block;height:100%;width:0;background:var(--primary);transition:width .35s ease;border-radius:999px}
.vn-toc-pct span{font-size:.74rem;color:var(--muted);font-weight:700}
.vn-toc a{display:flex;gap:10px;align-items:flex-start;padding:11px 18px;color:var(--ink);text-decoration:none;font-size:.92rem;border-left:3px solid transparent;cursor:pointer}
.vn-toc a:hover{background:#f6f9fc}
.vn-toc a.active{background:#eef6f8;border-left-color:var(--secondary);font-weight:600}
.vn-toc a .ic{flex-shrink:0;width:20px;height:20px;border-radius:50%;border:2px solid #cdd7e5;display:grid;place-items:center;font-size:12px;color:#cdd7e5;margin-top:1px}
.vn-toc a.done .ic{background:var(--ok);border-color:var(--ok);color:#fff}
.vn-toc a.active .ic{border-color:var(--secondary);color:var(--secondary)}
.vn-toc a.locked{opacity:.5}
/* main */
.vn-main{flex:1;min-width:0;display:flex;flex-direction:column}
.vn-stage{flex:1;max-width:860px;width:100%;margin:0 auto;padding:30px 28px 40px}
.vn-screen{display:none;animation:fade .35s ease}
.vn-screen.show{display:block}
@keyframes fade{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}
.vn-kicker{display:inline-block;background:#eef6f8;color:var(--secondary);font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.5px;padding:4px 11px;border-radius:999px;margin-bottom:10px}
.vn-screen h2{font-size:1.6rem;margin:.1em 0 .5em;color:#0f172a}
/* storytelling callout */
.vn-story{display:flex;gap:14px;background:linear-gradient(135deg,#fff7e6,#eef6f8);border:1px solid #ffe6ad;border-radius:14px;padding:16px 18px;margin:0 0 22px;align-items:flex-start}
.vn-story .av{position:relative;flex-shrink:0;width:66px;height:66px;border-radius:50%;overflow:hidden;background:#eef0f3;color:#fff;display:grid;place-items:center;font-weight:700;font-size:1.3rem;box-shadow:0 2px 8px rgba(20,35,59,.12)}
/* poses apiladas como capas: solo cambia cuál es visible (sin tocar src) → sin flash */
.vn-story .av .pose{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;display:block;opacity:0;transition:opacity .6s ease}
.vn-story .av .pose.active{opacity:1}
.vn-story .tx{font-size:.97rem;color:#33425c;flex:1;min-width:0}
.vn-story .gname{font-weight:700;color:var(--primary-d);margin-bottom:2px}
.vn-story .tx b{color:var(--primary-d)}
.vn-narr{display:block;width:100%;margin-top:11px;height:40px}
/* avatar: SOLO transición de poses (fade al cambiar de gesto). Sin cabeceo ni inclinación. */
.vn-story .av.talking{box-shadow:0 0 0 3px rgba(40,134,134,.18),0 2px 10px rgba(20,35,59,.14)}
.vn-story .avwrap{position:relative;flex-shrink:0}
.vn-eq{position:absolute;bottom:-3px;left:50%;transform:translateX(-50%);display:none;gap:2px;align-items:flex-end;height:12px}
.vn-eq.on{display:flex}
.vn-eq i{width:3px;background:var(--secondary);border-radius:2px;height:4px;animation:vneq .5s ease-in-out infinite}
.vn-eq i:nth-child(2){animation-delay:.12s}.vn-eq i:nth-child(3){animation-delay:.24s}.vn-eq i:nth-child(4){animation-delay:.36s}
@keyframes vneq{0%,100%{height:3px}50%{height:12px}}
/* video */
.vn-video{position:relative;aspect-ratio:16/9;background:#000;border-radius:12px;overflow:hidden;margin:0 0 22px}
.vn-video video{width:100%;height:100%;display:block}
/* video interactivo (decisiones con compuerta) */
.vn-ivideo .vn-video{margin-bottom:10px}
.vn-iv-hint{font-size:.86rem;color:#4a5b74;margin:0 0 18px;padding:9px 13px;background:#eef4f9;border:1px solid #cfe0ec;border-radius:8px}
.vn-iv-panel{position:absolute;inset:0;display:none;align-items:center;justify-content:center;background:rgba(9,20,32,.84);padding:16px;z-index:6}
.vn-iv-panel.show{display:flex}
.vn-iv-card{width:100%;max-width:660px;background:#fff;border-radius:14px;padding:18px 20px;box-shadow:0 14px 44px rgba(0,0,0,.45);max-height:100%;overflow:auto}
.vn-iv-q{font-size:1.06rem;font-weight:600;color:#15233b;margin:0 0 12px;line-height:1.4}
.vn-iv-badge{display:inline-block;background:var(--primary);color:#fff;font-size:.66rem;font-weight:700;letter-spacing:.5px;text-transform:uppercase;padding:3px 10px;border-radius:999px;margin-right:8px;vertical-align:middle}
.vn-iv-card .vn-opt{display:block;width:100%;text-align:left;margin:7px 0}
.vn-iv-card .vn-opt.wrong{border-color:#e2b4b4;background:#fdecec}
.vn-iv-card .vn-opt.correct{border-color:#a9d5bd;background:#eaf6ef}
.vn-iv-fb{margin-top:10px;font-size:.95rem;line-height:1.45}
.vn-iv-fb.ok{color:#1c6b3f}.vn-iv-fb.no{color:#b23838}
.vn-iv-cont{margin-top:6px;font-size:.84rem;color:#5b6b86;font-weight:600}
/* actividad embebida (biblioteca: storytelling / gamificada) */
.vn-embed{position:relative;width:100%;height:calc(100vh - 150px);min-height:680px;border-radius:12px;overflow:hidden;border:1px solid var(--line);background:#000;margin:6px 0 4px}
.vn-embed iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.vn-stage.embed{max-width:1180px}
/* content */
.vn-content h3{font-size:1.18rem;margin:22px 0 8px;color:#1e293b}
.vn-content p{margin:10px 0}
.vn-content ul,.vn-content ol{margin:10px 0 14px 26px}.vn-content li{margin:5px 0}
.vn-content img{max-width:100%;height:auto;border-radius:8px;display:block;margin:12px auto}
.vn-content table{border-collapse:collapse;width:100%;margin:14px 0}
.vn-content th,.vn-content td{border:1px solid var(--line);padding:8px 10px;text-align:left}
.vn-content th{background:#f1f5f9}
.vn-content .vn-speak{display:inline-flex;align-items:center;gap:.3em;cursor:pointer;background:#eef4f9;border:1px solid #cfe0ee;color:#15435f;border-radius:7px;padding:0 8px 0 6px;font-weight:600;line-height:1.75;transition:.12s;white-space:normal}
.vn-content .vn-speak:hover{background:#dceaf6;border-color:var(--primary)}
.vn-content .vn-speak::before{content:"🔊";font-size:.95em;flex:0 0 auto}
.vn-content .vn-speak.playing{background:var(--primary);color:#fff}
.vn-content .vn-speak.playing::before{content:"⏸"}
.vn-subsel{display:flex;flex-wrap:wrap;align-items:center;gap:6px;margin-top:8px;font-size:.86rem;color:var(--muted)}
.vn-subb{border:1.5px solid var(--line);background:#fff;border-radius:7px;padding:4px 10px;cursor:pointer;font-weight:600;font-size:.84rem;color:var(--ink)}
.vn-subb:hover{border-color:var(--secondary)}
.vn-subb.on{background:var(--primary);color:#fff;border-color:var(--primary)}
.vn-content blockquote{border-left:4px solid var(--primary);background:#fff8ec;padding:10px 16px;margin:14px 0;border-radius:0 8px 8px 0}
.vn-content kbd{background:#eef2f7;border:1px solid #cdd7e5;border-bottom-width:2px;border-radius:5px;padding:1px 6px;font-size:.85em}
/* check */
.vn-check{border:1px solid var(--line);border-radius:14px;background:#fff;padding:18px 20px;margin:26px 0 6px;box-shadow:0 4px 16px rgba(20,35,59,.05)}
.vn-check .q{font-weight:600;margin:0 0 12px;display:flex;gap:8px}
.vn-check .q .qic{color:var(--secondary)}
.vn-opt{display:block;width:100%;text-align:left;border:1.5px solid var(--line);background:#fff;border-radius:10px;padding:12px 14px;margin:8px 0;cursor:pointer;font-size:.95rem;transition:.15s}
.vn-opt:hover:not([disabled]){border-color:var(--secondary);background:#f6fbfc}
.vn-opt.correct{border-color:var(--ok);background:#f0fdf4}
.vn-opt.wrong{border-color:var(--bad);background:#fef2f2}
.vn-opt[disabled]{cursor:default}
.vn-fb{margin-top:12px;padding:12px 14px;border-radius:10px;font-size:.92rem;display:none}
.vn-fb.show{display:block}
.vn-fb.ok{background:#f0fdf4;color:#14532d;border:1px solid #bbf7d0}
.vn-fb.no{background:#fef2f2;color:#7f1d1d;border:1px solid #fecaca}
/* nav */
.vn-nav{border-top:1px solid var(--line);background:#fff;padding:14px 28px;display:flex;justify-content:space-between;max-width:860px;width:100%;margin:0 auto}
.vn-btn{display:inline-flex;align-items:center;gap:8px;border:0;border-radius:999px;padding:11px 22px;font-weight:700;font-size:.92rem;cursor:pointer}
.vn-btn.prev{background:#eef2f7;color:var(--ink)}
.vn-btn.next{background:var(--primary);color:#fff}
.vn-btn:disabled{opacity:.45;cursor:not-allowed}
/* done */
.vn-done{text-align:center;padding:30px 10px}
.vn-done .medal{font-size:3rem}
.vn-done .medal.spin{display:inline-block;animation:vnpop .6s ease, vnfloat 2.6s ease-in-out .6s infinite}
.vn-done h2{border:0}
@keyframes vnpop{0%{transform:scale(0) rotate(-25deg);opacity:0}60%{transform:scale(1.25) rotate(8deg)}100%{transform:scale(1) rotate(0);opacity:1}}
@keyframes vnfloat{0%,100%{transform:translateY(0)}50%{transform:translateY(-9px)}}
.vn-stats{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin:22px auto 6px;max-width:520px}
.vn-stats .st{background:#f4f7fb;border:1px solid var(--line);border-radius:14px;padding:13px 18px;min-width:96px}
.vn-stats .st b{display:block;font-size:1.5rem;color:var(--primary-d);line-height:1.1}
.vn-stats .st span{font-size:.72rem;color:var(--muted);text-transform:uppercase;letter-spacing:.4px}
.vn-cta{margin-top:10px;font-size:1.02rem}
.vn-opt.pop{animation:vnpop .45s ease}
.vn-try{display:inline-block;margin-left:6px;background:var(--ok);color:#fff;font-size:.7rem;font-weight:700;padding:1px 9px;border-radius:999px;vertical-align:middle}
.vn-try.no{background:var(--bad)}
.vn-toc-pct .crs{display:block;font-size:.7rem;color:var(--secondary);font-weight:700;margin-top:3px}
.vn-toc h4 .dur{font-weight:600;color:var(--muted);text-transform:none;letter-spacing:0}
.vn-toast{position:fixed;left:50%;bottom:26px;transform:translateX(-50%) translateY(20px);background:#1f2430;color:#fff;padding:11px 20px;border-radius:999px;font-size:.9rem;box-shadow:0 8px 30px rgba(0,0,0,.25);opacity:0;transition:.3s;z-index:60;max-width:90vw;text-align:center}
.vn-toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
@media(max-width:820px){
  .vn-toc{position:fixed;left:0;top:60px;bottom:0;z-index:25;transform:translateX(-100%);transition:transform .25s;box-shadow:4px 0 20px rgba(0,0,0,.12)}
  .vn-toc.open{transform:none}
  .vn-top .burger{display:grid;place-items:center}
  .vn-top .ttl b{white-space:normal}
}
/* marca de agua de licencia (disuasivo + trazable) */
.vn-wm{position:fixed;right:10px;bottom:8px;z-index:40;font-size:11px;color:rgba(31,36,48,.45);background:rgba(255,255,255,.6);border:1px solid rgba(0,0,0,.06);border-radius:6px;padding:3px 8px;pointer-events:none;user-select:none;backdrop-filter:blur(2px)}
.vn-foot-lic{margin:30px 0 0;padding-top:12px;border-top:1px dashed var(--line);font-size:.78rem;color:var(--muted)}
.vn-video .vn-vwm{position:absolute;bottom:8px;right:10px;z-index:5;font-size:11px;color:rgba(255,255,255,.7);background:rgba(0,0,0,.25);border-radius:5px;padding:2px 7px;pointer-events:none}
/* actividad interactiva NATIVA (práctica guiada sobre captura: clic + campos) */
.vn-stage.sim-wide{max-width:1180px}
.vn-sim{border:1px solid var(--line);border-radius:14px;background:#fff;padding:14px 16px;margin:22px 0 6px;box-shadow:0 4px 16px rgba(20,35,59,.05)}
.vn-sim-instr{font-size:1rem;line-height:1.5;margin:0 0 10px}
.vn-sim-instr .vn-tip{display:block;margin-top:5px;font-size:.85rem;color:var(--muted)}
.vn-sim-stage{position:relative;width:100%;aspect-ratio:1280/720;border-radius:8px;overflow:hidden;border:1px solid var(--line);background:#000}
.vn-sim-stage>img{position:absolute;inset:0;width:100%;height:100%;display:block;margin:0}
.vn-tg{position:absolute;border:2.5px dashed #ffd400;border-radius:6px;box-shadow:0 0 0 3px rgba(43,122,61,.25),0 0 18px rgba(255,212,0,.5);background:rgba(255,212,0,.12);cursor:pointer;animation:vntgp 1.3s ease-in-out infinite}
@keyframes vntgp{0%,100%{box-shadow:0 0 0 3px rgba(43,122,61,.22),0 0 8px rgba(255,212,0,.4)}50%{box-shadow:0 0 0 5px rgba(43,122,61,.32),0 0 24px rgba(255,212,0,.85)}}
.vn-tg.vn-choice{border:0!important;background:transparent!important;box-shadow:none!important;animation:none!important;border-radius:0}
.vn-tg.input{cursor:text;border:2px solid var(--primary);background:#fff;display:flex;align-items:center;gap:5px;width:auto!important;height:auto!important;min-height:30px;padding:2px 4px;box-shadow:0 4px 16px rgba(0,0,0,.28);animation:none;z-index:5}
.vn-tg.input input{min-width:140px;flex:1;border:0;background:#fff;font-size:14px;padding:2px 4px;outline:none;color:#111}
.vn-tg .vn-cf{border:0;background:var(--primary);color:#fff;border-radius:6px;padding:4px 10px;font-weight:700;cursor:pointer;font-size:12px;white-space:nowrap}
.vn-filled{position:absolute;line-height:1.25;color:#111;background:rgba(255,255,255,.94);padding:0 3px;border-radius:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;pointer-events:none;z-index:3;box-shadow:inset 0 0 0 1px rgba(43,122,61,.3)}
.vn-miss{position:absolute;width:24px;height:24px;margin:-12px 0 0 -12px;border-radius:50%;border:2px solid var(--bad);color:var(--bad);display:grid;place-items:center;font-weight:800;animation:vnfade .8s ease forwards;pointer-events:none;background:#fff}
@keyframes vnfade{0%{opacity:1;transform:scale(.6)}100%{opacity:0;transform:scale(1.4)}}
.vn-sim-foot{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-top:10px}
.vn-sim-dots{display:flex;gap:6px}
.vn-sim-dots i{width:22px;height:6px;border-radius:3px;background:#d7dee4}
.vn-sim-dots i.on{background:var(--primary)}.vn-sim-dots i.done{background:var(--ok)}
.vn-sim-done{font-weight:700;color:var(--ok)}
.vn-sim-introbox{background:linear-gradient(135deg,#fff7e6,#eef6f8);border:1px solid #ffe6ad;border-radius:12px;padding:14px 16px}
.vn-sim-introbox b{color:var(--primary-d);font-size:1.05rem}
.vn-sim-introbox p{margin:6px 0 0}
.vn-sim-narr{display:block;width:100%;max-width:440px;height:38px;margin:10px 0 0}
.vn-sim-start{margin-top:12px;border:0;border-radius:999px;background:var(--primary);color:#fff;font-weight:700;padding:10px 20px;cursor:pointer;font-size:.95rem}
.vn-sim-start:hover{background:var(--primary-d)}

/* --- Lightbox / zoom de las capturas de la leccion --- */
.vn-content figure img,.vn-content img{cursor:zoom-in}
.vn-content figure{position:relative}
.vn-content figure figcaption::after{content:" · 🔍 clic para ampliar";color:#8aa08a;font-style:italic}
.vn-lb{position:fixed;inset:0;z-index:99999;display:none;align-items:center;justify-content:center;background:rgba(15,20,16,.93);padding:24px;box-sizing:border-box;-webkit-user-select:none;user-select:none}
.vn-lb.show{display:flex}
.vn-lb img{max-width:96vw;max-height:86vh;border-radius:8px;box-shadow:0 10px 50px rgba(0,0,0,.55);transition:transform .18s ease;transform-origin:center center;cursor:zoom-in}
.vn-lb.zoom{overflow:auto;align-items:flex-start;justify-content:flex-start}
.vn-lb.zoom img{max-width:none;max-height:none;transform:scale(1.9);cursor:zoom-out}
.vn-lb-x{position:fixed;top:14px;right:18px;width:46px;height:46px;border:none;border-radius:50%;background:rgba(255,255,255,.16);color:#fff;font-size:22px;line-height:46px;text-align:center;cursor:pointer;z-index:100000}
.vn-lb-x:hover{background:rgba(255,255,255,.32)}
.vn-lb-hint{position:fixed;top:18px;left:20px;color:rgba(255,255,255,.7);font-size:.82em;z-index:100000}
.vn-lb-cap{position:fixed;bottom:16px;left:50%;transform:translateX(-50%);max-width:90vw;color:#e9efe9;font-size:.85em;line-height:1.35;text-align:center;background:rgba(0,0,0,.4);padding:7px 14px;border-radius:8px;z-index:100000}