:root{
  --rojo:#B93A34; --rojo-osc:#93291F; --azul:#1F5FA8; --azul-osc:#17497F;
  --verde:#2E8B57; --dorado:#D9A93C;
  --crema:#FBF6EA; --crema-2:#F4ECDA; --tinta:#26333B; --gris:#6B7B84; --linea:#E4DAC6;
  --sombra:0 14px 34px rgba(38,51,59,.13);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--crema);color:var(--tinta);font-family:Inter,system-ui,sans-serif;line-height:1.6}
h1,h2,.nombre,.rotulo,.etiqueta{font-family:Montserrat,Inter,sans-serif}
a{color:var(--azul)}
img{max-width:100%}

/* ---------- la barra ---------- */
.barra{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:16px 26px;
  background:var(--rojo);color:#fff;position:sticky;top:0;z-index:9;flex-wrap:wrap;
  transition:padding .3s ease, box-shadow .3s ease}
.barra.compacta{padding:9px 26px;box-shadow:0 6px 18px rgba(0,0,0,.18)}
.marca{display:flex;align-items:center;gap:10px;font-size:1.05rem}
.monograma{background:#fff;color:var(--rojo);font-weight:800;border-radius:50%;width:34px;height:34px;
  display:flex;align-items:center;justify-content:center;font-family:Montserrat,sans-serif;
  transition:transform .35s ease}
.marca:hover .monograma{transform:rotate(-8deg) scale(1.06)}
.nombre b{color:#FFE9A8}
.etiqueta{font-size:.82rem;opacity:.92;padding-right:6px}

main{max-width:1060px;margin:0 auto;padding:26px 20px 40px}

/* ---------- portada ---------- */
.portada{display:grid;grid-template-columns:1.02fr .98fr;gap:44px;align-items:center;padding:30px 0 26px}
.ceja{text-transform:uppercase;letter-spacing:.14em;font-size:.74rem;color:var(--rojo);font-weight:700;margin:0 0 8px}
.portada h1{font-size:2.3rem;line-height:1.16;margin:0 0 14px;font-weight:800}
.portada h1 em{font-style:normal;color:var(--azul);
  background-image:linear-gradient(transparent 60%, #F6E3A8 60%, #F6E3A8 96%, transparent 96%);
  padding:0 3px}
.bajada{font-size:1.05rem;color:#3C4A52;margin:0 0 18px}
.virtudes{list-style:none;padding:0;margin:0 0 22px}
.virtudes li{padding-left:30px;position:relative;margin-bottom:8px}
.virtudes li:before{content:"✦";position:absolute;left:2px;top:0;color:var(--dorado);font-size:1.05rem;
  transition:transform .25s ease}
.virtudes li:hover:before{transform:scale(1.25) rotate(12deg)}
.acciones{display:flex;gap:14px;flex-wrap:wrap;align-items:center}
.detalle-cta{font-size:.82rem;color:var(--gris);max-width:280px}
.boton{display:inline-block;border:1px solid var(--azul);background:transparent;color:var(--azul);
  padding:13px 24px;border-radius:10px;text-decoration:none;font-weight:600;cursor:pointer;font-size:.97rem;
  transition:background .2s ease, color .2s ease, transform .2s ease, box-shadow .2s ease}
.boton:hover{transform:translateY(-2px);box-shadow:0 8px 18px rgba(31,95,168,.22)}
.boton:active{transform:translateY(0)}
.boton.primario{background:var(--azul);color:#fff;border-color:var(--azul)}
.boton.primario:hover{background:var(--azul-osc)}
.boton.grande{font-size:1.05rem;padding:14px 22px;width:100%;text-align:center}
.boton:focus-visible,button:focus-visible,a:focus-visible{outline:3px solid var(--dorado);outline-offset:2px}

/* el libro real: la carátula y una página que asoma */
.visual{position:relative;min-height:500px;display:flex;align-items:center;justify-content:center;padding:16px 8px}
.visual img{border-radius:10px;box-shadow:var(--sombra)}
.pagina-detras{position:absolute;right:5%;top:14%;width:54%;transform:rotate(5deg);opacity:.92;
  border:1px solid var(--linea)}
.caratula{position:relative;width:58%;max-width:310px;transform:rotate(-2.5deg);border:1px solid #eadfca;
  animation:flotar 6s ease-in-out .4s infinite;transition:transform .35s ease, box-shadow .35s ease}
.visual:hover .caratula{transform:rotate(-1deg) translateY(-6px) scale(1.02);box-shadow:0 22px 44px rgba(38,51,59,.2)}
.sello-libro{position:absolute;left:4%;bottom:8%;background:#fff;border:1px solid var(--linea);color:var(--rojo);
  font-family:Montserrat,sans-serif;font-weight:700;font-size:.78rem;padding:7px 13px;border-radius:999px;
  box-shadow:0 8px 18px rgba(38,51,59,.12)}
@keyframes flotar{0%,100%{margin-top:0}50%{margin-top:-10px}}
@keyframes latido-suave{0%,100%{transform:scale(1)}50%{transform:scale(1.045)}}

/* la cita del libro */
.cita-libro{background:#fff;border:1px solid var(--linea);border-left:6px solid var(--dorado);
  border-radius:14px;padding:18px 22px;margin:6px 0 26px;color:var(--tinta)}
.cita-libro p{margin:0 0 6px;font-family:Montserrat,Inter,sans-serif;font-weight:600;font-size:1.06rem;color:var(--tinta)}
.cita-libro span{font-size:.82rem;color:var(--gris)}

/* aparición al bajar */
.por-aparecer{opacity:0;transform:translateY(18px);transition:opacity .6s ease, transform .6s ease}
.aparece{opacity:1;transform:none}
@supports (animation-timeline: view()){
  .por-aparecer{opacity:1;transform:none;animation:entrar linear both;animation-timeline:view();
    animation-range:entry 0% entry 60%}
  @keyframes entrar{from{opacity:0;transform:translateY(22px)}to{opacity:1;transform:none}}
}

/* el momento de entrada (al cargar) */
.hoja{animation:entrar-pagina .7s ease both}
.visual{animation:entrar-pagina .9s ease .12s both}
@keyframes entrar-pagina{from{opacity:0;transform:translateY(26px)}to{opacity:1;transform:none}}

.bloque{background:#fff;border:1px solid var(--linea);border-radius:16px;padding:22px;margin-bottom:24px}
.bloque h2{font-size:1.5rem;margin:0 0 6px}
.nota{color:var(--gris);margin:0 0 16px;font-size:.94rem}
.chip-curso{display:inline-block;background:#EAF1FA;color:var(--azul);border-radius:20px;padding:3px 12px;
  font-size:.8rem;font-weight:600;margin:0 0 10px 10px}

/* ---------- chat ---------- */
.chat .mensajes{max-height:min(62vh,620px);overflow-y:auto;display:flex;flex-direction:column;gap:12px;padding:4px 2px 10px}
.burbuja{border-radius:14px;padding:12px 14px;max-width:88%;font-size:.97rem;white-space:pre-wrap}
.burbuja.tutor{background:var(--crema-2);border:1px solid var(--linea);align-self:flex-start;
  animation:entrar-pagina .45s ease both}
.burbuja.alumno{background:var(--azul);color:#fff;align-self:flex-end;white-space:pre-wrap;
  animation:entrar-pagina .35s ease both}
.burbuja .pie{display:block;margin-top:8px;font-size:.76rem;color:var(--gris)}
.frac{display:inline-block;vertical-align:middle;text-align:center;margin:0 .14em;line-height:1.08;font-size:.94em}
.frac .num{display:block;padding:0 .26em;border-bottom:1.5px solid currentColor}
.frac .den{display:block;padding:0 .26em}
.frac.mixto{margin-left:.04em}
.burbuja sup{font-size:.7em;vertical-align:super;line-height:0}
.cita{margin-top:9px;padding-top:8px;border-top:1px dashed var(--linea);font-size:.8rem;color:var(--gris)}
.cita b{color:var(--azul)}
.sello{display:inline-block;background:#F6EBD2;color:#7A5A18;border-radius:20px;padding:2px 9px;
  font-size:.72rem;font-weight:600;margin-left:6px}
.escribir{display:flex;gap:8px;align-items:stretch;margin-top:8px}
.escribir input{flex:1;padding:12px 14px;border:1px solid var(--linea);border-radius:10px;font-size:1rem;
  font-family:inherit;background:#FFFDF8;color:var(--tinta);transition:border-color .2s ease, box-shadow .2s ease}
.escribir input:focus{outline:2px solid var(--azul);outline-offset:1px;box-shadow:0 4px 14px rgba(31,95,168,.12)}
.aviso{font-size:.85rem;color:var(--rojo);min-height:1.2em;margin:8px 0 0}

.inscripcion{display:flex;gap:10px;flex-wrap:wrap;align-items:stretch}
.inscripcion input{flex:1;min-width:220px;padding:12px 14px;border:1px solid var(--linea);border-radius:10px;
  font-size:1.02rem;font-family:inherit;background:#FFFDF8;color:var(--tinta);
  transition:border-color .2s ease, box-shadow .2s ease}
.inscripcion input:focus{outline:2px solid var(--azul);outline-offset:1px;box-shadow:0 4px 14px rgba(31,95,168,.12)}
.chico{font-size:.8rem;color:var(--gris);margin:10px 0 0}
.cerrar-sesion{border:0;background:transparent;color:var(--azul);font:inherit;font-size:.8rem;cursor:pointer;
  text-decoration:underline;margin-left:8px;padding:0;transition:color .2s ease}
.cerrar-sesion:hover{color:var(--azul-osc)}
.pie-sitio{text-align:center;padding:22px;color:var(--gris);font-size:.85rem;border-top:1px solid var(--linea)}
@media (max-width:760px){
  .portada{grid-template-columns:1fr}
  .portada h1{font-size:1.8rem}
  .visual{min-height:400px}
  .burbuja{max-width:100%}
}

/* ---------- chips (cursos y ejercicios) ---------- */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px;padding-top:10px;border-top:1px dashed var(--linea)}
.chip{text-align:left;font:inherit;font-size:.88rem;color:var(--tinta);background:#fff;border:1px solid var(--linea);
  border-left:4px solid var(--dorado);border-radius:10px;padding:9px 12px;cursor:pointer;
  transition:background .18s ease, border-color .18s ease, transform .18s ease, box-shadow .18s ease}
.chip:hover{background:var(--crema-2);border-left-color:var(--azul);transform:translateY(-2px);
  box-shadow:0 6px 14px rgba(38,51,59,.1)}
.chip:active{transform:translateY(0)}
.chip.titulo{background:transparent;border:none;border-left:none;padding:9px 2px 9px 0;font-weight:700;
  color:var(--gris);cursor:default;font-size:.84rem}
.chip.titulo:hover{transform:none;box-shadow:none;background:transparent}
@media(max-width:640px){.chip{font-size:.85rem;padding:10px 12px}}

/* ---------- figuras y página dentro de la respuesta ---------- */
.figura-libro{margin:12px 0 4px;display:flex;flex-direction:column;gap:6px}
.figura-libro img{width:100%;max-width:420px;height:auto;border:1px solid #d8dee4;border-radius:10px;background:#fff}
.figura-libro figcaption{font-size:12.5px;color:#5c6b7a;font-style:italic}
.linea-solucion{white-space:pre-wrap;margin:0 0 2px;line-height:1.55}
.figura-animada{margin:12px 0 4px}
.figura-animada svg{width:100%;max-width:460px;height:auto;display:block;background:#fff;border-radius:10px}
.repetir-dibujo{border:0;background:transparent;color:var(--azul);font:inherit;font-size:12.5px;cursor:pointer;
  text-decoration:underline;padding:2px 0}
.bloque-pagina{margin-top:10px}
.boton-pagina{border:1px solid var(--azul);background:#fff;color:var(--azul);border-radius:999px;padding:7px 13px;
  font:inherit;font-size:13px;cursor:pointer;transition:background .2s ease, color .2s ease, transform .2s ease}
.boton-pagina:hover{background:var(--azul);color:#fff;transform:translateY(-1px)}
.pagina-entera{margin:12px 0 4px;display:flex;flex-direction:column;gap:6px;animation:entrar-pagina .5s ease both}
.pagina-entera img{width:100%;max-width:520px;height:auto;border:1px solid #d8dee4;border-radius:10px;background:#fff}
.pagina-entera figcaption{font-size:12.5px;color:#5c6b7a;font-style:italic}
.aviso-codigo{font-size:13px;color:#a33;margin:0}

/* ---------- agrandar el cuaderno ---------- */
.chat{position:relative}
.agrandar{position:absolute;top:50%;right:-15px;transform:translateY(-50%);width:28px;height:58px;
  display:flex;align-items:center;justify-content:center;font-size:15px;line-height:1;padding:0;
  border:1px solid var(--azul);border-left:none;border-radius:0 16px 16px 0;background:#fff;color:var(--azul);
  cursor:pointer;box-shadow:3px 0 8px rgba(31,95,168,.13);z-index:6;transition:background .2s ease, color .2s ease}
.agrandar:hover{background:var(--azul);color:#fff}
.chat .mensajes{transition:max-height .35s ease}
.chat.ancho{width:min(96vw,1560px);left:50%;transform:translateX(-50%)}
.chat.ancho .mensajes{max-height:min(84vh,940px)}
.chat.ancho .burbuja{max-width:100%}
.chat.ancho .figura-animada svg{max-width:min(90vw,880px)}
.chat.ancho .figura-libro img,.chat.ancho .pagina-entera img{max-width:min(90vw,820px)}
@media (max-width:760px){.agrandar{right:-12px;width:24px;height:48px}}

/* ---------- micrófono ---------- */
.micro{border:1px solid var(--linea);background:#fff;border-radius:10px;padding:0 12px;font-size:1.15rem;
  line-height:1;cursor:pointer;color:var(--azul);flex:0 0 auto;transition:background .2s ease, border-color .2s ease}
.micro:hover{background:#f2f7f9;border-color:var(--azul)}
.micro.grabando{background:#d63333;border-color:#d63333;color:#fff}
@keyframes latido{0%,100%{transform:scale(1);box-shadow:0 0 0 0 rgba(214,51,51,.55)}50%{transform:scale(1.06);box-shadow:0 0 0 7px rgba(214,51,51,0)}}

/* ---------- para quien pide menos movimiento ---------- */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation:none !important;transition:none !important}
  html{scroll-behavior:auto}
  .por-aparecer{opacity:1;transform:none}
}