:root {
  --papel: #faf6ef;
  --papel-2: #f2ebe0;
  --tarjeta: #ffffff;
  --tinta: #2b2622;
  --tinta-2: #6b6158;
  --borde: #e6ddd0;
  --rojo: #c8372d;
  --rojo-2: #a82a22;
  --jade: #1f8a70;
  --oro: #d9a21b;
  --ok: #1f8a70;
  --mal: #c8372d;
  --sombra: 0 1px 2px rgba(60, 40, 20, .06), 0 4px 16px rgba(60, 40, 20, .06);
  /* Colores de tonos (convención Pleco) */
  --t1: #d6302f; --t2: #2e8b3e; --t3: #2f5fd0; --t4: #8a3fb5; --t5: #7c7c7c;
  --radio: 14px;
  --hz: 'Noto Sans SC', 'Microsoft YaHei', 'PingFang SC', sans-serif;
  --hz-serif: 'Noto Serif SC', 'SimSun', serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --papel: #1c1916; --papel-2: #26221e; --tarjeta: #2a2521; --tinta: #f3ede2; --tinta-2: #b3a797;
    --borde: #3d362f; --rojo: #e5574b; --rojo-2: #f06b5f; --jade: #3cbf9b; --oro: #e8b63a;
    --t1: #ff6b6a; --t2: #5fcf6f; --t3: #6f9bff; --t4: #c27ff0; --t5: #a0a0a0;
    --sombra: 0 1px 2px rgba(0,0,0,.3), 0 4px 16px rgba(0,0,0,.25);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--papel); color: var(--tinta);
  font: 16px/1.55 'Nunito', system-ui, sans-serif;
}
a { color: var(--rojo); }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; }
h2 { margin-top: 2rem; font-size: 1.4rem; }
h2 small, h1 small { color: var(--tinta-2); font-weight: 400; font-family: var(--hz); }
.hz { font-family: var(--hz); }
.nota { color: var(--tinta-2); font-size: .9rem; }
kbd { font: 600 .7rem/1 'Nunito', sans-serif; border: 1px solid var(--borde); border-radius: 4px; padding: 2px 5px; color: var(--tinta-2); }

/* Tonos */
.t1 { color: var(--t1); } .t2 { color: var(--t2); } .t3 { color: var(--t3); } .t4 { color: var(--t4); } .t5 { color: var(--t5); }

/* Barra superior */
.barra {
  position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; padding: .6rem clamp(1rem, 4vw, 2rem); background: color-mix(in srgb, var(--papel) 88%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--borde); flex-wrap: wrap;
}
.logo { font-weight: 800; text-decoration: none; color: var(--tinta); font-size: 1.1rem; white-space: nowrap; }
.logo .hz { color: var(--rojo); }
.barra nav { display: flex; gap: .25rem; flex-wrap: wrap; }
.barra nav a { text-decoration: none; color: var(--tinta-2); padding: .35rem .7rem; border-radius: 999px; font-weight: 600; font-size: .95rem; }
.barra nav a:hover { background: var(--papel-2); color: var(--tinta); }
.barra nav a.activo { background: var(--tinta); color: var(--papel); }
.badge { background: var(--rojo); color: #fff; border-radius: 999px; font-size: .7rem; padding: 1px 6px; margin-left: 2px; }

main { max-width: 1040px; margin: 0 auto; padding: 1.5rem clamp(1rem, 4vw, 2rem) 4rem; outline: none; }

/* Botones */
.btn {
  display: inline-flex; align-items: center; gap: .4rem; background: var(--rojo); color: #fff; border: 0;
  padding: .6rem 1.1rem; border-radius: 999px; font: 700 .95rem 'Nunito', sans-serif; cursor: pointer; text-decoration: none;
  transition: transform .1s, background .15s;
}
.btn:hover { background: var(--rojo-2); }
.btn:active { transform: scale(.97); }
.btn.sec { background: var(--papel-2); color: var(--tinta); border: 1px solid var(--borde); }
.btn.sec:hover { background: var(--borde); }
.btn.peligro { background: transparent; color: var(--mal); border: 1px solid var(--mal); }
.btn.off { opacity: .35; pointer-events: none; }
.btn kbd { color: rgba(255,255,255,.8); border-color: rgba(255,255,255,.4); }
.btn-audio { background: none; border: 0; cursor: pointer; font-size: 1.05rem; padding: 2px 4px; border-radius: 6px; }
.btn-audio:hover { background: var(--papel-2); }
.fila { display: flex; align-items: center; gap: .6rem; margin: .6rem 0; flex-wrap: wrap; }
.botones { gap: .5rem; }
.centrada { justify-content: center; }

/* Inicio */
.hero {
  display: grid; grid-template-columns: 1fr auto; gap: 1.5rem; align-items: center;
  background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: 1.5rem; box-shadow: var(--sombra);
  background-image: radial-gradient(circle at 100% 0, color-mix(in srgb, var(--rojo) 10%, transparent), transparent 40%);
}
.hero h1 { font-size: clamp(1.6rem, 4vw, 2.3rem); }
.hero h1 .hz { color: var(--rojo); font-family: var(--hz-serif); }
.hero p { margin: 0; color: var(--tinta-2); }
.stats { display: flex; gap: 1rem; }
.stats div { text-align: center; min-width: 70px; }
.stats b { display: block; font-size: 1.8rem; color: var(--rojo); }
.stats span { font-size: .8rem; color: var(--tinta-2); }
.aviso-repaso {
  display: flex; gap: .5rem; align-items: center; margin-top: 1rem; padding: .8rem 1.1rem; border-radius: var(--radio);
  background: color-mix(in srgb, var(--oro) 18%, var(--tarjeta)); border: 1px solid color-mix(in srgb, var(--oro) 50%, transparent);
  color: var(--tinta); text-decoration: none;
}
.aviso-repaso span { margin-left: auto; font-weight: 700; color: var(--rojo); }

.niveles { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: .9rem; margin-top: 1.5rem; }
.nivel-card, .leccion {
  display: grid; grid-template-columns: auto 1fr auto; gap: 1rem; align-items: center;
  background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: 1rem;
  text-decoration: none; color: var(--tinta); box-shadow: var(--sombra); transition: transform .15s, border-color .15s;
}
.nivel-card:hover, .leccion:hover { transform: translateY(-2px); border-color: var(--rojo); }
.nivel-card.bloqueado { opacity: .5; filter: grayscale(.6); }
.nivel-card.bloqueado:hover { transform: none; border-color: var(--borde); }
.nivel-num {
  width: 48px; height: 48px; border-radius: 12px; display: grid; place-items: center; font-weight: 800; font-size: 1.3rem;
  background: var(--rojo); color: #fff;
}
.nivel-info h3, .leccion h3 { margin: 0; font-size: 1.05rem; }
.nivel-info h3 .hz { color: var(--tinta-2); font-weight: 400; font-size: .9rem; }
.leccion p { margin: 0; color: var(--tinta-2); font-size: .9rem; }
.muestra { color: var(--tinta-2); font-size: 1.05rem; letter-spacing: .05em; margin: .2rem 0 .4rem; }
.barra-avance, .progreso-fino { height: 6px; background: var(--papel-2); border-radius: 99px; overflow: hidden; }
.barra-avance span, .progreso-fino span { display: block; height: 100%; background: linear-gradient(90deg, var(--jade), var(--oro)); border-radius: 99px; transition: width .3s; }
.progreso-fino { margin-bottom: 1rem; }
.estrellas span { color: var(--borde); font-size: 1.1rem; }
.estrellas span.on { color: var(--oro); }
.estrellas-grandes .estrellas span { font-size: 3rem; }
.lecciones { display: grid; gap: .8rem; }

.ajustes { margin-top: 2rem; background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: .8rem 1.1rem; }
.ajustes summary { cursor: pointer; font-weight: 700; }
.creditos { margin-top: 2rem; font-size: .8rem; color: var(--tinta-2); text-align: center; }

/* Portada de nivel */
.migas { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; font-weight: 600; }
.migas a { text-decoration: none; }
.marcador { color: var(--tinta-2); }
.portada { margin-bottom: 1.2rem; }
.portada h1 .hz { color: var(--rojo); font-family: var(--hz-serif); font-weight: 600; }
.portada p { color: var(--tinta-2); max-width: 70ch; }
.modos { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: .8rem; margin-bottom: 1.5rem; }
.modo {
  display: grid; gap: .2rem; padding: 1rem 1.1rem; background: var(--tarjeta); border: 1px solid var(--borde);
  border-radius: var(--radio); text-decoration: none; color: var(--tinta); box-shadow: var(--sombra); transition: transform .15s, border-color .15s;
}
.modo:hover { transform: translateY(-2px); border-color: var(--rojo); }
.modo .ico { font-size: 1.6rem; }
.modo small { color: var(--tinta-2); }
.modo.destacado { background: linear-gradient(135deg, var(--rojo), #e0653b); color: #fff; border: 0; }
.modo.destacado small { color: rgba(255,255,255,.85); }

.rejilla { display: grid; grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); gap: .6rem; }
.celda {
  display: grid; justify-items: center; gap: 0; padding: .7rem .4rem; background: var(--tarjeta); border: 2px solid var(--borde);
  border-radius: 12px; text-decoration: none; color: var(--tinta); text-align: center; transition: transform .1s;
}
.celda:hover { transform: scale(1.04); }
.celda .grande { font-size: 2.2rem; line-height: 1.2; }
.celda .py { font-weight: 700; font-size: .9rem; }
.celda .sig { font-size: .75rem; color: var(--tinta-2); line-height: 1.2; }
/* Dominio: del gris (nuevo) al verde jade (dominado) */
.dom0 { border-color: var(--borde); }
.dom1 { border-color: color-mix(in srgb, var(--rojo) 45%, var(--borde)); }
.dom2 { border-color: color-mix(in srgb, var(--oro) 55%, var(--borde)); }
.dom3 { border-color: color-mix(in srgb, var(--oro) 90%, var(--borde)); }
.dom4 { border-color: color-mix(in srgb, var(--jade) 60%, var(--borde)); }
.dom5 { border-color: var(--jade); background: color-mix(in srgb, var(--jade) 8%, var(--tarjeta)); }
.chips { display: flex; flex-wrap: wrap; gap: .35rem; margin: .5rem 0; }
.chip {
  display: inline-grid; place-items: center; min-width: 2.2rem; height: 2.2rem; padding: 0 .3rem; border: 2px solid var(--borde);
  border-radius: 8px; font: 1.2rem var(--hz); text-decoration: none; color: var(--tinta); background: var(--tarjeta);
}
.leyenda .chip { min-width: 1.8rem; height: 1.8rem; font-size: .9rem; vertical-align: middle; }

/* Ficha */
.ficha {
  display: grid; grid-template-columns: minmax(220px, 300px) 1fr; gap: 1.5rem; background: var(--tarjeta);
  border: 1px solid var(--borde); border-radius: var(--radio); padding: 1.4rem; box-shadow: var(--sombra);
}
.trazos-caja { background: var(--papel); border: 1px solid var(--borde); border-radius: 12px; aspect-ratio: 1; position: relative; overflow: hidden; }
.trazos-caja.grande { max-width: 300px; margin: 1rem auto; }
.hw { width: 100%; height: 100%; }
.hw svg { display: block; }
/* Cuadrícula 米字格 */
.trazos-caja::before, .trazos-caja::after { content: ''; position: absolute; inset: 0; pointer-events: none; }
.trazos-caja::before { background:
  linear-gradient(var(--borde), var(--borde)) center / 100% 1px no-repeat,
  linear-gradient(var(--borde), var(--borde)) center / 1px 100% no-repeat; opacity: .8; }
.trazos-caja::after { background:
  linear-gradient(45deg, transparent calc(50% - .5px), var(--borde) 50%, transparent calc(50% + .5px)),
  linear-gradient(-45deg, transparent calc(50% - .5px), var(--borde) 50%, transparent calc(50% + .5px)); opacity: .45; }
.sin-red { display: grid; place-items: center; height: 100%; font-size: 7rem; text-align: center; }
.sin-red small { font: .8rem 'Nunito', sans-serif; color: var(--tinta-2); display: block; }
.botones-trazo { display: flex; gap: .5rem; justify-content: center; margin: .8rem 0; flex-wrap: wrap; }
.meta { display: grid; grid-template-columns: 1fr 1fr; gap: .4rem .8rem; margin: 0; }
.meta div { background: var(--papel); border-radius: 8px; padding: .35rem .6rem; }
.meta dt { font-size: .72rem; color: var(--tinta-2); text-transform: uppercase; letter-spacing: .04em; }
.meta dd { margin: 0; font-weight: 700; }
.cabecera-char { display: flex; gap: 1.2rem; align-items: center; margin-bottom: .6rem; }
.enorme { font-size: clamp(4rem, 10vw, 6rem); line-height: 1; }
.py.grande { font-size: 1.8rem; font-weight: 800; }
.tono-etq { font-size: .8rem; color: var(--tinta-2); }
.significado { font-size: 1.25rem; font-weight: 700; }
.significado.grande { font-size: 1.8rem; text-align: center; }
.etq { display: inline-block; padding: .15rem .6rem; border-radius: 999px; font-size: .8rem; font-weight: 700; color: #fff; }
.tipo-P { background: var(--jade); } .tipo-S { background: #6c5ce7; } .tipo-I { background: var(--oro); color: #2b2622; } .tipo-F { background: #2f7fd0; }
.tipo small { color: var(--tinta-2); }
.descripcion { font-size: 1.05rem; }
.ficha h4 { margin: 1.2rem 0 .5rem; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--tinta-2); }
.composicion { display: flex; align-items: center; gap: .4rem; flex-wrap: wrap; }
.composicion.centrada { justify-content: center; }
.comp {
  display: grid; justify-items: center; padding: .4rem .7rem; border: 2px solid var(--borde); border-radius: 12px;
  text-decoration: none; color: var(--tinta); min-width: 64px; background: var(--tarjeta);
}
.comp .hz { font-size: 2rem; line-height: 1.2; }
.comp small { font-size: .75rem; color: var(--tinta-2); }
.comp em { font-size: .65rem; font-style: normal; font-weight: 700; text-transform: uppercase; }
.comp.sem { border-color: var(--jade); } .comp.sem em { color: var(--jade); }
.comp.fon { border-color: #2f7fd0; } .comp.fon em { color: #2f7fd0; }
.comp.resultado { border-style: dashed; border-color: var(--rojo); }
a.comp:hover { background: var(--papel-2); }
.mas { font-size: 1.4rem; color: var(--tinta-2); font-weight: 800; }
.ejemplos { list-style: none; padding: 0; margin: 0; display: grid; gap: .3rem; }
.ejemplos li { display: flex; align-items: baseline; gap: .5rem; flex-wrap: wrap; padding: .3rem .5rem; border-radius: 8px; background: var(--papel); }
.ejemplos .hz { font-size: 1.25rem; }
.ejemplos .py { font-weight: 700; color: var(--tinta-2); }
.paginador { display: flex; justify-content: space-between; align-items: center; margin-top: 1.2rem; gap: .5rem; }

/* Escribir */
.escribir { background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: 1.4rem; text-align: center; box-shadow: var(--sombra); }
.escribir .enunciado .nota { max-width: 50ch; margin: .4rem auto 0; }
#resultado-escritura { min-height: 1.5em; font-weight: 700; font-size: 1rem; color: var(--tinta); }

/* Preguntas */
.pregunta { background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: clamp(1rem, 3vw, 2rem); box-shadow: var(--sombra); }
.enunciado-q { text-align: center; font-weight: 700; color: var(--tinta-2); margin: 0; }
.enunciado-q small { font-weight: 400; margin-left: .4rem; }
.estimulo { text-align: center; margin: 1rem 0 1.4rem; min-height: 110px; display: grid; place-items: center; gap: .3rem; }
.sig-peq { color: var(--tinta-2); }
.opciones { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; }
.opciones.cinco { grid-template-columns: repeat(5, 1fr); }
.opcion {
  position: relative; display: grid; place-items: center; min-height: 64px; padding: .7rem 1rem; background: var(--papel);
  border: 2px solid var(--borde); border-radius: 12px; font: 600 1.05rem 'Nunito', sans-serif; color: var(--tinta); cursor: pointer;
  transition: border-color .15s, transform .1s, background .15s;
}
.opcion:hover:not(:disabled) { border-color: var(--tinta-2); transform: translateY(-1px); }
.opcion kbd { position: absolute; top: 6px; left: 8px; }
.opcion.correcta { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 15%, var(--tarjeta)); }
.opcion.incorrecta { border-color: var(--mal); background: color-mix(in srgb, var(--mal) 12%, var(--tarjeta)); animation: sacudir .3s; }
.opcion:disabled { cursor: default; }
.op-grande { font-size: 2.3rem; line-height: 1.1; }
.op-py { font-size: 1.4rem; font-weight: 800; }
.op-tono { display: grid; font-weight: 800; font-size: 1.1rem; }
.op-tono small { font-size: 1.4rem; }
.btn-escuchar { background: var(--papel); border: 2px solid var(--borde); border-radius: 50%; width: 120px; height: 120px; font-size: 2.6rem; cursor: pointer; display: grid; place-items: center; align-content: center; }
.btn-escuchar small { font-size: .65rem; color: var(--tinta-2); max-width: 90px; }
.btn-escuchar:hover { border-color: var(--rojo); }
.feedback { margin-top: 1.2rem; padding: 1rem 1.2rem; border-radius: 12px; border-left: 5px solid; animation: aparecer .2s; }
.feedback.ok { border-color: var(--ok); background: color-mix(in srgb, var(--ok) 10%, var(--tarjeta)); }
.feedback.mal { border-color: var(--mal); background: color-mix(in srgb, var(--mal) 8%, var(--tarjeta)); }
.fb-titulo { font-weight: 800; font-size: 1.1rem; }
.fb-char { display: flex; gap: .6rem; align-items: baseline; flex-wrap: wrap; margin: .3rem 0; }
.fb-char .hz { font-size: 2rem; text-decoration: none; color: var(--tinta); }
.fb-char .py { font-weight: 800; }
.feedback p { margin: .3rem 0 .8rem; color: var(--tinta-2); }
@keyframes sacudir { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }
@keyframes aparecer { from { opacity: 0; transform: translateY(6px); } }

.final { text-align: center; background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: 2rem; box-shadow: var(--sombra); }
.puntuacion { font-size: 1.4rem; margin: .5rem 0; }
.puntuacion b { font-size: 3.2rem; color: var(--rojo); }
.final .chips { justify-content: center; }
.desbloqueo { font-weight: 800; font-size: 1.1rem; }

/* Pinyin */
.tonos { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: .8rem; }
.tono-card { background: var(--tarjeta); border: 1px solid var(--borde); border-top: 5px solid currentColor; border-radius: var(--radio); padding: 1rem; color: inherit; }
.tono-card.t1 { border-top-color: var(--t1); } .tono-card.t2 { border-top-color: var(--t2); } .tono-card.t3 { border-top-color: var(--t3); }
.tono-card.t4 { border-top-color: var(--t4); } .tono-card.t5 { border-top-color: var(--t5); }
.tono-card h3 { color: var(--tinta); font-size: 1rem; }
.tono-card .marca { font-size: 1.4rem; }
.tono-card p { color: var(--tinta-2); font-size: .88rem; margin: .3rem 0; }
.tono-card .forma { font-weight: 700; color: var(--tinta); }
.contorno { width: 100%; height: 60px; }
.contorno .guia { stroke: var(--borde); stroke-width: .5; }
.contorno.t1 polyline { stroke: var(--t1); } .contorno.t2 polyline { stroke: var(--t2); } .contorno.t3 polyline { stroke: var(--t3); }
.contorno.t4 polyline { stroke: var(--t4); } .contorno.t5 polyline { stroke: var(--t5); }
.ej { background: var(--papel); border: 1px solid var(--borde); border-radius: 8px; padding: .4rem .6rem; cursor: pointer; font: inherit; color: var(--tinta); width: 100%; text-align: left; }
.ej .hz { font-size: 1.3rem; }
.grupo { font-size: 1rem; color: var(--tinta-2); margin: 1.2rem 0 .5rem; }
.sonidos { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: .5rem; }
.sonido {
  display: grid; grid-template-columns: auto 1fr; grid-template-rows: auto auto; column-gap: .7rem; text-align: left;
  background: var(--tarjeta); border: 1px solid var(--borde); border-radius: 10px; padding: .6rem .8rem; cursor: pointer; font: inherit; color: var(--tinta);
}
.sonido:hover { border-color: var(--rojo); }
.sonido b { grid-row: span 2; font-size: 1.5rem; color: var(--rojo); min-width: 2.2ch; }
.sonido span { font-size: .85rem; color: var(--tinta-2); }
.sonido em { font-style: normal; font-weight: 700; font-size: .9rem; }
.reglas { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: .7rem; }
.regla { background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: .9rem 1rem; }
.regla h4 { margin-bottom: .3rem; }
.regla p { margin: 0; color: var(--tinta-2); font-size: .92rem; }
.trazos-basicos { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: .5rem; }
.trazo { display: grid; justify-items: center; background: var(--tarjeta); border: 1px solid var(--borde); border-radius: 10px; padding: .6rem; text-align: center; }
.trazo .grande { font-size: 2.2rem; color: var(--rojo); }
.trazo small { color: var(--tinta-2); }
.orden li { margin: .3rem 0; }
.orden .hz { font-size: 1.2rem; margin-left: .4rem; color: var(--rojo); }

/* Componentes */
.familias { display: grid; grid-template-columns: repeat(auto-fill, minmax(92px, 1fr)); gap: .5rem; }
.familia {
  position: relative; display: grid; justify-items: center; padding: .6rem .3rem; background: var(--tarjeta); border: 1px solid var(--borde);
  border-radius: 12px; text-decoration: none; color: var(--tinta); text-align: center;
}
.familia:hover, .familia.activa { border-color: var(--rojo); }
.familia.activa { background: color-mix(in srgb, var(--rojo) 8%, var(--tarjeta)); }
.familia .grande { font-size: 2rem; line-height: 1.2; }
.familia small { font-size: .72rem; color: var(--tinta-2); line-height: 1.2; }
.familia em { position: absolute; top: 4px; right: 6px; font-style: normal; font-size: .7rem; font-weight: 800; color: var(--rojo); }
.detalle-familia { margin-top: 1.5rem; scroll-margin-top: 80px; }
.detalle-familia h2 .hz { font-size: 2.2rem; color: var(--rojo); }

/* Repaso */
.caja-repaso { background: var(--tarjeta); border: 1px solid var(--borde); border-radius: var(--radio); padding: 1.3rem; box-shadow: var(--sombra); }
.caja-repaso > b { font-size: 2rem; color: var(--rojo); }

/* Aviso flotante */
#toast {
  position: fixed; left: 50%; bottom: 1.5rem; transform: translate(-50%, 150%); background: var(--tinta); color: var(--papel);
  padding: .7rem 1.2rem; border-radius: 999px; font-weight: 600; transition: transform .25s, opacity .25s, visibility .25s;
  z-index: 20; max-width: 90vw; text-align: center; opacity: 0; visibility: hidden;
}
#toast.on { transform: translate(-50%, 0); opacity: 1; visibility: visible; }

/* Pantallas táctiles (iPhone, Android, tabletas) */
a, button { touch-action: manipulation; -webkit-tap-highlight-color: transparent; }
.escribir .hw, .escribir .trazos-caja { touch-action: none; -webkit-user-select: none; user-select: none; }
.pestanas .ico { display: none; }
@media (hover: none) {
  .nivel-card:hover, .leccion:hover, .modo:hover, .celda:hover, .opcion:hover:not(:disabled) { transform: none; }
  .nivel-card:active, .leccion:active, .modo:active, .celda:active, .opcion:active:not(:disabled) { transform: scale(.98); }
}

@media (max-width: 720px) {
  .hero { grid-template-columns: 1fr; }
  .stats { justify-content: space-around; }
  .ficha { grid-template-columns: 1fr; padding: 1rem; }
  .ficha-izq { max-width: 300px; margin: 0 auto; width: 100%; }
  .ficha-der { order: -1; }
  .cabecera-char { justify-content: center; }
  .opciones.cinco { grid-template-columns: repeat(3, 1fr); }
  .niveles { grid-template-columns: 1fr; }

  /* Cabecera compacta arriba (respetando el notch) */
  .barra {
    padding: calc(.5rem + env(safe-area-inset-top)) calc(1rem + env(safe-area-inset-right)) .5rem calc(1rem + env(safe-area-inset-left));
    justify-content: center;
    /* Sin backdrop-filter: haría que la barra de pestañas (fixed) se posicione dentro de la cabecera */
    backdrop-filter: none; -webkit-backdrop-filter: none; background: var(--papel);
  }

  /* Barra de pestañas inferior, al estilo iOS */
  .pestanas {
    position: fixed; left: 0; right: 0; bottom: 0; z-index: 15;
    display: grid !important; grid-template-columns: repeat(5, 1fr); gap: 0 !important;
    padding: .3rem env(safe-area-inset-right) calc(.3rem + env(safe-area-inset-bottom)) env(safe-area-inset-left);
    background: color-mix(in srgb, var(--papel) 92%, transparent);
    backdrop-filter: saturate(1.8) blur(14px); -webkit-backdrop-filter: saturate(1.8) blur(14px);
    border-top: 1px solid var(--borde);
  }
  .pestanas a {
    position: relative; display: grid; justify-items: center; gap: 1px; padding: .3rem 0 !important;
    border-radius: 10px !important; font-size: .68rem !important; font-weight: 700; color: var(--tinta-2);
  }
  .pestanas a:hover { background: none !important; }
  .pestanas a.activo { background: none !important; color: var(--rojo) !important; }
  .pestanas .ico { display: block; font-size: 1.35rem; line-height: 1.2; filter: grayscale(1); opacity: .6; }
  .pestanas a.activo .ico { filter: none; opacity: 1; }
  .pestanas .badge { position: absolute; top: 0; left: calc(50% + 6px); margin: 0; }

  main {
    padding: 1rem calc(1rem + env(safe-area-inset-right)) calc(5.5rem + env(safe-area-inset-bottom)) calc(1rem + env(safe-area-inset-left));
  }
  #toast { bottom: calc(5rem + env(safe-area-inset-bottom)); }
  .migas { position: sticky; top: calc(3rem + env(safe-area-inset-top)); z-index: 5; margin: -1rem -1rem 1rem; padding: .6rem 1rem;
    background: color-mix(in srgb, var(--papel) 92%, transparent); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); }
  .paginador .btn { padding: .75rem 1rem; }
  .btn-audio { font-size: 1.3rem; padding: 6px 8px; }
  h1 { font-size: 1.5rem; }
}

/* App instalada en la pantalla de inicio (sin barra de Safari) */
@media (display-mode: standalone) {
  body { overscroll-behavior-y: none; }
  .logo { pointer-events: none; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }