/* ============================================================
   GUÍA · Regulador de tensión serie (Transistor NPN + Zener)
   Misma familia visual que los cuestionarios. Sin dependencias externas.
   ============================================================ */
:root {
    color-scheme: dark;
    --azul-profundo: #050914; --azul-marino: #0a1128; --azul-panel: #10182f;
    --azul-electrico: #2e9dff; --azul-electrico-claro: #6bc2ff;
    --dorado: #f2c14e; --dorado-suave: #f7d97e;
    --blanco: #f4f7ff; --blanco-suave: #c8d2ea; --gris-azulado: #8b97ba;
    --correcto: #33d68f; --correcto-bg: rgba(51, 214, 143, 0.13);
    --incorrecto: #ff5d6c; --incorrecto-bg: rgba(255, 93, 108, 0.13);
    --borde-sutil: rgba(107, 194, 255, 0.2);
    --sombra: 0 20px 60px rgba(0, 0, 0, 0.45);
    --radio: 18px;
    --fuente: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
    --estrellas: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' width='300' height='300'><circle cx='169' cy='81' r='0.9' fill='%23f2c14e' fill-opacity='0.7'/><circle cx='52' cy='191' r='1.0' fill='%23b4d2ff' fill-opacity='0.37'/><circle cx='48' cy='226' r='0.9' fill='%23b4d2ff' fill-opacity='0.55'/><circle cx='34' cy='293' r='0.6' fill='%23b4d2ff' fill-opacity='0.6'/><circle cx='35' cy='207' r='0.5' fill='%23b4d2ff' fill-opacity='0.56'/><circle cx='72' cy='152' r='0.9' fill='%23b4d2ff' fill-opacity='0.56'/><circle cx='290' cy='96' r='0.6' fill='%23b4d2ff' fill-opacity='0.35'/><circle cx='53' cy='284' r='1.1' fill='%23b4d2ff' fill-opacity='0.59'/><circle cx='258' cy='276' r='0.9' fill='%23b4d2ff' fill-opacity='0.57'/><circle cx='236' cy='189' r='0.8' fill='%23b4d2ff' fill-opacity='0.63'/><circle cx='128' cy='45' r='1.0' fill='%23b4d2ff' fill-opacity='0.73'/><circle cx='233' cy='151' r='1.0' fill='%23f2c14e' fill-opacity='0.53'/><circle cx='88' cy='179' r='0.6' fill='%23b4d2ff' fill-opacity='0.27'/><circle cx='43' cy='289' r='1.0' fill='%23b4d2ff' fill-opacity='0.42'/><circle cx='183' cy='258' r='1.0' fill='%23b4d2ff' fill-opacity='0.71'/><circle cx='142' cy='246' r='1.1' fill='%23f2c14e' fill-opacity='0.65'/><circle cx='162' cy='232' r='0.8' fill='%23b4d2ff' fill-opacity='0.62'/><circle cx='15' cy='240' r='0.8' fill='%23b4d2ff' fill-opacity='0.52'/><circle cx='115' cy='151' r='0.6' fill='%23b4d2ff' fill-opacity='0.47'/><circle cx='258' cy='45' r='0.6' fill='%23b4d2ff' fill-opacity='0.4'/><circle cx='74' cy='224' r='1.3' fill='%23b4d2ff' fill-opacity='0.48'/><circle cx='187' cy='198' r='1.4' fill='%23b4d2ff' fill-opacity='0.35'/><circle cx='122' cy='123' r='0.5' fill='%23b4d2ff' fill-opacity='0.35'/><circle cx='148' cy='6' r='0.6' fill='%23b4d2ff' fill-opacity='0.59'/><circle cx='167' cy='68' r='1.1' fill='%23b4d2ff' fill-opacity='0.59'/><circle cx='31' cy='237' r='1.3' fill='%23b4d2ff' fill-opacity='0.73'/><circle cx='290' cy='204' r='0.9' fill='%23b4d2ff' fill-opacity='0.51'/><circle cx='209' cy='35' r='0.7' fill='%23b4d2ff' fill-opacity='0.49'/><circle cx='60' cy='178' r='1.0' fill='%23f2c14e' fill-opacity='0.56'/><circle cx='278' cy='55' r='1.4' fill='%23b4d2ff' fill-opacity='0.29'/><circle cx='110' cy='196' r='0.6' fill='%23b4d2ff' fill-opacity='0.44'/><circle cx='190' cy='246' r='0.6' fill='%23b4d2ff' fill-opacity='0.8'/><circle cx='242' cy='249' r='0.9' fill='%23f2c14e' fill-opacity='0.31'/><circle cx='179' cy='139' r='0.9' fill='%23b4d2ff' fill-opacity='0.53'/></svg>");
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
    margin: 0; min-height: 100vh; min-height: 100dvh; color: var(--blanco); font-family: var(--fuente); line-height: 1.6;
    background: radial-gradient(ellipse at 18% 8%, #0e1c40 0%, var(--azul-profundo) 55%) fixed;
    -webkit-tap-highlight-color: transparent; overflow-x: hidden;
}
body::before { content: ""; position: fixed; inset: 0; background-image: var(--estrellas); background-size: 300px 300px; opacity: .85; pointer-events: none; z-index: 0; }
h1, h2, h3, h4, p, ul, ol, figure { margin: 0; }
button, input { font: inherit; }
[hidden] { display: none !important; }
:focus-visible { outline: 3px solid var(--azul-electrico-claro); outline-offset: 2px; }
.saltar { position: absolute; left: 12px; top: -60px; z-index: 60; background: var(--dorado); color: #1a1200; padding: 10px 16px; border-radius: 10px; font-weight: 700; text-decoration: none; }
.saltar:focus { top: 12px; }

.app { position: relative; z-index: 1; width: 100%; max-width: 860px; margin: 0 auto; padding: max(16px, env(safe-area-inset-top)) max(14px, env(safe-area-inset-right)) max(48px, env(safe-area-inset-bottom)) max(14px, env(safe-area-inset-left)); }
.barra-superior { display: flex; align-items: center; justify-content: space-between; gap: 12px; font-size: .85rem; }
.enlace-portal { color: var(--azul-electrico-claro); text-decoration: none; font-weight: 600; padding: 10px 4px; min-height: 44px; display: inline-flex; align-items: center; }
.enlace-portal:hover { text-decoration: underline; }
.curso { color: var(--gris-azulado); }

/* Navegación de secciones (pegajosa, con desplazamiento horizontal en móvil) */
.nav-secciones {
    position: sticky; top: 0; z-index: 30; display: flex; gap: 8px; overflow-x: auto; padding: 8px 2px 10px; margin: 0 -2px 14px;
    background: linear-gradient(180deg, rgba(5, 9, 20, .96) 70%, rgba(5, 9, 20, 0)); scrollbar-width: thin; scroll-snap-type: x proximity;
}
.nav-secciones a {
    flex: 0 0 auto; scroll-snap-align: start; min-height: 44px; display: inline-flex; align-items: center; padding: 0 12px; border-radius: 22px;
    font-size: .85rem; font-weight: 600; color: var(--blanco-suave); text-decoration: none; white-space: nowrap;
    border: 1px solid var(--borde-sutil); background: rgba(16, 24, 47, .85);
}
.nav-secciones a:hover, .nav-secciones a.activa { color: #fff; border-color: var(--azul-electrico); background: rgba(46, 157, 255, .18); }

.tarjeta { background: linear-gradient(180deg, var(--azul-panel) 0%, var(--azul-marino) 100%); border: 1px solid var(--borde-sutil); border-radius: var(--radio); box-shadow: var(--sombra); padding: clamp(14px, 4vw, 32px); margin-bottom: 18px; }
.seccion { scroll-margin-top: 70px; }

/* Portada */
.hero { text-align: center; }
.hero-icono { width: 64px; height: 64px; margin: 0 auto 16px; border-radius: 50%; display: grid; place-items: center; color: #1a1200; background: radial-gradient(circle at 35% 30%, var(--dorado-suave), var(--dorado) 60%, #b8891f 100%); box-shadow: 0 0 26px rgba(242, 193, 78, .45); }
.hero-icono svg { width: 30px; height: 30px; }
.hero h1 { font-size: clamp(1.5rem, 6vw, 2.1rem); line-height: 1.2; }
.subtitulo { color: var(--azul-electrico-claro); font-weight: 600; margin: 8px 0 14px; }
.descripcion { color: var(--blanco-suave); max-width: 56ch; margin: 0 auto 20px; }
.datos { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.dato { background: rgba(46, 157, 255, .07); border: 1px solid var(--borde-sutil); border-radius: 12px; padding: 12px 6px; display: flex; flex-direction: column; align-items: center; gap: 2px; }
.dato b { font-size: 1.4rem; }
.dato span { font-size: .75rem; color: var(--gris-azulado); text-align: center; }

/* Encabezados de sección */
h2 { font-size: clamp(1.15rem, 4.4vw, 1.5rem); line-height: 1.3; margin-bottom: 12px; display: flex; gap: 12px; align-items: flex-start; }
h2 .num { flex: 0 0 auto; width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; font-size: .95rem; font-weight: 800; color: #1a1200; background: linear-gradient(135deg, var(--dorado-suave), var(--dorado)); margin-top: -2px; }
h3 { font-size: 1.08rem; color: var(--azul-electrico-claro); margin: 26px 0 8px; line-height: 1.35; }
h4 { font-size: 1rem; }
.lead { color: var(--blanco-suave); font-size: 1.02rem; margin-bottom: 16px; }
.seccion p + p, .seccion p + .eq, .seccion .eq + p { margin-top: 10px; }
.seccion > .tarjeta > p, .seccion p { color: var(--blanco-suave); }
.seccion strong { color: var(--blanco); }
sub { font-size: .75em; line-height: 0; }

/* Cajas de aviso */
.aviso { padding: 12px 14px; border-radius: 12px; border-left: 4px solid var(--dorado); background: rgba(242, 193, 78, .08); color: var(--blanco-suave); font-size: .95rem; margin: 14px 0; }
.aviso.ok { border-left-color: var(--correcto); background: var(--correcto-bg); }
.aviso.alerta { border-left-color: var(--incorrecto); background: var(--incorrecto-bg); }
.aviso.idea strong:first-child, .aviso strong { color: var(--blanco); }

/* Ecuaciones */
.eq { font-variant-numeric: tabular-nums; background: rgba(255, 255, 255, .04); border: 1px solid var(--borde-sutil); border-left: 3px solid var(--azul-electrico); border-radius: 8px; padding: 9px 12px; margin: 8px 0; color: var(--blanco); overflow-wrap: anywhere; line-height: 1.6; }
.eq.grande { font-size: 1.05rem; text-align: center; border-left-width: 1px; }
.eq b { color: var(--dorado-suave); }

/* Figura del circuito */
.figura-circuito { margin: 16px 0; padding: 12px; border-radius: 14px; background: rgba(46, 157, 255, .05); border: 1px solid var(--borde-sutil); }
.svg-circuito { display: block; width: 100%; height: auto; max-width: 520px; margin: 0 auto; }
.svg-circuito text, #svg-grafico text { fill: var(--blanco-suave); font: 500 11.5px var(--fuente); }
.svg-circuito .tit { fill: var(--blanco); font-weight: 700; font-size: 12.5px; }
.svg-circuito .ok-t { fill: var(--correcto); font-weight: 700; }
.svg-circuito .corr { fill: var(--dorado); font-weight: 700; }
.svg-circuito .linea { stroke: var(--azul-electrico-claro); stroke-width: 2.2; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.svg-circuito .grueso { stroke-width: 3.6; }
.svg-circuito .flecha { stroke: var(--dorado); stroke-width: 2; fill: none; stroke-linecap: round; stroke-linejoin: round; }
figcaption { margin-top: 10px; font-size: .85rem; color: var(--blanco-suave); text-align: center; }

.roles { display: grid; grid-template-columns: 1fr; gap: 10px; margin-bottom: 4px; }
@media (min-width: 640px) { .roles { grid-template-columns: 1fr 1fr; } }
.rol { display: flex; gap: 12px; padding: 12px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); }
.rol p { font-size: .88rem; margin-top: 2px !important; }
.rol-ic { flex: 0 0 auto; width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; font-weight: 800; font-size: .95rem; }
.rol-ic.z { background: rgba(176, 124, 255, .2); color: #d2b3ff; }
.rol-ic.r { background: rgba(242, 193, 78, .18); color: var(--dorado-suave); }
.rol-ic.t { background: rgba(46, 157, 255, .2); color: var(--azul-electrico-claro); }
.rol-ic.l { background: var(--correcto-bg); color: var(--correcto); }

/* Botones */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; min-height: 48px; padding: 12px 20px; border: 1px solid transparent; border-radius: 12px; font-weight: 700; font-size: .95rem; cursor: pointer; text-decoration: none; touch-action: manipulation; transition: transform .12s ease, filter .15s ease, background .15s ease; }
.btn:active:not(:disabled) { transform: scale(.98); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primario { background: linear-gradient(135deg, var(--azul-electrico), #1a6fd6); color: #fff; box-shadow: 0 8px 24px rgba(46, 157, 255, .28); }
.btn-primario:hover { filter: brightness(1.1); }
.btn-secundario { background: rgba(107, 194, 255, .1); color: var(--azul-electrico-claro); border-color: rgba(107, 194, 255, .35); }
.btn-secundario:hover { background: rgba(107, 194, 255, .18); }
.btn-terciario { background: transparent; color: var(--blanco-suave); text-decoration: underline; text-underline-offset: 3px; }
.btn-icono { min-width: 48px; padding: 0 12px; }
.acciones-fila { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.acciones { display: flex; flex-direction: column; gap: 10px; margin-top: 12px; }

/* Sección 2: comparativa de componentes */
.comp-grid { display: grid; grid-template-columns: 1fr; gap: 10px; margin: 12px 0 16px; }
@media (min-width: 640px) { .comp-grid { grid-template-columns: 1fr 1fr; } }
.comp { padding: 14px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); display: flex; flex-direction: column; gap: 4px; }
.comp .eq { font-size: .9rem; }
.comp p { font-size: .87rem; }
.badge { align-self: flex-start; margin-top: 6px; font-size: .72rem; font-weight: 800; padding: 3px 10px; border-radius: 20px; color: var(--dorado); border: 1px solid rgba(242, 193, 78, .4); background: rgba(242, 193, 78, .1); }
.badge.ok { color: var(--correcto); border-color: rgba(51, 214, 143, .4); background: var(--correcto-bg); }
.lista-ok { margin: 10px 0 10px; padding-left: 20px; color: var(--blanco-suave); display: flex; flex-direction: column; gap: 8px; }

.metodo { list-style: none; padding: 0; margin: 10px 0 16px; counter-reset: m; display: flex; flex-direction: column; gap: 8px; }
.metodo li { counter-increment: m; display: grid; grid-template-columns: 30px 1fr; column-gap: 10px; padding: 12px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); }
.metodo li::before { content: counter(m); grid-row: 1 / span 2; width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; font-weight: 800; background: rgba(46, 157, 255, .2); color: var(--azul-electrico-claro); }
.metodo strong { font-size: .98rem; }
.metodo span { font-size: .9rem; color: var(--blanco-suave); }

.tabla-scroll { overflow-x: auto; margin: 10px 0 6px; border-radius: 12px; border: 1px solid var(--borde-sutil); }
.tabla { width: 100%; border-collapse: collapse; font-size: .85rem; }
.tabla caption { text-align: left; padding: 10px 12px; font-weight: 700; color: var(--blanco); }
.tabla th, .tabla td { padding: 9px 12px; text-align: left; border-top: 1px solid var(--borde-sutil); }
.tabla th { color: var(--gris-azulado); font-size: .78rem; font-weight: 700; }
.tabla td { color: var(--blanco-suave); }

/* Widget: gráfico interactivo */
.widget { margin: 12px 0 14px; padding: 14px; border-radius: 14px; border: 1px solid var(--borde-sutil); background: rgba(46, 157, 255, .05); }
.widget-ctrl { display: flex; flex-direction: column; gap: 8px; margin-bottom: 10px; }
.widget-ctrl label { font-weight: 600; font-size: .95rem; color: var(--blanco); }
.widget-ctrl output { color: var(--dorado-suave); font-variant-numeric: tabular-nums; }
input[type="range"] { width: 100%; height: 34px; accent-color: var(--dorado); cursor: pointer; }
#svg-grafico { display: block; width: 100%; height: auto; max-width: 560px; margin: 0 auto; }
#svg-grafico .eje { stroke: var(--gris-azulado); stroke-width: 1.4; fill: none; }
#svg-grafico .rej { stroke: rgba(139, 151, 186, .3); stroke-width: 1; fill: none; }
#svg-grafico .c-div { stroke: var(--dorado); stroke-width: 2.4; fill: none; stroke-linecap: round; stroke-linejoin: round; }
#svg-grafico .c-reg { stroke: var(--correcto); stroke-width: 2.8; fill: none; stroke-linecap: round; stroke-linejoin: round; }
#svg-grafico .marca { stroke: var(--azul-electrico-claro); stroke-width: 1.3; stroke-dasharray: 4 3; }
.leyenda { display: flex; flex-wrap: wrap; gap: 6px 18px; justify-content: center; margin: 8px 0; font-size: .85rem; color: var(--blanco-suave); }
.ley i { display: inline-block; width: 22px; height: 4px; border-radius: 2px; vertical-align: middle; margin-right: 6px; }
.ley.div i { background: var(--dorado); } .ley.reg i { background: var(--correcto); }
.lecturas { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.lectura { padding: 10px; border-radius: 10px; text-align: center; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); }
.lectura span { display: block; font-size: .78rem; color: var(--gris-azulado); }
.lectura b { font-size: 1.35rem; font-variant-numeric: tabular-nums; }
.lectura.div b { color: var(--dorado-suave); } .lectura.reg b { color: var(--correcto); }
.msg-grafico { margin-top: 10px !important; font-size: .9rem; min-height: 2.9em; }

.ejemplo-error { padding: 14px; border-radius: 12px; border: 1px dashed rgba(255, 93, 108, .5); background: var(--incorrecto-bg); }
.cierre { margin-top: 14px !important; font-weight: 600; }

/* Sección 3 */
.formulas { display: grid; grid-template-columns: 1fr; gap: 10px; margin-bottom: 4px; }
@media (min-width: 600px) { .formulas { grid-template-columns: 1fr 1fr; } }
.fcard { padding: 12px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); }
.fcard .eq { margin-top: 0; }
.fcard p { font-size: .85rem; margin-top: 6px !important; }

/* Conceptos (details) */
.concepto { border: 1px solid var(--borde-sutil); border-radius: 12px; margin-bottom: 10px; background: rgba(255, 255, 255, .03); }
.concepto summary { list-style: none; cursor: pointer; padding: 14px 16px; display: flex; gap: 12px; align-items: flex-start; min-height: 52px; font-weight: 600; color: var(--blanco); }
.concepto summary::-webkit-details-marker { display: none; }
.concepto summary .c-id { flex: 0 0 auto; padding: 2px 9px; border-radius: 20px; font-size: .78rem; font-weight: 800; color: var(--dorado); border: 1px solid rgba(242, 193, 78, .4); margin-top: 2px; }
.concepto summary::after { content: "＋"; margin-left: auto; color: var(--azul-electrico-claro); font-weight: 700; }
.concepto[open] summary::after { content: "－"; }
.concepto .c-cuerpo { padding: 0 16px 16px 16px; color: var(--blanco-suave); border-top: 1px dashed var(--borde-sutil); padding-top: 12px; }
.concepto .c-cuerpo p + p, .concepto .c-cuerpo p + .eq, .concepto .c-cuerpo .eq + p { margin-top: 10px; }

/* Ejercicios */
.ejercicio { margin-bottom: 18px; }
.ej-cab { display: flex; gap: 14px; align-items: center; margin-bottom: 12px; }
.ej-num { flex: 0 0 auto; width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center; font-weight: 800; font-size: 1.4rem; color: #1a1200; background: linear-gradient(135deg, var(--dorado-suave), var(--dorado)); }
.ej-cab h3 { margin: 0; font-size: 1.15rem; color: var(--blanco); }
.ej-cab p { font-size: .85rem; color: var(--gris-azulado) !important; }
.ej-enun { font-size: .95rem; color: var(--blanco-suave); padding: 12px 14px; border-left: 3px solid var(--dorado); background: rgba(242, 193, 78, .07); border-radius: 0 10px 10px 0; margin-bottom: 12px; }
.chips-datos { list-style: none; padding: 0; margin: 0 0 14px; display: flex; flex-wrap: wrap; gap: 8px; }
.chips-datos li { padding: 5px 12px; border-radius: 20px; font-size: .88rem; border: 1px solid var(--borde-sutil); background: rgba(46, 157, 255, .08); color: var(--blanco); font-variant-numeric: tabular-nums; }
.chips-datos li span { color: var(--gris-azulado); }

.parte { padding: 12px; border-radius: 14px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .025); margin-top: 12px; }
.parte.extra { border-style: dashed; border-color: rgba(242, 193, 78, .45); }
.parte-tit { display: flex; gap: 12px; align-items: flex-start; font-size: 1rem; font-weight: 600; color: var(--blanco); line-height: 1.45; }
.letra { flex: 0 0 auto; width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; font-weight: 800; background: rgba(46, 157, 255, .2); color: var(--azul-electrico-claro); }
.parte.extra .letra { background: rgba(242, 193, 78, .2); color: var(--dorado); }
.pasos { list-style: none; padding: 0; margin: 12px 0 0; display: flex; flex-direction: column; gap: 10px; counter-reset: p; }
.paso { counter-increment: p; padding: 12px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(16, 24, 47, .8); animation: aparece .3s ease both; }
.paso-t { display: flex; align-items: flex-start; gap: 10px; font-weight: 700; color: var(--blanco); font-size: .97rem; line-height: 1.4; }
.paso-t::before { content: counter(p); flex: 0 0 26px; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; font-weight: 800; font-size: .82rem; background: rgba(46, 157, 255, .22); color: var(--azul-electrico-claro); }
.paso-x { font-size: .92rem; color: var(--blanco-suave); margin-top: 8px; }
.paso .eq { margin: 8px 0 0; }
.paso-x strong { color: var(--blanco); }
@keyframes aparece { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }

.controles { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 12px; }
.progreso-p { font-size: .82rem; color: var(--gris-azulado); font-variant-numeric: tabular-nums; }
.respuesta { margin-top: 12px; padding: 12px 14px; border-radius: 12px; border: 1px solid var(--correcto); background: var(--correcto-bg); animation: aparece .3s ease both; }
.respuesta .r-etq { display: block; font-size: .78rem; font-weight: 800; color: var(--correcto); margin-bottom: 2px; }
.respuesta .r-val { font-size: 1.05rem; font-weight: 700; color: var(--blanco); font-variant-numeric: tabular-nums; }
.respuesta .r-idea { margin-top: 8px !important; font-size: .88rem; color: var(--blanco-suave); padding-top: 8px; border-top: 1px dashed rgba(51, 214, 143, .4); }

/* Laboratorio */
.presets { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.presets .btn { min-height: 44px; padding: 8px 14px; font-size: .88rem; }
.lab-form { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-bottom: 14px; }
@media (min-width: 640px) { .lab-form { grid-template-columns: repeat(4, 1fr); } }
.lab-form label { display: flex; flex-direction: column; gap: 4px; font-size: .82rem; font-weight: 600; color: var(--gris-azulado); }
.lab-form input { min-height: 46px; padding: 8px 10px; border-radius: 10px; border: 1px solid var(--borde-sutil); background: var(--azul-profundo); color: var(--blanco); font-size: 1rem; width: 100%; font-variant-numeric: tabular-nums; }
.lab-form input:focus-visible { border-color: var(--azul-electrico); }
.lab-form input[aria-invalid="true"] { border-color: var(--incorrecto); }
.lab-estado { display: flex; flex-direction: column; gap: 8px; margin-bottom: 12px; }
.est { padding: 11px 14px; border-radius: 12px; font-size: .92rem; border: 1px solid var(--borde-sutil); }
.est strong { display: block; }
.est.ok { background: var(--correcto-bg); border-color: var(--correcto); color: #b5f5d8; }
.est.warn { background: rgba(242, 193, 78, .1); border-color: var(--dorado); color: var(--dorado-suave); }
.est.mal { background: var(--incorrecto-bg); border-color: var(--incorrecto); color: #ffc0c6; }
.lab-res { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; }
@media (min-width: 640px) { .lab-res { grid-template-columns: repeat(4, 1fr); } }
.res { padding: 10px; border-radius: 12px; border: 1px solid var(--borde-sutil); background: rgba(255, 255, 255, .03); text-align: center; }
.res span { display: block; font-size: .78rem; color: var(--gris-azulado); }
.res b { font-size: 1.15rem; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.nota-pequena { margin-top: 12px !important; font-size: .8rem; color: var(--gris-azulado) !important; }

/* Errores frecuentes */
.errores { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 8px; margin-bottom: 8px; }
.errores li { padding: 11px 14px; border-radius: 12px; border-left: 4px solid var(--incorrecto); background: var(--incorrecto-bg); }
.errores strong { display: block; }
.errores span { font-size: .9rem; color: var(--blanco-suave); }

/* Visor (dialog) */
dialog.visor { border: 0; padding: 0; background: rgba(3, 6, 16, .97); max-width: 100vw; max-height: 100vh; width: 100%; height: 100%; margin: 0; color: var(--blanco); }
dialog.visor::backdrop { background: rgba(3, 6, 16, .95); }
.visor-barra { position: sticky; top: 0; z-index: 2; display: flex; justify-content: space-between; gap: 10px; padding: max(10px, env(safe-area-inset-top)) 12px 10px; background: rgba(3, 6, 16, .9); }
.visor-cont { overflow: auto; padding: 8px 12px 24px; text-align: center; height: calc(100% - 70px); }
.visor-cont img { max-width: 100%; height: auto; border-radius: 10px; background: #fff; }
.visor-cont.real img { max-width: none; width: 1224px; }

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; } }
@media print {
    body { background: #fff; color: #000; } body::before, .nav-secciones, .barra-superior, .controles, .presets, .widget-ctrl, .saltar { display: none !important; }
    .tarjeta, .parte, .paso, .comp, .fcard { box-shadow: none; background: #fff; border-color: #999; color: #000; break-inside: avoid; }
    .paso[hidden] { display: grid !important; } * { color: #000 !important; }
}