/* =========================================================================
   Guía de estudio: Introducción a la IA
   Hoja de estilos única. Sin dependencias externas (ni CDN ni webfonts):
   permite una CSP estricta sin 'unsafe-inline' y carga instantánea.
   ========================================================================= */

/* ---------- 1. Tokens ---------------------------------------------------- */

:root {
  color-scheme: light;

  --bg:            #f6f7fb;
  --bg-elev:       #ffffff;
  --bg-sunken:     #eceef6;
  --bg-hover:      #e8eaf5;

  --text:          #1a1c2b;
  --text-soft:     #4d5169;
  --text-faint:    #7c819b;

  --border:        #dfe2ee;
  --border-strong: #c3c8dd;

  --accent:        #4c3fd6;
  --accent-hover:  #3d31b8;
  --accent-soft:   #eceafb;
  --accent-text:   #ffffff;

  --ok:            #10795b;
  --ok-soft:       #dff5ed;
  --warn:          #9a6100;
  --warn-soft:     #fdf0d5;
  --bad:           #b4232f;
  --bad-soft:      #fdeaec;
  --info:          #1667a8;
  --info-soft:     #e3f0fb;

  --u1:            #4c3fd6;
  --u2:            #0f7e8c;
  --u3:            #b4531f;
  --u4:            #7a3f9e;
  --u5:            #1f6b3a;
  --u6:            #a8203a;
  --u-soon:        #8b8fa6;

  --radius:        12px;
  --radius-sm:     8px;
  --radius-lg:     18px;

  --shadow-sm:     0 1px 2px rgba(20, 22, 45, .06), 0 1px 3px rgba(20, 22, 45, .04);
  --shadow-md:     0 4px 12px rgba(20, 22, 45, .08), 0 1px 3px rgba(20, 22, 45, .05);
  --shadow-lg:     0 12px 32px rgba(20, 22, 45, .14);

  --sidebar-w:     290px;
  --topbar-h:      60px;
  --content-max:   860px;

  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "Consolas", "SF Mono", Menlo, monospace;

  --ease: cubic-bezier(.4, 0, .2, 1);
}

:root[data-theme="dark"] {
  color-scheme: dark;

  --bg:            #10121c;
  --bg-elev:       #191c2a;
  --bg-sunken:     #0b0d15;
  --bg-hover:      #232739;

  --text:          #e9ebf5;
  --text-soft:     #b0b5cc;
  --text-faint:    #7f849e;

  --border:        #2b2f42;
  --border-strong: #3d4258;

  --accent:        #8b81ff;
  --accent-hover:  #a49cff;
  --accent-soft:   #232043;
  --accent-text:   #14162a;

  --ok:            #4fd3a5;
  --ok-soft:       #10291f;
  --warn:          #f0b95c;
  --warn-soft:     #2b220f;
  --bad:           #ff8b93;
  --bad-soft:      #2d151a;
  --info:          #6bb6f0;
  --info-soft:     #10222f;

  --u1:            #8b81ff;
  --u2:            #46c3ce;
  --u3:            #e08a4f;
  --u4:            #b98ae0;
  --u5:            #6cc48c;
  --u6:            #f08196;
  --u-soon:        #6a6f88;

  --shadow-sm:     0 1px 2px rgba(0, 0, 0, .4);
  --shadow-md:     0 4px 14px rgba(0, 0, 0, .45);
  --shadow-lg:     0 14px 36px rgba(0, 0, 0, .55);
}

/* ---------- 2. Reset y base --------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; font-weight: 650; letter-spacing: -.01em; }
h1 { font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.2rem); }
h2 { font-size: clamp(1.25rem, 1.05rem + .8vw, 1.5rem); margin-top: 2.2em; }
h3 { font-size: 1.08rem; margin-top: 1.8em; }
p  { margin: 0 0 1em; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent-hover); }

ul, ol { padding-left: 1.3em; margin: 0 0 1em; }
li { margin-bottom: .35em; }

code { font-family: var(--mono); font-size: .9em; background: var(--bg-sunken);
       padding: .12em .4em; border-radius: 5px; border: 1px solid var(--border); }

strong { font-weight: 650; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: -999px; top: 8px; z-index: 200;
  background: var(--accent); color: var(--accent-text);
  padding: .6em 1em; border-radius: var(--radius-sm); font-weight: 600;
}
.skip-link:focus { left: 8px; }

/* ---------- 3. Topbar ---------------------------------------------------- */

.topbar {
  position: sticky; top: 0; z-index: 60;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 12px;
  padding: 0 16px;
  background: var(--bg-elev);
  border-bottom: 1px solid var(--border);
}

.brand { display: flex; align-items: center; gap: 11px; text-decoration: none; color: inherit; min-width: 0; }
.brand-mark {
  flex: none;
  width: 34px; height: 34px; border-radius: 9px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--u2));
  color: #fff; font-weight: 800; font-size: .82rem; letter-spacing: .02em;
}
.brand-text { display: flex; flex-direction: column; min-width: 0; }
.brand-text strong { font-size: .93rem; line-height: 1.2; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.brand-text small  { font-size: .74rem; color: var(--text-faint); line-height: 1.3; }

.topbar-tools { margin-left: auto; display: flex; align-items: center; gap: 12px; }

.progress-wrap { display: flex; align-items: center; gap: 8px; }
.progress-bar {
  width: 110px; height: 7px; border-radius: 99px;
  background: var(--bg-sunken); border: 1px solid var(--border); overflow: hidden;
}
.progress-fill {
  display: block; height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--u2));
  transition: width .5s var(--ease);
}
.progress-label { font-size: .78rem; color: var(--text-faint); font-variant-numeric: tabular-nums; min-width: 2.4em; }

.icon-btn {
  flex: none;
  width: 36px; height: 36px; border-radius: 9px;
  border: 1px solid var(--border); background: var(--bg-elev); color: var(--text-soft);
  cursor: pointer; display: grid; place-items: center;
  transition: background .15s var(--ease), color .15s var(--ease);
}
.icon-btn:hover { background: var(--bg-hover); color: var(--text); }

/* En claro se muestra una luna (invita a pasar a oscuro); en oscuro, un sol. */
.theme-icon {
  width: 16px; height: 16px; border-radius: 50%;
  background: currentColor;
  box-shadow: inset 6px -5px 0 0 var(--bg-elev);
}
:root[data-theme="dark"] .theme-icon {
  width: 9px; height: 9px;
  box-shadow:
    0 -7px 0 -1.5px currentColor,  0 7px 0 -1.5px currentColor,
    -7px 0 0 -1.5px currentColor,  7px 0 0 -1.5px currentColor,
    -5px -5px 0 -2px currentColor, 5px 5px 0 -2px currentColor,
    -5px 5px 0 -2px currentColor,  5px -5px 0 -2px currentColor;
}

.menu-toggle { display: none; }
.burger, .burger::before, .burger::after {
  display: block; width: 17px; height: 2px; border-radius: 2px; background: currentColor;
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}
.burger { position: relative; }
.burger::before, .burger::after { content: ""; position: absolute; left: 0; }
.burger::before { top: -5px; }
.burger::after  { top: 5px; }
.menu-toggle[aria-expanded="true"] .burger { background: transparent; }
.menu-toggle[aria-expanded="true"] .burger::before { transform: translateY(5px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] .burger::after  { transform: translateY(-5px) rotate(-45deg); }

/* ---------- 4. Layout ---------------------------------------------------- */

.layout { display: flex; align-items: flex-start; }

.sidebar {
  position: sticky; top: var(--topbar-h);
  flex: none;
  width: var(--sidebar-w);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto; overscroll-behavior: contain;
  padding: 16px 12px 24px;
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column; gap: 14px;
}

.content {
  flex: 1 1 auto; min-width: 0;
  padding: 34px clamp(18px, 4vw, 48px) 96px;
}
.content:focus { outline: none; }
.view { max-width: var(--content-max); margin: 0 auto; }

.scrim {
  position: fixed; inset: var(--topbar-h) 0 0 0; z-index: 45;
  background: rgba(10, 12, 22, .5);
  backdrop-filter: blur(2px);
  animation: fade-in .2s var(--ease);
}

/* ---------- 5. Sidebar: buscador, navegación ---------------------------- */

.search-box input {
  width: 100%;
  padding: .55em .8em;
  font: inherit; font-size: .88rem;
  color: var(--text);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}
.search-box input::placeholder { color: var(--text-faint); }
.search-box input:focus { border-color: var(--accent); background: var(--bg-elev); }

/* Índice lateral: Inicio suelto arriba, y después grupos con encabezado.
   Ocho enlaces planos se leen como una lista de compras; agrupados por para
   qué sirven, se encuentran. */
.nav-quick { display: flex; flex-direction: column; gap: 1px; }
.nav-quick ul { list-style: none; padding: 0; margin: 0 0 2px; display: flex; flex-direction: column; gap: 1px; }
.nav-quick li { margin: 0; }
.nav-quick a {
  display: block; padding: .42em .7em; border-radius: var(--radius-sm);
  font-size: .87rem; font-weight: 550; color: var(--text-soft); text-decoration: none;
  transition: background .12s var(--ease), color .12s var(--ease);
}
.nav-quick a:hover { background: var(--bg-hover); color: var(--text); }
.nav-quick a.active { background: var(--accent-soft); color: var(--accent); }
.nav-quick .nav-inicio { font-weight: 640; margin-bottom: 6px; }
.nav-group {
  margin: 12px 0 3px; padding: 0 .7em;
  font-size: .68rem; font-weight: 800; letter-spacing: .09em;
  text-transform: uppercase; color: var(--text-faint);
}

.nav-tree { flex: 1 1 auto; }

.nav-unit { margin-bottom: 6px; }

.nav-unit-btn {
  width: 100%; display: flex; align-items: flex-start; gap: 8px;
  padding: .5em .6em; border: 0; border-radius: var(--radius-sm);
  background: transparent; color: var(--text); font: inherit; font-size: .87rem;
  font-weight: 620; text-align: left; cursor: pointer;
  transition: background .12s var(--ease);
}
.nav-unit-btn:hover { background: var(--bg-hover); }
.nav-unit-btn .chev {
  flex: none; margin-top: .42em; width: 6px; height: 6px;
  border-right: 1.8px solid var(--text-faint); border-bottom: 1.8px solid var(--text-faint);
  transform: rotate(-45deg); transition: transform .2s var(--ease);
}
.nav-unit-btn[aria-expanded="true"] .chev { transform: rotate(45deg); }
.nav-unit-btn .unit-num {
  flex: none; width: 20px; height: 20px; margin-top: .12em; border-radius: 6px;
  display: grid; place-items: center; font-size: .7rem; font-weight: 700;
  background: var(--accent-soft); color: var(--accent);
}
.nav-unit[data-unit="u2"] .unit-num { background: color-mix(in srgb, var(--u2) 16%, transparent); color: var(--u2); }
.nav-unit[data-unit="u3"] .unit-num { background: color-mix(in srgb, var(--u3) 16%, transparent); color: var(--u3); }
.nav-unit[data-unit="u4"] .unit-num { background: color-mix(in srgb, var(--u4) 16%, transparent); color: var(--u4); }
.nav-unit[data-unit="u5"] .unit-num { background: color-mix(in srgb, var(--u5) 16%, transparent); color: var(--u5); }
.nav-unit[data-unit="u6"] .unit-num { background: color-mix(in srgb, var(--u6) 16%, transparent); color: var(--u6); }
.nav-unit[data-estado="proximamente"] .unit-num { background: var(--bg-sunken); color: var(--u-soon); }
.nav-unit[data-estado="proximamente"] .nav-unit-btn { color: var(--text-faint); cursor: default; }
.nav-unit[data-estado="proximamente"] .nav-unit-btn:hover { background: transparent; }

.nav-topics { list-style: none; padding: 0 0 4px 30px; margin: 2px 0 0; }
.nav-topics[hidden] { display: none; }
.nav-topics a {
  display: flex; align-items: center; gap: 7px;
  padding: .34em .6em; border-radius: var(--radius-sm);
  font-size: .82rem; line-height: 1.35; color: var(--text-soft); text-decoration: none;
  transition: background .12s var(--ease), color .12s var(--ease);
}
.nav-topics a:hover { background: var(--bg-hover); color: var(--text); }
.nav-topics a.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-topics li { margin: 0; }

.dot {
  flex: none; width: 7px; height: 7px; border-radius: 50%;
  border: 1.5px solid var(--border-strong); background: transparent;
}
.dot.leido    { background: var(--info); border-color: var(--info); }
.dot.aprobado { background: var(--ok);   border-color: var(--ok); }
/* Dominado = quiz aprobado + todos los ejercicios resueltos sin errores. */
.dot.dominado { background: var(--warn); border-color: var(--warn);
                box-shadow: 0 0 0 2px color-mix(in srgb, var(--warn) 28%, transparent); }

.soon-badge {
  display: inline-block; margin-left: auto;
  font-size: .64rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase;
  padding: .15em .5em; border-radius: 99px;
  background: var(--bg-sunken); color: var(--u-soon); border: 1px solid var(--border);
}

.sidebar-footer { border-top: 1px solid var(--border); padding-top: 12px; }

.nav-empty { padding: 1em .7em; font-size: .83rem; color: var(--text-faint); }

/* ---------- 6. Botones y controles -------------------------------------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5em;
  padding: .6em 1.1em; border-radius: var(--radius-sm);
  border: 1px solid transparent; background: var(--accent); color: var(--accent-text);
  font: inherit; font-size: .9rem; font-weight: 600; cursor: pointer;
  transition: background .15s var(--ease), transform .1s var(--ease), border-color .15s var(--ease);
}
.btn:hover  { background: var(--accent-hover); }
.btn:active { transform: translateY(1px); }
.btn[disabled] { opacity: .45; cursor: not-allowed; }
.btn[disabled]:active { transform: none; }

.btn-ghost { background: transparent; color: var(--text-soft); border-color: var(--border-strong); }
.btn-ghost:hover { background: var(--bg-hover); color: var(--text); border-color: var(--border-strong); }

.btn-sm { padding: .38em .8em; font-size: .82rem; }

.btn-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 1.2em 0; }

/* ---------- 7. Componentes de contenido --------------------------------- */

.eyebrow {
  display: inline-block;
  font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent); margin-bottom: .5em;
}

.lead { font-size: 1.08rem; color: var(--text-soft); margin-bottom: 1.6em; }

.topic-head { border-bottom: 1px solid var(--border); padding-bottom: 1.2em; margin-bottom: 1.8em; }
.topic-meta { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; font-size: .78rem; color: var(--text-faint); }
.chip {
  display: inline-flex; align-items: center; gap: .35em;
  padding: .2em .65em; border-radius: 99px;
  background: var(--bg-sunken); border: 1px solid var(--border);
  font-size: .76rem; font-weight: 550; color: var(--text-soft);
}
.chip.u1 { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.chip.u2 { background: color-mix(in srgb, var(--u2) 14%, transparent); color: var(--u2); border-color: transparent; }
.chip.u3 { background: color-mix(in srgb, var(--u3) 14%, transparent); color: var(--u3); border-color: transparent; }
.chip.u4 { background: color-mix(in srgb, var(--u4) 14%, transparent); color: var(--u4); border-color: transparent; }
.chip.u5 { background: color-mix(in srgb, var(--u5) 14%, transparent); color: var(--u5); border-color: transparent; }
.chip.u6 { background: color-mix(in srgb, var(--u6) 14%, transparent); color: var(--u6); border-color: transparent; }

.card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  box-shadow: var(--shadow-sm);
}

.grid { display: grid; gap: 14px; margin: 1.4em 0; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }

.concept {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 15px 17px;
  transition: border-color .15s var(--ease), transform .15s var(--ease), box-shadow .15s var(--ease);
}
.concept:hover { border-color: var(--border-strong); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.concept h4 { margin: 0 0 .3em; font-size: .95rem; }
.concept p  { margin: 0; font-size: .88rem; color: var(--text-soft); }
.concept .concept-icon { font-size: 1.2rem; display: block; margin-bottom: .3em; line-height: 1; }
/* Tarjeta que además es enlace: mismo aspecto, comportamiento de link. */
.concept-link { display: block; text-decoration: none; color: inherit; }
.concept-link:hover { border-color: var(--accent); color: inherit; }
.concept-link h4 { color: var(--accent); }

.callout {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 14px 18px; margin: 1.5em 0;
}
.callout p:last-child { margin-bottom: 0; }
.callout .callout-label {
  display: block; font-size: .7rem; font-weight: 700; letter-spacing: .07em;
  text-transform: uppercase; color: var(--accent); margin-bottom: .35em;
}
.callout.warn { border-left-color: var(--warn); background: var(--warn-soft); }
.callout.warn .callout-label { color: var(--warn); }
.callout.info { border-left-color: var(--info); background: var(--info-soft); }
.callout.info .callout-label { color: var(--info); }

.source-note {
  font-size: .78rem; color: var(--text-faint);
  border-top: 1px dashed var(--border); padding-top: .8em; margin-top: 2.2em;
}

/* Tablas */
.table-wrap { overflow-x: auto; margin: 1.4em 0; border: 1px solid var(--border); border-radius: var(--radius); }
table { border-collapse: collapse; width: 100%; font-size: .88rem; }
th, td { padding: .65em .9em; text-align: left; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--bg-sunken); font-weight: 640; font-size: .82rem; white-space: nowrap; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: var(--bg-hover); }

/* Dependencias del tema */
.deps { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); margin: 1.6em 0; }
.deps-box { background: var(--bg-sunken); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 14px; }
.deps-box h4 { margin: 0 0 .5em; font-size: .74rem; letter-spacing: .06em; text-transform: uppercase; color: var(--text-faint); }
.deps-box ul { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.deps-box li { margin: 0; }
.deps-box a {
  display: inline-block; padding: .25em .7em; border-radius: 99px;
  background: var(--bg-elev); border: 1px solid var(--border);
  font-size: .8rem; text-decoration: none; color: var(--text-soft);
}
.deps-box a:hover { border-color: var(--accent); color: var(--accent); }

/* Paginación entre temas */
.topic-nav { display: flex; gap: 12px; margin-top: 3em; padding-top: 1.5em; border-top: 1px solid var(--border); }
.topic-nav a {
  flex: 1 1 0; min-width: 0;
  padding: 12px 16px; border-radius: var(--radius);
  border: 1px solid var(--border); background: var(--bg-elev);
  text-decoration: none; color: inherit;
  transition: border-color .15s var(--ease), background .15s var(--ease);
}
.topic-nav a:hover { border-color: var(--accent); background: var(--accent-soft); }
.topic-nav .dir { display: block; font-size: .72rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: .06em; }
.topic-nav .ttl { display: block; font-size: .88rem; font-weight: 600; }
.topic-nav .next { text-align: right; }

/* ---------- 8. Piezas interactivas -------------------------------------- */

.interactive {
  margin: 1.8em 0;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.interactive-head {
  display: flex; align-items: center; gap: 9px;
  padding: 12px 18px;
  background: var(--bg-sunken);
  border-bottom: 1px solid var(--border);
}
.interactive-head h3 { margin: 0; font-size: .9rem; font-weight: 640; }
.interactive-head .tag {
  margin-left: auto; font-size: .68rem; font-weight: 700; letter-spacing: .05em;
  text-transform: uppercase; color: var(--accent);
  background: var(--accent-soft); padding: .18em .6em; border-radius: 99px;
}
.interactive-body { padding: 18px; }

.hint { font-size: .82rem; color: var(--text-faint); margin: 0 0 1em; }

.ia-svg { display: block; width: 100%; height: auto; max-width: 100%; }
.ia-svg text { font-family: var(--font); }

.opt-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 1em; }

.toggle-btn {
  padding: .4em .85em; border-radius: 99px;
  border: 1px solid var(--border-strong); background: var(--bg-elev);
  color: var(--text-soft); font: inherit; font-size: .82rem; cursor: pointer;
  transition: all .15s var(--ease);
}
.toggle-btn:hover { border-color: var(--accent); color: var(--accent); }
.toggle-btn[aria-pressed="true"], .toggle-btn.on {
  background: var(--accent); border-color: var(--accent); color: var(--accent-text);
}

.switch-grid { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); margin-bottom: 1.2em; }
.switch {
  display: flex; align-items: center; gap: 10px;
  background: var(--bg-sunken); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 10px 12px;
}
.switch-track {
  flex: none; width: 42px; height: 23px; border-radius: 99px; border: 0;
  background: var(--border-strong); cursor: pointer; position: relative; padding: 0;
  transition: background .2s var(--ease);
}
.switch-track::after {
  content: ""; position: absolute; top: 3px; left: 3px;
  width: 17px; height: 17px; border-radius: 50%; background: #fff;
  transition: transform .2s var(--ease);
}
.switch-track[aria-checked="true"] { background: var(--accent); }
.switch-track[aria-checked="true"]::after { transform: translateX(19px); }
.switch-labels { font-size: .82rem; line-height: 1.3; }
.switch-labels .on-label  { font-weight: 620; }
.switch-labels .off-label { color: var(--text-faint); }

.result-panel {
  background: var(--bg-sunken); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 14px 16px; font-size: .88rem;
  animation: fade-in .25s var(--ease);
}
.result-panel h4 { margin: 0 0 .4em; font-size: .9rem; }
.result-panel p:last-child { margin-bottom: 0; }

/* Chat del simulador de Turing */
.chat { display: flex; flex-direction: column; gap: 10px; margin-bottom: 1.2em; }
.chat-line { display: flex; gap: 10px; align-items: flex-start; animation: slide-up .3s var(--ease); }
.chat-who {
  flex: none; width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center;
  font-size: .72rem; font-weight: 700; background: var(--bg-sunken); color: var(--text-soft);
  border: 1px solid var(--border);
}
.chat-line.judge .chat-who { background: var(--accent-soft); color: var(--accent); border-color: transparent; }
.chat-bubble {
  background: var(--bg-sunken); border: 1px solid var(--border);
  border-radius: 4px 12px 12px 12px; padding: 9px 13px; font-size: .88rem; max-width: 100%;
}
.chat-line.judge .chat-bubble { background: var(--accent-soft); border-color: transparent; }

/* Cuarto chino */
.room-stage { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); margin-bottom: 1.2em; }
.room-panel {
  border: 1px solid var(--border); border-radius: var(--radius); padding: 14px;
  background: var(--bg-sunken); text-align: center;
  transition: border-color .25s var(--ease), background .25s var(--ease), transform .25s var(--ease);
}
.room-panel.active { border-color: var(--accent); background: var(--accent-soft); transform: translateY(-2px); }
.room-panel .glyph { font-size: 1.7rem; line-height: 1.2; display: block; margin-bottom: .3em; }
.room-panel .label { font-size: .74rem; text-transform: uppercase; letter-spacing: .05em; color: var(--text-faint); }
.room-panel .body  { font-size: .84rem; margin-top: .4em; }

/* Motor de inferencia */
.rule {
  display: flex; gap: 10px; align-items: baseline;
  padding: 8px 12px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-sunken);
  font-size: .85rem; margin-bottom: 7px;
  transition: all .25s var(--ease);
}
.rule.fired { border-color: var(--ok); background: var(--ok-soft); }
.rule .rid { font-family: var(--mono); font-size: .76rem; color: var(--text-faint); flex: none; }
.fact-chip {
  display: inline-block; padding: .2em .7em; border-radius: 99px; margin: 0 5px 5px 0;
  font-size: .8rem; background: var(--info-soft); color: var(--info); border: 1px solid transparent;
}
.fact-chip.derived { background: var(--ok-soft); color: var(--ok); }

/* Slider de umbral */
.slider-row { display: flex; align-items: center; gap: 12px; margin: 1em 0; flex-wrap: wrap; }
.slider-row input[type="range"] { flex: 1 1 180px; accent-color: var(--accent); }
.slider-row output { font-variant-numeric: tabular-nums; font-weight: 650; min-width: 3.2em; }

.meter-pair { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); }
.meter { background: var(--bg-sunken); border: 1px solid var(--border); border-radius: var(--radius); padding: 11px 13px; }
.meter .meter-label { display: flex; justify-content: space-between; font-size: .8rem; margin-bottom: .4em; }
.meter .meter-track { height: 8px; border-radius: 99px; background: var(--border); overflow: hidden; }
.meter .meter-fill { display: block; height: 100%; width: 0%; transition: width .25s var(--ease); }
.meter.fp .meter-fill { background: var(--warn); }
.meter.fn .meter-fill { background: var(--bad); }

/* Línea de tiempo */
.timeline { position: relative; padding-left: 26px; }
.timeline::before {
  content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px;
  background: linear-gradient(180deg, var(--accent), var(--u2));
  border-radius: 2px;
}
.tl-item { position: relative; margin-bottom: 8px; }
.tl-item::before {
  content: ""; position: absolute; left: -23px; top: 13px;
  width: 11px; height: 11px; border-radius: 50%;
  background: var(--bg-elev); border: 2.5px solid var(--accent);
  transition: transform .2s var(--ease), background .2s var(--ease);
}
.tl-item.open::before { background: var(--accent); transform: scale(1.25); }
.tl-btn {
  width: 100%; text-align: left; display: flex; gap: 12px; align-items: baseline;
  padding: 9px 13px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-elev);
  font: inherit; cursor: pointer; color: inherit;
  transition: border-color .15s var(--ease), background .15s var(--ease);
}
.tl-btn:hover { border-color: var(--accent); background: var(--accent-soft); }
.tl-year { flex: none; font-family: var(--mono); font-size: .78rem; font-weight: 700; color: var(--accent); min-width: 5.4em; }
.tl-title { font-size: .89rem; font-weight: 600; }
.tl-detail {
  padding: 10px 13px 4px 13px; font-size: .86rem; color: var(--text-soft);
  animation: slide-up .25s var(--ease);
}
.tl-detail[hidden] { display: none; }

/* Comparador de dos/tres columnas */
.compare { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.compare-col {
  border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
  background: var(--bg-elev);
  animation: slide-up .3s var(--ease);
}
.compare-col header { padding: 10px 14px; font-weight: 640; font-size: .9rem; border-bottom: 1px solid var(--border); }
.compare-col.a header { background: var(--accent-soft); color: var(--accent); }
.compare-col.b header { background: color-mix(in srgb, var(--u2) 14%, transparent); color: var(--u2); }
.compare-col.c header { background: var(--ok-soft); color: var(--ok); }
.compare-col ul { margin: 0; padding: 12px 14px 12px 30px; font-size: .86rem; }

/* Tabla revelada por filas */
.reveal-row td, .reveal-row th { transition: opacity .3s var(--ease); }
.reveal-row.hidden-row td, .reveal-row.hidden-row th { opacity: .12; }

/* Cadena de valor / pipeline */
.chain { display: flex; flex-wrap: wrap; gap: 8px; align-items: stretch; margin-bottom: 1.2em; }
.chain-step {
  flex: 1 1 120px; text-align: center; cursor: pointer;
  border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 10px;
  background: var(--bg-sunken); font: inherit; color: inherit;
  transition: all .2s var(--ease);
}
.chain-step:hover { border-color: var(--accent); }
.chain-step.on { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }
.chain-step .step-n { display: block; font-size: .68rem; letter-spacing: .06em; color: var(--text-faint); }
.chain-step .step-t { display: block; font-size: .84rem; font-weight: 650; margin-top: .15em; }

/* Tarjetas expandibles (hitos) */
.flip-grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); }
.expand-card {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--bg-elev); overflow: hidden; text-align: left;
  font: inherit; color: inherit; cursor: pointer; padding: 0;
  transition: border-color .18s var(--ease), transform .18s var(--ease), box-shadow .18s var(--ease);
}
.expand-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.expand-card .ec-head { padding: 14px 15px 12px; }
.expand-card .ec-icon { font-size: 1.5rem; display: block; line-height: 1; margin-bottom: .3em; }
.expand-card .ec-title { font-size: .93rem; font-weight: 650; }
.expand-card .ec-sub { font-size: .78rem; color: var(--text-faint); }
.expand-card .ec-body {
  padding: 0 15px 14px; font-size: .85rem; color: var(--text-soft);
  animation: slide-up .25s var(--ease);
}
.expand-card .ec-body[hidden] { display: none; }
.expand-card.on { border-color: var(--accent); }

/* ---------- 9. Flashcards ------------------------------------------------ */

.fc-stage { display: grid; place-items: center; margin: 1.5em 0; }
.fc-card {
  width: 100%; max-width: 460px; min-height: 210px;
  perspective: 1100px; background: none; border: 0; padding: 0; cursor: pointer;
  font: inherit; color: inherit;
}
.fc-inner {
  position: relative; width: 100%; min-height: 210px;
  transform-style: preserve-3d;
  transition: transform .5s var(--ease);
}
.fc-card.flipped .fc-inner { transform: rotateY(180deg); }
.fc-face {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: .5em;
  padding: 24px; text-align: center;
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  background: var(--bg-elev); box-shadow: var(--shadow-md);
  backface-visibility: hidden; -webkit-backface-visibility: hidden;
}
.fc-face.back { transform: rotateY(180deg); background: var(--accent-soft); border-color: transparent; }
.fc-term { font-size: 1.22rem; font-weight: 650; }
.fc-def  { font-size: .95rem; color: var(--text-soft); line-height: 1.55; }
.fc-face.back .fc-def { color: var(--text); }
.fc-flip-hint { font-size: .74rem; color: var(--text-faint); }
.fc-controls { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; align-items: center; margin-top: 1.2em; }
.fc-counter { font-size: .85rem; color: var(--text-faint); font-variant-numeric: tabular-nums; }
.fc-deck-pick { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 1.2em; }

/* ---------- 10. Quiz ----------------------------------------------------- */

.quiz { margin: 2em 0; }
.quiz-q {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px 20px; margin-bottom: 14px;
}
.quiz-q > .q-num {
  font-size: .72rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase;
  color: var(--text-faint);
}
.quiz-q > .q-text { font-size: 1rem; font-weight: 600; margin: .3em 0 1em; }

.q-options { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 8px; }
.q-options li { margin: 0; }
.q-opt {
  width: 100%; display: flex; gap: 11px; align-items: flex-start; text-align: left;
  padding: 11px 14px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-sunken);
  font: inherit; font-size: .9rem; color: inherit; cursor: pointer;
  transition: border-color .15s var(--ease), background .15s var(--ease);
}
.q-opt:hover:not([disabled]) { border-color: var(--accent); background: var(--accent-soft); }
.q-opt[disabled] { cursor: default; }
.q-letter {
  flex: none; width: 22px; height: 22px; border-radius: 6px;
  display: grid; place-items: center; font-size: .74rem; font-weight: 700;
  background: var(--bg-elev); border: 1px solid var(--border-strong); color: var(--text-soft);
}
.q-opt.chosen  { border-color: var(--accent); background: var(--accent-soft); }
.q-opt.chosen .q-letter { background: var(--accent); border-color: var(--accent); color: var(--accent-text); }
.q-opt.correct   { border-color: var(--ok);  background: var(--ok-soft); }
.q-opt.correct .q-letter { background: var(--ok); border-color: var(--ok); color: #fff; }
.q-opt.incorrect { border-color: var(--bad); background: var(--bad-soft); }
.q-opt.incorrect .q-letter { background: var(--bad); border-color: var(--bad); color: #fff; }

.q-feedback {
  margin-top: 12px; padding: 12px 15px; border-radius: var(--radius-sm);
  font-size: .87rem; animation: slide-up .25s var(--ease);
  border-left: 3px solid var(--info); background: var(--info-soft);
}
.q-feedback.ok  { border-left-color: var(--ok);  background: var(--ok-soft); }
.q-feedback.bad { border-left-color: var(--bad); background: var(--bad-soft); }
.q-feedback .fb-title { font-weight: 650; display: block; margin-bottom: .2em; }
.q-feedback p:last-child { margin-bottom: 0; }
.q-feedback .fb-source { display: block; margin-top: .5em; font-size: .76rem; color: var(--text-faint); }

.quiz-summary {
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 22px; text-align: center; background: var(--bg-elev);
  animation: slide-up .3s var(--ease);
}
.score-big { font-size: 2.6rem; font-weight: 750; line-height: 1; font-variant-numeric: tabular-nums; }
.score-big.pass { color: var(--ok); }
.score-big.fail { color: var(--bad); }
.score-sub { color: var(--text-soft); font-size: .92rem; }

.exam-bar {
  position: sticky; top: var(--topbar-h); z-index: 30;
  display: flex; flex-wrap: wrap; align-items: center; gap: 14px;
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 10px 16px; margin-bottom: 18px;
  box-shadow: var(--shadow-sm);
}
.exam-timer { font-family: var(--mono); font-size: 1rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.exam-timer.low { color: var(--bad); }
.exam-count { font-size: .85rem; color: var(--text-soft); }
.exam-bar .btn { margin-left: auto; }

.review-item { border-left: 3px solid var(--border); padding-left: 14px; margin-bottom: 1.6em; }
.review-item.ok  { border-left-color: var(--ok); }
.review-item.bad { border-left-color: var(--bad); }

/* ---------- 11. Mapa de dependencias ------------------------------------ */

.map-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius-lg);
            background: var(--bg-elev); padding: 10px; }
.map-node rect { transition: fill .18s var(--ease), stroke .18s var(--ease); cursor: pointer; }
.map-node text { pointer-events: none; }
.map-node:hover rect { stroke-width: 2.2; }
.map-legend { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 1em; font-size: .82rem; color: var(--text-soft); }
.map-legend span { display: inline-flex; align-items: center; gap: 6px; }
.map-swatch { width: 12px; height: 12px; border-radius: 3px; display: inline-block; }

/* ---------- 12. Inicio y cronograma ------------------------------------- */

.hero {
  border-radius: var(--radius-lg); padding: 34px clamp(20px, 4vw, 40px);
  background: linear-gradient(135deg, var(--accent-soft), color-mix(in srgb, var(--u2) 12%, transparent));
  border: 1px solid var(--border); margin-bottom: 2em;
}
.hero h1 { margin-bottom: .3em; }
.hero p  { color: var(--text-soft); max-width: 60ch; }

.unit-cards { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.unit-card {
  display: block; text-decoration: none; color: inherit;
  border: 1px solid var(--border); border-left: 4px solid var(--accent);
  border-radius: var(--radius); background: var(--bg-elev); padding: 18px 20px;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), border-color .18s var(--ease);
}
.unit-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.unit-card[data-unit="u2"] { border-left-color: var(--u2); }
.unit-card[data-unit="u3"] { border-left-color: var(--u3); }
.unit-card[data-unit="u4"] { border-left-color: var(--u4); }
.unit-card[data-unit="u5"] { border-left-color: var(--u5); }
.unit-card[data-unit="u6"] { border-left-color: var(--u6); }
.unit-card.soon { border-left-color: var(--u-soon); opacity: .72; cursor: default; }
.unit-card.soon:hover { transform: none; box-shadow: none; }
.unit-card h3 { margin: .2em 0 .35em; font-size: 1.05rem; }
.unit-card p  { font-size: .87rem; color: var(--text-soft); margin-bottom: .8em; }
.unit-card .uc-meta { display: flex; align-items: center; gap: 8px; font-size: .76rem; color: var(--text-faint); }
.unit-card .uc-bar { height: 5px; border-radius: 99px; background: var(--bg-sunken); overflow: hidden; margin-top: .7em; }
.unit-card .uc-bar span { display: block; height: 100%; background: var(--accent); width: 0; transition: width .5s var(--ease); }
.unit-card[data-unit="u2"] .uc-bar span { background: var(--u2); }
.unit-card[data-unit="u3"] .uc-bar span { background: var(--u3); }
.unit-card[data-unit="u4"] .uc-bar span { background: var(--u4); }
.unit-card[data-unit="u5"] .uc-bar span { background: var(--u5); }
.unit-card[data-unit="u6"] .uc-bar span { background: var(--u6); }

.crono-row.simulacro td { background: var(--warn-soft); }
.crono-row.parcial td   { background: var(--bad-soft); font-weight: 550; }
.crono-row.repaso td    { background: var(--info-soft); }
.crono-row.simulacro:hover td, .crono-row.parcial:hover td, .crono-row.repaso:hover td { filter: brightness(.97); }

/* ---------- 12b. Señal de "esto se toca" -------------------------------- */
/*
   Todo control interactuable late suavemente hasta que el usuario interactúa
   con él. Tres reglas de diseño:

   1. El latido se APAGA en cuanto se toca la pieza (`.tocado` en el ancestro):
      una vez que entendiste que es interactivo, seguir parpadeando molesta.
   2. Va escalonado con `--attn-i`, para que no latan todos al unísono,
      un tablero entero pulsando en sincronía parece un error, no una invitación.
   3. Con `prefers-reduced-motion` no late: queda un anillo estático que cumple
      la misma función de señalar sin movimiento.
*/

@keyframes attn-pulse {
  0%, 55%, 100% { box-shadow: 0 0 0 0   var(--attn-a); }
  25%           { box-shadow: 0 0 0 5px var(--attn-b); }
}

@keyframes attn-stroke {
  0%, 55%, 100% { stroke-width: 1.6; }
  25%           { stroke-width: 3.2; }
}

:root {
  /* Primero un valor plano de reserva: si el navegador no soporta color-mix,
     la declaración siguiente es inválida y prevalece esta. */
  --attn-a: rgba(76, 63, 214, .34);
  --attn-b: rgba(76, 63, 214, 0);
  --attn-a: color-mix(in srgb, var(--accent) 34%, transparent);
  --attn-b: color-mix(in srgb, var(--accent) 0%,  transparent);
}
:root[data-theme="dark"] {
  --attn-a: rgba(139, 129, 255, .42);
  --attn-b: rgba(139, 129, 255, 0);
  --attn-a: color-mix(in srgb, var(--accent) 42%, transparent);
  --attn-b: color-mix(in srgb, var(--accent) 0%,  transparent);
}

.attn {
  --attn-i: 0;
  animation: attn-pulse 2.6s var(--ease) infinite;
  animation-delay: calc(var(--attn-i) * .16s);
}

/* Se apaga al primer contacto con la pieza, o si el control ya cumplió su rol. */
.tocado .attn,
.attn[disabled],
.attn.attn-off {
  animation: none;
}

.attn-svg {
  --attn-i: 0;
  animation: attn-stroke 2.6s var(--ease) infinite;
  animation-delay: calc(var(--attn-i) * .16s);
}
.tocado .attn-svg { animation: none; }

/* La tarjeta de flashcard es grande: un anillo de 5px se ve desproporcionado. */
.fc-card.attn { animation-name: attn-pulse; animation-duration: 3s; }
.fc-card.flipped { animation: none; }

@media (prefers-reduced-motion: reduce) {
  .attn { box-shadow: 0 0 0 2px var(--attn-a); }
  .tocado .attn, .attn[disabled], .attn.attn-off { box-shadow: none; }
  .attn-svg { stroke-width: 2.6; }
}

/* ---------- 12c. ELI5: la versión fácil, a un clic --------------------- */
/*
   Progressive disclosure: la explicación alternativa está siempre disponible
   al pie de cada sección, pero no ocupa lugar hasta que alguien la pide.
   El panel se despliega con una transición de altura para que se entienda
   de dónde salió, que es el mismo criterio que usan los "explainers"
   interactivos para moverse entre niveles de abstracción sin desorientar.
*/

.eli5-badge {
  display: inline-block;
  font-size: .62rem; font-weight: 800; letter-spacing: .07em;
  padding: .22em .5em; border-radius: 5px;
  background: var(--u2); color: #fff;
  line-height: 1.15;
}
:root[data-theme="dark"] .eli5-badge { color: #08222a; }

/* Botón de la barra superior: abre o cierra todos de una */
.eli5-toggle {
  display: inline-flex; align-items: center; gap: 7px;
  padding: .3em .7em .3em .45em; border-radius: 99px;
  border: 1px solid var(--border-strong); background: var(--bg-sunken);
  font: inherit; font-size: .78rem; font-weight: 600; color: var(--text-soft);
  cursor: pointer; white-space: nowrap;
  transition: border-color .18s var(--ease), color .18s var(--ease),
              background .18s var(--ease);
}
.eli5-toggle:hover { border-color: var(--u2); color: var(--text); }
.eli5-toggle[aria-pressed="true"] {
  border-color: var(--u2);
  background: color-mix(in srgb, var(--u2) 14%, transparent);
  color: var(--u2);
}
.eli5-toggle[aria-pressed="true"] .eli5-toggle-txt::before { content: "✓ "; }

/* El desplegable dentro del tema */
.eli5 { margin: 1.1em 0 1.8em; }

.eli5-btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: .5em .95em .5em .6em; border-radius: 99px;
  border: 1px dashed var(--u2); background: transparent;
  font: inherit; font-size: .84rem; font-weight: 600; color: var(--u2);
  cursor: pointer; text-align: left;
  transition: background .18s var(--ease), transform .12s var(--ease);
}
.eli5-btn:hover { background: color-mix(in srgb, var(--u2) 10%, transparent); }
.eli5-btn:active { transform: translateY(1px); }

.eli5-chev {
  width: 6px; height: 6px; margin-left: 1px;
  border-right: 1.9px solid currentColor; border-bottom: 1.9px solid currentColor;
  transform: rotate(45deg) translate(-1px, -1px);
  transition: transform .25s var(--ease);
}
.eli5.abierto .eli5-chev { transform: rotate(-135deg) translate(-2px, -2px); }
.eli5.abierto .eli5-btn {
  border-style: solid;
  background: color-mix(in srgb, var(--u2) 12%, transparent);
}

.eli5-panel {
  margin-top: 10px;
  border-left: 3px solid var(--u2);
  background: color-mix(in srgb, var(--u2) 8%, transparent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 15px 19px;
  animation: eli5-abrir .32s var(--ease);
}
.eli5-panel[hidden] { display: none; }
.eli5-panel h4 {
  margin: 0 0 .5em; font-size: .95rem; color: var(--u2);
}
.eli5-panel p:last-child, .eli5-panel ul:last-child, .eli5-panel ol:last-child { margin-bottom: 0; }
.eli5-panel ul, .eli5-panel ol { margin-bottom: .8em; }
.eli5-panel li { margin-bottom: .5em; }

/* El texto fácil respira más: frases cortas necesitan más aire, no menos. */
.eli5-panel p { line-height: 1.75; font-size: .93rem; }

@keyframes eli5-abrir {
  from { opacity: 0; transform: translateY(-6px); clip-path: inset(0 0 100% 0); }
  to   { opacity: 1; transform: none;            clip-path: inset(0 0 0 0); }
}

.analogia {
  border-left: 3px solid var(--u2);
  background: color-mix(in srgb, var(--u2) 9%, transparent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 13px 17px; margin: 1.4em 0;
}
.analogia .callout-label { color: var(--u2); }

@media (max-width: 720px) {
  .eli5-toggle .eli5-toggle-txt { display: none; }
  .eli5-toggle { padding: .3em .45em; }
}

/* ---------- 12d. Ejercicios de práctica --------------------------------- */

.ej {
  margin: 1.8em 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-elev);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.ej-head {
  display: flex; align-items: center; gap: 9px;
  padding: 12px 18px;
  background: var(--bg-sunken);
  border-bottom: 1px solid var(--border);
}
.ej-head h3 { margin: 0; font-size: .9rem; font-weight: 640; }
.ej-head .tag {
  margin-left: auto; font-size: .68rem; font-weight: 700; letter-spacing: .05em;
  text-transform: uppercase; color: var(--u2);
  background: color-mix(in srgb, var(--u2) 15%, transparent);
  padding: .18em .6em; border-radius: 99px;
}
.ej-body { padding: 18px; }
.ej-consigna { font-size: .9rem; color: var(--text-soft); margin: 0 0 1.1em; }

/* Barra de avance del ejercicio */
.ej-bar {
  height: 5px; border-radius: 99px; background: var(--bg-sunken);
  overflow: hidden; margin-bottom: 1.1em; border: 1px solid var(--border);
}
.ej-bar span {
  display: block; height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--u2), var(--accent));
  transition: width .35s var(--ease);
}

/* Fichas arrastrables / seleccionables */
.ej-pool {
  display: flex; flex-wrap: wrap; gap: 8px;
  min-height: 46px; padding: 10px;
  border: 1.5px dashed var(--border-strong); border-radius: var(--radius);
  background: var(--bg-sunken); margin-bottom: 1.1em;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.ej-pool.vacia::after {
  content: "Todas las fichas están colocadas";
  font-size: .82rem; color: var(--text-faint); margin: auto;
}
.ej-pool.drop-activo, .ej-bucket.drop-activo {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.ej-ficha {
  display: inline-flex; align-items: center; gap: .45em;
  padding: .42em .85em; border-radius: 99px;
  border: 1px solid var(--border-strong); background: var(--bg-elev);
  font: inherit; font-size: .85rem; color: var(--text);
  cursor: grab; text-align: left;
  animation: ej-pop .28s var(--ease) backwards;
  transition: transform .16s var(--ease), border-color .16s var(--ease),
              background .16s var(--ease), box-shadow .16s var(--ease);
}
.ej-ficha:hover { border-color: var(--accent); transform: translateY(-1px); }
.ej-ficha:active { cursor: grabbing; }
.ej-ficha.sel {
  border-color: var(--accent); background: var(--accent-soft); color: var(--accent);
  box-shadow: 0 0 0 3px var(--attn-a);
}
.ej-ficha.arrastrando { opacity: .45; }
.ej-ficha.ok  { border-color: var(--ok);  background: var(--ok-soft);  color: var(--ok);  animation: ej-flash-ok .5s var(--ease); }
.ej-ficha.mal { border-color: var(--bad); background: var(--bad-soft); color: var(--bad); animation: ej-shake .4s var(--ease); }
.ej-ficha[disabled] { cursor: default; }

/* Canastos de clasificación */
.ej-buckets { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); }
.ej-bucket {
  border: 1.5px dashed var(--border-strong); border-radius: var(--radius);
  padding: 12px; background: var(--bg-sunken); min-height: 108px;
  display: flex; flex-direction: column; gap: 8px;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.ej-bucket > h4 { margin: 0; font-size: .84rem; font-weight: 650; }
.ej-bucket > .pista { font-size: .76rem; color: var(--text-faint); margin: -4px 0 0; }
.ej-bucket .ej-drop { display: flex; flex-wrap: wrap; gap: 7px; flex: 1 1 auto; align-content: flex-start; }

/* Ordenar secuencia */
.ej-seq { list-style: none; padding: 0; margin: 0 0 1.1em; counter-reset: paso; }
.ej-seq li { margin: 0 0 8px; }
.ej-paso {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-sunken);
  animation: ej-pop .28s var(--ease) backwards;
  transition: transform .25s var(--ease), border-color .16s var(--ease), background .16s var(--ease);
}
.ej-paso.ok  { border-color: var(--ok);  background: var(--ok-soft);  animation: ej-flash-ok .5s var(--ease); }
.ej-paso.mal { border-color: var(--bad); background: var(--bad-soft); animation: ej-shake .4s var(--ease); }
.ej-paso .n {
  flex: none; width: 24px; height: 24px; border-radius: 7px;
  display: grid; place-items: center; font-size: .76rem; font-weight: 700;
  background: var(--bg-elev); border: 1px solid var(--border-strong); color: var(--text-soft);
}
.ej-paso.ok .n  { background: var(--ok);  border-color: var(--ok);  color: #fff; }
.ej-paso.mal .n { background: var(--bad); border-color: var(--bad); color: #fff; }
.ej-paso .txt { flex: 1 1 auto; font-size: .87rem; }
.ej-paso .mover { display: flex; flex-direction: column; gap: 2px; flex: none; }
.ej-paso .mover button {
  width: 24px; height: 17px; padding: 0; line-height: 1;
  border: 1px solid var(--border-strong); background: var(--bg-elev);
  color: var(--text-soft); font-size: .6rem; cursor: pointer; border-radius: 5px;
}
.ej-paso .mover button:hover:not([disabled]) { border-color: var(--accent); color: var(--accent); }
.ej-paso .mover button[disabled] { opacity: .3; cursor: default; }

/* Emparejar */
.ej-match { display: grid; gap: 12px; grid-template-columns: 1fr 1fr; margin-bottom: 1.1em; }
.ej-match-col { display: flex; flex-direction: column; gap: 8px; }
.ej-match-col h4 { margin: 0 0 2px; font-size: .76rem; text-transform: uppercase;
                   letter-spacing: .06em; color: var(--text-faint); }
.ej-op {
  text-align: left; padding: .55em .8em; border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong); background: var(--bg-sunken);
  font: inherit; font-size: .84rem; color: var(--text); cursor: pointer;
  transition: all .16s var(--ease);
}
.ej-op:hover:not([disabled]) { border-color: var(--accent); }
.ej-op.sel { border-color: var(--accent); background: var(--accent-soft); color: var(--accent);
             box-shadow: 0 0 0 3px var(--attn-a); }
.ej-op.usada { opacity: .32; pointer-events: none; }

.ej-pares { display: flex; flex-direction: column; gap: 8px; }
.ej-par {
  display: flex; align-items: center; gap: 9px; flex-wrap: wrap;
  padding: 9px 12px; border-radius: var(--radius-sm);
  border: 1px solid var(--border); background: var(--bg-sunken);
  font-size: .84rem;
  animation: ej-pop .3s var(--ease) backwards;
}
.ej-par .une { color: var(--text-faint); flex: none; }
.ej-par .quitar {
  margin-left: auto; border: 0; background: none; cursor: pointer;
  color: var(--text-faint); font-size: 1rem; line-height: 1; padding: 0 .2em;
}
.ej-par .quitar:hover { color: var(--bad); }
.ej-par.ok  { border-color: var(--ok);  background: var(--ok-soft);  animation: ej-flash-ok .5s var(--ease); }
.ej-par.mal { border-color: var(--bad); background: var(--bad-soft); animation: ej-shake .4s var(--ease); }

/* Completar huecos */
.ej-cloze { font-size: .95rem; line-height: 2.3; margin-bottom: 1.2em; }
.ej-hueco {
  display: inline-block; min-width: 110px; padding: .18em .7em; margin: 0 .15em;
  border: 0; border-bottom: 2px solid var(--border-strong);
  background: var(--bg-sunken); border-radius: 6px 6px 0 0;
  font: inherit; font-size: .88rem; color: var(--text-faint); cursor: pointer;
  text-align: center; vertical-align: baseline;
  transition: all .16s var(--ease);
}
.ej-hueco:hover { border-bottom-color: var(--accent); }
.ej-hueco.sel { border-bottom-color: var(--accent); background: var(--accent-soft);
                box-shadow: 0 0 0 3px var(--attn-a); }
.ej-hueco.lleno { color: var(--text); font-weight: 600; animation: ej-pop .25s var(--ease); }
.ej-hueco.ok  { border-bottom-color: var(--ok);  background: var(--ok-soft);  color: var(--ok);
                animation: ej-flash-ok .5s var(--ease); }
.ej-hueco.mal { border-bottom-color: var(--bad); background: var(--bad-soft); color: var(--bad);
                animation: ej-shake .4s var(--ease); }

/* Ráfaga verdadero / falso */
.ej-rafaga { text-align: center; }
.ej-timer {
  height: 6px; border-radius: 99px; background: var(--bg-sunken);
  overflow: hidden; border: 1px solid var(--border); margin-bottom: 1.2em;
}
.ej-timer span { display: block; height: 100%; background: var(--u2); width: 100%; }
.ej-timer span.corriendo { transition: width linear; }
.ej-timer span.poco { background: var(--bad); }
.ej-afirmacion {
  min-height: 92px; display: grid; place-items: center;
  padding: 18px; margin-bottom: 1.1em;
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--bg-sunken); font-size: 1.02rem; line-height: 1.5;
  animation: ej-slide-in .3s var(--ease);
}
.ej-afirmacion.ok  { border-color: var(--ok);  background: var(--ok-soft);  animation: ej-flash-ok .5s var(--ease); }
.ej-afirmacion.mal { border-color: var(--bad); background: var(--bad-soft); animation: ej-shake .4s var(--ease); }
.ej-vf { display: flex; gap: 10px; justify-content: center; margin-bottom: 1em; }
.ej-vf .btn { min-width: 120px; }
.ej-racha {
  display: inline-flex; align-items: center; gap: .4em;
  font-size: .85rem; color: var(--text-faint); font-variant-numeric: tabular-nums;
}
.ej-racha strong { color: var(--u2); font-size: 1.05rem; }
.ej-racha.sube strong { animation: ej-pop .35s var(--ease); }

/* Resultado del ejercicio */
.ej-result {
  border-radius: var(--radius); padding: 16px 18px; margin-top: 1.2em;
  border: 1px solid var(--border); background: var(--bg-sunken);
  animation: slide-up .3s var(--ease);
}
.ej-result.perfecto { border-color: var(--ok); background: var(--ok-soft); }
.ej-result h4 { margin: 0 0 .4em; font-size: .95rem; }
.ej-result ul { margin: .6em 0 0; padding-left: 1.2em; font-size: .86rem; }
.ej-result li { margin-bottom: .4em; }
.ej-score { font-size: 1.5rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.ej-score.perfecto { color: var(--ok); }

.ej-medalla {
  display: inline-block; font-size: 1.6rem; line-height: 1;
  animation: ej-medalla .6s var(--ease);
}

/* Lista de ejercicios de la vista dedicada */
.ej-index { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.ej-card {
  display: block; text-decoration: none; color: inherit;
  border: 1px solid var(--border); border-left: 4px solid var(--u2);
  border-radius: var(--radius); background: var(--bg-elev); padding: 15px 17px;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease);
}
.ej-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-md); }
.ej-card.hecho { border-left-color: var(--ok); }
.ej-card h4 { margin: .2em 0 .3em; font-size: .95rem; }
.ej-card p { margin: 0 0 .6em; font-size: .83rem; color: var(--text-soft); }
.ej-card .uc-meta { display: flex; gap: 8px; align-items: center; font-size: .75rem; color: var(--text-faint); }

@keyframes ej-pop {
  0%   { opacity: 0; transform: scale(.82); }
  60%  { opacity: 1; transform: scale(1.06); }
  100% { opacity: 1; transform: scale(1); }
}
@keyframes ej-shake {
  0%, 100% { transform: translateX(0); }
  18%      { transform: translateX(-6px); }
  38%      { transform: translateX(5px); }
  58%      { transform: translateX(-3px); }
  78%      { transform: translateX(2px); }
}
@keyframes ej-flash-ok {
  0%   { box-shadow: 0 0 0 0 var(--attn-a); }
  45%  { box-shadow: 0 0 0 7px color-mix(in srgb, var(--ok) 22%, transparent); }
  100% { box-shadow: 0 0 0 0 var(--attn-b); }
}
@keyframes ej-slide-in {
  from { opacity: 0; transform: translateY(12px) scale(.98); }
  to   { opacity: 1; transform: none; }
}
@keyframes ej-medalla {
  0%   { transform: scale(0) rotate(-25deg); }
  65%  { transform: scale(1.25) rotate(8deg); }
  100% { transform: scale(1) rotate(0); }
}

@media (max-width: 560px) {
  .ej-match { grid-template-columns: 1fr; }
  .ej-cloze { line-height: 2.5; }
}

/* ---------- 12e. Línea de tiempo ---------------------------------------- */

/* Vista general comprimida: los 80 años de un vistazo */
.tl-mini {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  padding: 8px 4px;
  margin-bottom: 1.2em;
  overflow-x: auto;
}
.tl-mini .ia-svg { min-width: 560px; }
.tl-tick { cursor: pointer; }
.tl-tick rect, .tl-tick circle { transition: opacity .15s var(--ease); }
.tl-tick:hover rect, .tl-tick:hover circle { opacity: .55; }
.tl-tick:focus-visible rect { stroke: var(--text); stroke-width: 1.5; }

/* Controles */
.tl-controls {
  display: flex; flex-wrap: wrap; gap: 12px; align-items: center;
  justify-content: space-between; margin-bottom: .8em;
}
.tl-chips { display: flex; flex-wrap: wrap; gap: 7px; }
.tl-chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: .28em .7em; border-radius: 99px;
  border: 1px solid var(--border-strong); background: var(--bg-elev);
  font: inherit; font-size: .78rem; color: var(--text-faint);
  cursor: pointer; opacity: .55;
  transition: opacity .16s var(--ease), border-color .16s var(--ease), color .16s var(--ease);
}
.tl-chip.on { opacity: 1; color: var(--text); border-color: var(--chip-color, var(--border-strong)); }
.tl-chip:hover { opacity: 1; }
.tl-dot { width: 9px; height: 9px; border-radius: 50%; flex: none; }
.tl-acciones { display: flex; gap: 8px; flex-wrap: wrap; }
.tl-contador { margin-bottom: 1.2em; }

/* La línea */
.tl-linea {
  position: relative;
  padding-left: 30px;
  border-left: 2px solid var(--border);
  margin-left: 6px;
}

/* Franjas de época, detrás de las tarjetas */
.tl-bandas { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.tl-banda {
  position: absolute; left: -30px; right: -8px;
  border-radius: var(--radius);
  transition: top .3s var(--ease), height .3s var(--ease);
}
/* Hito sin desplegable: no es un boton, asi que no promete apertura. */
.tl-card-fija { cursor: default; opacity: .82; }
.tl-card-fija:hover { background: none; }
.tl-banda.auge     { background: color-mix(in srgb, var(--u2) 7%, transparent); }
.tl-banda[hidden]  { display: none; }
.tl-banda-label {
  position: absolute; top: 6px; right: 10px;
  font-size: .68rem; font-weight: 700; letter-spacing: .06em;
  text-transform: uppercase; color: var(--text-faint);
}

/* Marcador de década */
.tl-decada {
  position: relative; z-index: 1;
  margin: 1.6em 0 .7em -30px;
  padding-left: 30px;
}
.tl-decada[hidden] { display: none; }
.tl-decada span {
  display: inline-block;
  font-size: .74rem; font-weight: 800; letter-spacing: .1em;
  color: var(--text-faint);
  background: var(--bg);
  padding: .1em .55em;
  border-radius: 99px;
  border: 1px solid var(--border);
}

/* Tarjeta de evento */
.tl-card {
  position: relative; z-index: 1;
  margin-bottom: 9px;
  border: 1px solid var(--border);
  border-left: 3px solid var(--cat-color, var(--accent));
  border-radius: var(--radius);
  background: var(--bg-elev);
  transition: transform .3s var(--ease), opacity .3s var(--ease),
              box-shadow .2s var(--ease), border-color .2s var(--ease);
}
.tl-card[hidden] { display: none; }
.tl-card:hover { box-shadow: var(--shadow-md); }
.tl-card.inflexion { border-left-width: 5px; }
.tl-card.resaltado {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--cat-color) 32%, transparent), var(--shadow-md);
}

/* Punto sobre el eje */
.tl-punto {
  position: absolute; left: -37px; top: 17px;
  width: 11px; height: 11px; border-radius: 50%;
  background: var(--bg); border: 2.5px solid var(--cat-color, var(--accent));
  transition: transform .2s var(--ease), background .2s var(--ease);
}
.tl-card.inflexion .tl-punto { width: 14px; height: 14px; left: -38px; background: var(--cat-color); }
.tl-card.abierto .tl-punto { background: var(--cat-color); transform: scale(1.15); }

/* Entrada escalonada */
.tl-card.por-entrar { opacity: 0; transform: translateY(14px); }

.tl-card-btn {
  width: 100%; display: flex; align-items: flex-start; gap: 11px;
  padding: 12px 15px; border: 0; background: none; border-radius: var(--radius);
  font: inherit; color: inherit; text-align: left; cursor: pointer;
}
.tl-anio {
  flex: none; font-family: var(--mono); font-size: .82rem; font-weight: 700;
  color: var(--cat-color, var(--accent)); min-width: 3.4em; padding-top: .1em;
}
.tl-card-txt { flex: 1 1 auto; min-width: 0; display: flex; flex-direction: column; gap: .18em; }
.tl-titulo { font-size: .95rem; font-weight: 640; }
.tl-resumen { font-size: .85rem; color: var(--text-soft); }
.tl-flag { flex: none; color: var(--warn); font-size: .9rem; line-height: 1.5; }
.tl-mas {
  flex: none; width: 7px; height: 7px; margin-top: .5em;
  border-right: 1.9px solid var(--text-faint); border-bottom: 1.9px solid var(--text-faint);
  transform: rotate(45deg); transition: transform .25s var(--ease);
}
.tl-card.abierto .tl-mas { transform: rotate(-135deg); }

.tl-detalle {
  padding: 0 15px 14px 60px;
  font-size: .88rem; color: var(--text-soft);
  animation: slide-up .28s var(--ease);
}
.tl-detalle[hidden] { display: none; }
.tl-detalle p { margin-bottom: .6em; }
.tl-detalle p:last-child { margin-bottom: 0; }
.tl-enlace a { font-size: .84rem; font-weight: 600; }
.tl-fuera { font-size: .78rem; color: var(--text-faint); font-style: italic; }

@media (max-width: 560px) {
  .tl-linea { padding-left: 20px; margin-left: 4px; }
  .tl-punto { left: -27px; }
  .tl-card.inflexion .tl-punto { left: -28px; }
  .tl-decada { margin-left: -20px; padding-left: 20px; }
  .tl-banda { left: -20px; }
  .tl-detalle { padding-left: 15px; }
  .tl-card-btn { flex-wrap: wrap; }
}

@media print {
  .tl-mini, .tl-controls { display: none !important; }
  .tl-detalle[hidden] { display: block !important; }
  .tl-card { break-inside: avoid; }
}

/* ---------- 12f. Modelo de examen resuelto ------------------------------ */
/*
   La resolución arranca oculta a propósito. Ver la respuesta antes de
   intentar la consigna produce la sensación de entender sin el trabajo de
   entender, que es justo lo que falla después en el parcial.
*/

.me-item {
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  background: var(--bg-elev);
  padding: 18px 20px;
  margin-bottom: 16px;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.me-item.abierta { border-left-color: var(--ok); box-shadow: var(--shadow-sm); }

.me-head { display: flex; align-items: flex-start; gap: 12px; margin-bottom: .9em; }
.me-num {
  flex: none; width: 30px; height: 30px; border-radius: 9px;
  display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
  font-weight: 800; font-size: .9rem;
}
.me-item.abierta .me-num { background: var(--ok-soft); color: var(--ok); }
.me-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.me-tema { font-size: .78rem; }

.me-consigna {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 13px 17px;
  margin-bottom: .9em;
  font-size: .96rem;
}
.me-consigna .callout-label { color: var(--accent); }
.me-consigna p { margin: 0; }

.me-evalua {
  font-size: .85rem; color: var(--text-soft);
  border-left: 2px dashed var(--border-strong);
  padding-left: 12px; margin-bottom: 1em;
}

.me-resolucion {
  margin-top: 1em; padding: 16px 18px;
  border-radius: var(--radius);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  animation: slide-up .3s var(--ease);
}
.me-resolucion[hidden] { display: none; }
.me-resolucion > h4 {
  margin: 0 0 .7em; font-size: .8rem; letter-spacing: .07em;
  text-transform: uppercase; color: var(--ok);
}
.me-resolucion > h4 ~ h4 { margin-top: 1.4em; color: var(--bad); }
.me-resolucion p { font-size: .9rem; }
.me-resolucion table { font-size: .84rem; }

.me-cierre {
  border-left: 3px solid var(--ok);
  background: var(--ok-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 12px 16px; margin: 1.2em 0 .4em;
  font-size: .88rem;
}
.me-cierre .callout-label { color: var(--ok); }

.me-errores { font-size: .87rem; }
.me-errores li { margin-bottom: .45em; }

@media print {
  .me-ver, .me-item .btn-row { display: none !important; }
  .me-resolucion[hidden] { display: block !important; }
  .me-item { break-inside: avoid; }
}

/* ---------- 12f-bis. Aviso de procedencia de las unidades 3 a 6 --------- */
/*
   Las unidades 1 y 2 salen de los PPT de la cátedra; las 3 a 6 se
   desarrollaron para la guía. La distinción tiene que estar a la vista y no
   en una nota al pie: es la diferencia entre "esto se toma" y "esto ayuda".
*/
.aviso-origen {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin: 0 0 1.4em;
  padding: 12px 16px;
  border: 1px solid var(--warn);
  border-left-width: 4px;
  border-radius: var(--radius);
  background: var(--warn-soft);
}
.aviso-origen p { margin: 0; font-size: .84rem; color: var(--text); }
.aviso-origen-tag {
  flex: none;
  font-size: .68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--warn);
  border: 1px solid var(--warn);
  border-radius: 99px;
  padding: .18em .7em;
  margin-top: .1em;
}
.unit-card .origen-badge {
  display: inline-block;
  font-size: .68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--warn);
  background: var(--warn-soft);
  border-radius: 99px;
  padding: .12em .6em;
  margin-top: .5em;
}
.nav-unit .origen-punto {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--warn);
  margin-left: .4em;
  vertical-align: middle;
}

/* ---------- 12g. Piezas explorables (explorables.js) -------------------- */
/*
   Seis piezas nuevas, cada una modelada sobre un explicador conocido.
   Regla común: el color nunca es la única señal. La celda visitada también
   cambia de opacidad, el punto mal clasificado también cambia de forma, y
   el eslabón roto también deja de moverse.
*/

/* Nota de procedencia al pie de cada pieza */
.ref-nota {
  margin-top: 1.4em;
  padding-top: .9em;
  border-top: 1px dashed var(--border);
}
.ref-tag {
  display: inline-block;
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 99px;
  padding: .12em .6em;
  margin-right: .2em;
}
.ref-nota a { color: var(--text-soft); }
.ref-nota a:hover { color: var(--accent); }

/* --- 1. Búsqueda en el espacio de estados ------------------------------- */

.ss-grid { max-width: 460px; margin: 0 auto 1em; }

.ss-cell {
  fill: var(--bg-sunken);
  stroke: var(--border);
  stroke-width: 1;
  cursor: pointer;
  transition: fill .18s var(--ease), stroke .18s var(--ease);
}
.ss-cell:hover     { stroke: var(--accent); }
.ss-cell.muro      { fill: var(--border-strong); stroke: var(--border-strong); cursor: pointer; }
.ss-cell.frontera  { fill: var(--warn-soft);  stroke: var(--warn); }
.ss-cell.visitado  { fill: var(--info-soft);  stroke: var(--info-soft); }
.ss-cell.camino    { fill: var(--ok);         stroke: var(--ok); }
.ss-cell.inicio,
.ss-cell.meta      { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 2; }
.ss-cell.meta.hallada { fill: var(--ok-soft); stroke: var(--ok); }

.ss-marca {
  font-size: 13px;
  font-weight: 800;
  fill: var(--accent);
  pointer-events: none;
}

.ss-marcador {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  font-size: .82rem;
  color: var(--text-soft);
  margin: 0 0 1em;
  font-variant-numeric: tabular-nums;
}
.ss-marcador strong { color: var(--text); font-size: .95rem; }
.ss-marcador .ok strong { color: var(--ok); }

/* --- 2. Perceptrón ------------------------------------------------------ */

.pc-plot { max-width: 320px; margin: 0 auto .6em; }

.pc-fondo { fill: var(--bg-sunken); stroke: var(--border); }
.pc-zona  { fill: transparent; }

.pc-recta {
  stroke: var(--accent);
  stroke-width: 2.5;
  stroke-linecap: round;
  transition: all .18s var(--ease);
}

.pc-pt {
  stroke: var(--bg-elev);
  stroke-width: 1.5;
  transition: fill .2s var(--ease), r .2s var(--ease);
}
.pc-pt.c0 { fill: var(--u2); }
.pc-pt.c1 { fill: var(--accent); }
/* Mal clasificado: no alcanza con el color, cambia también el contorno */
.pc-pt.mal {
  stroke: var(--bad);
  stroke-width: 3;
  stroke-dasharray: 3 2;
}

.pc-sliders { margin: .4em 0 1em; }
.pc-sliders .slider-row { margin: .5em 0; }
.pc-sliders .hint { min-width: 4.6em; }

.meter.ok-meter .meter-fill { background: var(--ok); }

/* --- 3. CAPTCHA --------------------------------------------------------- */

.cap-svg { max-width: 340px; margin: 0 auto .4em; }
.cap-fondo { fill: var(--bg-sunken); stroke: var(--border); }
.cap-letra {
  font-family: var(--mono);
  font-size: 30px;
  font-weight: 700;
  fill: var(--text);
}
.cap-tachon {
  fill: none;
  stroke: var(--text-faint);
  stroke-width: 2;
  stroke-linecap: round;
}

/* --- 4. Duelo generador / detector -------------------------------------- */

.gan-svg { max-width: 360px; margin: 0 auto .6em; }

.gan-real {
  fill: var(--ok-soft);
  stroke: var(--ok);
  stroke-dasharray: 4 3;
  transition: x .3s var(--ease), width .3s var(--ease);
}
.gan-eje  { stroke: var(--border-strong); stroke-width: 1.5; }
.gan-tick { font-size: 10px; fill: var(--text-faint); }

.gan-pt {
  transition: transform .45s var(--ease);
}
.gan-pt circle {
  fill: var(--bad);
  stroke: var(--bg-elev);
  stroke-width: 1.5;
  transition: fill .3s var(--ease);
}
/* La muestra que ya pasa por real cambia de color Y de contorno */
.gan-pt.cuela circle { fill: var(--ok); stroke: var(--ok-soft); stroke-width: 3; }

/* --- 5. Ciclo datos → modelos → acción ---------------------------------- */

.ciclo-svg { max-width: 340px; margin: 0 auto .8em; }

.ciclo-anillo {
  fill: none;
  stroke: var(--border);
  stroke-width: 2;
}
.ciclo-flujo {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2.5;
  stroke-linecap: round;
  opacity: .75;
}
.ciclo-flujo.frenado {
  stroke: var(--bad);
  stroke-dasharray: 2 7;
  opacity: .5;
  animation: none;
}

.ciclo-nodo { cursor: pointer; }
.ciclo-nodo circle {
  fill: var(--bg-elev);
  stroke: var(--border-strong);
  stroke-width: 2;
  transition: fill .2s var(--ease), stroke .2s var(--ease);
}
.ciclo-nodo text {
  font-size: 12px;
  font-weight: 650;
  fill: var(--text-soft);
  pointer-events: none;
  transition: fill .2s var(--ease);
}
.ciclo-nodo:hover circle { stroke: var(--accent); }
.ciclo-nodo.on circle    { fill: var(--accent-soft); stroke: var(--accent); }
.ciclo-nodo.on text      { fill: var(--accent); }
.ciclo-nodo.roto circle  { fill: var(--bad-soft); stroke: var(--bad); stroke-dasharray: 5 3; }
.ciclo-nodo.roto text    { fill: var(--bad); }
.ciclo-nodo:focus-visible circle { stroke: var(--accent); stroke-width: 3; }

/* --- 6. La máquina de demostrar ----------------------------------------- */

.gd-lista {
  margin: 0 0 1em;
  padding-left: 1.6em;
  min-height: 2em;
  font-size: .88rem;
}
.gd-item {
  margin: .28em 0;
  font-family: var(--mono);
  font-size: .82rem;
  color: var(--text-soft);
  opacity: 0;
  transform: translateX(-8px);
  transition: opacity .28s var(--ease), transform .28s var(--ease);
}
.gd-item.puesto { opacity: 1; transform: none; }

.gd-estado {
  font-size: .85rem;
  font-weight: 620;
  margin: 0 0 1em;
  padding: .5em .8em;
  border-radius: var(--radius-sm);
  background: var(--bg-sunken);
  color: var(--text-soft);
  border-left: 3px solid var(--border-strong);
}
.gd-estado.trabajando { background: var(--info-soft); color: var(--info); border-left-color: var(--info); }
.gd-estado.ok         { background: var(--ok-soft);   color: var(--ok);   border-left-color: var(--ok); }
.gd-estado.colgado    { background: var(--warn-soft); color: var(--warn); border-left-color: var(--warn); }

.gd-g {
  margin: 1em 0;
  padding: 14px 16px;
  border: 2px dashed var(--warn);
  border-radius: var(--radius);
  background: var(--warn-soft);
}
.gd-g[hidden] { display: none; }
.gd-g-txt { margin: 0 0 .5em; font-size: .92rem; color: var(--text); }
.gd-contador {
  margin: 0;
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--warn);
  font-variant-numeric: tabular-nums;
}

/* ---------- 12h. Piezas jugables (juegos.js) ---------------------------- */
/*
   Ocho juegos. Criterio visual común: el resultado de una decisión se marca
   por color, por icono textual y por borde, nunca por color solo.
*/

/* Marcador compartido */
.juego-marcador {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  font-size: .82rem;
  color: var(--text-soft);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .5em .9em;
  margin-bottom: 1.2em;
  font-variant-numeric: tabular-nums;
}
.juego-marcador strong { color: var(--text); }
.juego-racha {
  padding: .1em .6em;
  border-radius: 99px;
  background: var(--border);
  color: var(--text-soft);
  transition: background .25s var(--ease), color .25s var(--ease);
}
.juego-marcador.en-racha .juego-racha { background: var(--ok-soft); color: var(--ok); font-weight: 700; }

/* Variantes de panel de resultado, compartidas por los ocho */
.result-panel.bien  { border-color: var(--ok);   background: var(--ok-soft); }
.result-panel.aviso { border-color: var(--warn); background: var(--warn-soft); }
.result-panel.malo  { border-color: var(--bad);  background: var(--bad-soft); }
.result-panel.bien h4  { color: var(--ok); }
.result-panel.aviso h4 { color: var(--warn); }
.result-panel.malo h4  { color: var(--bad); }

/* --- 1. Armá el sistema -------------------------------------------------- */

.as-tarea { margin: 0 0 .8em; font-size: .95rem; }

.as-grilla {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  margin-bottom: 1.2em;
}
.as-cap {
  display: flex;
  align-items: center;
  gap: 8px;
  text-align: left;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text-soft);
  font: inherit;
  font-size: .84rem;
  cursor: pointer;
  transition: border-color .2s var(--ease), background .2s var(--ease), color .2s var(--ease);
}
.as-cap:hover { border-color: var(--accent); }
.as-icono { font-size: 1.15rem; line-height: 1; flex: none; }
.as-label { flex: 1; }
.as-luz {
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--border-strong); flex: none;
  transition: background .2s var(--ease), box-shadow .2s var(--ease);
}
.as-cap.on { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); font-weight: 620; }
.as-cap.on .as-luz { background: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.as-cap.usada { border-color: var(--ok); background: var(--ok-soft); color: var(--ok); }
.as-cap.usada .as-luz { background: var(--ok); box-shadow: none; }
/* La que faltaba: además del color, borde punteado */
.as-cap.fallo {
  border-color: var(--bad);
  border-style: dashed;
  background: var(--bad-soft);
  color: var(--bad);
}
.as-cap.fallo .as-luz { background: var(--bad); }

/* --- 2. La pregunta de Turing -------------------------------------------- */

.pt-caja { margin-bottom: .4em; }
.pt-pregunta {
  font-size: .92rem;
  margin: 0 0 1em;
  padding: .8em 1em;
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.pt-opciones { display: grid; gap: 8px; margin-bottom: 1em; }
.pt-opt {
  text-align: left;
  padding: 11px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  font-size: .87rem;
  cursor: pointer;
  transition: border-color .18s var(--ease), background .18s var(--ease);
}
.pt-opt:hover:not([disabled]) { border-color: var(--accent); background: var(--accent-soft); }
.pt-opt[disabled] { cursor: default; opacity: .75; }
.pt-opt.bien { border-color: var(--ok); background: var(--ok-soft); color: var(--ok); font-weight: 620; opacity: 1; }
.pt-opt.mal  { border-color: var(--bad); border-style: dashed; background: var(--bad-soft); color: var(--bad); }

.pt-gestos { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); margin-bottom: 1.2em; }
.pt-gesto {
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-sunken);
  animation: slide-up .3s var(--ease);
}
.pt-gesto h4 { margin: .2em 0 .4em; font-size: .92rem; }
.pt-gesto p { margin: 0; font-size: .85rem; color: var(--text-soft); }
.pt-anio {
  font-family: var(--mono);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .04em;
}
.pt-gesto.a { border-top: 3px solid var(--accent); }
.pt-gesto.a .pt-anio { color: var(--accent); }
.pt-gesto.b { border-top: 3px solid var(--u2); }
.pt-gesto.b .pt-anio { color: var(--u2); }

/* --- 3. El sesgo que se hereda ------------------------------------------- */

.sh-eleccion { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); margin-bottom: 1.2em; }
.sh-opt {
  display: flex;
  flex-direction: column;
  gap: .35em;
  text-align: left;
  padding: 12px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  cursor: pointer;
  transition: border-color .18s var(--ease), background .18s var(--ease);
}
.sh-opt:hover { border-color: var(--accent); }
.sh-opt.on { border-color: var(--accent); background: var(--accent-soft); }
.sh-opt strong { font-size: .88rem; }
.sh-opt .hint { margin: 0; }

.sh-svg { max-width: 360px; margin: 0 auto 1em; }
.sh-eje { stroke: var(--border-strong); stroke-width: 1.5; }
.sh-paridad { stroke: var(--ok); stroke-width: 1; stroke-dasharray: 4 4; }
.sh-tick { font-size: 9px; fill: var(--text-faint); }
.sh-valor { font-size: 10px; font-weight: 700; fill: var(--text-soft); }

.sh-barra rect {
  fill: var(--accent);
  opacity: .55;
  transition: height .35s var(--ease), y .35s var(--ease), fill .3s var(--ease);
}
.sh-barra.ultima rect { opacity: 1; }
.sh-barra.ultima .sh-valor { fill: var(--text); }

/* --- 4. Qué mide el test ------------------------------------------------- */

.qm-lista { display: grid; gap: 8px; margin-bottom: 1.2em; }
.qm-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 11px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  cursor: pointer;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.qm-item:hover { border-color: var(--accent); }
.qm-nombre { font-size: .88rem; font-weight: 620; }
.qm-estado {
  float: right;
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--text-faint);
  padding-top: .2em;
}
.qm-detalle { margin: .6em 0 0; font-size: .84rem; color: var(--text-soft); animation: slide-up .25s var(--ease); }
.qm-item.visible { border-color: var(--ok); background: var(--ok-soft); cursor: default; }
.qm-item.visible .qm-estado { color: var(--ok); font-weight: 700; }
/* No observable: además del color, el bloque queda atenuado y con borde punteado */
.qm-item.opaca {
  border-color: var(--border-strong);
  border-style: dashed;
  background: var(--bg-sunken);
  cursor: default;
}
.qm-item.opaca .qm-nombre { color: var(--text-faint); text-decoration: line-through; }
.qm-item.opaca .qm-estado { color: var(--warn); font-weight: 700; }

.qm-medidor { margin-bottom: 1em; }
.qm-track { height: 10px; border-radius: 99px; background: var(--border); overflow: hidden; }
.qm-fill { display: block; height: 100%; width: 0%; background: var(--ok); transition: width .3s var(--ease); }
.qm-leyenda { margin: .5em 0 0; font-size: .8rem; color: var(--text-faint); }

/* --- 5. Tres jueces ------------------------------------------------------ */

.tj-evidencia {
  font-size: .92rem;
  font-style: italic;
  margin: 0 0 1em;
  color: var(--text);
}
.tj-tablero { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); margin-bottom: 1.2em; }
.tj-juez {
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-sunken);
  transition: border-color .25s var(--ease), transform .25s var(--ease);
}
.tj-juez.activo { transform: translateY(-2px); }
.tj-juez h4 { margin: 0 0 .2em; font-size: .88rem; }
.tj-pregunta { margin: 0 0 .7em; font-size: .8rem; color: var(--text-faint); font-style: italic; }
.tj-detalle { margin: .6em 0 0; font-size: .82rem; color: var(--text-soft); }
.tj-verdicto {
  display: inline-block;
  font-size: .78rem;
  font-weight: 700;
  padding: .15em .6em;
  border-radius: 99px;
  background: var(--border);
  color: var(--text-soft);
}
.tj-verdicto.v-convencido  { background: var(--ok-soft);   color: var(--ok); }
.tj-verdicto.v-parcial     { background: var(--warn-soft); color: var(--warn); }
.tj-verdicto.v-esceptico   { background: var(--bad-soft);  color: var(--bad); }
.tj-verdicto.v-sin-datos,
.tj-verdicto.v-indiferente { background: var(--bg-hover);   color: var(--text-faint); }
.tj-juez.conductual { border-top: 3px solid var(--accent); }
.tj-juez.interno    { border-top: 3px solid var(--u2); }
.tj-juez.ingenieril { border-top: 3px solid var(--warn); }

/* --- 6. Contestale a Searle ---------------------------------------------- */

.ds-menu { display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); margin-bottom: .8em; }
.ds-opt {
  padding: 10px 13px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color .18s var(--ease), background .18s var(--ease);
}
.ds-opt:hover { border-color: var(--accent); }
.ds-opt.on { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }

.ds-contador { font-size: .8rem; color: var(--text-faint); margin: 0 0 1.2em; }

.ds-escena { display: flex; flex-direction: column; gap: 10px; }
.ds-linea { display: flex; gap: 10px; align-items: flex-start; animation: slide-up .3s var(--ease); }
.ds-quien {
  flex: none;
  min-width: 4.4em;
  font-size: .74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .04em;
  padding-top: .55em;
  color: var(--text-faint);
}
.ds-burbuja {
  flex: 1;
  padding: 10px 14px;
  border-radius: var(--radius);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  font-size: .86rem;
}
.ds-linea.vos .ds-quien { color: var(--accent); }
.ds-linea.vos .ds-burbuja { background: var(--accent-soft); border-color: transparent; }
.ds-linea.searle .ds-quien { color: var(--u2); }
.ds-pensando { color: var(--text-faint); letter-spacing: .3em; }

.ds-replicas { display: grid; gap: 8px; margin-bottom: 1em; }
.ds-replica {
  text-align: left;
  padding: 10px 13px;
  border: 1.5px dashed var(--border-strong);
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
  font: inherit;
  font-size: .85rem;
  cursor: pointer;
  transition: border-color .18s var(--ease), background .18s var(--ease);
}
.ds-replica:hover:not([disabled]) { border-color: var(--accent); background: var(--accent-soft); }
.ds-replica[disabled] { cursor: default; opacity: .55; }
.ds-replica.fuerte { border-style: solid; border-color: var(--ok); background: var(--ok-soft); color: var(--ok); opacity: 1; }
.ds-replica.floja  { border-color: var(--warn); background: var(--warn-soft); color: var(--warn); opacity: 1; }

/* --- 7. Armá el enfoque -------------------------------------------------- */

.ee-problema {
  font-size: .9rem;
  margin: 0 0 1em;
  padding: .8em 1em;
  background: var(--bg-sunken);
  border-left: 3px solid var(--u2);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.ee-enfoques .toggle-btn[disabled] { opacity: .5; cursor: default; }

/* --- 8. De la PoC al valor ----------------------------------------------- */

.pv-presupuesto { font-size: .86rem; color: var(--text-soft); margin: 0 0 .8em; }
.pv-presupuesto strong { font-size: 1.05rem; color: var(--accent); font-variant-numeric: tabular-nums; }

.pv-rubros { display: grid; gap: 6px; margin-bottom: 1.2em; }
.pv-rubro {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.pv-rubro.con-fichas { border-color: var(--accent); background: var(--accent-soft); }
.pv-nombre { font-size: .85rem; }
.pv-controles { display: flex; align-items: center; gap: 8px; flex: none; }
.pv-puntos {
  min-width: 4.2em;
  text-align: center;
  font-size: .95rem;
  letter-spacing: .1em;
  color: var(--accent);
}
.pv-btn {
  width: 26px; height: 26px;
  border-radius: 50%;
  border: 1px solid var(--border-strong);
  background: var(--bg-elev);
  color: var(--text-soft);
  font: inherit;
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  transition: border-color .15s var(--ease), color .15s var(--ease);
}
.pv-btn:hover:not([disabled]) { border-color: var(--accent); color: var(--accent); }
.pv-btn[disabled] { opacity: .3; cursor: not-allowed; }

.pv-relato { margin: .6em 0 0; padding-left: 1.2em; font-size: .85rem; }
.pv-relato li { margin: .3em 0; }
.pv-relato li.ok  { color: var(--ok); }
.pv-relato li.mal { color: var(--bad); }

/* ---------- 12i. Motores genéricos (motores.js) -------------------------- */
/*
   Cinco formatos que dan las 24 piezas de las unidades 3 a 6.
   Mismo criterio que el resto: el resultado nunca se marca solo por color.
*/

/* --- desafío --- */

.df-paso {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--text-faint);
  margin: 0 0 .5em;
}
.df-enunciado {
  font-size: .95rem;
  margin: 0 0 .8em;
  padding: .85em 1.1em;
  background: var(--bg-sunken);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.df-pista { margin: -.4em 0 1em; font-style: italic; }
.df-pista[hidden] { display: none; }

.df-opciones { display: grid; gap: 8px; margin-bottom: 1em; }
.df-opt {
  text-align: left;
  padding: 11px 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  font-size: .87rem;
  line-height: 1.45;
  cursor: pointer;
  transition: border-color .18s var(--ease), background .18s var(--ease);
}
.df-opt:hover:not([disabled]) { border-color: var(--accent); background: var(--accent-soft); }
.df-opt[disabled] { cursor: default; opacity: .7; }
.df-opt.elegida { border-color: var(--accent); background: var(--accent-soft); }
.df-opt.correcta {
  border-color: var(--ok);
  background: var(--ok-soft);
  color: var(--ok);
  font-weight: 600;
  opacity: 1;
}
.df-opt.correcta::before { content: "✓  "; font-weight: 800; }
.df-opt.errada {
  border-color: var(--bad);
  border-style: dashed;
  background: var(--bad-soft);
  color: var(--bad);
  opacity: 1;
}
.df-opt.errada::before { content: "✗  "; font-weight: 800; }

/* --- recorrido --- */

.rc-mapa {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 1.2em;
}
.rc-marca {
  flex: 1 1 130px;
  display: flex;
  align-items: center;
  gap: 8px;
  text-align: left;
  padding: 9px 11px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  color: var(--text-soft);
  font: inherit;
  font-size: .78rem;
  cursor: pointer;
  transition: border-color .2s var(--ease), background .2s var(--ease), color .2s var(--ease);
}
.rc-marca:hover { border-color: var(--accent); }
.rc-num {
  flex: none;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--border);
  color: var(--text-soft);
  font-size: .7rem;
  font-weight: 800;
  line-height: 20px;
  text-align: center;
  transition: background .2s var(--ease), color .2s var(--ease);
}
.rc-tit { line-height: 1.25; }
.rc-marca.visto { border-color: var(--ok); color: var(--ok); }
.rc-marca.visto .rc-num { background: var(--ok); color: var(--accent-text); }
.rc-marca.on {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 620;
}
.rc-marca.on .rc-num { background: var(--accent); color: var(--accent-text); }

/* --- balanza --- */

.bl-cabeza {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 1em;
  font-size: .86rem;
  font-weight: 640;
}
.bl-lado { flex: 1; padding: .5em .8em; border-radius: var(--radius-sm); text-align: center; }
.bl-lado.izq { background: var(--accent-soft); color: var(--accent); }
.bl-lado.der { background: var(--bg-sunken); color: var(--u2); }
.bl-vs { flex: none; font-size: .75rem; color: var(--text-faint); }

.bl-filas { display: grid; gap: 6px; }
.bl-fila { border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.bl-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  width: 100%;
  text-align: left;
  padding: 10px 14px;
  border: 0;
  background: var(--bg-elev);
  color: var(--text);
  font: inherit;
  font-size: .86rem;
  cursor: pointer;
  transition: background .18s var(--ease);
}
.bl-btn:hover { background: var(--bg-hover); }
.bl-dim { font-weight: 620; }
.bl-gana {
  flex: none;
  font-size: .74rem;
  font-weight: 700;
  padding: .12em .65em;
  border-radius: 99px;
  background: var(--border);
  color: var(--text-faint);
}
.bl-gana.g-izq    { background: var(--accent-soft); color: var(--accent); }
.bl-gana.g-der    { background: var(--info-soft);   color: var(--info); }
.bl-gana.g-empate { background: var(--warn-soft);   color: var(--warn); }

.bl-cuerpo {
  display: grid;
  gap: 10px;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  padding: 12px 14px;
  background: var(--bg-sunken);
  border-top: 1px solid var(--border);
  animation: slide-up .25s var(--ease);
}
.bl-cuerpo[hidden] { display: none; }
.bl-celda { font-size: .84rem; padding-left: 10px; border-left: 3px solid var(--border-strong); }
.bl-celda.izq { border-left-color: var(--accent); }
.bl-celda.der { border-left-color: var(--u2); }
.bl-nota { grid-column: 1 / -1; margin: .2em 0 0; }

/* --- sistema --- */

.sis-grilla {
  display: grid;
  gap: 8px;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  margin-bottom: 1.2em;
}
.sis-pieza {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  text-align: left;
  padding: 11px 13px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--text-soft);
  font: inherit;
  font-size: .84rem;
  cursor: pointer;
  transition: border-color .2s var(--ease), background .2s var(--ease), color .2s var(--ease);
}
.sis-pieza:hover { border-color: var(--accent); }
.sis-label { line-height: 1.3; }
.sis-luz {
  flex: none;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--border-strong);
  transition: background .2s var(--ease), box-shadow .2s var(--ease);
}
.sis-pieza.on {
  border-color: var(--ok);
  background: var(--ok-soft);
  color: var(--ok);
  font-weight: 620;
}
.sis-pieza.on .sis-luz { background: var(--ok); box-shadow: 0 0 0 3px color-mix(in srgb, var(--ok) 22%, transparent); }

/* --- palancas --- */

.pal-label { min-width: 12em; }
.pal-cuadro {
  display: grid;
  gap: 6px;
  margin: 1em 0;
}
.pal-fila {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  padding: 9px 13px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-sunken);
  font-size: .86rem;
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.pal-fila.gana { border-color: var(--ok); background: var(--ok-soft); }
.pal-fila.gana .pal-f-val { color: var(--ok); }
.pal-f-lab { color: var(--text-soft); }
.pal-f-val { font-weight: 700; font-variant-numeric: tabular-nums; }

@media (max-width: 560px) {
  .pal-label { min-width: 0; flex: 1 1 100%; }
  .bl-cabeza { font-size: .8rem; }
}

/* ---------- 12j. Selector entre los dos modelos de examen -------------- */
.me-selector { margin-bottom: 1.2em; }
.me-selector .toggle-btn {
  display: inline-flex;
  align-items: baseline;
  gap: .3em;
  text-decoration: none;
}
.me-selector .toggle-btn strong { font-weight: 650; }
.me-sel-sub { font-size: .78rem; opacity: .75; }

/* ---------- 13. Animaciones --------------------------------------------- */

@keyframes fade-in  { from { opacity: 0; } to { opacity: 1; } }
@keyframes slide-up { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
@keyframes pulse-ring {
  0%   { transform: scale(.9); opacity: .9; }
  70%  { transform: scale(1.5); opacity: 0; }
  100% { transform: scale(1.5); opacity: 0; }
}
@keyframes dash-flow { to { stroke-dashoffset: -22; } }

.view { animation: fade-in .25s var(--ease); }

.flow-line { stroke-dasharray: 6 5; animation: dash-flow 1.1s linear infinite; }
.pulse { animation: pulse-ring 1.8s var(--ease) infinite; transform-origin: center; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  html { scroll-behavior: auto; }
}

/* ---------- 14. Responsive ---------------------------------------------- */

@media (max-width: 900px) {
  .menu-toggle { display: grid; }
  .progress-wrap .progress-bar { width: 70px; }
  .brand-text small { display: none; }

  .sidebar {
    position: fixed; top: var(--topbar-h); left: 0; z-index: 50;
    height: calc(100vh - var(--topbar-h));
    transform: translateX(-100%);
    transition: transform .25s var(--ease);
    box-shadow: var(--shadow-lg);
    width: min(300px, 86vw);
  }
  .sidebar.open { transform: none; }
  .content { padding: 24px 18px 80px; }
  .topic-nav { flex-direction: column; }
}

@media (max-width: 520px) {
  body { font-size: 15px; }
  .progress-wrap { display: none; }
  .brand-text strong { font-size: .84rem; }
  .interactive-body { padding: 14px; }
  .hero { padding: 24px 18px; }
}

/* ---------- 15. Impresión ----------------------------------------------- */

@media print {
  .topbar, .sidebar, .scrim, .topic-nav, .btn, .exam-bar, .fc-controls,
  .skip-link, .interactive-head .tag,
  /* Los controles de las piezas no sirven en papel: lo que sí sirve es el
     texto que producen, así que se ocultan los botones y se despliega todo. */
  .juego-marcador, .opt-row, .df-opciones, .sis-grilla, .as-grilla,
  .rc-mapa, .pv-controles, .ds-menu, .ds-replicas, .me-ver, .eli5-btn,
  .ej-controles, .tl-mini, .tl-chips { display: none !important; }

  body { background: #fff; color: #000; font-size: 11pt; }
  .content { padding: 0; }
  .view { max-width: none; }
  .card, .interactive, .quiz-q, .concept, .me-item, .result-panel,
  .eli5, .bl-fila, .tl-card { break-inside: avoid; box-shadow: none; border-color: #bbb; }

  /* Todo lo plegable se imprime abierto: en papel no hay clic. */
  .tl-detail[hidden], .ec-body[hidden], .tl-detalle[hidden],
  .me-resolucion[hidden], .eli5-panel[hidden], .bl-cuerpo[hidden],
  .gd-g[hidden] { display: block !important; }

  /* El aviso de procedencia tiene que sobrevivir a la impresión. */
  .aviso-origen { border: 1.5px solid #000; background: #fff; }

  a { color: #000; text-decoration: underline; }
  a[href^="#"]::after { content: ""; }
}