/* =============================================================
   EstudIA — hoja de estilos única
   1 Tokens · 2 Reset · 3 Utilidades · 4 Tipografía · 5 Componentes
   6 Secciones · 7 Anuncios · 8 Responsive · 9 Reduced motion
   ============================================================= */

/* 1. Tokens ---------------------------------------------------- */
:root {
  --bg: #f7f8fc;
  --surface: #ffffff;
  --surface-2: #f1f3fa;
  --line: #e2e6f0;
  --line-strong: #cfd5e6;
  --ink: #151a2d;
  --ink-2: #4a5270;
  --ink-3: #757e9c;
  --accent: #4a5bd6;
  --accent-ink: #ffffff;
  --accent-soft: #eceffd;
  --accent-2: #12a074;
  --warn: #b06a00;
  --warn-soft: #fff5e2;
  --err: #c22f42;
  --err-soft: #fdeef0;
  --ok: #12805e;
  --ok-soft: #e6f6f0;

  --radius: 14px;
  --radius-s: 10px;
  --shadow: 0 1px 2px rgba(21, 26, 45, .05), 0 10px 30px -12px rgba(21, 26, 45, .18);
  --shadow-s: 0 1px 2px rgba(21, 26, 45, .06);
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --ease-out: cubic-bezier(.16, 1, .3, 1);
  --gutter: clamp(1rem, 4vw, 2rem);
  --maxw: 1200px;
  --contentw: 760px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1220;
    --surface: #171b2e;
    --surface-2: #1e2338;
    --line: #2a3050;
    --line-strong: #3a4166;
    --ink: #eef1fb;
    --ink-2: #b3bbd6;
    --ink-3: #8891af;
    --accent: #8b97ff;
    --accent-ink: #0f1220;
    --accent-soft: #232a4d;
    --accent-2: #35c99a;
    --warn: #f0b45e;
    --warn-soft: #2e2513;
    --err: #ff8896;
    --err-soft: #33191f;
    --ok: #4bd3a6;
    --ok-soft: #14302a;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 14px 34px -14px rgba(0, 0, 0, .7);
    --shadow-s: 0 1px 2px rgba(0, 0, 0, .35);
  }
}

/* 2. Reset ----------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; }
html { -webkit-text-size-adjust: 100%; tab-size: 2; scroll-behavior: smooth; }
body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
}
img, svg, video, canvas { display: block; max-width: 100%; }
img { height: auto; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
input, select, textarea { font: inherit; color: inherit; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
p { text-wrap: pretty; }
h1, h2, h3, h4 { text-wrap: balance; line-height: 1.15; letter-spacing: -.02em; font-weight: 700; }
::selection { background: var(--accent); color: var(--accent-ink); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }
[hidden] { display: none !important; }

/* 3. Utilidades ------------------------------------------------ */
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
.prose { max-width: var(--contentw); }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: fixed; top: -100px; left: 1rem; z-index: 999;
  padding: .6rem 1rem; background: var(--accent); color: var(--accent-ink);
  border-radius: 8px; font-weight: 600;
}
.skip-link:focus { top: 1rem; }
.center { text-align: center; }
.muted { color: var(--ink-3); }

/* 4. Tipografía ------------------------------------------------ */
h1 { font-size: clamp(1.75rem, 1.2rem + 2.2vw, 2.6rem); }
h2 { font-size: clamp(1.35rem, 1.1rem + 1.1vw, 1.8rem); margin-block: 2.2rem .7rem; }
h3 { font-size: 1.12rem; margin-block: 1.4rem .4rem; }
.prose p, .prose li { color: var(--ink-2); }
.prose p { margin-block: .8rem; }
.prose ul, .prose ol { margin-block: .8rem; padding-left: 1.3rem; }
.prose li { margin-block: .3rem; }
.lead { font-size: 1.08rem; color: var(--ink-2); max-width: 62ch; }

/* 5. Componentes ----------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  padding: .78rem 1.3rem; border-radius: var(--radius-s);
  background: var(--accent); color: var(--accent-ink);
  font-weight: 600; text-decoration: none; line-height: 1.2;
  transition: transform .18s var(--ease-out), filter .18s var(--ease-out), opacity .18s;
  text-align: center;
}
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn[disabled], .btn[aria-disabled="true"] { opacity: .45; cursor: not-allowed; }
.btn--lg { padding: 1rem 1.7rem; font-size: 1.05rem; width: 100%; }
.btn--ghost { background: var(--surface); color: var(--ink); border: 1px solid var(--line-strong); }
.btn--ghost:hover { background: var(--surface-2); filter: none; }
.btn--soft { background: var(--accent-soft); color: var(--accent); }
.btn--soft:hover { filter: none; background: var(--accent-soft); box-shadow: inset 0 0 0 1px var(--accent); }
.btn--sm { padding: .5rem .85rem; font-size: .88rem; border-radius: 8px; }
.btn-row { display: flex; flex-wrap: wrap; gap: .6rem; }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow-s);
}

.field { display: block; margin-block: .9rem; }
.field > span { display: block; font-weight: 600; font-size: .92rem; margin-bottom: .35rem; }
.field small { display: block; font-weight: 400; color: var(--ink-3); font-size: .84rem; }
input[type="text"], input[type="number"], input[type="password"], select, textarea {
  width: 100%; padding: .68rem .8rem; border-radius: 9px;
  border: 1px solid var(--line-strong); background: var(--surface);
  transition: border-color .15s;
}
input:focus, select:focus, textarea:focus { border-color: var(--accent); }
.grid-2 { display: grid; gap: .9rem; grid-template-columns: 1fr; }
@media (min-width: 540px) { .grid-2 { grid-template-columns: 1fr 1fr; } }

/* Segmented control (dificultad, formato…) */
.seg { display: flex; gap: 0; border: 1px solid var(--line-strong); border-radius: 10px; overflow: hidden; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label {
  flex: 1; text-align: center; padding: .55rem .4rem; font-size: .92rem; font-weight: 600;
  cursor: pointer; color: var(--ink-2); background: var(--surface);
  border-right: 1px solid var(--line-strong); transition: background .15s, color .15s;
}
.seg label:last-of-type { border-right: 0; }
.seg input:checked + label { background: var(--accent); color: var(--accent-ink); }
.seg input:focus-visible + label { outline: 2px solid var(--accent); outline-offset: -2px; }

.badge {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .3rem .65rem; border-radius: 999px; font-size: .82rem; font-weight: 600;
  background: var(--accent-soft); color: var(--accent);
}
.badge--ok { background: var(--ok-soft); color: var(--ok); }
.badge--warn { background: var(--warn-soft); color: var(--warn); }
.badge--soon { background: var(--surface-2); color: var(--ink-3); }

.note {
  padding: .8rem 1rem; border-radius: var(--radius-s); font-size: .93rem;
  background: var(--surface-2); color: var(--ink-2); border: 1px solid var(--line);
}
.note--warn { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.note--err { background: var(--err-soft); color: var(--err); border-color: transparent; }
.note--ok { background: var(--ok-soft); color: var(--ok); border-color: transparent; }

/* Cabecera / pie */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .container { display: flex; align-items: center; gap: 1rem; height: 60px; }
.logo { display: inline-flex; align-items: center; gap: .5rem; font-weight: 800; letter-spacing: -.03em; color: var(--ink); font-size: 1.15rem; }
.logo:hover { text-decoration: none; }
.logo-mark {
  width: 28px; height: 28px; border-radius: 8px; display: grid; place-items: center;
  background: var(--accent); color: var(--accent-ink); font-size: .85rem; font-weight: 800;
}
.site-nav { margin-left: auto; display: flex; gap: .3rem; align-items: center; }
.site-nav a { color: var(--ink-2); font-weight: 600; font-size: .93rem; padding: .45rem .7rem; border-radius: 8px; }
.site-nav a:hover { background: var(--surface-2); color: var(--ink); text-decoration: none; }
@media (max-width: 539px) { .site-nav a.is-optional { display: none; } }

.site-footer { border-top: 1px solid var(--line); margin-top: 3.5rem; padding-block: 2rem 2.5rem; color: var(--ink-3); font-size: .9rem; }
.site-footer a { color: var(--ink-2); }
.footer-links { display: flex; flex-wrap: wrap; gap: .4rem 1.1rem; margin-bottom: .8rem; }

/* Layout con lateral de anuncio */
.page { display: grid; gap: 2rem; grid-template-columns: minmax(0, 1fr); align-items: start; }
@media (min-width: 1280px) {
  .page.has-aside { grid-template-columns: minmax(0, 1fr) 300px; }
}

/* 6. Herramienta ----------------------------------------------- */
.tool-intro { padding-top: 1.6rem; }
.tool-intro h1 { margin-bottom: .4rem; }
.tool-card { padding: clamp(1rem, 3vw, 1.6rem); margin-top: 1.2rem; }

.dropzone {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: .5rem; text-align: center;
  padding: clamp(1.4rem, 6vw, 2.6rem) 1rem;
  border: 2px dashed var(--line-strong); border-radius: var(--radius);
  background: var(--surface-2); cursor: pointer;
  transition: border-color .18s, background .18s;
}
.dropzone:hover, .dropzone:focus-within { border-color: var(--accent); background: var(--accent-soft); }
.dropzone.is-over { border-color: var(--accent); background: var(--accent-soft); transform: scale(1.005); }
.dropzone strong { font-size: 1.05rem; }
.dropzone .dz-icon { color: var(--accent); }
.dropzone input[type="file"] { position: absolute; width: 1px; height: 1px; opacity: 0; }

.privacy-badge {
  display: flex; align-items: flex-start; gap: .5rem; margin-top: .9rem;
  font-size: .88rem; color: var(--ink-2);
}
.privacy-badge svg { flex: none; margin-top: 2px; color: var(--ok); }

.progress { height: 8px; border-radius: 999px; background: var(--surface-2); overflow: hidden; }
.progress > i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .25s var(--ease-out); }
.status-line { display: flex; align-items: center; gap: .6rem; margin-bottom: .6rem; font-size: .95rem; color: var(--ink-2); }
.spinner {
  width: 16px; height: 16px; border-radius: 50%; flex: none;
  border: 2px solid var(--line-strong); border-top-color: var(--accent);
  animation: spin .7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Estados de la tarjeta */
.tool-card [data-when] { display: none; }
.tool-card[data-state="idle"]    [data-when~="idle"],
.tool-card[data-state="loading"] [data-when~="loading"],
.tool-card[data-state="config"]  [data-when~="config"],
.tool-card[data-state="working"] [data-when~="working"],
.tool-card[data-state="done"]    [data-when~="done"],
.tool-card[data-state="error"]   [data-when~="error"] { display: block; }
.tool-card [data-when~="flex"] { display: none; }
.tool-card[data-state="config"] [data-when~="config"][data-when~="flex"],
.tool-card[data-state="done"]   [data-when~="done"][data-when~="flex"] { display: flex; }

.file-chip {
  display: flex; align-items: center; gap: .7rem; padding: .7rem .9rem;
  border: 1px solid var(--line); border-radius: var(--radius-s); background: var(--surface-2);
}
.file-chip .fc-name { font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.file-chip .fc-meta { color: var(--ink-3); font-size: .85rem; }
.file-chip button { margin-left: auto; color: var(--ink-3); font-size: .88rem; text-decoration: underline; }

/* Pestañas del documento (examen / resumen / esquema / flashcards) */
.doc-tabs { display: flex; gap: .35rem; flex-wrap: wrap; margin: 1.2rem 0 0; }
.doc-tabs button {
  padding: .5rem .85rem; border-radius: 999px; font-weight: 600; font-size: .9rem;
  background: var(--surface-2); color: var(--ink-2); border: 1px solid transparent;
}
.doc-tabs button[aria-selected="true"] { background: var(--accent); color: var(--accent-ink); }
.doc-tabs button:hover { border-color: var(--line-strong); }

/* Examen */
.quiz-q { padding: 1.1rem 0; border-top: 1px solid var(--line); }
.quiz-q:first-child { border-top: 0; }
.quiz-q .q-head { display: flex; gap: .6rem; align-items: baseline; }
.quiz-q .q-num {
  flex: none; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent); font-size: .8rem; font-weight: 700;
}
.quiz-q .q-text { font-weight: 600; }
.quiz-q .q-text b { background: var(--accent-soft); color: var(--accent); padding: 0 .35em; border-radius: 5px; }
.opts { list-style: none; padding: 0; margin: .7rem 0 0; display: grid; gap: .45rem; }
.opts label {
  display: flex; gap: .6rem; align-items: flex-start; padding: .6rem .8rem;
  border: 1px solid var(--line-strong); border-radius: var(--radius-s);
  cursor: pointer; transition: background .15s, border-color .15s;
}
.opts label:hover { background: var(--surface-2); }
.opts input { margin-top: .3rem; flex: none; accent-color: var(--accent); }
.opts input:checked + span { font-weight: 600; }
.quiz-q.is-right label.is-answer { border-color: var(--ok); background: var(--ok-soft); }
.quiz-q.is-wrong label.is-answer { border-color: var(--ok); background: var(--ok-soft); }
.quiz-q.is-wrong label.is-chosen { border-color: var(--err); background: var(--err-soft); }
.explain {
  margin-top: .7rem; padding: .75rem .9rem; border-left: 3px solid var(--accent);
  background: var(--surface-2); border-radius: 0 var(--radius-s) var(--radius-s) 0; font-size: .93rem;
}
.explain q { display: block; margin-top: .35rem; color: var(--ink-2); font-style: italic; }
.explain .src { display: block; margin-top: .35rem; color: var(--ink-3); font-size: .84rem; }

.score {
  display: flex; align-items: center; gap: 1.1rem; padding: 1.1rem 1.2rem;
  border-radius: var(--radius); background: var(--accent-soft); margin-bottom: 1rem;
}
.score .score-num { font-size: 2.4rem; font-weight: 800; line-height: 1; color: var(--accent); letter-spacing: -.04em; }
.score .score-num small { font-size: 1rem; font-weight: 600; color: var(--ink-3); }

/* Flashcards */
.fc-deck { display: grid; gap: .7rem; }
.flashcard {
  border: 1px solid var(--line-strong); border-radius: var(--radius);
  padding: 1rem 1.1rem; background: var(--surface); cursor: pointer;
}
.flashcard .fc-q { font-weight: 600; }
.flashcard .fc-a { margin-top: .6rem; padding-top: .6rem; border-top: 1px dashed var(--line-strong); color: var(--ink-2); }
.flashcard[aria-expanded="false"] .fc-a { display: none; }
.flashcard .fc-hint { font-size: .82rem; color: var(--ink-3); margin-top: .4rem; }

/* Resumen / esquema */
.outline { list-style: none; padding-left: 0; }
.outline ul { list-style: none; padding-left: 1.1rem; border-left: 1px solid var(--line); margin-left: .35rem; }
.outline li { margin-block: .35rem; }
.outline > li > .o-title { font-weight: 700; }
.outline .o-title { color: var(--ink); }
.outline .o-item { color: var(--ink-2); }
.summary-block p { margin-block: .7rem; }
.summary-block h4 { margin-top: 1.2rem; font-size: 1rem; color: var(--accent); }
mark { background: var(--accent-soft); color: inherit; border-radius: 4px; padding: 0 .2em; }

/* Apuntes limpios y presentación */
.apuntes { max-width: none; }
.apuntes .ap-titulo { font-size: 1.4rem; margin: .2rem 0 1rem; }
.apuntes h4 { color: var(--accent); margin-top: 1.4rem; font-size: 1.08rem; }
.apuntes h5 { margin-top: 1.1rem; font-size: 1rem; }
.apuntes h6 { margin-top: .9rem; font-size: .95rem; font-style: italic; color: var(--ink-2); }
.apuntes .ap-vineta { padding-left: 1.4rem; position: relative; }
.apuntes .ap-vineta::before { content: "•"; position: absolute; left: .3rem; color: var(--accent); }

.diapos { display: grid; gap: .7rem; grid-template-columns: 1fr; }
@media (min-width: 720px) { .diapos { grid-template-columns: 1fr 1fr; } }
.diapo {
  position: relative; padding: .9rem 1rem .9rem 2.2rem; min-height: 150px;
  border: 1px solid var(--line-strong); border-radius: var(--radius-s);
  background: var(--surface); font-size: .85rem;
}
.diapo--portada { display: grid; place-content: center; text-align: center; background: var(--accent-soft); }
.diapo-n {
  position: absolute; top: .4rem; left: .5rem; width: 20px; height: 20px; border-radius: 50%;
  display: grid; place-items: center; background: var(--surface-2); color: var(--ink-3);
  font-size: .7rem; font-weight: 700;
}
.diapo strong { display: block; color: var(--accent); margin-bottom: .4rem; font-size: .95rem; }
.diapo ul { margin: 0; padding-left: 1rem; color: var(--ink-2); }
.diapo li { margin-block: .2rem; }

/* Bibliografía */
#biblio-form label:has(textarea) { grid-column: 1 / -1; }
.referencias { margin-top: .6rem; }
.ref {
  padding-left: 2.2rem; text-indent: -2.2rem;
  margin-block: .9rem; line-height: 1.8; color: var(--ink);
}
.ref-cita { color: var(--ink-3); font-size: .88em; white-space: nowrap; }

/* Planificador de estudio */
.dias-semana { display: flex; gap: .4rem; flex-wrap: wrap; }
.dias-semana label { position: relative; }
.dias-semana input { position: absolute; opacity: 0; pointer-events: none; }
.dias-semana span {
  display: grid; place-items: center; width: 42px; height: 42px; border-radius: 10px;
  border: 1px solid var(--line-strong); background: var(--surface);
  font-weight: 700; cursor: pointer; transition: background .15s, color .15s, border-color .15s;
}
.dias-semana input:checked + span { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }
.dias-semana input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.row-item--tema { grid-template-columns: minmax(0, 1fr) 140px 36px; }
.plan-lista { display: grid; gap: .6rem; margin-top: 1rem; }
.dia-plan { border: 1px solid var(--line); border-radius: var(--radius-s); background: var(--surface); padding: .6rem .8rem; }
.dia-cab { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: .4rem; }
.dia-cab strong { text-transform: capitalize; }
.sesion { display: flex; align-items: center; gap: .6rem; padding: .25rem 0; font-size: .93rem; }
.sesion > span:nth-child(2) { flex: 1; min-width: 0; }
.sesion .muted { font-size: .85rem; white-space: nowrap; }

/* Mapa conceptual */
.mapa-caja {
  overflow-x: auto; padding: .5rem;
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
}
.mapa-caja svg { display: block; margin-inline: auto; max-width: 100%; height: auto; }
.mapa-nodo rect { transition: filter .15s; }
.mapa-nodo:hover rect { filter: brightness(.96); }

/* Rejilla de páginas de un PDF */
.pag-grid {
  display: grid; gap: .7rem; margin-top: 1.2rem;
  grid-template-columns: repeat(auto-fill, minmax(108px, 1fr));
}
.pag {
  position: relative; padding: .4rem; text-align: center; cursor: pointer;
  border: 2px solid var(--line); border-radius: 10px; background: var(--surface);
  overflow: hidden; transition: border-color .15s, background .15s;
}
.pag:hover { border-color: var(--line-strong); }
.pag.is-on { border-color: var(--accent); background: var(--accent-soft); }
.pag-lienzo {
  display: grid; place-items: center; min-height: 120px;
  transition: transform .25s var(--ease-out);
}
.pag-lienzo canvas { max-width: 100%; height: auto; border-radius: 3px; box-shadow: var(--shadow-s); }
.pag-esqueleto { width: 76px; height: 108px; border-radius: 4px; background: var(--surface-2); }
.pag-num { display: block; margin-top: .35rem; font-size: .78rem; font-weight: 600; color: var(--ink-3); }
.pag.is-on .pag-num { color: var(--accent); }
.pag-giro { position: absolute; top: .3rem; right: .45rem; color: var(--accent); opacity: 0; font-size: .95rem; }
.pag.is-on .pag-giro { opacity: 1; }

/* Rejilla de herramientas */
.tool-grid { display: grid; gap: .8rem; grid-template-columns: 1fr; margin-top: 1rem; }
@media (min-width: 540px) { .tool-grid { grid-template-columns: 1fr 1fr; } }
@media (min-width: 960px) { .tool-grid { grid-template-columns: repeat(3, 1fr); } }
.tool-tile {
  display: block; padding: 1rem 1.1rem; border-radius: var(--radius);
  border: 1px solid var(--line); background: var(--surface); box-shadow: var(--shadow-s);
  transition: transform .18s var(--ease-out), box-shadow .18s var(--ease-out), border-color .18s;
  color: var(--ink);
}
a.tool-tile:hover { text-decoration: none; transform: translateY(-2px); box-shadow: var(--shadow); border-color: var(--line-strong); }
.tool-tile .tt-name { font-weight: 700; display: flex; align-items: center; gap: .5rem; }
.tool-tile .tt-desc { color: var(--ink-3); font-size: .9rem; margin-top: .25rem; }
.tool-tile.is-soon { opacity: .62; }
.tool-tile.is-star { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset, var(--shadow-s); }

/* Hero de la home */
.hero { padding-block: clamp(2rem, 6vw, 3.4rem) 1rem; text-align: center; }
.hero h1 { font-size: clamp(2rem, 1.3rem + 3vw, 3.2rem); }
.hero .lead { margin: .8rem auto 0; }
.hero-cta { margin-top: 1.4rem; display: flex; gap: .6rem; justify-content: center; flex-wrap: wrap; }
.cat-nav { display: flex; gap: .5rem; justify-content: center; flex-wrap: wrap; margin-top: 1.6rem; }
.cat-nav a {
  padding: .5rem 1rem; border-radius: 999px; background: var(--surface);
  border: 1px solid var(--line-strong); color: var(--ink); font-weight: 600; font-size: .93rem;
}
.cat-nav a:hover { text-decoration: none; border-color: var(--accent); color: var(--accent); }

.steps { display: grid; gap: 1rem; grid-template-columns: 1fr; margin-top: 1rem; }
@media (min-width: 720px) { .steps { grid-template-columns: repeat(3, 1fr); } }
.step { padding: 1rem 1.1rem; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--line); }
.step .s-num {
  width: 26px; height: 26px; border-radius: 50%; background: var(--accent); color: var(--accent-ink);
  display: grid; place-items: center; font-weight: 700; font-size: .85rem; margin-bottom: .5rem;
}
.step h3 { margin: 0 0 .2rem; font-size: 1rem; }
.step p { color: var(--ink-3); font-size: .92rem; margin: 0; }

/* FAQ */
.faq details {
  border: 1px solid var(--line); border-radius: var(--radius-s);
  background: var(--surface); margin-block: .5rem; overflow: hidden;
}
.faq summary { padding: .85rem 1rem; font-weight: 600; cursor: pointer; list-style: none; display: flex; gap: .6rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; margin-left: auto; color: var(--accent); font-weight: 700; }
.faq details[open] summary::after { content: "−"; }
.faq details > div { padding: 0 1rem 1rem; color: var(--ink-2); }
.faq details > div > p { margin-block: .5rem; }

/* Tabla de notas */
.rows { display: grid; gap: .5rem; margin-top: .6rem; }
.row-item {
  display: grid; gap: .5rem; align-items: end;
  grid-template-columns: minmax(0, 1fr) 84px 84px 36px;
}
.row-item .field { margin: 0; }
.row-item .del { color: var(--ink-3); font-size: 1.2rem; line-height: 1; padding: .55rem 0; }
.row-item .del:hover { color: var(--err); }
.rows-head {
  display: grid; gap: .5rem; grid-template-columns: minmax(0, 1fr) 84px 84px 36px;
  font-size: .82rem; font-weight: 600; color: var(--ink-3);
}
.result-big {
  margin-top: 1.1rem; padding: 1.1rem 1.2rem; border-radius: var(--radius);
  background: var(--accent-soft); display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
}
.result-big .rb-num { font-size: 2.6rem; font-weight: 800; line-height: 1; color: var(--accent); letter-spacing: -.04em; }
.result-big .rb-label { color: var(--ink-2); font-size: .95rem; }

/* 7. Anuncios --------------------------------------------------
   Un hueco solo ocupa sitio cuando lleva un anuncio real dentro: sin código
   de bloque configurado no se ve nada, y si Google no tiene anuncio que
   servir, el espacio se cierra en lugar de quedarse en blanco. */
.ad-slot { display: none; }
.ad-slot--activo {
  display: block; text-align: center; margin-block: 1.6rem;
  overflow: hidden;
}
.ad-slot--activo::before {
  content: "Publicidad"; display: block; margin-bottom: .3rem;
  font-size: .68rem; letter-spacing: .16em; font-weight: 700; color: var(--ink-3);
}
.ad-slot--activo ins.adsbygoogle { display: block; }
ins.adsbygoogle[data-ad-status="unfilled"] { display: none !important; }
.ad-slot--leaderboard.ad-slot--activo { min-height: 100px; }
@media (min-width: 960px) { .ad-slot--leaderboard.ad-slot--activo { min-height: 120px; } }
.ad-slot--incontent.ad-slot--activo { min-height: 250px; }
.ad-slot--aside.ad-slot--activo { min-height: 600px; position: sticky; top: 76px; margin-top: 0; }
@media (max-width: 1279px) { .page-aside { display: none; } }
.ad-slot--dialog.ad-slot--activo { min-height: 250px; width: 100%; margin: 0; }

dialog.ad-dialog {
  border: 0; border-radius: var(--radius); padding: 0; max-width: 420px; width: calc(100% - 2rem);
  background: var(--surface); color: var(--ink); box-shadow: var(--shadow);
}
dialog.ad-dialog::backdrop { background: rgba(10, 12, 24, .55); backdrop-filter: blur(2px); }
.ad-dialog .adg-head { display: flex; align-items: center; gap: .6rem; padding: .9rem 1rem .4rem; }
.ad-dialog .adg-head strong { font-size: .95rem; }
.ad-dialog .adg-close {
  margin-left: auto; width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center;
  background: var(--surface-2); color: var(--ink-2); font-size: 1.1rem; line-height: 1;
}
.ad-dialog .adg-close:hover { background: var(--line); }
.ad-dialog .adg-body { padding: .4rem 1rem 1rem; }
.ad-dialog .adg-foot { padding: 0 1rem 1rem; }

.ad-toast {
  position: fixed; right: 1rem; bottom: 1rem; z-index: 80; width: min(300px, calc(100% - 2rem));
  background: var(--surface); border: 1px solid var(--line-strong); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: .7rem .8rem;
  transform: translateY(140%); transition: transform .35s var(--ease-out);
}
.ad-toast.is-open { transform: translateY(0); }
.ad-toast .adt-head { display: flex; align-items: center; gap: .5rem; font-size: .72rem; letter-spacing: .16em; font-weight: 700; color: var(--ink-3); }
.ad-toast .adt-close { margin-left: auto; color: var(--ink-3); font-size: 1rem; line-height: 1; padding: .1rem .3rem; }
.ad-toast .ad-slot--activo { min-height: 90px; margin: .5rem 0 0; }
.ad-toast .ad-slot--activo::before { content: none; }

/* 8. Responsive extra ------------------------------------------ */
@media (min-width: 720px) {
  .btn--lg { width: auto; }
}

/* 9. Reduced motion -------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .ad-toast { transition: none; }
  .pag-lienzo { transition: none; }
  .spinner { animation-duration: 1.6s; }
}

/* Sin JavaScript */
.nojs-warn { display: none; }
html.no-js .nojs-warn { display: block; }
html.no-js .tool-card [data-when] { display: none !important; }