/* =========================================================================
   Mates Bachillerato · Estilos generales
   ========================================================================= */

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

:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #f0f2f7;
  --text: #141a2e;
  --muted: #5d6579;
  --border: #e2e6ee;
  --ok: #15803d;
  --ok-soft: #e7f6ed;
  --err: #dc2626;
  --err-soft: #fdeded;
  --warn: #b45309;
  --warn-soft: #fdf4e3;
  --c-1c: #2563eb;
  --c-1s: #0d9488;
  --c-2c: #7c3aed;
  --c-2s: #ea580c;
  --c-def: #4f46e5;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 1px 2px rgb(16 24 40 / .04), 0 6px 20px rgb(16 24 40 / .06);
  --shadow-lg: 0 2px 4px rgb(16 24 40 / .05), 0 16px 40px rgb(16 24 40 / .10);
  --font: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  color-scheme: light;
}

[data-theme="dark"] {
  --bg: #0d1120;
  --surface: #151a2d;
  --surface-2: #1d2338;
  --text: #e8ebf4;
  --muted: #9aa3b8;
  --border: #2a3149;
  --ok: #4ade80;
  --ok-soft: rgb(74 222 128 / .12);
  --err: #f87171;
  --err-soft: rgb(248 113 113 / .12);
  --warn: #fbbf24;
  --warn-soft: rgb(251 191 36 / .12);
  --c-1c: #60a5fa;
  --c-1s: #2dd4bf;
  --c-2c: #a78bfa;
  --c-2s: #fb923c;
  --c-def: #818cf8;
  --shadow: 0 1px 2px rgb(0 0 0 / .3), 0 8px 24px rgb(0 0 0 / .25);
  --shadow-lg: 0 2px 4px rgb(0 0 0 / .3), 0 16px 40px rgb(0 0 0 / .35);
  color-scheme: dark;
}

body {
  --accent: var(--c-def);
  --accent-soft: color-mix(in srgb, var(--accent) 12%, transparent);
  --accent-softer: color-mix(in srgb, var(--accent) 6%, transparent);
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
body[data-curso="1c"] { --accent: var(--c-1c); }
body[data-curso="1s"] { --accent: var(--c-1s); }
body[data-curso="2c"] { --accent: var(--c-2c); }
body[data-curso="2s"] { --accent: var(--c-2s); }

main { flex: 1; }
a { color: var(--accent); }
img { max-width: 100%; }
h1, h2, h3, h4 { line-height: 1.25; letter-spacing: -0.015em; margin: 0 0 .5em; }
h1 { font-size: clamp(1.7rem, 3vw, 2.3rem); font-weight: 800; }
h2 { font-size: 1.45rem; font-weight: 700; }
h3 { font-size: 1.15rem; font-weight: 650; }
p { margin: 0 0 1em; }
button { font: inherit; color: inherit; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }
svg.icon { width: 1.15em; height: 1.15em; flex: none; vertical-align: -0.2em; }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 40px 0; }

/* ---------- Cabecera ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; gap: 20px; height: 64px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.1rem; color: var(--text); text-decoration: none; white-space: nowrap; }
.logo b { color: var(--accent); font-weight: 800; }
.logo-mark {
  display: grid; place-items: center; width: 34px; height: 34px; border-radius: 10px;
  background: var(--accent); color: #fff; font-size: 1.2rem; font-weight: 700;
}
.site-nav { display: flex; gap: 4px; margin-left: 12px; }
.site-nav a {
  padding: 8px 14px; border-radius: 999px; color: var(--muted); text-decoration: none;
  font-weight: 550; font-size: .95rem; transition: background .15s, color .15s;
}
.site-nav a:hover { color: var(--text); background: var(--surface-2); }
.site-nav a.activo { color: var(--accent); background: var(--accent-soft); }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.curso-select select {
  appearance: none; -webkit-appearance: none;
  font: inherit; font-size: .9rem; font-weight: 600; color: var(--accent);
  background: var(--accent-soft) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23888' stroke-width='3'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 12px center;
  border: 1px solid transparent; border-radius: 999px; padding: 8px 34px 8px 14px; cursor: pointer; max-width: 210px;
}
.curso-select select:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.curso-select option { color: var(--text); background: var(--surface); }
.icon-btn {
  display: grid; place-items: center; width: 40px; height: 40px; border-radius: 12px;
  border: 1px solid var(--border); background: var(--surface); cursor: pointer; color: var(--muted);
}
.icon-btn:hover { color: var(--text); }
.nav-toggle { display: none; }

@media (max-width: 860px) {
  .nav-toggle { display: grid; }
  .site-nav {
    display: none; position: absolute; top: 64px; left: 0; right: 0; margin: 0;
    flex-direction: column; padding: 12px 20px 18px; background: var(--surface);
    border-bottom: 1px solid var(--border); box-shadow: var(--shadow);
  }
  .site-nav.abierto { display: flex; }
  .site-nav a { padding: 12px 14px; border-radius: 10px; }
  .header-inner { gap: 10px; }
  .curso-select select { max-width: 150px; }
}
@media (max-width: 420px) {
  .logo span:last-child { display: none; }
}

/* ---------- Botones ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 18px; border-radius: 12px; border: 1px solid var(--border);
  background: var(--surface); color: var(--text); font-weight: 600; font-size: .95rem;
  cursor: pointer; text-decoration: none; transition: transform .1s, background .15s, border-color .15s, box-shadow .15s;
  white-space: nowrap;
}
.btn:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 88%, #000); border-color: transparent; }
.btn-soft { background: var(--accent-soft); border-color: transparent; color: var(--accent); }
.btn-ghost { background: transparent; border-color: transparent; color: var(--muted); }
.btn-ghost:hover { background: var(--surface-2); color: var(--text); }
.btn-sm { padding: 7px 12px; font-size: .88rem; border-radius: 10px; }
.btn-link { background: none; border: 0; padding: 0; color: var(--muted); cursor: pointer; font-weight: 550; display: inline-flex; align-items: center; gap: 6px; }
.btn-link:hover { color: var(--accent); }
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; }

/* ---------- Tarjetas y chips ---------- */
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow);
}
.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 3px 10px; border-radius: 999px;
  font-size: .78rem; font-weight: 600; background: var(--surface-2); color: var(--muted);
}
.chip-accent { background: var(--accent-soft); color: var(--accent); }
.chip-ok { background: var(--ok-soft); color: var(--ok); }
.chip-warn { background: var(--warn-soft); color: var(--warn); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.eyebrow { font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }

/* ---------- Inicio ---------- */
.hero { padding: 64px 0 32px; position: relative; overflow: hidden; }
.hero::before {
  content: ''; position: absolute; inset: -40% -10% auto auto; width: 620px; height: 620px; border-radius: 50%;
  background: radial-gradient(circle, var(--accent-soft), transparent 65%); pointer-events: none;
}
.hero h1 { font-size: clamp(2rem, 5vw, 3.2rem); max-width: 760px; }
.hero h1 span { color: var(--accent); }
.hero .lead { font-size: 1.15rem; color: var(--muted); max-width: 640px; }
.hero-formula { font-size: 1.1rem; color: var(--muted); margin-top: 20px; }

.curso-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
@media (max-width: 960px) { .curso-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .curso-grid { grid-template-columns: 1fr; } }
.curso-card {
  --ca: var(--c-def);
  position: relative; text-align: left; display: flex; flex-direction: column; gap: 4px;
  padding: 22px; border-radius: var(--radius); border: 1.5px solid var(--border); background: var(--surface);
  cursor: pointer; box-shadow: var(--shadow); transition: transform .15s, border-color .15s, box-shadow .15s;
  overflow: hidden;
}
.curso-card::before { content: ''; position: absolute; left: 0; top: 0; right: 0; height: 4px; background: var(--ca); }
.curso-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: color-mix(in srgb, var(--ca) 45%, var(--border)); }
.curso-card.seleccionado { border-color: var(--ca); box-shadow: 0 0 0 4px color-mix(in srgb, var(--ca) 18%, transparent), var(--shadow); }
.curso-card[data-id="1c"] { --ca: var(--c-1c); }
.curso-card[data-id="1s"] { --ca: var(--c-1s); }
.curso-card[data-id="2c"] { --ca: var(--c-2c); }
.curso-card[data-id="2s"] { --ca: var(--c-2s); }
.curso-nivel { font-size: .82rem; font-weight: 700; color: var(--ca); text-transform: uppercase; letter-spacing: .05em; }
.curso-nombre { font-size: 1.3rem; font-weight: 750; }
.curso-asig { color: var(--muted); font-size: .92rem; }
.curso-temas { margin-top: 10px; font-size: .82rem; color: var(--muted); }
.curso-check { position: absolute; top: 16px; right: 16px; color: var(--ca); display: none; }
.curso-card.seleccionado .curso-check { display: block; }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 860px) { .feature-grid { grid-template-columns: 1fr; } }
.feature {
  display: flex; flex-direction: column; gap: 6px; text-decoration: none; color: var(--text);
  transition: transform .15s, box-shadow .15s;
}
.feature:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); }
.feature .icono {
  display: grid; place-items: center; width: 48px; height: 48px; border-radius: 14px;
  background: var(--accent-soft); color: var(--accent); margin-bottom: 10px;
}
.feature .icono svg { width: 24px; height: 24px; }
.feature h3 { margin: 0; }
.feature p { color: var(--muted); margin: 0; font-size: .95rem; }
.feature .ir { margin-top: 12px; color: var(--accent); font-weight: 600; font-size: .92rem; display: inline-flex; gap: 6px; align-items: center; }

.como-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
@media (max-width: 960px) { .como-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .como-grid { grid-template-columns: 1fr; } }
.como-item { padding: 20px; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--border); }
.como-item .num { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: var(--accent); color: #fff; font-weight: 700; margin-bottom: 12px; }
.como-item h3 { font-size: 1rem; margin-bottom: 4px; }
.como-item p { font-size: .92rem; color: var(--muted); margin: 0; }

.section-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.section-head h2 { margin: 0; }

/* ---------- Progreso ---------- */
.progreso-panel { display: grid; grid-template-columns: 1.4fr 1fr; gap: 20px; }
@media (max-width: 860px) { .progreso-panel { grid-template-columns: 1fr; } }
.tema-progreso { display: grid; grid-template-columns: 1fr auto; gap: 4px 12px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--border); }
.tema-progreso:last-child { border-bottom: 0; }
.tema-progreso .nombre { font-weight: 600; }
.tema-progreso .dato { font-size: .85rem; color: var(--muted); }
.barra { grid-column: 1 / -1; height: 8px; border-radius: 999px; background: var(--surface-2); overflow: hidden; }
.barra > span { display: block; height: 100%; border-radius: inherit; background: var(--accent); transition: width .5s ease; }
.recomendacion { display: flex; gap: 12px; padding: 14px; border-radius: 12px; background: var(--accent-softer); border: 1px solid var(--accent-soft); margin-bottom: 10px; text-decoration: none; color: var(--text); }
.recomendacion:hover { border-color: var(--accent); }
.recomendacion .icono { color: var(--accent); margin-top: 2px; }
.recomendacion strong { display: block; }
.recomendacion span { font-size: .9rem; color: var(--muted); }
.informe-form { display: flex; gap: 8px; margin-top: 16px; flex-wrap: wrap; }
.input {
  font: inherit; color: var(--text); background: var(--surface); border: 1.5px solid var(--border);
  border-radius: 12px; padding: 10px 14px; min-width: 0; flex: 1;
}
.input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }

/* ---------- Disposición con barra lateral ---------- */
.page-head { padding: 32px 0 8px; }
.page-head p { color: var(--muted); max-width: 680px; }
.layout { display: grid; grid-template-columns: 270px minmax(0, 1fr); gap: 28px; padding-top: 20px; padding-bottom: 56px; align-items: start; }
.layout > * { min-width: 0; }
.sidebar { min-width: 0; position: sticky; top: 84px; display: flex; flex-direction: column; gap: 18px; max-height: calc(100vh - 100px); overflow: auto; padding-bottom: 8px; }
.side-group h4 { font-size: .75rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 6px 10px; }
.side-link {
  display: flex; flex-direction: column; gap: 6px; width: 100%; text-align: left; padding: 10px 12px; border-radius: 12px;
  border: 0; background: none; cursor: pointer; color: var(--text); font-weight: 550; font-size: .95rem; text-decoration: none;
}
.side-link:hover { background: var(--surface-2); }
.side-link.activo { background: var(--accent-soft); color: var(--accent); }
.side-link .mini { display: flex; align-items: center; gap: 8px; font-size: .78rem; color: var(--muted); font-weight: 500; }
.side-link .mini .barra { flex: 1; height: 5px; }
@media (max-width: 900px) {
  .layout { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .sidebar { position: static; max-height: none; flex-direction: row; overflow-x: auto; gap: 8px; padding-bottom: 6px; }
  .side-group { display: contents; }
  .side-group h4 { display: none; }
  .side-link { width: auto; flex: none; white-space: nowrap; border: 1px solid var(--border); background: var(--surface); padding: 8px 14px; border-radius: 999px; }
  .side-link .mini { display: none; }
}

.vacio { text-align: center; padding: 56px 24px; }
.vacio .icono { display: inline-grid; place-items: center; width: 64px; height: 64px; border-radius: 20px; background: var(--accent-soft); color: var(--accent); margin-bottom: 16px; }
.vacio .icono svg { width: 30px; height: 30px; }

/* ---------- Apuntes ---------- */
.tema-head { margin-bottom: 20px; }
.tema-head p { color: var(--muted); }
.toc { margin-bottom: 24px; padding: 16px 20px; }
.toc h4 { font-size: .8rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 8px; }
.toc ol { margin: 0; padding-left: 20px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 40px; }
.toc li { margin: 2px 0; }
.toc a { color: var(--text); text-decoration: none; }
.toc a:hover { color: var(--accent); }
@media (max-width: 600px) { .toc ol { grid-template-columns: 1fr; } }

.apunte { font-size: 1.04rem; line-height: 1.75; padding: 36px clamp(20px, 4vw, 48px); }
.apunte h2 { margin: 1.8em 0 .6em; padding-left: 14px; border-left: 4px solid var(--accent); scroll-margin-top: 90px; }
.apunte h2:first-child { margin-top: 0; }
.apunte h3 { margin: 1.5em 0 .5em; }
.apunte h4 { margin: 1.2em 0 .4em; font-size: 1rem; }
.apunte ul, .apunte ol { padding-left: 1.4em; margin: 0 0 1em; }
.apunte li { margin: .3em 0; }
.apunte .katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
.apunte .centro { text-align: center; }
.apunte blockquote { margin: 0 0 1em; padding: 4px 16px; border-left: 3px solid var(--border); color: var(--muted); }
.apunte code { font-size: .9em; background: var(--surface-2); padding: 1px 6px; border-radius: 6px; }
.apunte .sc { font-variant: small-caps; }
.apunte-img { display: block; margin: 16px auto; border-radius: 10px; }
.tabla-wrap { overflow-x: auto; margin: 0 0 1.2em; }
.tabla { border-collapse: collapse; min-width: 60%; margin: 0 auto; font-size: .97rem; }
.tabla th, .tabla td { border: 1px solid var(--border); padding: 8px 14px; text-align: center; }
.tabla th { background: var(--surface-2); font-weight: 650; }

.caja {
  --cc: var(--accent);
  margin: 1.2em 0; padding: 16px 20px; border-radius: 12px;
  background: color-mix(in srgb, var(--cc) 7%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--cc) 22%, transparent);
  border-left: 4px solid var(--cc);
}
.caja > :last-child { margin-bottom: 0; }
.caja-titulo { font-weight: 700; color: var(--cc); margin-bottom: 6px; font-size: .95rem; }
.caja-sub { font-weight: 500; color: var(--muted); }
.caja-teo { --cc: #7c3aed; }
.caja-ej { --cc: #059669; }
.caja-obs { --cc: #d97706; }
.caja-imp { --cc: #dc2626; }
.caja-dem { --cc: var(--muted); background: transparent; }
[data-theme="dark"] .caja-teo { --cc: #a78bfa; }
[data-theme="dark"] .caja-ej { --cc: #34d399; }
[data-theme="dark"] .caja-obs { --cc: #fbbf24; }
[data-theme="dark"] .caja-imp { --cc: #f87171; }
.caja-libre { --cc: var(--caja); }
[data-theme="dark"] .caja-libre { --cc: color-mix(in srgb, var(--caja) 55%, white); }
.caja-libre > .caja-titulo { font-size: 1rem; }

/* Elementos de los apuntes importados de LaTeX */
.apunte hr { border: 0; border-top: 1px solid var(--border); margin: 1.2em 0; }
.apunte .fs-xl { font-size: 1.45em; }
.apunte .fs-l { font-size: 1.25em; }
.apunte .fs-m { font-size: 1.1em; }
.apunte .fs-s { font-size: .9em; }
.apunte .fs-xs { font-size: .8em; }
.apunte .fbox { display: inline-block; border: 1px solid currentColor; border-radius: 6px; padding: 2px 10px; }
.apunte .marcado { padding: 0 4px; border-radius: 4px; }
[data-theme="dark"] .apunte .marcado { color: #111827; }
[data-theme="dark"] .apunte span[style^="color"] { filter: brightness(1.7); }
.apunte .leyenda { display: block; font-size: .88em; color: var(--muted); text-align: center; margin-top: 4px; }
.apunte .figura { margin: 1em 0; text-align: center; }
.apunte .minipagina { display: inline-block; vertical-align: top; width: calc(var(--w) - 2%); margin-right: 2%; }
.apunte .multicol { column-count: var(--cols); column-gap: 2.5rem; }
.apunte .multicol > * { break-inside: avoid; }
.apunte-img { max-width: 100%; height: auto; background: #fff; padding: 6px; }
@media (max-width: 700px) {
  .apunte .minipagina { display: block; width: 100%; margin-right: 0; }
  .apunte .multicol { column-count: 1; }
  /* Fórmulas largas que no caben: se desplazan dentro de su párrafo, no la página */
  .apunte p, .apunte li, .apunte .minipagina { overflow-x: auto; overflow-y: hidden; }
}
.apunte .centro .caja { text-align: left; }
/* El MathML oculto de KaTeX va en posición absoluta: así se queda dentro de su fórmula */
.katex { position: relative; }

/* ---------- Vídeos ---------- */
.filtros { display: flex; flex-wrap: wrap; gap: 8px; margin: 8px 0 24px; }
.filtro {
  padding: 8px 16px; border-radius: 999px; border: 1px solid var(--border); background: var(--surface);
  cursor: pointer; font-weight: 550; font-size: .92rem; color: var(--muted);
}
.filtro:hover { color: var(--text); }
.filtro.activo { background: var(--accent); border-color: var(--accent); color: #fff; }
.video-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; padding-bottom: 56px; }
@media (max-width: 400px) { .video-grid { grid-template-columns: 1fr; } }
.video-card { padding: 0; overflow: hidden; display: flex; flex-direction: column; }
.video-media { position: relative; aspect-ratio: 16 / 9; background: var(--surface-2); }
.video-media iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video-play { position: absolute; inset: 0; width: 100%; border: 0; padding: 0; cursor: pointer; background: #000; }
.video-play img { width: 100%; height: 100%; object-fit: cover; opacity: .9; transition: opacity .2s; }
.video-play:hover img { opacity: 1; }
.video-play .boton {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  display: grid; place-items: center; width: 64px; height: 64px; border-radius: 50%;
  background: rgb(255 255 255 / .92); color: #111; box-shadow: 0 8px 24px rgb(0 0 0 / .3);
}
.video-play .boton svg { width: 26px; height: 26px; margin-left: 3px; }
.video-pendiente {
  position: absolute; inset: 0; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
  color: var(--muted); text-align: center; padding: 16px;
  background: repeating-linear-gradient(135deg, var(--surface-2) 0 14px, color-mix(in srgb, var(--surface-2) 70%, var(--surface)) 14px 28px);
}
.video-pendiente svg { width: 34px; height: 34px; color: var(--accent); }
.video-info { padding: 16px 18px 18px; display: flex; flex-direction: column; gap: 6px; flex: 1; }
.video-info h3 { font-size: 1.02rem; margin: 0; }
.video-info p { font-size: .9rem; color: var(--muted); margin: 0; }
.video-info .acciones { margin-top: auto; padding-top: 8px; display: flex; gap: 14px; flex-wrap: wrap; font-size: .88rem; }
.video-info .acciones a { text-decoration: none; font-weight: 600; display: inline-flex; align-items: center; gap: 4px; }

/* ---------- Práctica ---------- */
.ej-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 16px; }
.ej-card {
  display: flex; flex-direction: column; gap: 10px; text-align: left; cursor: pointer; padding: 20px;
  transition: transform .15s, box-shadow .15s, border-color .15s;
}
.ej-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.ej-card h3 { margin: 0; font-size: 1.05rem; }
.ej-card .pie { margin-top: auto; display: flex; align-items: center; justify-content: space-between; font-size: .85rem; color: var(--muted); }
.nivel { display: inline-flex; gap: 3px; align-items: center; }
.nivel i { width: 7px; height: 7px; border-radius: 50%; background: var(--border); }
.nivel i.on { background: var(--accent); }

.player { max-width: 820px; }
.player-head { margin: 14px 0 18px; }
.player-head h1 { font-size: clamp(1.5rem, 3vw, 2rem); margin: 8px 0 0; }
.pasos-progreso { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; font-size: .88rem; color: var(--muted); font-weight: 550; }
.pasos-progreso .barra { flex: 1; }
.enunciado { margin-bottom: 18px; border-top: 4px solid var(--accent); }
.etiqueta { font-size: .75rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
.enunciado-texto { font-size: 1.08rem; }
.enunciado-texto .katex-display { margin: .6em 0; overflow-x: auto; overflow-y: hidden; }
.figura { margin-top: 12px; display: flex; justify-content: center; }
.figura svg { max-width: 320px; width: 100%; height: auto; }
.svg-grid { stroke: var(--border); stroke-width: 1; }
.svg-eje { stroke: var(--muted); stroke-width: 1.5; }
.svg-recta { stroke: var(--muted); stroke-width: 1.5; stroke-dasharray: 5 4; }
.svg-region { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 2.5; stroke-linejoin: round; }
.svg-punto { fill: var(--accent); }
.svg-texto { fill: var(--muted); font-size: 11px; font-family: var(--font); }

.pasos { display: flex; flex-direction: column; gap: 14px; }
.paso { padding: 20px 22px; border-left: 4px solid var(--border); animation: aparecer .35s ease; }
.paso.activo { border-left-color: var(--accent); box-shadow: var(--shadow-lg); }
.paso.hecho { border-left-color: var(--ok); }
.paso.visto { border-left-color: var(--warn); }
@keyframes aparecer { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.paso-num { font-size: .78rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin-bottom: 6px; display: flex; align-items: center; gap: 8px; }
.paso.hecho .paso-num { color: var(--ok); }
.paso.visto .paso-num { color: var(--warn); }
.paso-texto { margin-bottom: 14px; }
.paso-texto .katex-display { overflow-x: auto; overflow-y: hidden; }
.resp-fila { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.resp-fila .prefijo { font-size: 1.05rem; }
.resp-fila .input { flex: 1 1 220px; font-size: 1.05rem; font-family: ui-monospace, 'Cascadia Code', Consolas, monospace; }
.preview { min-height: 1.6em; margin-top: 8px; font-size: .92rem; color: var(--muted); display: flex; gap: 8px; align-items: baseline; flex-wrap: wrap; }
.preview .katex { color: var(--text); font-size: 1.12em; }
.ayuda-formato { font-size: .8rem; color: var(--muted); margin-top: 4px; }
.ayuda-formato code { background: var(--surface-2); padding: 1px 5px; border-radius: 5px; font-size: .95em; }
.paso-acciones { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
.paso-acciones .btn.destacar { animation: latido 1.2s ease 2; background: var(--warn-soft); color: var(--warn); }
@keyframes latido { 50% { transform: scale(1.05); } }
.respuesta-dada { font-size: .95rem; color: var(--muted); margin-bottom: 4px; }
.respuesta-dada .katex { color: var(--text); }

.matriz-wrap { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.matriz {
  display: inline-grid; gap: 8px; padding: 8px 12px; position: relative;
}
.matriz::before, .matriz::after {
  content: ''; position: absolute; top: 0; bottom: 0; width: 10px; border: 2px solid var(--muted);
}
.matriz::before { left: 0; border-right: 0; border-radius: 10px 0 0 10px; }
.matriz::after { right: 0; border-left: 0; border-radius: 0 10px 10px 0; }
.matriz .input { width: 72px; text-align: center; flex: none; padding: 8px 6px; font-family: ui-monospace, Consolas, monospace; }

.opciones { display: grid; gap: 10px; }
.opcion {
  display: flex; align-items: center; gap: 12px; text-align: left; padding: 12px 16px; border-radius: 12px;
  border: 1.5px solid var(--border); background: var(--surface); cursor: pointer; font-size: 1rem; transition: border-color .15s, background .15s;
}
.opcion:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-softer); }
.opcion .letra { display: grid; place-items: center; width: 28px; height: 28px; border-radius: 8px; background: var(--surface-2); font-weight: 700; font-size: .85rem; flex: none; }
.opcion.mal { border-color: var(--err); background: var(--err-soft); opacity: .75; cursor: default; }
.opcion.bien { border-color: var(--ok); background: var(--ok-soft); }
.opcion:disabled { cursor: default; }

.fb { display: flex; gap: 12px; padding: 14px 16px; border-radius: 12px; margin-top: 14px; font-size: .97rem; animation: aparecer .25s ease; }
.fb > svg { margin-top: 3px; }
.fb > div > :last-child { margin-bottom: 0; }
.fb-ok { background: var(--ok-soft); color: var(--text); }
.fb-ok > svg { color: var(--ok); }
.fb-err { background: var(--err-soft); }
.fb-err > svg { color: var(--err); }
.fb-warn { background: var(--warn-soft); }
.fb-warn > svg { color: var(--warn); }
.fb-pista { background: var(--accent-softer); border: 1px dashed color-mix(in srgb, var(--accent) 40%, transparent); }
.fb-pista > svg { color: var(--accent); }
.fb-titulo { font-weight: 700; display: block; margin-bottom: 2px; }

.final { margin-top: 20px; }
.resultado { text-align: center; padding: 32px 24px; }
.anillo {
  --p: 0; width: 132px; height: 132px; border-radius: 50%; margin: 0 auto 16px; display: grid; place-items: center;
  background: conic-gradient(var(--accent) calc(var(--p) * 1%), var(--surface-2) 0);
}
.anillo span { display: grid; place-items: center; width: 104px; height: 104px; border-radius: 50%; background: var(--surface); font-size: 1.8rem; font-weight: 800; }
.resumen-pasos { list-style: none; padding: 0; margin: 20px auto; max-width: 420px; text-align: left; }
.resumen-pasos li { display: flex; align-items: center; gap: 10px; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: .94rem; }
.resumen-pasos li:last-child { border-bottom: 0; }
.resumen-pasos .ok { color: var(--ok); }
.resumen-pasos .medio { color: var(--warn); }
.resumen-pasos .no { color: var(--err); }
.resultado .btn-row { justify-content: center; }

/* ---------- Pie ---------- */
.site-footer { border-top: 1px solid var(--border); padding: 28px 0; color: var(--muted); font-size: .88rem; }
.site-footer .container { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* ---------- Impresión de apuntes ---------- */
@media print {
  .site-header, .sidebar, .site-footer, .no-print, .toc { display: none !important; }
  body { background: #fff; color: #000; }
  .layout { display: block; padding: 0; }
  .card { box-shadow: none; border: 0; padding: 0; }
  .caja { break-inside: avoid; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}