/* ============================================================
   BALEXUS — Fundamentos de IA
   Infografías en CSS/SVG, sin iframes: la página tiene siete y
   embeberlas costaría medio megabyte. Se revelan al entrar en
   pantalla (clase .visible que añade js/fundamentos.js).

   Regla aprendida a golpes: nada queda en opacity:0 sin salida.
   Si no hay JS, o el visitante pidió menos movimiento, todo se
   ve igual — solo sin la animación de entrada.
   ============================================================ */

.fu-hero { padding-bottom: 32px; }
.fu-hero .px-lede { max-width: 60ch; }

.fu-indice { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 28px; }
.fu-indice a {
    font-family: var(--px-mono); font-size: 12px; color: var(--text-secondary);
    border: 1px solid var(--px-line-strong); border-radius: 100px; padding: 7px 14px;
    text-decoration: none; transition: color .15s, border-color .15s;
}
.fu-indice a:hover { color: var(--accent-primary); border-color: var(--accent-primary); }

.fu-bloque { scroll-margin-top: 80px; }
.fu-texto { color: var(--text-secondary); font-size: 16.5px; max-width: 68ch; margin: 16px 0 0; line-height: 1.65; }
.fu-texto strong { color: var(--text-primary); }
.fu-consecuencia {
    margin-top: 26px; max-width: 68ch; font-size: 15px; color: var(--text-secondary);
    border-left: 2px solid var(--accent-primary); padding-left: 16px; line-height: 1.6;
}
.fu-consecuencia b { color: var(--text-primary); }
.fu-academia { margin-top: 22px; font-size: 13px; color: var(--px-faint); }
.fu-academia a { color: var(--accent-primary); text-decoration: none; border-bottom: 1px solid rgba(56,214,196,.35); }

/* Entrada al hacer scroll */
.fu-viz { margin-top: 32px; opacity: 0; transform: translateY(14px); transition: opacity .55s ease, transform .55s ease; }
.fu-viz.visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
    .fu-viz { opacity: 1 !important; transform: none !important; transition: none; }
}

/* ---------- 01 · predicción de la siguiente palabra ---------- */
.fu-tokens { border: 1px solid var(--px-line-strong); border-radius: 14px; background: var(--bg-card); padding: 28px; }
.fu-frase { font-size: clamp(20px, 2.6vw, 28px); font-weight: 650; color: var(--text-primary); display: flex; flex-wrap: wrap; gap: 10px; align-items: baseline; }
.fu-frase span { opacity: .55; }
.fu-cursor { color: var(--accent-primary); opacity: 1 !important; animation: fuBlink 1s steps(1) infinite; }
@keyframes fuBlink { 50% { opacity: 0; } }
.fu-barras { margin-top: 24px; display: flex; flex-direction: column; gap: 10px; max-width: 560px; }
.fu-barra { display: grid; grid-template-columns: 130px 1fr 44px; gap: 12px; align-items: center; font-size: 13.5px; }
.fu-tok { font-family: var(--px-mono); color: var(--text-primary); }
.fu-barra i { height: 10px; border-radius: 100px; background: var(--px-line-strong); display: block; width: 0; }
.fu-viz.visible .fu-barra i { width: var(--w); transition: width 1.1s cubic-bezier(.2,.7,.3,1); }
.fu-barra:first-child i { background: var(--accent-primary); }
.fu-pct { font-family: var(--px-mono); font-size: 12px; color: var(--px-faint); text-align: right; }
.fu-pie { margin-top: 20px; font-size: 13px; color: var(--px-faint); }
@media (prefers-reduced-motion: reduce) { .fu-barra i { width: var(--w) !important; } }

/* ---------- 02 · generativa vs agéntica ---------- */
.fu-comparar { display: grid; grid-template-columns: 0.85fr 1.15fr; gap: 20px; }
.fu-lado { border: 1px solid var(--px-line-strong); border-radius: 14px; background: var(--bg-card); padding: 24px; }
.fu-lado--destacado { border-color: rgba(56,214,196,.35); }
.fu-lado-tag { font-family: var(--px-mono); font-size: 10.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--px-faint); }
.fu-lado--destacado .fu-lado-tag { color: var(--accent-primary); }
.fu-flujo { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 18px 0 14px; }
.fu-paso { font-size: 13px; color: var(--text-primary); border: 1px solid var(--px-line-strong); border-radius: 8px; padding: 8px 12px; }
.fu-paso--modelo { border-color: rgba(124,107,255,.4); color: var(--accent-secondary); }
.fu-flecha { color: var(--px-faint); }
.fu-ciclo { border: 1px dashed rgba(56,214,196,.4); border-radius: 12px; padding: 12px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; background: var(--px-accent-dim); }
.fu-ciclo-paso { font-size: 12.5px; color: var(--text-secondary); border: 1px solid var(--px-line-strong); border-radius: 8px; padding: 6px 10px; background: var(--bg-card); }
.fu-viz.visible .fu-ciclo-paso { animation: fuPulso 3.6s ease-in-out infinite; }
.fu-ciclo-paso[data-i="2"] { animation-delay: 1.2s; }
.fu-ciclo-paso[data-i="3"] { animation-delay: 2.4s; }
@keyframes fuPulso {
    0%, 66%, 100% { border-color: var(--px-line-strong); color: var(--text-secondary); }
    12%, 40% { border-color: var(--accent-primary); color: var(--text-primary); }
}
.fu-ciclo-vuelta { font-family: var(--px-mono); font-size: 11px; color: var(--accent-primary); width: 100%; }
.fu-lado-pie { font-size: 13px; color: var(--px-faint); }
@media (prefers-reduced-motion: reduce) { .fu-viz.visible .fu-ciclo-paso { animation: none; } }

/* ---------- 03 · tres formas de usarla ---------- */
.fu-formas { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.fu-forma { border: 1px solid var(--px-line); border-radius: 14px; background: var(--bg-card); padding: 24px; position: relative; }
.fu-forma--destacada { border-color: rgba(56,214,196,.35); }
.fu-forma-num { font-family: var(--px-mono); font-size: 11px; color: var(--px-faint); }
.fu-forma h3 { font-size: 17px; margin: 8px 0 8px; color: var(--text-primary); }
.fu-forma-desc { font-size: 14px; color: var(--text-secondary); margin-bottom: 16px; }
.fu-meta { display: flex; flex-direction: column; gap: 12px; margin: 0 0 18px; }
.fu-meta dt { font-family: var(--px-mono); font-size: 10.5px; text-transform: uppercase; letter-spacing: .08em; color: var(--px-faint); margin-bottom: 3px; }
.fu-meta dd { margin: 0; font-size: 13px; color: var(--text-secondary); line-height: 1.5; }
.fu-medidas { display: flex; gap: 18px; border-top: 1px solid var(--px-line); padding-top: 14px; }
.fu-medida { font-size: 11px; color: var(--px-faint); display: flex; align-items: center; gap: 8px; }
.fu-medida b { font-family: var(--px-mono); font-weight: 500; text-transform: uppercase; letter-spacing: .06em; }
.fu-medida i { display: flex; gap: 3px; }
.fu-medida i::before { content: ''; }
.fu-medida i { width: 42px; height: 6px; border-radius: 100px; background: var(--px-line-strong); position: relative; overflow: hidden; }
.fu-medida i::after { content: ''; position: absolute; inset: 0; width: calc(var(--n) * 33.3%); background: var(--accent-primary); border-radius: 100px; }

/* ---------- 04 · fallas y antídotos ---------- */
.fu-fallas { display: flex; flex-direction: column; gap: 14px; }
.fu-falla { display: grid; grid-template-columns: 1fr 40px 1fr; gap: 12px; align-items: stretch; }
.fu-falla-mal, .fu-falla-bien { border: 1px solid var(--px-line); border-radius: 12px; padding: 18px 20px; background: var(--bg-card); }
.fu-falla-mal { border-color: rgba(232,184,107,.28); }
.fu-falla-bien { border-color: rgba(56,214,196,.28); }
.fu-falla b { display: block; font-size: 15px; color: var(--text-primary); margin: 8px 0 6px; }
.fu-falla p { font-size: 13.5px; color: var(--text-secondary); line-height: 1.55; }
.fu-tag-mal, .fu-tag-bien { font-family: var(--px-mono); font-size: 10px; letter-spacing: .1em; text-transform: uppercase; }
.fu-tag-mal { color: var(--px-warm); }
.fu-tag-bien { color: var(--accent-primary); }
.fu-falla-flecha { align-self: center; height: 2px; background: linear-gradient(90deg, rgba(232,184,107,.5), var(--accent-primary)); border-radius: 2px; position: relative; }
.fu-falla-flecha::after { content: '▸'; position: absolute; right: -4px; top: -9px; color: var(--accent-primary); font-size: 12px; }

/* ---------- 05 · casos por segmento ---------- */
.fu-casos { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.fu-caso { border: 1px solid var(--px-line); border-radius: 14px; background: var(--bg-card); padding: 24px; display: flex; flex-direction: column; }
.fu-caso h3 { font-size: 17px; color: var(--text-primary); margin-bottom: 14px; }
.fu-caso ul { list-style: none; padding: 0; margin: 0 0 18px; display: flex; flex-direction: column; gap: 11px; flex: 1; }
.fu-caso li { font-size: 13.5px; color: var(--text-secondary); line-height: 1.5; padding-left: 16px; position: relative; }
.fu-caso li::before { content: '·'; position: absolute; left: 2px; color: var(--accent-primary); font-weight: 700; }
.fu-caso li b { color: var(--text-primary); font-weight: 600; }
.fu-caso-link { font-size: 13.5px; font-weight: 600; color: var(--accent-primary); text-decoration: none; }

/* ---------- 06 · ruta y errores ---------- */
.fu-ruta { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.fu-paso-ruta { border-top: 2px solid var(--px-line-strong); padding-top: 18px; }
.fu-paso-ruta .fu-num { font-family: var(--px-mono); font-size: 12px; color: var(--accent-primary); }
.fu-paso-ruta b { display: block; font-size: 15.5px; color: var(--text-primary); margin: 8px 0 6px; }
.fu-paso-ruta p { font-size: 13.5px; color: var(--text-secondary); line-height: 1.55; }
.fu-errores { margin-top: 24px; border: 1px dashed rgba(232,184,107,.3); border-radius: 12px; padding: 18px 22px; display: flex; flex-wrap: wrap; gap: 10px 14px; align-items: center; }
.fu-errores-tag { font-family: var(--px-mono); font-size: 11px; letter-spacing: .1em; text-transform: uppercase; color: var(--px-warm); }
.fu-error { font-size: 13px; color: var(--text-secondary); border: 1px solid var(--px-line-strong); border-radius: 100px; padding: 6px 13px; background: var(--bg-card); }

.fu-cierre .px-h2 { max-width: 26ch; }
.fu-cierre p { max-width: 56ch; }

@media (max-width: 940px) {
    .fu-comparar, .fu-formas, .fu-casos { grid-template-columns: 1fr; }
    .fu-ruta { grid-template-columns: repeat(2, 1fr); }
    .fu-falla { grid-template-columns: 1fr; }
    .fu-falla-flecha { height: 26px; width: 2px; justify-self: center; background: linear-gradient(180deg, rgba(232,184,107,.5), var(--accent-primary)); }
    .fu-falla-flecha::after { content: '▾'; right: -5px; top: auto; bottom: -6px; }
    .fu-barra { grid-template-columns: 96px 1fr 40px; }
}
@media (max-width: 620px) {
    .fu-ruta { grid-template-columns: 1fr; }
}