/* ============================================================================
   Proyecto Integrador — Inocuidad alimentaria en lácteos (QFB)
   Estética académica formal: AZUL MARINO + GRIS sobre BLANCO. Texto negro.
   Tipografía: Montserrat (títulos, rúbrica-aprobada) + Open Sans (cuerpo).
   Cumple rúbrica: sobrio, legible, responsive, ligero.
   ============================================================================ */
:root{
  --navy:#15294f; --navy2:#1d3a6b; --navy-soft:#2a4a82;
  --gray:#5b6675; --gray-l:#eef1f6; --gray-l2:#f7f9fc; --line:#dfe5ee;
  --ink:#1a1f2b; --white:#ffffff;
  --accent:#c0392b; /* rojo del logo QFB, solo para detalles mínimos */
  --r:12px; --rs:8px; --sh:0 6px 24px rgba(21,41,79,.10); --sh-s:0 3px 12px rgba(21,41,79,.07);
  --font:"Open Sans",Arial,system-ui,sans-serif; --head:"Montserrat",Arial,sans-serif;
  --wrap:1080px;
}
*{box-sizing:border-box;margin:0;padding:0}
[hidden]{display:none!important}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--white);line-height:1.7;font-size:16.5px}
img{max-width:100%;display:block}
a{color:var(--navy2);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3,h4{font-family:var(--head);color:var(--navy);line-height:1.2;font-weight:700}

/* ---------- Header / marca ---------- */
.site-header{position:sticky;top:0;z-index:50;background:var(--white);box-shadow:var(--sh-s);border-top:3px solid var(--navy)}
.brandbar{max-width:var(--wrap);margin:0 auto;display:flex;align-items:center;justify-content:center;
  gap:22px;padding:14px 20px;text-align:center;flex-wrap:wrap}
.brandbar img{height:62px;width:auto}
.brandbar .inst{display:flex;flex-direction:column;line-height:1.25}
.brandbar .inst strong{font-family:var(--head);color:var(--navy);font-size:1.05rem}
.brandbar .inst span{color:var(--gray);font-size:.86rem}

/* ---------- Navegación ---------- */
.nav{background:var(--navy)}
.nav ul{width:96%;max-width:1700px;margin:0 auto;display:flex;justify-content:space-between;flex-wrap:wrap;list-style:none}
.nav a{display:block;color:#dbe4f3;font-family:var(--head);font-weight:600;font-size:.8rem;
  padding:13px 5px;letter-spacing:0;white-space:nowrap;transition:.2s}
.nav a:hover{background:var(--navy2);color:#fff;text-decoration:none}
.nav a.active{background:var(--white);color:var(--navy)}
.burger{display:none;background:none;border:0;cursor:pointer;padding:14px 18px;flex-direction:column;gap:5px}
.burger span{width:24px;height:2px;background:#fff;display:block}

/* ---------- Layout general ---------- */
.page{max-width:var(--wrap);margin:0 auto;padding:46px 20px 70px}
.page-head{margin-bottom:34px}
.page-head .crumb{display:inline-block;color:var(--gray);font-family:var(--head);font-weight:600;font-size:.8rem;
  text-transform:uppercase;letter-spacing:.12em;margin-bottom:10px}
/* Título grande con la banda gris + barra azul (fusiona el título antes repetido) */
.page-head h1{font-size:clamp(1.7rem,3.6vw,2.5rem);margin-top:0;padding:14px 20px;
  background:linear-gradient(90deg,var(--gray-l),var(--gray-l2) 72%,#fff);
  border-left:6px solid var(--navy);border-radius:0 var(--rs) var(--rs) 0}
.page-head p{color:var(--gray);margin-top:12px;max-width:760px}

h2.sec{font-size:clamp(1.3rem,2.6vw,1.7rem);color:var(--navy);margin:36px 0 14px;
  padding:10px 16px;background:linear-gradient(90deg,var(--gray-l),var(--gray-l2) 72%,#fff);
  border-left:5px solid var(--navy);border-radius:0 var(--rs) var(--rs) 0}
h3.sub{font-size:1.12rem;color:var(--navy2);margin:22px 0 8px}
p{margin-bottom:14px}
ul.list,ol.list{margin:0 0 16px 22px}
ul.list li,ol.list li{margin-bottom:7px}
.lead{font-size:1.08rem;color:#2c3340}
strong{color:var(--navy)}
.cite{display:block;color:var(--gray);font-size:.82rem;font-style:italic;margin-top:-6px;margin-bottom:16px}

/* ---------- Inicio / portada ---------- */
.cover{text-align:center;padding:34px 26px 28px;background:linear-gradient(180deg,var(--gray-l2),#fff);
  border:1px solid var(--line);border-radius:var(--r);box-shadow:var(--sh-s)}
.cover .logos{display:flex;justify-content:center;gap:34px;align-items:center;margin-bottom:18px;flex-wrap:wrap}
.cover .logos img{height:120px}
.cover .school{font-family:var(--head);color:var(--gray);font-weight:600;letter-spacing:.04em;margin-bottom:4px}
.cover h1{font-size:clamp(1.2rem,3.4vw,2.35rem);max-width:920px;margin:10px auto 0;color:var(--navy);
  text-transform:uppercase;letter-spacing:.015em;line-height:1.22;text-wrap:balance;overflow-wrap:break-word}
.cover h1::after{content:"";display:block;width:96px;height:4px;border-radius:2px;margin:18px auto 0;
  background:linear-gradient(90deg,var(--navy),var(--accent))}
.cover .authors{margin:22px auto 0;max-width:640px;background:var(--gray-l);border-radius:var(--r);
  padding:20px 24px}
.cover .authors h4{color:var(--navy);font-size:.82rem;text-transform:uppercase;letter-spacing:.1em;margin-bottom:8px}
.cover .authors ul{list-style:none;display:flex;flex-direction:column;gap:3px}
.cover .authors .meta{margin-top:12px;color:var(--gray);font-weight:600}
.cover-img{margin:30px auto 0;max-width:860px;border-radius:var(--r);box-shadow:var(--sh);overflow:hidden}

/* ---------- Hero de portada (pantalla completa, solo inicio) ---------- */
.hero{position:relative;min-height:100vh;display:grid;place-items:center;text-align:center;
  padding:90px 22px;color:#fff;background:#0c1830 url("img/fondo.webp") center/cover no-repeat}
.hero::before{content:"";position:absolute;inset:0;background:rgba(0,0,0,.80)}
.hero-inner{position:relative;z-index:1;max-width:1120px;margin:0 auto}
.hero h1{color:#fff;font-size:clamp(1.35rem,3.4vw,2.45rem);text-transform:uppercase;letter-spacing:.015em;
  line-height:1.2;text-wrap:balance;text-shadow:0 3px 20px rgba(0,0,0,.75);max-width:1060px;margin:0 auto}
.hero h1::after{content:"";display:block;width:110px;height:4px;border-radius:2px;margin:20px auto 0;
  background:linear-gradient(90deg,#fff,var(--accent))}
.hero-authors{margin-top:26px;text-shadow:0 2px 12px rgba(0,0,0,.8)}
.hero-authors h4{color:#fff;font-size:.82rem;text-transform:uppercase;letter-spacing:.1em;margin-bottom:10px}
.hero-authors ul{list-style:none;display:flex;flex-direction:column;gap:5px;font-size:1.05rem}
.hero-authors .meta{margin-top:14px;font-weight:700;color:#eaf0f9}
@media(max-width:640px){.hero-authors ul{font-size:.96rem}}

.intro-cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin-top:40px}
.icard{display:block;background:var(--white);border:1px solid var(--line);border-radius:var(--r);
  padding:24px;transition:.22s;text-decoration:none}
.icard:hover{transform:translateY(-4px);box-shadow:var(--sh);border-color:var(--navy);text-decoration:none}
.icard i{font-size:1.5rem;color:var(--navy);background:var(--gray-l);width:52px;height:52px;border-radius:12px;
  display:grid;place-items:center;margin-bottom:14px}
.icard h3{font-size:1.15rem;margin-bottom:6px}
.icard p{color:var(--gray);font-size:.92rem;margin:0}
.icard .link-pill{display:inline-block;margin-top:10px;padding:6px 12px;background:var(--navy);color:#fff;
  border-radius:999px;font-size:.78rem;font-weight:600;letter-spacing:.02em}
.icard .link-pill i{font-size:.75rem;margin-right:4px}

/* ---------- Tarjetas de Interacciones (horizontales tipo botón) ---------- */
.act-list{display:flex;flex-direction:column;gap:14px;margin-top:24px}
.act-card{display:flex;align-items:center;gap:18px;background:var(--white);border:1px solid var(--line);
  border-radius:var(--r);padding:16px 20px;text-decoration:none;color:inherit;transition:.22s}
.act-card:hover{transform:translateY(-2px);box-shadow:var(--sh);border-color:var(--navy);text-decoration:none}
.act-card .act-ico{flex-shrink:0;width:44px;height:44px;border-radius:10px;background:var(--gray-l);
  color:var(--navy);font-size:1.15rem;display:grid;place-items:center;margin:0}
.act-card .act-body{flex:1;min-width:0}
.act-card .act-body h3{font-size:1.05rem;margin:0 0 2px;color:var(--navy)}
.act-card .act-body p{color:var(--gray);font-size:.9rem;margin:0;text-align:left;hyphens:none}
.act-card .link-pill{flex-shrink:0;margin:0;padding:8px 16px;background:var(--navy);color:#fff;
  border-radius:999px;font-size:.82rem;font-weight:700;white-space:nowrap}
.act-card .link-pill i{font-size:.75rem;margin-right:4px}
@media(max-width:640px){
  .act-card{flex-wrap:wrap;gap:12px;padding:14px 16px}
  .act-card .act-body{flex:1 1 calc(100% - 60px)}
  .act-card .link-pill{margin-left:auto}
}
/* Aparición escalonada de las tarjetas al hacer scroll (resalta sobre todo en móvil) */
.intro-cards .icard{opacity:0;transform:translateY(26px) scale(.97);
  transition:opacity .6s ease,transform .6s cubic-bezier(.2,.75,.25,1)}
.intro-cards .icard.pop{opacity:1;transform:none}
.intro-cards .icard.pop i{animation:icardIcon .65s cubic-bezier(.2,.75,.25,1) both;animation-delay:var(--d,0ms)}
@keyframes icardIcon{0%{transform:scale(.4) rotate(-10deg);opacity:0}
  60%{transform:scale(1.18) rotate(0)}100%{transform:scale(1)}}
@media(prefers-reduced-motion:reduce){
  .intro-cards .icard{opacity:1;transform:none;transition:none}
  .intro-cards .icard.pop i{animation:none}
}

/* ---------- Bloques de contenido ---------- */
.box{background:var(--gray-l2);border:1px solid var(--line);border-left:4px solid var(--navy-soft);
  border-radius:var(--r);padding:22px 24px;margin:18px 0}
.box.alert{border-left:5px solid var(--accent);background:#fdf3f2}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:24px;align-items:center;margin:22px 0}
.grid2 img{border-radius:var(--r);box-shadow:var(--sh-s)}
.figure{margin:22px 0}
.figure img{border-radius:var(--r);box-shadow:var(--sh-s);width:100%}
.figure figcaption{color:var(--gray);font-size:.84rem;font-style:italic;margin-top:8px;text-align:center}
.pill-row{display:flex;flex-wrap:wrap;gap:10px;margin:16px 0}
.pill{background:var(--navy);color:#fff;font-family:var(--head);font-weight:600;font-size:.84rem;
  padding:6px 14px;border-radius:999px}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:10px 30px}
@media(max-width:760px){.two-col{grid-template-columns:1fr}}

/* tarjetas de patógeno / norma */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:18px 0}
.card{background:var(--white);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;box-shadow:var(--sh-s);transition:.2s}
.card:hover{transform:translateY(-3px);box-shadow:var(--sh);border-color:var(--navy-soft)}
.card .card-h{background:var(--navy);color:#fff;font-family:var(--head);font-weight:700;padding:12px 16px;font-size:1rem}
.card .card-h a{color:#fff;text-decoration:underline;text-underline-offset:2px}
.card .card-h a:hover{opacity:.85}
.card .card-b{padding:16px}
.card h4{color:var(--navy2);font-size:.9rem;margin:10px 0 4px;text-transform:uppercase;letter-spacing:.04em}
.card ul{margin:0 0 0 18px}
.card li{font-size:.92rem;margin-bottom:4px}

/* ---------- Sub-índice de Desarrollo ---------- */
.subindex{position:sticky;top:128px;background:var(--white);border:1px solid var(--line);border-radius:var(--r);
  padding:14px 16px;margin-bottom:26px;z-index:10}
.subindex strong{display:block;font-family:var(--head);color:var(--navy);font-size:.8rem;text-transform:uppercase;
  letter-spacing:.1em;margin-bottom:8px}
.subindex .chips{display:flex;flex-wrap:wrap;gap:8px}
.subindex a{font-size:.85rem;font-family:var(--head);font-weight:600;color:var(--navy2);background:var(--gray-l);
  padding:6px 12px;border-radius:999px}
.subindex a:hover{background:var(--navy);color:#fff;text-decoration:none}
.theme{scroll-margin-top:150px;padding-top:8px;margin-bottom:10px}

/* ---------- Video ---------- */
.video{position:relative;padding-bottom:56.25%;height:0;border-radius:var(--r);overflow:hidden;
  box-shadow:var(--sh-s);margin:16px 0}
.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.video-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px}

/* ---------- Galería ---------- */
.gallery{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.gallery figure{border-radius:var(--r);overflow:hidden;cursor:pointer;box-shadow:var(--sh-s);position:relative;background:#000}
.gallery img{width:100%;aspect-ratio:3/2;object-fit:cover;transition:.4s}
.gallery figure:hover img{transform:scale(1.06);opacity:.85}
.facts{background:var(--navy);color:#fff;border-radius:var(--r);padding:26px 28px;margin:26px 0}
.facts h2{color:#fff}
.facts ul{margin:12px 0 0 20px}
.facts li{margin-bottom:8px}

/* ---------- Referencias ---------- */
.refs{list-style:none;counter-reset:r}
.refs li{position:relative;padding:12px 12px 12px 44px;border-bottom:1px solid var(--line);font-size:.95rem}
.refs li::before{counter-increment:r;content:counter(r);position:absolute;left:0;top:12px;width:30px;height:30px;
  background:var(--navy);color:#fff;border-radius:50%;display:grid;place-items:center;font-family:var(--head);
  font-weight:700;font-size:.82rem}
.refs a{word-break:break-all}

/* ---------- Contacto ---------- */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px;margin-top:10px}
.contact-card{background:var(--gray-l2);border:1px solid var(--line);border-radius:var(--r);padding:24px}
.contact-card h3{margin-bottom:10px}
.contact-card .row{display:flex;align-items:center;gap:12px;margin-bottom:10px}
.contact-card .row i{color:var(--navy);width:34px;height:34px;background:var(--gray-l);border-radius:9px;
  display:grid;place-items:center;flex:0 0 auto}
.social-btn{display:inline-flex;align-items:center;gap:10px;background:var(--navy);color:#fff;font-family:var(--head);
  font-weight:600;padding:11px 18px;border-radius:999px;margin:6px 8px 0 0}
.social-btn:hover{background:var(--navy2);text-decoration:none}

/* ---------- Footer ---------- */
.site-footer{background:var(--navy);color:#cdd8ea;margin-top:50px;padding:40px 20px 20px}
.foot-grid{max-width:var(--wrap);margin:0 auto;display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.foot-grid h4{color:#fff;font-size:.95rem;margin-bottom:10px}
.foot-grid a{color:#cdd8ea}.foot-grid a:hover{color:#fff}
.foot-grid p{margin-bottom:6px;font-size:.92rem}
.foot-copy{max-width:var(--wrap);margin:24px auto 0;padding-top:16px;border-top:1px solid rgba(255,255,255,.15);
  text-align:center;font-size:.82rem;color:#9fb1cf}

/* ---------- Lightbox ---------- */
.lightbox{position:fixed;inset:0;z-index:80;background:rgba(10,18,35,.94);display:grid;place-items:center;padding:30px}
.lightbox img{max-width:92vw;max-height:86vh;border-radius:var(--rs)}
.lb-close{position:absolute;top:18px;right:24px;background:none;border:0;color:#fff;font-size:2rem;cursor:pointer}
.lb-nav{position:absolute;top:50%;transform:translateY(-50%);background:rgba(255,255,255,.15);border:0;color:#fff;
  width:50px;height:50px;border-radius:50%;font-size:1.3rem;cursor:pointer}
.lb-nav:hover{background:var(--navy2)}.lb-prev{left:20px}.lb-next{right:20px}

/* ---------- Popup de video de bienvenida ---------- */
.modal-video{position:fixed;inset:0;z-index:100;background:rgba(10,18,35,.92);display:grid;place-items:center;padding:24px}
.mv-box{position:relative;width:min(880px,94vw)}
.mv-box .video{margin:0;box-shadow:0 12px 44px rgba(0,0,0,.55)}
.mv-close{position:absolute;top:-16px;right:-16px;width:44px;height:44px;border-radius:50%;border:0;
  background:var(--navy);color:#fff;font-size:1.7rem;line-height:1;cursor:pointer;box-shadow:var(--sh)}
.mv-close:hover{background:var(--accent)}
@media(max-width:640px){.mv-close{top:-12px;right:-4px;width:38px;height:38px;font-size:1.4rem}}

/* ---------- Reveal ---------- */
.reveal{opacity:0;transform:translateY(18px);transition:.6s ease}
.reveal.in{opacity:1;transform:none}

/* ---------- Enlaces de contenido + texto justificado ---------- */
.page section:not(.cover) p:not(.cite),
.page section:not(.cover) li{text-align:justify;-webkit-hyphens:auto;hyphens:auto}
.page section p a,.page section li a,h3.sub a{text-decoration:underline;text-underline-offset:2px}
.page section p a:hover,.page section li a:hover,h3.sub a:hover{color:var(--navy)}

/* ---------- Responsive ---------- */
@media(max-width:820px){
  .intro-cards,.cards,.gallery,.video-grid,.contact-grid,.foot-grid{grid-template-columns:1fr 1fr}
  .grid2{grid-template-columns:1fr}
}
@media(max-width:640px){
  body{font-size:16px}
  /* TODO en UNA sola fila: logo uni · título · logo QFB · ☰ hamburguesa */
  .site-header{display:flex;flex-wrap:nowrap;align-items:center;gap:8px;padding:8px 10px}
  .brandbar{flex:1 1 auto;min-width:0;flex-wrap:nowrap;justify-content:flex-start;gap:6px;padding:0}
  .brandbar img{height:42px;flex:0 0 auto}
  .brandbar .inst{flex:1 1 auto;min-width:0;text-align:left}
  .brandbar .inst strong{font-size:.7rem;line-height:1.1}
  .brandbar .inst span{font-size:.58rem;line-height:1.1}
  /* La barra de nav se reduce al botón; el azul queda SOLO en la hamburguesa */
  .nav{flex:0 0 auto;background:transparent;border:0;padding:0;display:flex;align-items:center}
  .burger{display:flex;background:var(--navy);border-radius:8px;padding:11px 13px}
  .burger span{background:#fff}
  /* Menú desplegable: a la DERECHA (bajo la ☰), ancho según contenido, fondo gris claro, texto azul */
  .nav ul{display:none;position:absolute;top:100%;right:10px;left:auto;min-width:200px;max-width:86%;
    flex-direction:column;background:var(--gray-l);box-shadow:var(--sh);border:1px solid var(--line);
    border-radius:10px;overflow:hidden;z-index:60}
  .nav ul.open{display:flex}
  .nav a{color:var(--navy);padding:12px 18px;border-top:1px solid var(--line);text-align:left}
  .nav li:first-child a{border-top:0}
  .nav a:hover{background:#fff;color:var(--navy)}
  .nav a.active{background:#fff;color:var(--navy);font-weight:700;box-shadow:inset 3px 0 0 var(--navy)}
  .cover .logos img{height:84px}
  .intro-cards,.cards,.gallery,.video-grid,.contact-grid,.foot-grid{grid-template-columns:1fr}
  .subindex{position:static}
}