/* Rumbo a la NASA — hoja de estilos */

:root{
  --azul-espacio:#0b1021;
  --azul-noche:#141c33;
  --azul-nasa:#1b4fd8;
  --azul-claro:#a9c0ff;
  --texto:#1b2130;
  --texto-suave:#4b5568;
  --fondo:#ffffff;
  --fondo-alt:#f5f7fb;
  --borde:#e2e6ef;
  --blanco:#ffffff;
  --radio:14px;
  --ancho:1080px;
  --ancho-lectura:720px;
  --fuente-titulos:"Space Grotesk","Segoe UI",system-ui,-apple-system,Arial,sans-serif;
  --fuente-texto:"Segoe UI",system-ui,-apple-system,Roboto,Helvetica,Arial,sans-serif;
}

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

html{scroll-behavior:smooth;scroll-padding-top:76px;}

body{
  margin:0;
  font-family:var(--fuente-texto);
  color:var(--texto);
  background:var(--fondo);
  font-size:1.06rem;
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;height:auto;display:block;}

a{color:var(--azul-nasa);}
a:hover{color:#12379e;}

h1,h2,h3{font-family:var(--fuente-titulos);line-height:1.2;color:var(--azul-espacio);}

.sr-only,.skip-link{
  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:focus{
  position:fixed;top:10px;left:10px;width:auto;height:auto;clip:auto;
  background:var(--blanco);color:var(--azul-espacio);padding:10px 16px;border-radius:8px;z-index:200;
}

.wrap{max-width:var(--ancho);margin:0 auto;padding:0 22px;}
.wrap--narrow{max-width:var(--ancho-lectura);}

/* ---------- Encabezado y navegación ---------- */

.site-header{background:var(--azul-espacio);color:var(--blanco);}

.nav{
  max-width:var(--ancho);margin:0 auto;padding:14px 22px;
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  position:sticky;top:0;z-index:100;background:rgba(11,16,33,0.92);
  backdrop-filter:saturate(140%) blur(6px);
}

.nav__brand{
  font-family:var(--fuente-titulos);font-weight:700;font-size:1.15rem;
  color:var(--blanco);text-decoration:none;letter-spacing:0.2px;
}

.nav__menu{
  list-style:none;display:flex;gap:22px;margin:0;padding:0;
}
.nav__menu a{
  color:#d7ddec;text-decoration:none;font-size:0.98rem;padding:6px 2px;
  border-bottom:2px solid transparent;
}
.nav__menu a:hover,.nav__menu a:focus{color:var(--blanco);border-bottom-color:var(--azul-nasa);}

.nav__toggle{
  display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px;
}
.nav__toggle span:not(.sr-only){width:26px;height:2px;background:var(--blanco);display:block;}

/* ---------- Portada ---------- */

.hero{
  position:relative;
  min-height:74vh;
  display:flex;align-items:center;
  background:linear-gradient(rgba(9,13,28,0.55),rgba(9,13,28,0.78)),url("assets/img/earth.jpg");
  background-size:cover;background-position:center;
  padding:80px 0;
}
.hero__text{max-width:var(--ancho);margin:0 auto;padding:0 22px;width:100%;}
.hero__eyebrow{
  text-transform:uppercase;letter-spacing:2px;font-size:0.8rem;color:#a9c0ff;margin:0 0 10px;
}
.hero h1{
  color:var(--blanco);font-size:clamp(2.4rem,6vw,4rem);margin:0 0 18px;
}
.hero__lead{
  color:#e7ebf6;font-size:clamp(1.05rem,2.4vw,1.3rem);max-width:36ch;margin:0 0 28px;
}

.btn{
  display:inline-block;background:var(--azul-nasa);color:var(--blanco);
  text-decoration:none;font-weight:600;padding:13px 24px;border-radius:999px;
  font-family:var(--fuente-titulos);
}
.btn:hover{background:#12379e;color:var(--blanco);}

/* Escudo del colegio y del IB */
.crest{
  display:flex;align-items:center;gap:14px;
  background:var(--blanco);color:var(--texto);
  padding:10px 16px;border-radius:14px;
  box-shadow:0 10px 30px rgba(0,0,0,0.28);
  width:max-content;max-width:100%;
  margin-top:40px;
}
.crest img{height:44px;width:auto;display:block;flex:0 0 auto;}
.crest__sep{width:1px;height:34px;background:#d7dbe6;flex:0 0 auto;}
.crest__text{
  font-family:var(--fuente-texto);font-size:0.78rem;line-height:1.35;
  color:var(--texto-suave);
}

@media (min-width:900px){
  .hero__text{position:relative;}
  .crest{position:absolute;right:22px;bottom:0;margin-top:0;}
}

/* ---------- Secciones ---------- */

.section{padding:66px 0;}
.section--alt{background:var(--fondo-alt);border-top:1px solid var(--borde);border-bottom:1px solid var(--borde);}
.section--intro{padding:56px 0;background:var(--fondo-alt);border-bottom:1px solid var(--borde);}

.section__kicker{
  text-transform:uppercase;letter-spacing:2px;font-size:0.78rem;font-weight:600;
  color:var(--azul-nasa);margin:0 0 8px;
}
.section h2{font-size:clamp(1.7rem,3.6vw,2.3rem);margin:0 0 18px;}
.section p{color:var(--texto);}
.section--intro p{color:var(--texto-suave);}

.wrap--narrow > p{margin:0 0 16px;}

/* ---------- Requisitos ---------- */

.req{
  background:var(--blanco);border:1px solid var(--borde);border-radius:var(--radio);
  padding:22px 24px;margin:18px 0;
}
.section--alt .req{box-shadow:0 1px 2px rgba(16,24,48,0.04);}
.req h3{font-size:1.2rem;margin:0 0 10px;}
.req p{margin:0 0 10px;}
.req__source{font-size:0.92rem;color:var(--texto-suave);margin:12px 0 0;}

/* ---------- Pasos ---------- */

.steps{margin:8px 0 0;padding-left:1.2em;}
.steps li{margin:0 0 14px;padding-left:6px;}

/* ---------- Preguntas ---------- */

.faq{border-top:1px solid var(--borde);padding:18px 0;}
.faq:last-child{border-bottom:1px solid var(--borde);}
.faq h3{font-size:1.12rem;margin:0 0 8px;}
.faq p{margin:0;color:var(--texto-suave);}

/* ---------- Fuentes ---------- */

.sources{margin:10px 0 0;padding-left:1.2em;}
.sources li{margin:0 0 22px;}
.sources__title{font-weight:600;color:var(--azul-espacio);margin:0 0 4px;}
.sources li p{margin:0 0 4px;color:var(--texto-suave);}
.sources__link{word-break:break-word;}

/* ---------- Figuras ---------- */

.figure{max-width:var(--ancho);margin:34px auto 0;padding:0 22px;}
.figure img{border-radius:var(--radio);width:100%;}
.figure figcaption{
  font-size:0.9rem;color:var(--texto-suave);margin-top:10px;text-align:center;
}

/* ---------- Pie de página ---------- */

.site-footer{background:var(--azul-espacio);color:#dfe4f2;padding:56px 0 30px;}
.site-footer h2{color:var(--blanco);}
.footer__grid{
  display:flex;gap:40px;align-items:center;justify-content:space-between;flex-wrap:wrap;
}
.footer__grid > div{flex:1 1 320px;}
.footer__title{font-size:1.4rem;margin:0 0 12px;}
.footer__grid p{margin:0 0 10px;}
.footer__url{
  font-family:var(--fuente-titulos);font-weight:600;color:#a9c0ff;
  background:rgba(255,255,255,0.06);padding:8px 14px;border-radius:8px;display:inline-block;
}
.qr{margin:0;background:var(--blanco);padding:14px;border-radius:var(--radio);flex:0 0 auto;}
.qr img{width:200px;height:200px;}
.footer__note{
  max-width:var(--ancho-lectura);margin:36px auto 0;padding:0 22px;
  font-size:0.88rem;color:#9aa4be;text-align:center;
}

/* ---------- Animación de entrada, con red de seguridad ---------- */

.reveal{opacity:1;transform:none;}

@media (prefers-reduced-motion:no-preference){
  .js .reveal{opacity:0;transform:translateY(18px);transition:opacity .6s ease,transform .6s ease;}
  .js .reveal.is-visible{opacity:1;transform:none;}
}

/* ---------- Responsive ---------- */

@media (max-width:760px){
  .nav__toggle{display:flex;}
  .nav__menu{
    position:absolute;top:100%;left:0;right:0;
    flex-direction:column;gap:0;background:var(--azul-espacio);
    max-height:0;overflow:hidden;transition:max-height .3s ease;
  }
  .nav__menu.is-open{max-height:340px;border-top:1px solid rgba(255,255,255,0.12);}
  .nav__menu li{width:100%;}
  .nav__menu a{display:block;padding:14px 22px;border-bottom:1px solid rgba(255,255,255,0.08);}
  .nav__menu a:hover{border-bottom-color:rgba(255,255,255,0.08);}
  .hero{min-height:70vh;}
  .footer__grid{justify-content:center;text-align:center;}
}