/* ==========================================================================
   Mundial CanSat 2027 — hoja de estilos principal
   Sin dependencias externas (sin Bootstrap ni jQuery). CSS moderno:
   custom properties, Grid/Flexbox, clamp() para tipografía fluida.
   ========================================================================== */

/* ---------- 1. Design tokens ---------- */
:root {
  --font-heading: 'Space Grotesk', 'Segoe UI', sans-serif;
  --font-body: 'Inter', 'Segoe UI', sans-serif;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;

  --shadow-sm: 0 2px 10px rgba(0,0,0,.15);
  --shadow-md: 0 10px 30px rgba(0,0,0,.25);

  --container-w: 1160px;
  --transition: 200ms ease;
}

/*
 * Paleta tomada directamente de la portada de la Guía de Misión CanSat 2027:
 * fondo casi negro/madera oscura, dorado envejecido del cartel (papel),
 * y el azul/cian holográfico con el que brilla el "2027" y el contorno
 * del rover. No se usa ningún color fuera de esta gama.
 */
:root,
:root[data-theme="dark"] {
  --color-bg: #070a12;
  --color-bg-alt: #0d1220;
  --color-surface: rgba(255,255,255,.05);
  --color-surface-strong: rgba(255,255,255,.09);
  --color-border: rgba(120,170,210,.16);
  --color-text: #f1efe6;
  --color-text-muted: #9aa3bd;
  --color-primary: #cd9a4e;
  --color-primary-contrast: #1a1300;
  --color-accent: #35c3f0;
  --color-header-bg: rgba(7,10,18,.72);
}

:root[data-theme="light"] {
  --color-bg: #f7f5f0;
  --color-bg-alt: #ffffff;
  --color-surface: #ffffff;
  --color-surface-strong: #f1ede2;
  --color-border: #e5decb;
  --color-text: #17130d;
  --color-text-muted: #5c5646;
  --color-primary: #9a6a24;
  --color-primary-contrast: #ffffff;
  --color-accent: #0e83ad;
  --color-header-bg: rgba(255,255,255,.8);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --color-bg: #f7f5f0;
    --color-bg-alt: #ffffff;
    --color-surface: #ffffff;
    --color-surface-strong: #f1ede2;
    --color-border: #e5decb;
    --color-text: #17130d;
    --color-text-muted: #5c5646;
    --color-primary: #9a6a24;
    --color-primary-contrast: #ffffff;
    --color-accent: #0e83ad;
    --color-header-bg: rgba(255,255,255,.8);
  }
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body, h1, h2, h3, p, ul, ol, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; background: none; border: 0; color: inherit; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: min(100% - 2.5rem, var(--container-w));
  margin-inline: auto;
}

h1, h2, h3 { font-family: var(--font-heading); font-weight: 700; line-height: 1.15; }
h2 { font-size: clamp(1.7rem, 1.2rem + 2vw, 2.6rem); margin-bottom: .75rem; }
h3 { font-size: 1.15rem; margin-bottom: .4rem; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 999;
  background: var(--color-primary); color: var(--color-primary-contrast);
  padding: .75rem 1.25rem; border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

.section-eyebrow {
  text-transform: uppercase; letter-spacing: .12em; font-size: .78rem;
  font-weight: 600; color: var(--color-accent); margin-bottom: .5rem;
}
.section-lead { color: var(--color-text-muted); max-width: 60ch; margin-bottom: 2rem; }

.text-gradient {
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* ---------- 3. Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: .85rem 1.6rem; border-radius: 999px; font-weight: 600; font-size: .95rem;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
  border: 1px solid transparent;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary { background: var(--color-primary); color: var(--color-primary-contrast); box-shadow: var(--shadow-sm); }
.btn-primary:hover { box-shadow: var(--shadow-md); }
.btn-outline { border-color: var(--color-border); color: var(--color-text); }
.btn-outline:hover { border-color: var(--color-accent); color: var(--color-accent); }
.btn-ghost { color: var(--color-text-muted); }
.btn-ghost:hover { color: var(--color-text); }
.btn-sm { padding: .55rem 1.1rem; font-size: .85rem; }

.link-arrow { color: var(--color-accent); font-weight: 600; display: inline-block; margin-top: 1rem; }
.link-arrow:hover { text-decoration: underline; }

/* ---------- 4. Header ---------- */
.site-header {
  position: fixed; inset: 0 0 auto 0; z-index: 100;
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  background: var(--color-header-bg);
  border-bottom: 1px solid var(--color-border);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding-block: .7rem;
}
.brand { display: flex; align-items: center; gap: .6rem; font-family: var(--font-heading); }
.brand-mark { border-radius: 50%; }
.brand-text { font-size: 1rem; }
.brand-text strong { color: var(--color-primary); margin-left: .2rem; }

.main-nav ul { display: flex; gap: 1.75rem; }
.nav-link {
  font-size: .92rem; font-weight: 500; color: var(--color-text-muted);
  position: relative; padding-block: .25rem;
}
.nav-link::after {
  content: ""; position: absolute; left: 0; bottom: -2px; height: 2px; width: 0;
  background: var(--color-primary); transition: width var(--transition);
}
.nav-link:hover, .nav-link.is-active { color: var(--color-text); }
.nav-link:hover::after, .nav-link.is-active::after { width: 100%; }

.header-actions { display: flex; align-items: center; gap: .5rem; }
.icon-btn {
  width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center;
  color: var(--color-text); transition: background var(--transition);
}
.icon-btn:hover { background: var(--color-surface-strong); }
.icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: block; }
.lang-toggle {
  font-size: .8rem; font-weight: 700; border: 1px solid var(--color-border);
  border-radius: 999px; padding: .3rem .65rem;
}
.lang-toggle:hover { border-color: var(--color-accent); color: var(--color-accent); }

.nav-toggle { display: none; flex-direction: column; gap: 4px; padding: 8px; }
.nav-toggle span { width: 20px; height: 2px; background: currentColor; border-radius: 2px; transition: transform var(--transition), opacity var(--transition); }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

@media (max-width: 860px) {
  .nav-toggle { display: flex; }
  .main-nav {
    position: fixed; inset: 64px 0 auto 0; background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    max-height: 0; overflow: hidden; transition: max-height var(--transition);
  }
  .main-nav.is-open { max-height: 420px; }
  .main-nav ul { flex-direction: column; gap: 0; padding: .5rem 1.25rem 1.25rem; }
  .main-nav li { border-bottom: 1px solid var(--color-border); }
  .nav-link { display: block; padding: .9rem 0; }
  .lang-toggle { display: none; }
}

/* ---------- 5. Hero ---------- */
.hero {
  position: relative; min-height: 100svh; display: flex; align-items: center;
  background-size: cover; background-position: center 18%; overflow: hidden;
  padding-top: 90px;
}
/*
 * El cartel (portada de la Guía de Misión) se deja lo más visible posible:
 * degradado suave de izquierda (donde va el texto) hacia la derecha, y solo
 * un desvanecido inferior para fundir con el resto del sitio. Nada de un
 * velo oscuro plano cubriendo toda la imagen.
 */
.hero-overlay {
  position: absolute; inset: 0;
  background:
    linear-gradient(100deg, rgba(7,10,18,.88) 0%, rgba(7,10,18,.58) 38%, rgba(7,10,18,.12) 62%, rgba(7,10,18,.05) 100%),
    linear-gradient(180deg, rgba(7,10,18,0) 55%, rgba(7,10,18,.65) 85%, var(--color-bg) 100%);
}
:root[data-theme="light"] .hero-overlay {
  background:
    linear-gradient(100deg, rgba(7,10,18,.82) 0%, rgba(7,10,18,.5) 38%, rgba(7,10,18,.14) 62%, rgba(7,10,18,.06) 100%),
    linear-gradient(180deg, rgba(7,10,18,0) 55%, rgba(7,10,18,.55) 85%, var(--color-bg) 100%);
}

@media (max-width: 720px) {
  /* En pantallas angostas el cartel completo no cabe junto al texto:
     se vuelve a un velo más cubriente para que el texto siga siendo legible. */
  .hero { background-position: center 12%; }
  .hero-overlay {
    background: linear-gradient(180deg, rgba(7,10,18,.55) 0%, rgba(7,10,18,.82) 55%, var(--color-bg) 100%);
  }
}
.hero-inner { position: relative; z-index: 1; max-width: 760px; color: #f4f6ff; }
.eyebrow {
  text-transform: uppercase; letter-spacing: .14em; font-size: .8rem; font-weight: 600;
  color: var(--color-primary); margin-bottom: 1rem;
}
.hero h1 { font-size: clamp(2.4rem, 1.6rem + 4vw, 4.4rem); margin-bottom: 1.2rem; }
.hero-lead { font-size: clamp(1rem, .9rem + .4vw, 1.2rem); color: #d7dcf5; max-width: 62ch; margin-bottom: 1rem; }
.hero-dates { color: var(--color-accent); font-weight: 600; margin-bottom: 2rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .85rem; margin-bottom: 2.2rem; }
.hero-social { display: flex; gap: .9rem; }
.hero-social a {
  width: 40px; height: 40px; border: 1px solid rgba(255,255,255,.25); border-radius: 50%;
  display: grid; place-items: center; font-size: 1rem; transition: border-color var(--transition), transform var(--transition);
}
.hero-social a:hover { border-color: var(--color-primary); transform: translateY(-3px); }

.scroll-cue {
  position: absolute; left: 50%; bottom: 28px; transform: translateX(-50%);
  width: 26px; height: 42px; border: 2px solid rgba(255,255,255,.5); border-radius: 999px; z-index: 1;
}
.scroll-cue span {
  position: absolute; top: 6px; left: 50%; width: 4px; height: 8px; margin-left: -2px;
  background: var(--color-primary); border-radius: 999px; animation: scrollCue 1.8s infinite;
}
@keyframes scrollCue { 0% { opacity: 1; top: 6px; } 80% { opacity: 0; top: 22px; } 100% { opacity: 0; } }

/* ---------- 6. Sections ---------- */
.section { padding-block: clamp(3.5rem, 3rem + 3vw, 6rem); }
.section-alt { background: var(--color-bg-alt); }

/* ---------- 7. Countdown ---------- */
.countdown-section { padding-block: clamp(3rem, 2.5rem + 2vw, 4.5rem); text-align: center; }
.countdown {
  display: flex; justify-content: center; gap: clamp(.6rem, 1vw, 1.4rem); margin: 1.8rem 0 .75rem;
  flex-wrap: wrap;
}
.countdown-unit {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 1.1rem 1.4rem; min-width: 92px; backdrop-filter: blur(6px);
}
.countdown-value {
  display: block; font-family: var(--font-heading); font-size: clamp(1.8rem, 1.4rem + 1.6vw, 2.6rem);
  font-weight: 700; color: var(--color-primary); font-variant-numeric: tabular-nums;
}
.countdown-caption { display: block; font-size: .75rem; text-transform: uppercase; letter-spacing: .08em; color: var(--color-text-muted); margin-top: .2rem; }
.countdown-note { color: var(--color-text-muted); font-size: .85rem; }

/* ---------- 8. Mission ---------- */
.mission-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(2rem, 4vw, 4rem); align-items: center; }
.mission-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.stat-card {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 1.4rem; text-align: center; transition: transform var(--transition), border-color var(--transition);
}
.stat-card:hover { transform: translateY(-4px); border-color: var(--color-accent); }
.stat-value { display: block; font-family: var(--font-heading); font-size: 1.6rem; font-weight: 700; color: var(--color-primary); margin-bottom: .3rem; }
.stat-label { font-size: .82rem; color: var(--color-text-muted); }

@media (max-width: 860px) {
  .mission-grid { grid-template-columns: 1fr; }
}

/* ---------- 9. Timeline ---------- */
.timeline { position: relative; max-width: 780px; margin-inline: auto; padding-left: 2.4rem; }
.timeline::before {
  content: ""; position: absolute; left: 9px; top: 8px; bottom: 8px; width: 2px;
  background: linear-gradient(var(--color-primary), var(--color-accent));
}
.timeline-item { position: relative; padding-bottom: 2.1rem; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: ""; position: absolute; left: -2.4rem; top: 4px; width: 18px; height: 18px;
  border-radius: 50%; background: var(--color-bg); border: 3px solid var(--color-primary);
}
.timeline-item-highlight::before { border-color: var(--color-accent); background: var(--color-accent); }
.timeline-date { font-family: var(--font-heading); font-weight: 700; color: var(--color-primary); font-size: .9rem; margin-bottom: .25rem; }
.timeline-item-highlight .timeline-date { color: var(--color-accent); }
.timeline-body {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 1.1rem 1.3rem;
}
.timeline-body p { color: var(--color-text-muted); font-size: .93rem; }

/* ---------- 10. Tabs (Recomendaciones) ---------- */
.tabs { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: 1.75rem; }
.tab-btn {
  padding: .6rem 1.1rem; border-radius: 999px; border: 1px solid var(--color-border);
  color: var(--color-text-muted); font-size: .87rem; font-weight: 600;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.tab-btn:hover { border-color: var(--color-accent); color: var(--color-text); }
.tab-btn.is-active { background: var(--color-primary); color: var(--color-primary-contrast); border-color: var(--color-primary); }

.tab-panel {
  display: none; grid-template-columns: 1fr 1fr; gap: 1rem 1.5rem;
}
.tab-panel.is-active { display: grid; }
.tab-panel li {
  background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 1.1rem 1.3rem; font-size: .93rem; color: var(--color-text-muted);
}
.tab-panel li b { color: var(--color-text); display: block; margin-bottom: .3rem; }

@media (max-width: 720px) {
  .tab-panel { grid-template-columns: 1fr; }
}

/* ---------- 11. Referencias / Cards ---------- */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.25rem; }
.resource-card {
  display: block; background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius-md); padding: 1.5rem; transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.resource-card:hover { transform: translateY(-4px); border-color: var(--color-accent); box-shadow: var(--shadow-sm); }
.resource-tag {
  display: inline-block; font-size: .72rem; text-transform: uppercase; letter-spacing: .08em;
  color: var(--color-accent); font-weight: 700; margin-bottom: .6rem;
}
.resource-card h3 { font-size: 1rem; font-weight: 600; color: var(--color-text); }

/* ---------- 12. CTA ---------- */
.cta-section { text-align: center; }
.cta-inner { max-width: 620px; }
.cta-inner p { color: var(--color-text-muted); margin: .8rem 0 1.75rem; }
.cta-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: .85rem; }

/* ---------- 13. Footer ---------- */
.site-footer { background: var(--color-bg-alt); border-top: 1px solid var(--color-border); padding-block: 3.5rem 2rem; }
.footer-sponsors { display: flex; flex-wrap: wrap; align-items: center; gap: 2.5rem; margin-bottom: 3rem; opacity: .9; }
.footer-grid { display: grid; grid-template-columns: 1.3fr 1fr 1fr; gap: 2rem; margin-bottom: 2.5rem; }
.footer-grid h3 { font-size: .95rem; margin-bottom: .9rem; }
.footer-grid p { color: var(--color-text-muted); font-size: .9rem; }
.footer-links li { margin-bottom: .55rem; }
.footer-links a { color: var(--color-text-muted); font-size: .9rem; }
.footer-links a:hover { color: var(--color-accent); }
.footer-bottom { border-top: 1px solid var(--color-border); padding-top: 1.5rem; color: var(--color-text-muted); font-size: .82rem; }
.footer-bottom p { margin-bottom: .3rem; }

@media (max-width: 720px) {
  .footer-grid { grid-template-columns: 1fr; }
}

/* ---------- 14. Back to top ---------- */
.back-to-top {
  position: fixed; right: 1.4rem; bottom: 1.4rem; width: 46px; height: 46px; border-radius: 50%;
  background: var(--color-primary); color: var(--color-primary-contrast); font-size: 1.2rem;
  display: grid; place-items: center; box-shadow: var(--shadow-md);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity var(--transition), transform var(--transition), visibility var(--transition);
  z-index: 90;
}
.back-to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }

/* ---------- 15. Cookie banner ---------- */
.cookie-banner {
  position: fixed; left: 1rem; right: 1rem; bottom: 1rem; z-index: 200; max-width: 560px; margin-inline: auto;
  background: var(--color-surface-strong); border: 1px solid var(--color-border); border-radius: var(--radius-md);
  padding: 1.25rem 1.4rem; backdrop-filter: blur(10px); box-shadow: var(--shadow-md);
  display: none; flex-direction: column; gap: 1rem;
}
.cookie-banner.is-visible { display: flex; }
.cookie-banner p { font-size: .85rem; color: var(--color-text-muted); }
.cookie-actions { display: flex; justify-content: flex-end; gap: .6rem; }

/* ---------- 16. Guía de Misión: estados y visor ---------- */

/* Botones que reutilizan estilos de enlace/tarjeta pero son <button> */
.link-arrow, .resource-card, .footer-link-btn, .guia-nav-btn {
  font-family: inherit; text-align: left; width: auto;
}
.link-arrow { color: var(--color-accent); font-weight: 600; display: inline-block; margin-top: 1rem; }
.link-arrow:hover { text-decoration: underline; }

.notice-box {
  margin-top: 1.5rem; padding: 1.25rem 1.4rem; border-radius: var(--radius-md);
  background: var(--color-surface); border: 1px solid var(--color-primary);
  border-left-width: 4px;
}
.notice-box p { color: var(--color-text); font-size: .95rem; margin-bottom: .3rem; }
.notice-box p strong { color: var(--color-primary); }
.notice-placeholder { display: block; color: var(--color-text-muted); font-size: .88rem; margin-top: .3rem; }
.notice-placeholder strong { color: var(--color-text); }

.btn-disabled {
  display: inline-flex; align-items: center; justify-content: center;
  padding: .85rem 1.6rem; border-radius: 999px; font-weight: 600; font-size: .95rem;
  border: 1px dashed var(--color-border); color: var(--color-text-muted); cursor: default;
}
.btn-disabled em { font-style: normal; margin-left: .35rem; font-size: .8rem; opacity: .8; }

.guia-nav-btn { color: var(--color-text-muted); }
.guia-nav-btn:not(:disabled):hover { color: var(--color-text); }
.guia-nav-placeholder { color: var(--color-text-muted); opacity: .6; cursor: default; }
.guia-nav-placeholder em { font-style: normal; }

.resource-card-placeholder { cursor: default; opacity: .75; }
.resource-card-placeholder:hover { transform: none; border-color: var(--color-border); box-shadow: none; }
.resource-note { color: var(--color-text-muted); font-size: .82rem; margin-top: .5rem; }

.footer-link-btn { color: var(--color-text-muted); font-size: .9rem; }
.footer-link-btn:hover { color: var(--color-accent); }

/* Estado disponible/oculto controlado por js/guia.js. Mientras un
   elemento [data-guia-link] tiene el atributo `hidden`, se muestra su
   placeholder [data-guia-placeholder] hermano; al revelarse ocurre lo
   contrario. Ver js/guia.js. */
[data-guia-link][hidden] + [data-guia-placeholder] { display: inline-flex; }
[data-guia-placeholder] { display: none; }

/* Visor modal del PDF */
.modal-overlay {
  position: fixed; inset: 0; z-index: 300; display: flex; align-items: center; justify-content: center;
  background: rgba(4,6,12,.75); backdrop-filter: blur(4px); padding: 1.25rem;
}
.modal-overlay[hidden] { display: none; }
.modal {
  width: min(100%, 900px); max-height: 88vh; display: flex; flex-direction: column;
  background: var(--color-bg-alt); border: 1px solid var(--color-border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md); overflow: hidden;
}
.modal-header {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 1rem 1.3rem; border-bottom: 1px solid var(--color-border);
}
.modal-header h2 { font-size: 1.05rem; margin: 0; }
.modal-close {
  width: 34px; height: 34px; border-radius: 50%; font-size: 1.3rem; line-height: 1;
  display: grid; place-items: center; color: var(--color-text-muted);
}
.modal-close:hover { background: var(--color-surface-strong); color: var(--color-text); }
.modal-body { flex: 1; min-height: 60vh; background: #1a1a1a; }
.modal-body iframe { width: 100%; height: 100%; min-height: 60vh; border: 0; display: block; }
.modal-footer { display: flex; justify-content: flex-end; gap: .6rem; padding: 1rem 1.3rem; border-top: 1px solid var(--color-border); }

body.modal-open { overflow: hidden; }

/* ---------- 17. Reveal on scroll ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s ease; }
.reveal.is-visible { opacity: 1; transform: translateY(0); }