/* ============================================================
   Ciencia en el Cole — main.css  [DISEÑO ORIGINAL]
   Paleta: fondo claro neutro + acentos púrpura/teal vibrantes
   ============================================================ */

:root {
  /* Acentos de marca — únicos y originales */
  --clr-purple:      #6C63FF;
  --clr-purple-dk:   #4F46E5;
  --clr-purple-lt:   #EEF2FF;
  --clr-teal:        #00C9B1;
  --clr-teal-lt:     #E6FAF8;
  --clr-amber:       #F59E0B;
  --clr-amber-lt:    #FEF3C7;
  --clr-rose:        #F43F5E;
  --clr-lime:        #22C55E;

  /* Página (fondo claro) */
  --clr-bg:      #F5F7FF;
  --clr-card:    #FFFFFF;
  --clr-border:  #E0E7FF;
  --clr-border2: #C7D2FE;

  /* Texto */
  --clr-text:    #1E1B4B;
  --clr-text2:   #4338CA;
  --clr-muted:   #8B8FC9;
  --clr-white:   #FFFFFF;

  /* Visor oscuro (página de lección) */
  --clr-lab:     #12101F;
  --clr-lab2:    #1A1730;
  --clr-lab3:    #221E3A;
  --clr-lab-b:   #2E2952;
  --clr-lab-txt: #C8C5E8;
  --clr-lab-mut: #6E6A96;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --r-xs:  6px;   --r-sm: 10px;  --r-md: 16px;
  --r-lg:  22px;  --r-xl: 32px;  --r-f:  9999px;

  --sh-sm: 0 2px 8px rgba(108,99,255,.12);
  --sh-md: 0 6px 24px rgba(108,99,255,.18);
  --sh-lg: 0 16px 48px rgba(108,99,255,.22);

  --nav-h: 64px;
  --ease:  all .22s cubic-bezier(.4,0,.2,1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0 }
html { scroll-behavior: smooth }
body { font-family: var(--font); -webkit-font-smoothing: antialiased; line-height: 1.6 }
img  { display: block; max-width: 100% }
a    { color: inherit; text-decoration: none }
button { font-family: var(--font); cursor: pointer; border: none; background: none }

::-webkit-scrollbar { width: 5px; height: 5px }
::-webkit-scrollbar-track { background: transparent }
::-webkit-scrollbar-thumb { background: var(--clr-border2); border-radius: 3px }

/* ══════════════════════════════════════════════════
   NAVBAR
══════════════════════════════════════════════════ */
.navbar {
  position: sticky; top: 0; z-index: 200;
  height: var(--nav-h);
  background: rgba(245,247,255,.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--clr-border);
  display: flex; align-items: center;
  padding: 0 28px; gap: 20px;
}

.navbar__brand {
  display: flex; align-items: center; gap: 11px; flex-shrink: 0;
}

.navbar__logo {
  width: 40px; height: 40px;
  background: var(--clr-purple);
  border-radius: var(--r-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 24px;
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(108,99,255,.45);
}

.navbar__text-wrap { display: flex; flex-direction: column; line-height: 1.2 }
.navbar__name { font-size: 15px; font-weight: 800; color: var(--clr-text); letter-spacing: -.4px }
.navbar__sub  { font-size: 10.5px; color: var(--clr-muted); font-weight: 500 }

.navbar__nav { display: flex; align-items: center; gap: 2px; flex: 1; padding: 0 12px }

.navbar__link {
  font-size: 13px; font-weight: 500;
  color: var(--clr-muted);
  padding: 7px 13px; border-radius: var(--r-xs);
  transition: var(--ease);
}
.navbar__link:hover      { color: var(--clr-purple); background: var(--clr-purple-lt) }
.navbar__link--active    { color: var(--clr-purple); background: var(--clr-purple-lt); font-weight: 600 }

.navbar__actions { display: flex; align-items: center; gap: 10px; margin-left: auto }

/* ── Toggle ES/EN ─────────────────────────────────────────── */
.lang-toggle {
  display: flex; align-items: center; gap: 2px;
  background: var(--clr-purple-lt);
  border: 1.5px solid var(--clr-border2);
  border-radius: var(--r-f); padding: 3px;
}
.lang-toggle__btn {
  font-size: 11.5px; font-weight: 700; letter-spacing: .7px;
  padding: 4px 14px; border-radius: var(--r-f);
  color: var(--clr-muted); transition: var(--ease);
}
.lang-toggle__btn--active {
  background: var(--clr-purple); color: var(--clr-white);
  box-shadow: 0 2px 10px rgba(108,99,255,.4);
}
.lang-toggle__btn:not(.lang-toggle__btn--active):hover {
  color: var(--clr-purple);
}

/* ── Volver ───────────────────────────────────────────────── */
.back-btn {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13px; font-weight: 600; color: var(--clr-muted);
  padding: 6px 14px; border-radius: var(--r-f);
  border: 1.5px solid var(--clr-border); background: var(--clr-card);
  transition: var(--ease);
}
.back-btn:hover { color: var(--clr-purple); border-color: var(--clr-border2); background: var(--clr-purple-lt) }

/* ── Footer ───────────────────────────────────────────────── */
.footer {
  background: var(--clr-card); border-top: 1px solid var(--clr-border);
  padding: 24px 28px; text-align: center;
}
.footer__text { font-size: 13px; color: var(--clr-muted) }

/* ── Animaciones ──────────────────────────────────────────── */
@keyframes fadeUp { from{opacity:0;transform:translateY(18px)} to{opacity:1;transform:translateY(0)} }
@keyframes spin   { from{transform:rotate(0)} to{transform:rotate(360deg)} }
@keyframes pulse  { 0%,100%{opacity:1} 50%{opacity:.55} }
@keyframes glow   { 0%,100%{box-shadow:0 0 12px rgba(108,99,255,.3)} 50%{box-shadow:0 0 28px rgba(108,99,255,.7)} }

.fade-up { animation: fadeUp .4s cubic-bezier(.4,0,.2,1) both }

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 768px) {
  .navbar__nav { display: none }
  .navbar { padding: 0 16px }
}