/* ============================================================
   Base compartida — reset mínimo y utilidades comunes.
   Deliberadamente corta: cada propuesta define su propio sistema.
   ============================================================ */

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

html { -webkit-text-size-adjust: 100%; }

body, h1, h2, h3, h4, p, figure, blockquote, dl, dd, ul, ol {
  margin: 0;
  padding: 0;
}

/* Prototipos de maqueta: ninguna lista lleva viñeta por defecto. */
ul, ol { list-style: none; }

img, picture, video, canvas, svg {
  display: block;
  max-width: 100%;
}

input, button, textarea, select { font: inherit; color: inherit; }

button {
  background: none;
  border: 0;
  cursor: pointer;
}

a { color: inherit; text-decoration: none; }

body {
  min-height: 100vh;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* --- Accesibilidad --- */

:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 3px;
}

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: 0; left: 50%;
  transform: translate(-50%, -110%);
  z-index: 9999;
  padding: 0.75rem 1.5rem;
  background: #fff;
  color: #000;
  font: 500 0.8rem/1 system-ui, sans-serif;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: transform 0.2s ease;
}
.skip-link:focus { transform: translate(-50%, 0); }

/* Respeta la preferencia del sistema: sin movimiento, sin animaciones. */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ============================================================
   Botón "Volver a propuestas" — único elemento verdaderamente
   compartido por las tres homes. Discreto, pero siempre visible.
   ============================================================ */

.volver {
  position: fixed;
  left: 1.25rem;
  bottom: 1.25rem;
  z-index: 900;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.6rem 1rem 0.6rem 0.85rem;
  font: 500 0.68rem/1 'Jost', system-ui, sans-serif;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #fff;
  background: rgba(18, 18, 18, 0.72);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: background 0.25s ease, border-color 0.25s ease, transform 0.25s ease;
}
.volver:hover {
  background: rgba(18, 18, 18, 0.92);
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
}
.volver svg { width: 12px; height: 12px; flex: none; }

@media (max-width: 640px) {
  .volver {
    left: 0.75rem;
    bottom: 0.75rem;
    padding: 0.5rem 0.8rem 0.5rem 0.7rem;
    font-size: 0.6rem;
  }
}

/* Utilidad de reveal por scroll, compartida por las tres propuestas.
   El estado inicial sólo se aplica si JS está activo (clase en <html>),
   para que sin JS el contenido siga siendo visible. */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(22px);
}
.js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
  transition: opacity 0.9s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.9s cubic-bezier(0.16, 1, 0.3, 1);
}