/* =====================================================================
   BASE — Reset, tipografía y utilidades. Sin frameworks, sin build step:
   pensado para servirse directamente desde hosting compartido.
   ===================================================================== */

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

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
  max-width: 100%;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  max-width: 100%;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: var(--lh-heading);
  margin: 0 0 var(--space-4);
  color: var(--color-text-primary);
}

p { margin: 0 0 var(--space-4); color: var(--color-text-secondary); }

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

button { font-family: inherit; cursor: pointer; }

ul, ol { margin: 0; padding: 0; list-style: none; }

/* --- Accesibilidad: foco siempre visible --- */
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}

/* --- Contenedor --- */
.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

/* --- Secciones --- */
.section {
  padding-block: var(--space-11);
}
@media (max-width: 720px) {
  .section { padding-block: var(--space-9); }
}

.section-kicker {
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  letter-spacing: var(--tracking-wider);
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
  display: inline-block;
}

.section-title { font-size: var(--fs-h2); letter-spacing: var(--tracking-tight); }
.section-lead {
  font-size: var(--fs-lead);
  color: var(--color-text-secondary);
  max-width: 640px;
}

/* --- Botones --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 15px 28px;
  font-weight: 600;
  font-size: var(--fs-small);
  letter-spacing: 0.01em;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: transform var(--duration-fast) var(--ease-standard),
              box-shadow var(--duration-fast) var(--ease-standard),
              background-color var(--duration-fast) var(--ease-standard);
}

.btn-primary {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
}
.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-accent-glow);
}
.btn-primary:active { transform: translateY(0); }

.btn-ghost {
  background: transparent;
  border-color: var(--color-border-strong);
  color: var(--color-text-primary);
}
.btn-ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}

/* --- Utilidades --- */
.u-visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap;
}

.u-center-text { text-align: center; }

/* --- Sistema de revelado en scroll (progresivo, respeta reduced-motion) --- */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity var(--duration-slow) var(--ease-out-expo),
              transform var(--duration-slow) var(--ease-out-expo);
}
.reveal.in-view { opacity: 1; transform: translateY(0); }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* Retraso escalonado para grupos de tarjetas */
.reveal-group > * { transition-delay: calc(var(--stagger-index, 0) * 70ms); }