/* ============================================================
   layout.css — Container + Grid + Flex utilities + Sections
   ============================================================ */

/* Skip link (accesibilidad) */
.skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-4);
  z-index: var(--z-fixed);
  background: var(--brand-primary);
  color: var(--neutral-50);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: var(--fw-semibold);
  text-decoration: none;
  transition: top var(--t-fast);
}

.skip-link:focus {
  top: var(--space-4);
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-xl);
  margin-inline: auto;
  padding-inline: var(--container-padding);
}

.container-sm { max-width: var(--container-sm); }
.container-md { max-width: var(--container-md); }
.container-lg { max-width: var(--container-lg); }
.container-xl { max-width: var(--container-xl); }
.container-2xl { max-width: var(--container-2xl); }

/* Section */
.section {
  padding-block: var(--space-20);
}

.section-sm { padding-block: var(--space-12); }
.section-lg { padding-block: var(--space-32); }
.section-xl { padding-block: var(--space-40); }

/* Section header */
.section-header {
  margin-bottom: var(--space-12);
  max-width: 65ch;
}

.section-header--center {
  margin-inline: auto;
  text-align: center;
}

/* Grid utilities */
.grid {
  display: grid;
  gap: var(--space-6);
}

.grid-2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr)); }

/* Flex utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-2 { gap: var(--space-2); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Stack (vertical rhythm) */
.stack > * + * { margin-top: var(--space-4); }
.stack-sm > * + * { margin-top: var(--space-2); }
.stack-lg > * + * { margin-top: var(--space-8); }

/* Display */
.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }

/* Width utilities */
.w-full { width: 100%; }
.max-w-prose { max-width: 65ch; }

/* Position */
.relative { position: relative; }
.absolute { position: absolute; }
.sticky { position: sticky; }

/* Text alignment */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* Backgrounds */
.bg-primary { background-color: var(--brand-primary); color: var(--neutral-50); }
.bg-secondary { background-color: var(--neutral-100); }
.bg-accent-soft { background-color: oklch(from var(--brand-accent) l c h / 0.08); }

/* Aspect ratios */
.aspect-video { aspect-ratio: 16 / 9; }
.aspect-square { aspect-ratio: 1; }

/* Visually hidden (accessible) */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Divider */
.divider {
  border: 0;
  height: 1px;
  background: var(--neutral-200);
  margin-block: var(--space-8);
}