/* ==========================================================================
   Structural, reusable page-skeleton classes. No visual styling of contents
   — buttons/text/links inside these wrappers are styled in components.css.
   Mobile-first: base rules = smallest screen, min-width media queries add
   larger-screen overrides only.
   ========================================================================== */

.container {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

section {
  padding: var(--space-2xl) 0;
}

@media (min-width: 768px) {
  section {
    padding: var(--space-3xl) 0;
  }
}

/* ── Three-column grid primitive ── */
.three-col-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .three-col-grid {
    flex-direction: row;
    gap: var(--space-md);
  }

  .three-col-grid .col-1 {
    flex: 33 1 0%;
  }

  .three-col-grid .col-2 {
    flex: 34 1 0%;
  }

  .three-col-grid .col-3 {
    flex: 33 1 0%;
  }
}

/* ── Site header wrapper ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-nav-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav-inner {
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  height: var(--space-2xl);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ── Site footer wrapper ── */
footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-lg) 0 var(--space-xl);
  background: var(--color-surface);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-lg);
}

@media (min-width: 768px) {
  .footer-inner {
    flex-direction: row;
    align-items: flex-end;
  }
}