/* ============================================================
   layout.css — design system v0 — header/footer/main + utilities
   Owner: xilrian-agent (XA) · 2026-05-08
   ============================================================
   Pré-requis : tokens.css + base.css.
   ============================================================ */

/* ----- Container — wrapper avec padding cohérent + max-width ----- */
.ds-container {
  width: 100%;
  margin-inline: auto;
  padding-inline: var(--ds-page-padding-x);
  max-width: var(--ds-container-base);
}

.ds-container--narrow { max-width: var(--ds-container-narrow); }
.ds-container--wide   { max-width: var(--ds-container-wide); }
.ds-container--full   { max-width: var(--ds-container-full); }

/* ----- Page skeleton — sticky footer pattern ----- */
.ds-page {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
}

.ds-page__main {
  flex: 1 0 auto;
  padding-block: var(--ds-space-6);
}

@media (min-width: 768px) {
  .ds-page__main {
    padding-block: var(--ds-space-7);
  }
}

/* ----- Header ----- */
.ds-header {
  width: 100%;
  padding-block: var(--ds-space-3);
  border-bottom: var(--ds-border-width-1) solid var(--surface-color-rule, #e0e0e0);
  background-color: var(--surface-color-header-bg, transparent);
}

.ds-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--ds-space-4);
}

.ds-header__brand {
  display: inline-flex;
  align-items: center;
  gap: var(--ds-space-2);
  font-weight: var(--ds-font-weight-semibold);
  font-size: var(--ds-font-size-lg);
  text-decoration: none;
  color: inherit;
}

.ds-header__brand:hover {
  text-decoration: none;
}

/* ----- Footer ----- */
.ds-footer {
  flex: 0 0 auto;
  width: 100%;
  padding-block: var(--ds-space-5);
  border-top: var(--ds-border-width-1) solid var(--surface-color-rule, #e0e0e0);
  font-size: var(--ds-font-size-sm);
  color: var(--surface-color-muted, #666);
  background-color: var(--surface-color-footer-bg, transparent);
}

.ds-footer__inner {
  display: flex;
  flex-direction: column;
  gap: var(--ds-space-3);
}

@media (min-width: 768px) {
  .ds-footer__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.ds-footer__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--ds-space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

/* ----- Grid utilities ----- */
.ds-grid {
  display: grid;
  gap: var(--ds-space-4);
}

.ds-grid--cols-2 { grid-template-columns: repeat(1, 1fr); }
.ds-grid--cols-3 { grid-template-columns: repeat(1, 1fr); }
.ds-grid--cols-4 { grid-template-columns: repeat(1, 1fr); }

@media (min-width: 640px) {
  .ds-grid--cols-2 { grid-template-columns: repeat(2, 1fr); }
  .ds-grid--cols-3 { grid-template-columns: repeat(2, 1fr); }
  .ds-grid--cols-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .ds-grid--cols-3 { grid-template-columns: repeat(3, 1fr); }
  .ds-grid--cols-4 { grid-template-columns: repeat(4, 1fr); }
}

/* ----- Stack — vertical rhythm utility ----- */
.ds-stack {
  display: flex;
  flex-direction: column;
  gap: var(--ds-space-4);
}

.ds-stack--tight   { gap: var(--ds-space-2); }
.ds-stack--snug    { gap: var(--ds-space-3); }
.ds-stack--loose   { gap: var(--ds-space-6); }
.ds-stack--xloose  { gap: var(--ds-space-8); }

/* ----- Cluster — horizontal flow with wrapping ----- */
.ds-cluster {
  display: flex;
  flex-wrap: wrap;
  gap: var(--ds-space-3);
  align-items: center;
}

/* ----- Visually hidden (a11y) ----- */
.ds-visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ----- Skip link (a11y) ----- */
.ds-skip-link {
  position: absolute;
  top: -100px;
  left: var(--ds-space-2);
  padding: var(--ds-space-2) var(--ds-space-4);
  background: var(--surface-color-bg, #fff);
  color: var(--surface-color-text, #1a1a1a);
  z-index: var(--ds-z-toast);
  text-decoration: none;
  border-radius: var(--ds-radius-base);
  transition: top var(--ds-transition-fast);
}

.ds-skip-link:focus {
  top: var(--ds-space-2);
}