/**
 * VOLET A11y – 05.11.16
 * Skip link, focus-visible, reduced-motion, color contrast.
 */

/* ---------- Color contrast (05.11.16.03) ---------- */
/* Dùng design-tokens cho text/nền; không override bằng màu tương phản thấp. */
/* Placeholder: --color-placeholder (text-2). Disabled: opacity 0.65–0.7, vẫn đọc được. */
/* Badge/alert: nền nhạt + text đậm (success, warning, error). Dark mode: text-muted = 94a3b8. */

/* ---------- Screen reader (05.11.16.04) ---------- */
.volet-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;
}

/* ---------- Skip link (05.11.16.02) ---------- */
.volet-skip-link {
  position: absolute;
  top: -100px;
  left: var(--space-md, 16px);
  z-index: 9999;
  padding: var(--space-sm, 8px) var(--space-md, 16px);
  font-size: var(--text-body-sm, 0.8125rem);
  font-weight: var(--font-medium, 500);
  color: var(--color-text);
  background: var(--color-bg);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-sm, 8px);
  box-shadow: var(--shadow-md, 0 4px 12px rgba(15, 23, 42, 0.08));
  transition: top 0.15s ease;
}

.volet-skip-link:focus {
  top: var(--space-md, 16px);
  outline: none;
  box-shadow: 0 0 0 3px var(--color-primary-50, #eef2ff);
}

/* ---------- Focus visible (05.11.16.02) ---------- */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.volet-btn:focus-visible,
.volet-header-nav a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ---------- Reduced motion (05.11.16.05) ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .volet-skip-link {
    transition: none;
  }
}

/* ---------- Language switcher (05.11.21.02) ---------- */
.volet-lang-switcher {
  display: inline-flex;
  align-items: center;
  gap: 2px;
}

.volet-lang-option {
  background: none;
  border: none;
  padding: 4px 8px;
  font-size: 0.8125rem;
  color: var(--color-text-2);
  cursor: pointer;
  border-radius: var(--radius-xs, 4px);
  transition: background var(--duration-fast), color var(--duration-fast);
}

.volet-lang-option:hover {
  color: var(--color-text);
  background: var(--color-primary-50);
}

.volet-lang-option.is-active {
  font-weight: 600;
  color: var(--color-primary);
  cursor: default;
}

.volet-lang-sep {
  color: var(--color-text-muted);
  font-size: 0.75rem;
}

.volet-footer .volet-lang-option {
  color: rgba(255, 255, 255, 0.7);
}

.volet-footer .volet-lang-option:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
}

.volet-footer .volet-lang-option.is-active {
  color: #fff;
}

.volet-footer .volet-lang-sep {
  color: rgba(255, 255, 255, 0.5);
}