/*
 * Minimal accessibility helpers — không thay đổi layout/color hiện tại,
 * chỉ thêm focus-visible ring và disabled state cho keyboard/screen-reader users.
 */

/* Bỏ outline cũ (browser default) khi user dùng chuột; chỉ hiện outline khi tab. */
:focus:not(:focus-visible) {
    outline: none;
}

/* Focus ring nhất quán cho keyboard users — tương thích Bootstrap */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[role="button"]:focus-visible,
[tabindex]:focus-visible {
    outline: 2px solid #2563eb;
    outline-offset: 2px;
    border-radius: 2px;
}

/* Disabled state rõ ràng — opacity + cursor */
button:disabled,
[type="button"]:disabled,
[type="submit"]:disabled,
[type="reset"]:disabled,
input:disabled,
select:disabled,
textarea:disabled,
[aria-disabled="true"] {
    opacity: 0.55;
    cursor: not-allowed;
}

/* Skip-link cho keyboard navigation (ẩn nhưng visible khi focus) */
.skip-link {
    position: absolute;
    left: -9999px;
    top: auto;
    width: 1px;
    height: 1px;
    overflow: hidden;
}
.skip-link:focus {
    position: fixed;
    left: 1rem;
    top: 1rem;
    z-index: 9999;
    padding: 0.5rem 1rem;
    background: #111;
    color: #fff;
    text-decoration: none;
    border-radius: 4px;
    width: auto;
    height: auto;
}

/* Honor user reduce-motion preference */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}