/* ============================================
   Accessibility Layer — WCAG 2.1 AA Compliance
   Biz-Retriever Design System v2.0

   This file MUST be loaded AFTER components.css
   ============================================ */

/* ============================================
   Skip Navigation
   ============================================ */
.skip-link {
    position: absolute;
    top: -100%;
    left: var(--spacing-4);
    z-index: calc(var(--z-notification) + 10);
    padding: var(--spacing-2-5) var(--spacing-5);
    background: var(--primary);
    color: #fff;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
    text-decoration: none;
    box-shadow: var(--shadow-lg);
    transition: top var(--duration-150) var(--ease-out);
}

.skip-link:focus {
    top: 0;
    outline: none;
    color: #fff;
}

/* ============================================
   Focus Visible — Keyboard-only focus ring
   Uses :focus-visible to avoid showing focus
   ring on mouse click
   ============================================ */
:focus-visible {
    outline: 2px solid var(--blue-500);
    outline-offset: 2px;
}

/* Buttons, links — use box-shadow ring instead of outline */
.btn:focus-visible,
.btn-icon:focus-visible,
.nav-link:focus-visible,
a:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring-offset);
}

/* Form elements */
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: none;
    border-color: var(--input-border-focus);
    box-shadow: var(--focus-ring);
}

/* Cards — subtle ring */
.card:focus-visible,
.bid-card:focus-visible,
.kanban-card:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring-offset);
}

/* ============================================
   Reduced Motion
   ============================================ */
@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;
    }

    .btn:hover,
    .btn:active {
        transform: none !important;
    }

    .modal-content {
        animation: none !important;
    }

    .toast {
        transition: opacity 0.01ms !important;
    }
}

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

.sr-only-focusable:focus {
    position: static;
    width: auto;
    height: auto;
    padding: inherit;
    margin: inherit;
    overflow: visible;
    clip: auto;
    white-space: normal;
}

/* ============================================
   High Contrast Mode (Windows)
   ============================================ */
@media (forced-colors: active) {
    .btn {
        border: 2px solid ButtonText;
    }

    .btn-primary {
        background: Highlight;
        color: HighlightText;
        forced-color-adjust: none;
    }

    .badge {
        border: 1px solid;
    }

    .stat-card,
    .card,
    .kanban-card,
    .bid-card {
        border: 2px solid;
    }

    input,
    textarea,
    select {
        border: 2px solid;
    }

    :focus-visible {
        outline: 3px solid Highlight;
        outline-offset: 2px;
    }

    .skeleton {
        background: Canvas;
        border: 1px solid;
        animation: none;
    }
}

/* ============================================
   Touch Target — WCAG 2.5.8 (44x44px minimum)
   ============================================ */
.btn,
.btn-icon,
.nav-link,
.toggle-password,
.modal-close,
.close-btn,
.pagination button,
.dropdown-menu button {
    min-height: 44px;
    min-width: 44px;
}

/* ============================================
   ARIA States
   ============================================ */
[aria-disabled="true"] {
    opacity: 0.45;
    cursor: not-allowed;
    pointer-events: none;
}

[aria-busy="true"] {
    cursor: wait;
}

/* Validation */
[aria-invalid="true"] {
    border-color: var(--danger) !important;
}

[aria-invalid="true"]:focus-visible {
    box-shadow: var(--focus-ring-error) !important;
}

.form-error {
    color: var(--danger);
    font-size: var(--font-size-xs);
    margin-top: var(--spacing-1-5);
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
    line-height: var(--line-height-normal);
}

/* ============================================
   Modal Accessibility
   ============================================ */
body.modal-open {
    overflow: hidden;
}

/* ============================================
   Table Accessibility — Sortable headers
   ============================================ */
table[role="grid"] th[aria-sort] {
    cursor: pointer;
    user-select: none;
    position: relative;
    padding-right: var(--spacing-6);
}

table[role="grid"] th[aria-sort]::after {
    content: '';
    position: absolute;
    right: var(--spacing-3);
    top: 50%;
    transform: translateY(-50%);
    display: inline-block;
    width: 0;
    height: 0;
}

table[role="grid"] th[aria-sort="ascending"]::after {
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-bottom: 5px solid currentColor;
}

table[role="grid"] th[aria-sort="descending"]::after {
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 5px solid currentColor;
}

/* ============================================
   Dark Mode Toggle
   ============================================ */
.dark-mode-toggle {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 44px;
    min-height: 44px;
    border-radius: var(--radius-lg);
    transition: background var(--transition-fast);
}

.dark-mode-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.dark-mode-toggle[aria-pressed="true"] {
    background: rgba(255, 255, 255, 0.08);
}

/* ============================================
   Color Contrast — Minimum 4.5:1 for text
   ============================================ */
.text-muted {
    color: var(--text-secondary); /* 6.0:1 on white */
}