/* Skip Links */
.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    z-index: var(--z-skiplink);
    transition: top 0.2s ease;
}

.skip-link:focus {
    top: 0;
    outline: none;
    box-shadow: 0 0 0 3px rgba(var(--primary-color-rgb), 0.5);
}

/* 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: 0;
}

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

/* Focus Styles */
:focus {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: 2px;
}

:focus:not(:focus-visible) {
    outline: none;
}

:focus-visible {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: 2px;
    box-shadow: 0 0 0 4px rgba(var(--focus-ring-color-rgb), 0.2);
}

/* Keyboard Focus Indicator */
body:not(.user-is-tabbing) *:focus {
    outline: none !important;
    box-shadow: none !important;
}

/* ARIA States */
[aria-busy="true"] {
    cursor: progress;
}

[aria-disabled="true"] {
    cursor: not-allowed;
    opacity: 0.7;
}

[aria-hidden="true"] {
    display: none !important;
}

/* Live Regions */
[aria-live] {
    position: fixed;
    top: -10000px;
    left: -10000px;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

[aria-live="polite"],
[aria-live="assertive"] {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    width: auto;
    height: auto;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-elevated);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    z-index: var(--z-toast);
    transition: transform 0.3s ease, opacity 0.3s ease;
}

/* Color Contrast Helpers */
.high-contrast {
    color: var(--text-high-contrast);
}

.enhanced-contrast {
    font-weight: var(--font-weight-medium);
}

/* Motion Reduction */
@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;
    }
}

/* Touch Target Sizes */
@media (pointer: coarse) {
    button,
    .btn,
    a,
    input[type="checkbox"],
    input[type="radio"] {
        min-height: 44px;
        min-width: 44px;
        padding: var(--spacing-sm) var(--spacing-md);
    }

    input[type="checkbox"],
    input[type="radio"] {
        transform: scale(1.5);
        margin: var(--spacing-sm);
    }
}

/* High Contrast Mode */
@media (forced-colors: active) {
    :root {
        --focus-ring-color: Highlight;
    }

    .btn,
    .input,
    .card {
        border: 1px solid ButtonText;
    }

    a {
        color: LinkText;
        text-decoration: underline;
    }

    img {
        forced-color-adjust: none;
    }
}

/* Print Accessibility */
@media print {
    .no-print {
        display: none !important;
    }

    @page {
        margin: 2cm;
    }

    body {
        min-width: 992px !important;
        color: #000;
        background: #fff;
    }

    a[href]::after {
        content: " (" attr(href) ")";
    }

    abbr[title]::after {
        content: " (" attr(title) ")";
    }
}

/* Form Accessibility */
input:invalid,
select:invalid,
textarea:invalid {
    border-color: var(--error-color);
    box-shadow: none;
}

input:invalid:focus,
select:invalid:focus,
textarea:invalid:focus {
    outline-color: var(--error-color);
}

/* Error Messages */
.error-message {
    color: var(--error-color);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.error-message::before {
    content: '!';
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 16px;
    height: 16px;
    background: var(--error-color);
    color: white;
    border-radius: 50%;
    font-size: 12px;
    font-weight: bold;
}

/* Focus Trap for Modals */
.focus-trap {
    position: fixed;
    top: 0;
    left: 0;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Status Messages */
.status-message {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.status-message[aria-hidden="false"] {
    position: static;
    width: auto;
    height: auto;
    margin: 0;
    overflow: visible;
    clip: auto;
    white-space: normal;
}

/* Landmark Roles */
[role="banner"] {
    position: relative;
    z-index: var(--z-header);
}

[role="navigation"] {
    display: flex;
    align-items: center;
}

[role="navigation"] ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

/* Navigation Accessibility */
.nav-link {
    position: relative;
    display: inline-flex;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

.nav-link:focus-visible {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: -2px;
    border-radius: var(--border-radius-sm);
}

/* User Menu Accessibility */
.user-menu-trigger:focus-visible {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: 2px;
    border-radius: var(--border-radius);
}

.user-menu-content:focus {
    outline: none;
}

.user-menu-content[aria-hidden="false"] {
    display: block;
}

/* Auth Buttons Accessibility */
.auth-buttons {
    display: flex;
    gap: var(--spacing-sm);
}

.auth-buttons .btn:focus-visible {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: 2px;
}

/* Mobile Menu Accessibility */
.mobile-menu-toggle {
    padding: var(--spacing-sm);
    margin: calc(var(--spacing-sm) * -1);
}

.mobile-menu-toggle:focus-visible {
    outline: 2px solid var(--focus-ring-color);
    outline-offset: 2px;
    border-radius: var(--border-radius);
}

/* Skip Link Enhancement */
.skip-link:focus {
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: auto;
    height: auto;
    overflow: visible;
    clip: auto;
    white-space: normal;
    z-index: calc(var(--z-header) + 1);
}

/* Dialog Accessibility */
[role="dialog"],
[role="alertdialog"] {
    outline: none;
}

/* Table Accessibility */
.responsive-table {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

/* List Accessibility */
ul[role="list"],
ol[role="list"] {
    list-style: none;
    margin: 0;
    padding: 0;
}

/* Image Accessibility */
img {
    max-width: 100%;
    height: auto;
}

img[role="presentation"] {
    pointer-events: none;
}

/* Video Accessibility */
video {
    max-width: 100%;
    height: auto;
}

/* Audio Controls */
audio {
    width: 100%;
    max-width: 500px;
}

/* Progress Indicators */
progress {
    vertical-align: baseline;
}

[role="progressbar"] {
    display: inline-block;
    vertical-align: middle;
}