/**
 * Accessibility & Form Validation Styles
 * Academic Legal Website - Phase 8
 * 
 * Includes skip link, focus states, form validation, and ARIA enhancements
 */

/* ============================================================================
   SKIP LINK (Accessibility)
   ========================================================================= */

.skip-link {
    position: absolute;
    top: -100px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10000;
    padding: var(--space-sm) var(--space-lg);
    background: var(--primary);
    color: white;
    font-weight: var(--font-semibold);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: top 0.2s ease;
}

.skip-link:focus {
    top: var(--space-md);
    outline: 3px solid var(--accent);
    outline-offset: 2px;
}

/* ============================================================================
   SCREEN READER ONLY (sr-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:focus,
.sr-only-focusable:active {
    position: static;
    width: auto;
    height: auto;
    overflow: visible;
    clip: auto;
    white-space: normal;
}

/* ============================================================================
   ENHANCED FOCUS STATES
   ========================================================================= */

/* Default focus outline for all interactive elements */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
[tabindex]:focus-visible {
    outline: 3px solid var(--accent);
    outline-offset: 2px;
}

/* Remove default focus outline when using mouse */
a:focus:not(:focus-visible),
button:focus:not(:focus-visible),
input:focus:not(:focus-visible),
select:focus:not(:focus-visible),
textarea:focus:not(:focus-visible) {
    outline: none;
}

/* Custom focus for form inputs */
.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(26, 54, 93, 0.15);
    outline: none;
}

[data-theme="dark"] .form-input:focus,
[data-theme="dark"] .form-textarea:focus,
[data-theme="dark"] .form-select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.2);
}

/* ============================================================================
   FORM VALIDATION STATES
   ========================================================================= */

/* Valid state */
.form-input.is-valid,
.form-textarea.is-valid,
.form-select.is-valid,
input:valid:not(:placeholder-shown) {
    border-color: var(--success, #38a169);
}

.form-input.is-valid:focus,
input:valid:not(:placeholder-shown):focus {
    box-shadow: 0 0 0 3px rgba(56, 161, 105, 0.15);
}

/* Invalid state */
.form-input.is-invalid,
.form-textarea.is-invalid,
.form-select.is-invalid,
input:invalid:not(:placeholder-shown):not(:focus) {
    border-color: var(--error, #e53e3e);
}

.form-input.is-invalid:focus,
input:invalid:not(:placeholder-shown):focus {
    border-color: var(--error, #e53e3e);
    box-shadow: 0 0 0 3px rgba(229, 62, 62, 0.15);
}

/* Validation messages */
.form-feedback {
    display: block;
    font-size: var(--text-sm);
    margin-top: var(--space-xs);
}

.form-feedback.is-valid {
    color: var(--success, #38a169);
}

.form-feedback.is-invalid {
    color: var(--error, #e53e3e);
}

/* Validation icons */
.form-group {
    position: relative;
}

.form-group .validation-icon {
    position: absolute;
    right: var(--space-md);
    top: 50%;
    transform: translateY(-50%);
    font-size: var(--text-lg);
    pointer-events: none;
}

.form-group .validation-icon.is-valid::after {
    content: "✓";
    color: var(--success, #38a169);
}

.form-group .validation-icon.is-invalid::after {
    content: "✗";
    color: var(--error, #e53e3e);
}

/* ============================================================================
   LOADING STATES
   ========================================================================= */

.btn.is-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}

.btn.is-loading::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: btn-spinner 0.6s linear infinite;
}

@keyframes btn-spinner {
    to {
        transform: rotate(360deg);
    }
}

/* Form loading overlay */
.form-loading {
    position: relative;
    pointer-events: none;
    opacity: 0.7;
}

.form-loading::before {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.5);
    z-index: 10;
}

/* ============================================================================
   ALERT MESSAGES (Success/Error)
   ========================================================================= */

.alert {
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
}

.alert-icon {
    flex-shrink: 0;
    font-size: var(--text-xl);
}

.alert-content {
    flex: 1;
}

.alert-title {
    font-weight: var(--font-semibold);
    margin-bottom: var(--space-xs);
}

.alert-message {
    font-size: var(--text-sm);
}

/* Success alert */
.alert-success {
    background: rgba(56, 161, 105, 0.1);
    border: 1px solid rgba(56, 161, 105, 0.3);
    color: var(--success, #276749);
}

[data-theme="dark"] .alert-success {
    background: rgba(56, 161, 105, 0.15);
    color: #68d391;
}

/* Error alert */
.alert-error {
    background: rgba(229, 62, 62, 0.1);
    border: 1px solid rgba(229, 62, 62, 0.3);
    color: var(--error, #c53030);
}

[data-theme="dark"] .alert-error {
    background: rgba(229, 62, 62, 0.15);
    color: #fc8181;
}

/* Info alert */
.alert-info {
    background: rgba(49, 130, 206, 0.1);
    border: 1px solid rgba(49, 130, 206, 0.3);
    color: #2b6cb0;
}

[data-theme="dark"] .alert-info {
    background: rgba(49, 130, 206, 0.15);
    color: #90cdf4;
}

/* Warning alert */
.alert-warning {
    background: rgba(237, 137, 54, 0.1);
    border: 1px solid rgba(237, 137, 54, 0.3);
    color: #c05621;
}

[data-theme="dark"] .alert-warning {
    background: rgba(237, 137, 54, 0.15);
    color: #fbd38d;
}

/* ============================================================================
   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.is-loading::after {
        animation: none;
    }
}

/* ============================================================================
   HIGH CONTRAST MODE SUPPORT
   ========================================================================= */

@media (forced-colors: active) {
    .skip-link:focus {
        outline: 3px solid CanvasText;
    }
    
    .form-input:focus,
    .form-textarea:focus,
    .form-select:focus {
        outline: 2px solid CanvasText;
    }
    
    .btn {
        border: 2px solid currentColor;
    }
}