/**
 * Loading States CSS
 *

 * Consistent loading, skeleton, and empty state styles
 * for Custom Assessment Hub, Dashboard Builder, and My Dashboards.
 */

/* ============================================
   CSS Variables
   ============================================ */
:root {
    --skeleton-base: var(--bg-tertiary, #e5e7eb);
    --skeleton-shine: var(--bg-secondary, #f3f4f6);
    --skeleton-animation-duration: 1.5s;
}

.dark-mode {
    --skeleton-base: var(--bg-tertiary, #374151);
    --skeleton-shine: var(--bg-secondary, #4b5563);
}

/* ============================================
   Shimmer Animation
   ============================================ */
@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

/* ============================================
   Base Skeleton Element
   ============================================ */
.loading-skeleton {
    background: linear-gradient(
        90deg,
        var(--skeleton-base) 25%,
        var(--skeleton-shine) 50%,
        var(--skeleton-base) 75%
    );
    background-size: 200% 100%;
    animation: shimmer var(--skeleton-animation-duration) infinite ease-in-out;
    border-radius: 4px;
}

.loading-skeleton--title {
    height: 20px;
    width: 60%;
    margin-bottom: 8px;
}

.loading-skeleton--title-short {
    width: 40%;
}

.loading-skeleton--text {
    height: 14px;
    width: 100%;
    margin-bottom: 6px;
}

.loading-skeleton--text-short {
    width: 70%;
}

.loading-skeleton--badge {
    height: 24px;
    width: 64px;
    border-radius: 12px;
}

.loading-skeleton--chip {
    height: 20px;
    width: 80px;
    border-radius: 10px;
}

.loading-skeleton--icon {
    height: 32px;
    width: 32px;
    border-radius: 8px;
}

.loading-skeleton--value {
    height: 36px;
    width: 80px;
    margin-bottom: 8px;
}

.loading-skeleton--progress {
    height: 8px;
    width: 120px;
    border-radius: 4px;
}

/* ============================================
   Skeleton Card
   ============================================ */
.loading-skeleton-card {
    background: var(--bg-primary, #fff);
    border: 1px solid var(--border-color, #e5e7eb);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.loading-skeleton-card__header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.loading-skeleton-card__meta {
    display: flex;
    gap: 8px;
    margin-top: auto;
}

/* Card sizes */
.loading-skeleton-card--small {
    padding: 12px;
    min-height: 100px;
}

.loading-skeleton-card--medium {
    padding: 16px;
    min-height: 160px;
}

.loading-skeleton-card--large {
    padding: 20px;
    min-height: 200px;
}

/* ============================================
   Skeleton Stat Card
   ============================================ */
.loading-skeleton-stat {
    background: var(--bg-primary, #fff);
    border: 1px solid var(--border-color, #e5e7eb);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    min-height: 120px;
}

.loading-skeleton-stat__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* ============================================
   Skeleton Row
   ============================================ */
.loading-skeleton-row {
    background: var(--bg-primary, #fff);
    border: 1px solid var(--border-color, #e5e7eb);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 8px;
}

.loading-skeleton-row__content {
    flex: 1;
}

.loading-skeleton-row__aside {
    flex-shrink: 0;
}

/* ============================================
   Empty State
   ============================================ */
.loading-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 48px 24px;
    min-height: 300px;
}

.loading-empty-state__icon {
    color: var(--text-tertiary, #9ca3af);
    margin-bottom: 16px;
}

.loading-empty-state__icon svg {
    width: 64px;
    height: 64px;
}

.loading-empty-state__title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary, #111827);
    margin: 0 0 8px 0;
}

.loading-empty-state__description {
    font-size: 0.875rem;
    color: var(--text-secondary, #6b7280);
    margin: 0 0 24px 0;
    max-width: 400px;
}

.loading-empty-state__action {
    display: flex;
    gap: 12px;
}

/* ============================================
   Error State
   ============================================ */
.loading-error-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 48px 24px;
    min-height: 300px;
}

.loading-error-state__icon {
    color: var(--color-error, #ef4444);
    margin-bottom: 16px;
}

.loading-error-state__icon svg {
    width: 48px;
    height: 48px;
}

.loading-error-state__title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary, #111827);
    margin: 0 0 8px 0;
}

.loading-error-state__message {
    font-size: 0.875rem;
    color: var(--text-secondary, #6b7280);
    margin: 0 0 8px 0;
    max-width: 400px;
}

.loading-error-state__details {
    font-size: 0.75rem;
    color: var(--text-tertiary, #9ca3af);
    margin: 0 0 24px 0;
    font-family: monospace;
    background: var(--bg-tertiary, #f3f4f6);
    padding: 8px 12px;
    border-radius: 4px;
}

.loading-error-state__action {
    display: flex;
    gap: 12px;
}

/* ============================================
   Loading Spinner
   ============================================ */
.loading-spinner {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.loading-spinner__circle {
    width: 32px;
    height: 32px;
    border: 3px solid var(--skeleton-base);
    border-top-color: var(--color-primary, #3b82f6);
    border-radius: 50%;
    animation: spinner-rotate 0.8s linear infinite;
}

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

.loading-spinner__message {
    font-size: 0.875rem;
    color: var(--text-secondary, #6b7280);
}

/* Spinner sizes */
.loading-spinner--small .loading-spinner__circle {
    width: 20px;
    height: 20px;
    border-width: 2px;
}

.loading-spinner--large .loading-spinner__circle {
    width: 48px;
    height: 48px;
    border-width: 4px;
}

/* ============================================
   Save Overlay
   ============================================ */
.loading-save-overlay {
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    border-radius: inherit;
}

.dark-mode .loading-save-overlay {
    background: rgba(17, 24, 39, 0.9);
}

.loading-save-overlay__content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.loading-save-overlay__message {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary, #6b7280);
}

/* ============================================
   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;
}

/* ============================================
   Responsive Adjustments
   ============================================ */
@media (max-width: 768px) {
    .loading-empty-state,
    .loading-error-state {
        padding: 32px 16px;
        min-height: 240px;
    }

    .loading-empty-state__icon svg,
    .loading-error-state__icon svg {
        width: 48px;
        height: 48px;
    }

    .loading-empty-state__title,
    .loading-error-state__title {
        font-size: 1.125rem;
    }
}

@media (max-width: 480px) {
    .loading-empty-state__action {
        flex-direction: column;
        width: 100%;
    }

    .loading-empty-state__action .btn {
        width: 100%;
    }
}