/* =================================================================
 * SKELETON LOADING SCREENS
 * ================================================================= */

/*
 * This module provides skeleton loading states for all major components.
 * Skeletons improve perceived performance by showing content placeholders
 * during loading states.
 * 
 * Dependencies: design-system.css
 * Used by: All components with loading states
 */

/* --- Base Skeleton Styles --- */
.skeleton {
    background: linear-gradient(
        90deg,
        var(--skeleton-base) 0%,
        var(--skeleton-highlight) 50%,
        var(--skeleton-base) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
    border-radius: 4px;
    position: relative;
    overflow: hidden;
}

/* Light mode skeleton colors */
:root {
    --skeleton-base: rgba(0, 0, 0, 0.06);
    --skeleton-highlight: rgba(0, 0, 0, 0.12);
}

/* Dark mode skeleton colors */
.dark-mode {
    --skeleton-base: rgba(255, 255, 255, 0.06);
    --skeleton-highlight: rgba(255, 255, 255, 0.12);
}

@keyframes shimmer {
    0% {
        background-position: -200% 0;
    }
    100% {
        background-position: 200% 0;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .skeleton {
        animation: none;
        background: var(--skeleton-base);
    }
}

/* --- Skeleton Variants --- */
.skeleton-text {
    height: 1em;
    margin-bottom: 0.5em;
    border-radius: 4px;
}

.skeleton-text:last-child {
    margin-bottom: 0;
}

.skeleton-text.short {
    width: 60%;
}

.skeleton-text.medium {
    width: 80%;
}

.skeleton-text.long {
    width: 100%;
}

.skeleton-heading {
    height: 1.5em;
    width: 40%;
    margin-bottom: 1em;
    border-radius: 6px;
}

.skeleton-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.skeleton-avatar.large {
    width: 60px;
    height: 60px;
}

.skeleton-avatar.small {
    width: 32px;
    height: 32px;
}

.skeleton-button {
    height: 40px;
    width: 100px;
    border-radius: 8px;
}

.skeleton-input {
    height: 52px;
    border-radius: 26px;
}

.skeleton-card {
    height: 120px;
    border-radius: 12px;
    margin-bottom: 12px;
}

.skeleton-icon {
    width: 20px;
    height: 20px;
    border-radius: 4px;
}

/* --- Message Skeleton --- */
.skeleton-message {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    padding: 1rem;
    margin-bottom: 1rem;
    animation: fadeIn 0.3s ease;
}

.skeleton-message-user {
    align-items: flex-end;
}

.skeleton-message-bot {
    align-items: flex-start;
}

.skeleton-message-bubble {
    max-width: 85%;
    padding: 1rem;
    border-radius: 12px;
    background: var(--skeleton-base);
}

.skeleton-message-user .skeleton-message-bubble {
    background: linear-gradient(
        90deg,
        rgba(31, 41, 55, 0.1) 0%,
        rgba(31, 41, 55, 0.2) 50%,
        rgba(31, 41, 55, 0.1) 100%
    );
    background-size: 200% 100%;
    animation: shimmer 1.5s ease-in-out infinite;
}

.dark-mode .skeleton-message-user .skeleton-message-bubble {
    background: linear-gradient(
        90deg,
        rgba(229, 231, 235, 0.1) 0%,
        rgba(229, 231, 235, 0.2) 50%,
        rgba(229, 231, 235, 0.1) 100%
    );
    background-size: 200% 100%;
}

.skeleton-message-content {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* --- Chat Loading Skeleton --- */
.skeleton-chat-container {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
    height: 100%;
}

/* --- Profile Dropdown Skeleton --- */
.skeleton-profile-dropdown {
    padding: 0.875rem;
}

.skeleton-profile-header {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    padding: 0.875rem;
    margin-bottom: 1rem;
}

.skeleton-profile-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.skeleton-menu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 0.625rem;
    margin-bottom: 0.5rem;
    border-radius: 10px;
}

.skeleton-menu-item:last-child {
    margin-bottom: 0;
}

/* --- Context Window Skeleton --- */
.skeleton-context-window {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 8px;
    padding: 10px;
}

.skeleton-session-item {
    height: 60px;
    border-radius: 8px;
}

/* --- Settings Panel Skeleton --- */
.skeleton-settings-panel {
    padding: 1rem 1.25rem;
}

.skeleton-form-group {
    margin-bottom: 1.5rem;
}

.skeleton-label {
    height: 1em;
    width: 30%;
    margin-bottom: 0.5rem;
    border-radius: 4px;
}

.skeleton-input-field {
    height: 42px;
    border-radius: 10px;
}

/* --- Task List Skeleton --- */
.skeleton-task-list {
    padding: 1rem;
}

.skeleton-task-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 1rem;
    margin-bottom: 0.75rem;
    border-radius: 0.75rem;
    background: var(--skeleton-base);
}

.skeleton-task-checkbox {
    width: 20px;
    height: 20px;
    border-radius: 4px;
    flex-shrink: 0;
}

.skeleton-task-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

/* --- File Preview Skeleton --- */
.skeleton-file-preview {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: 12px;
    background: var(--skeleton-base);
    margin-bottom: 8px;
}

.skeleton-file-icon {
    width: 24px;
    height: 24px;
    border-radius: 4px;
}

.skeleton-file-name {
    flex: 1;
    height: 1em;
    border-radius: 4px;
}

/* --- Notification Skeleton --- */
.skeleton-notification {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    border-radius: 50px;
    min-width: 200px;
    max-width: 360px;
    background: var(--skeleton-base);
}

.skeleton-notification-icon {
    width: 18px;
    height: 18px;
    border-radius: 50%;
}

.skeleton-notification-text {
    flex: 1;
    height: 1em;
    border-radius: 4px;
}

/* --- Code Block Skeleton --- */
.skeleton-code-block {
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.skeleton-code-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 1rem;
    background: var(--skeleton-base);
}

.skeleton-code-info {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.skeleton-code-content {
    height: 120px;
    background: var(--skeleton-highlight);
}

/* --- Mermaid Diagram Skeleton --- */
.skeleton-mermaid-block {
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.skeleton-mermaid-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: var(--skeleton-base);
}

.skeleton-mermaid-content {
    height: 200px;
    background: var(--skeleton-highlight);
}

/* --- Artifact Skeleton --- */
.skeleton-artifact {
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 1rem;
}

.skeleton-artifact-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--skeleton-base);
}

.skeleton-artifact-content {
    height: 300px;
    background: var(--skeleton-highlight);
}

/* --- Welcome Screen Skeleton --- */
.skeleton-welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 2rem;
    text-align: center;
}

.skeleton-welcome-heading {
    height: 3rem;
    width: 60%;
    border-radius: 8px;
}

.skeleton-welcome-subheading {
    height: 1.5rem;
    width: 40%;
    border-radius: 6px;
}

/* --- Container Classes --- */
.skeleton-container {
    position: relative;
    min-height: 100px;
}

.skeleton-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-color);
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Hide skeleton when content is loaded */
.skeleton-container.loaded .skeleton-overlay {
    display: none;
}

/* --- Utility Classes --- */
.skeleton-pulse {
    animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.skeleton-fade-in {
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* --- Responsive Adjustments --- */
@media (max-width: 768px) {
    .skeleton-message-bubble {
        max-width: 95%;
    }
    
    .skeleton-context-window {
        grid-template-columns: 1fr;
    }
    
    .skeleton-welcome-heading {
        width: 80%;
    }
    
    .skeleton-welcome-subheading {
        width: 60%;
    }
}

/* --- Accessibility --- */
.skeleton[aria-busy="true"] {
    pointer-events: none;
}

.skeleton::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

/* Screen reader only text */
.skeleton-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;
}