/**
 * Markdown Previewer Styles
 *
 * Uses CSS variables from main.css for theming and consistency.
 * Features:
 * - Dual-panel layout (50/50 split on desktop)
 * - Mobile tabs for responsive design
 * - GitHub-style Markdown preview
 * - Syntax highlighting for code blocks
 * - RTL support
 */

/* ==========================================================================
   App Container
   ========================================================================== */

.md-app-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-4);
}

.md-container {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

/* ==========================================================================
   Controls Bar
   ========================================================================== */

.md-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
}

.md-controls-group {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-2);
}

.md-controls-left {
    justify-content: flex-start;
}

.md-controls-right {
    justify-content: flex-end;
}

/* Buttons */
.md-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    font-size: var(--font-size-sm);
    font-weight: 500;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
    min-height: 36px;
}

.md-btn:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.md-btn:active {
    transform: scale(0.98);
}

.md-btn svg {
    flex-shrink: 0;
}

.md-btn-primary {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

.md-btn-primary:hover {
    background: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
}

.md-btn-secondary {
    background: var(--color-bg);
    color: var(--color-text);
    border-color: var(--color-border);
}

.md-btn-secondary:hover {
    background: var(--color-bg-alt);
    border-color: var(--color-border-dark);
}

/* Toggle */
.md-toggle-label {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--font-size-sm);
    color: var(--color-text);
    cursor: pointer;
    user-select: none;
}

.md-toggle-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--color-primary);
}

/* ==========================================================================
   Mobile Tabs
   ========================================================================== */

.md-mobile-tabs {
    display: none;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-bg-alt);
}

.md-tab {
    flex: 1;
    padding: var(--space-3) var(--space-4);
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--color-text-muted);
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    cursor: pointer;
    transition: color var(--transition-fast), border-color var(--transition-fast);
}

.md-tab:hover {
    color: var(--color-text);
}

.md-tab:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring) inset;
}

.md-tab-active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
}

/* ==========================================================================
   Panels
   ========================================================================== */

.md-panels {
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-height: 500px;
}

.md-panel {
    display: flex;
    flex-direction: column;
}

.md-editor-panel {
    border-right: 1px solid var(--color-border);
}

/* RTL support */
[dir="rtl"] .md-editor-panel {
    border-right: none;
    border-left: 1px solid var(--color-border);
}

/* Editor */
.md-editor {
    flex: 1;
    width: 100%;
    padding: var(--space-4);
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-relaxed);
    color: var(--color-text);
    background: var(--color-bg);
    border: none;
    resize: none;
}

.md-editor:focus {
    outline: none;
}

.md-editor::placeholder {
    color: var(--color-text-muted);
}

/* Preview */
.md-preview-panel {
    overflow: hidden;
}

.md-preview {
    flex: 1;
    padding: var(--space-4);
    overflow-y: auto;
    background: var(--color-bg);
}

.md-placeholder {
    color: var(--color-text-muted);
    font-style: italic;
}

/* ==========================================================================
   Markdown Preview Styling (GitHub-style)
   ========================================================================== */

.md-preview h1,
.md-preview h2,
.md-preview h3,
.md-preview h4,
.md-preview h5,
.md-preview h6 {
    margin-top: var(--space-6);
    margin-bottom: var(--space-4);
    font-weight: 600;
    line-height: var(--line-height-tight);
    color: var(--color-text);
}

.md-preview h1:first-child,
.md-preview h2:first-child,
.md-preview h3:first-child {
    margin-top: 0;
}

.md-preview h1 {
    font-size: var(--font-size-3xl);
    padding-bottom: var(--space-2);
    border-bottom: 1px solid var(--color-border);
}

.md-preview h2 {
    font-size: var(--font-size-2xl);
    padding-bottom: var(--space-2);
    border-bottom: 1px solid var(--color-border);
}

.md-preview h3 {
    font-size: var(--font-size-xl);
}

.md-preview h4 {
    font-size: var(--font-size-lg);
}

.md-preview h5 {
    font-size: var(--font-size-base);
}

.md-preview h6 {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

.md-preview p {
    margin-bottom: var(--space-4);
    line-height: var(--line-height-relaxed);
}

.md-preview a {
    color: var(--color-primary);
    text-decoration: underline;
}

.md-preview a:hover {
    color: var(--color-primary-dark);
}

/* Lists */
.md-preview ul,
.md-preview ol {
    margin-bottom: var(--space-4);
    padding-left: var(--space-6);
}

[dir="rtl"] .md-preview ul,
[dir="rtl"] .md-preview ol {
    padding-left: 0;
    padding-right: var(--space-6);
}

.md-preview li {
    margin-bottom: var(--space-2);
}

.md-preview li > ul,
.md-preview li > ol {
    margin-top: var(--space-2);
    margin-bottom: 0;
}

/* Task lists */
.md-preview ul.contains-task-list {
    list-style: none;
    padding-left: var(--space-4);
}

[dir="rtl"] .md-preview ul.contains-task-list {
    padding-left: 0;
    padding-right: var(--space-4);
}

.md-preview .task-list-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-2);
}

.md-preview .task-list-item input[type="checkbox"] {
    margin-top: 0.35em;
    cursor: default;
}

/* Blockquotes */
.md-preview blockquote {
    margin: 0 0 var(--space-4);
    padding: var(--space-3) var(--space-4);
    color: var(--color-text-muted);
    border-left: 4px solid var(--color-border-dark);
    background: var(--color-bg-alt);
}

[dir="rtl"] .md-preview blockquote {
    border-left: none;
    border-right: 4px solid var(--color-border-dark);
}

.md-preview blockquote p:last-child {
    margin-bottom: 0;
}

/* Code - inline */
.md-preview code {
    padding: 0.2em 0.4em;
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--color-bg-alt);
    border-radius: var(--radius-sm);
}

/* Code - blocks */
.md-preview pre {
    margin-bottom: var(--space-4);
    padding: var(--space-4);
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    line-height: var(--line-height-normal);
    background: var(--color-bg-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.md-preview pre code {
    padding: 0;
    background: transparent;
    border-radius: 0;
}

/* Tables */
.md-preview table {
    width: 100%;
    margin-bottom: var(--space-4);
    border-collapse: collapse;
    border-spacing: 0;
}

.md-preview th,
.md-preview td {
    padding: var(--space-2) var(--space-3);
    border: 1px solid var(--color-border);
    text-align: left;
}

[dir="rtl"] .md-preview th,
[dir="rtl"] .md-preview td {
    text-align: right;
}

.md-preview th {
    font-weight: 600;
    background: var(--color-bg-alt);
}

.md-preview tr:nth-child(even) {
    background: var(--color-bg-alt);
}

/* Horizontal rule */
.md-preview hr {
    height: 1px;
    margin: var(--space-6) 0;
    background: var(--color-border);
    border: none;
}

/* Images */
.md-preview img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
}

/* Strong and emphasis */
.md-preview strong {
    font-weight: 600;
}

.md-preview em {
    font-style: italic;
}

/* Strikethrough */
.md-preview del {
    text-decoration: line-through;
}

/* ==========================================================================
   Status Bar
   ========================================================================== */

.md-status {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    background: var(--color-bg-alt);
    border-top: 1px solid var(--color-border);
}

.md-status-item {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
}

.md-status-divider {
    color: var(--color-border);
}

/* ==========================================================================
   Help Panel
   ========================================================================== */

.help-panel {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.help-panel[hidden] {
    display: none;
}

.help-content {
    width: 100%;
    max-width: 600px;
    max-height: 80vh;
    background: var(--color-bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.help-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4);
    border-bottom: 1px solid var(--color-border);
}

.help-header h2 {
    margin: 0;
    font-size: var(--font-size-xl);
}

.help-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    font-size: var(--font-size-2xl);
    color: var(--color-text-muted);
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition-fast), color var(--transition-fast);
}

.help-close:hover {
    background: var(--color-bg-alt);
    color: var(--color-text);
}

.help-close:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.help-body {
    flex: 1;
    padding: var(--space-4);
    overflow-y: auto;
}

.help-section {
    margin-bottom: var(--space-6);
}

.help-section:last-child {
    margin-bottom: 0;
}

.help-section h3 {
    margin-bottom: var(--space-3);
    font-size: var(--font-size-lg);
    font-weight: 600;
}

.help-section ul,
.help-section ol {
    margin: 0;
    padding-left: var(--space-5);
}

[dir="rtl"] .help-section ul,
[dir="rtl"] .help-section ol {
    padding-left: 0;
    padding-right: var(--space-5);
}

.help-section li {
    margin-bottom: var(--space-2);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   Use Cases Section
   ========================================================================== */

.use-cases {
    max-width: 800px;
    margin: var(--space-12) auto 0;
    padding: 0 var(--space-4);
}

.use-cases h2 {
    margin-bottom: var(--space-6);
    font-size: var(--font-size-2xl);
    text-align: center;
}

.use-cases-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.use-cases-list li {
    margin-bottom: var(--space-4);
    padding: var(--space-4);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
}

.use-cases-list strong {
    display: block;
    margin-bottom: var(--space-2);
    color: var(--color-primary);
}

.use-cases-list p {
    margin: 0;
    color: var(--color-text-muted);
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */

.faq-section {
    max-width: 800px;
    margin: var(--space-12) auto;
    padding: 0 var(--space-4);
}

.faq-section h2 {
    margin-bottom: var(--space-6);
    font-size: var(--font-size-2xl);
    text-align: center;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.faq-item {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.faq-question {
    padding: var(--space-4);
    font-weight: 500;
    cursor: pointer;
    list-style: none;
    transition: background var(--transition-fast);
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-question::before {
    content: "+";
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    margin-right: var(--space-3);
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-primary);
    background: var(--color-bg-alt);
    border-radius: var(--radius-sm);
    transition: transform var(--transition-fast);
}

[dir="rtl"] .faq-question::before {
    margin-right: 0;
    margin-left: var(--space-3);
}

.faq-item[open] .faq-question::before {
    content: "-";
}

.faq-question:hover {
    background: var(--color-bg-alt);
}

.faq-question:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring) inset;
}

.faq-answer {
    padding: 0 var(--space-4) var(--space-4);
    margin: 0;
    color: var(--color-text-muted);
    line-height: var(--line-height-relaxed);
}

/* ==========================================================================
   Responsive Design
   ========================================================================== */

@media (max-width: 768px) {
    .md-app-container {
        padding: var(--space-3);
    }

    /* Show mobile tabs */
    .md-mobile-tabs {
        display: flex;
    }

    /* Stack panels vertically, show only active */
    .md-panels {
        grid-template-columns: 1fr;
        min-height: 400px;
    }

    .md-panel {
        display: none;
    }

    .md-panel.md-panel-active {
        display: flex;
    }

    .md-editor-panel {
        border-right: none;
    }

    [dir="rtl"] .md-editor-panel {
        border-left: none;
    }

    /* Adjust controls */
    .md-controls {
        flex-direction: column;
        gap: var(--space-2);
    }

    .md-controls-group {
        width: 100%;
        justify-content: center;
    }

    .md-btn-label {
        display: none;
    }

    .md-toggle-label {
        width: 100%;
        justify-content: center;
        padding: var(--space-2) 0;
    }

    /* Status bar */
    .md-status {
        justify-content: center;
        flex-wrap: wrap;
    }

    /* Use cases */
    .use-cases {
        margin-top: var(--space-8);
    }

    .use-cases-list li {
        padding: var(--space-3);
    }

    /* FAQ */
    .faq-section {
        margin-top: var(--space-8);
        margin-bottom: var(--space-8);
    }
}

@media (max-width: 480px) {
    .md-btn span:not(.visually-hidden) {
        display: none;
    }

    .md-btn {
        padding: var(--space-2);
        min-width: 36px;
        justify-content: center;
    }

    .help-content {
        max-height: 90vh;
    }

    .help-header {
        padding: var(--space-3);
    }

    .help-body {
        padding: var(--space-3);
    }
}

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    .md-btn,
    .md-tab,
    .faq-question,
    .faq-question::before,
    .help-close {
        transition: none;
    }
}

/* ==========================================================================
   Dark Mode Highlight.js Override
   ========================================================================== */

[data-theme="dark"] .md-preview pre,
[data-theme="dark"] .hljs {
    background: var(--color-bg-alt);
}

/* ==========================================================================
   Visually Hidden (for accessibility)
   ========================================================================== */

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}