/* CSS Reset and Variables */
:root {
    --bg-primary: #f5f5f5;
    --bg-secondary: #ffffff;
    --bg-tertiary: #fafafa;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --border-color: #e0e0e0;
    --success-color: #10b981;
    --error-color: #ef4444;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    --radius: 8px;
    --radius-sm: 4px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* App Container */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 24px;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    z-index: 10;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-color);
}

/* Menu Toggle Button (hidden on desktop) */
.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    padding: 8px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.menu-toggle:hover {
    background-color: var(--bg-tertiary);
}

.menu-icon {
    width: 20px;
    height: 2px;
    background-color: var(--text-primary);
    position: relative;
}

.menu-icon::before,
.menu-icon::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 2px;
    background-color: var(--text-primary);
    left: 0;
}

.menu-icon::before {
    top: -6px;
}

.menu-icon::after {
    top: 6px;
}

.export-btn {
    padding: 10px 24px;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

.export-btn:hover {
    background-color: var(--accent-hover);
}

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

.export-btn:disabled {
    background-color: var(--text-muted);
    cursor: not-allowed;
}

/* Main Content - 5 Column Layout (with resize handles) */
.main-content {
    display: grid;
    grid-template-columns: 220px 4px 1fr 4px 1fr;
    flex: 1;
    overflow: hidden;
}

/* Resize Handles */
.resize-handle {
    background-color: var(--border-color);
    cursor: col-resize;
    transition: background-color 0.2s;
    position: relative;
    z-index: 5;
}

.resize-handle:hover,
.resize-handle.dragging {
    background-color: var(--accent-color);
}

.resize-handle::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: -4px;
    right: -4px;
}

/* Sidebar */
.sidebar {
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: 20px;
    overflow-y: auto;
}

.sidebar-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.setting-group {
    margin-bottom: 24px;
}

.setting-group > label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.setting-group select,
.setting-group input[type="number"] {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.setting-group select:focus,
.setting-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2);
}

/* Margin Inputs Grid */
.margin-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.margin-input {
    display: flex;
    flex-direction: column;
}

.margin-input label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.margin-input input {
    width: 100%;
}

/* Range Input */
.setting-group input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.setting-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
}

/* Hint */
.setting-group.hint {
    background-color: var(--bg-tertiary);
    padding: 12px;
    border-radius: var(--radius-sm);
    border: 1px dashed var(--border-color);
}

.setting-group.hint p {
    font-size: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.setting-group.hint code {
    background-color: var(--bg-secondary);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    font-size: 0.7rem;
}

/* Advanced Settings Toggle */
.advanced-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 8px 0;
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-align: left;
}

.advanced-toggle:hover {
    color: var(--accent-color);
}

.advanced-toggle-icon {
    width: 0;
    height: 0;
    border-left: 5px solid currentColor;
    border-top: 4px solid transparent;
    border-bottom: 4px solid transparent;
    transition: transform 0.2s ease;
}

.advanced-toggle.expanded .advanced-toggle-icon {
    transform: rotate(90deg);
}

.advanced-settings {
    padding: 12px 0 0 0;
}

.advanced-settings[hidden] {
    display: none;
}

.setting-item {
    margin-bottom: 12px;
}

.setting-item label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
    color: var(--text-primary);
    cursor: pointer;
}

.setting-item input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--accent-color);
}

/* Template inputs */
.template-input {
    width: 100%;
    padding: 6px 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
}

.template-input:focus {
    outline: none;
    border-color: var(--accent-color);
}

/* Setting divider */
.setting-divider {
    height: 1px;
    background-color: var(--border-color);
    margin: 16px 0;
}

/* Setting hint for template tokens */
.setting-hint {
    margin-top: 4px;
    padding: 4px 8px;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.setting-hint small {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
}

/* Editor Panel */
.editor-panel {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-tertiary);
    border-right: 1px solid var(--border-color);
    overflow: hidden;
}

.panel-title {
    font-size: 0.875rem;
    font-weight: 600;
    padding: 12px 16px;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
}

#markdown-input {
    flex: 1;
    width: 100%;
    padding: 16px;
    border: none;
    resize: none;
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    font-size: 0.875rem;
    line-height: 1.7;
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

#markdown-input:focus {
    outline: none;
}

#markdown-input::placeholder {
    color: var(--text-muted);
}

/* Preview Panel */
.preview-panel {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-primary);
    overflow: hidden;
}

/* View toggle button group */
.view-toggle-group {
    display: flex;
    background-color: var(--bg-tertiary);
    border-radius: var(--radius-sm);
    padding: 2px;
    gap: 2px;
}

.view-toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 28px;
    background: none;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--text-muted);
    transition: background-color 0.2s, color 0.2s;
}

.view-toggle-btn:hover {
    color: var(--text-primary);
}

.view-toggle-btn.active {
    background-color: var(--bg-secondary);
    color: var(--accent-color);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.view-toggle-btn svg {
    width: 16px;
    height: 16px;
}

/* View modes - sidebar always visible */
/* Editor only mode */
.main-content.view-editor-only {
    grid-template-columns: 220px 4px 1fr 0 0;
}

.main-content.view-editor-only .preview-panel,
.main-content.view-editor-only .resize-handle[data-resize="editor"] {
    display: none;
}

/* Preview only mode */
.main-content.view-preview-only {
    grid-template-columns: 220px 4px 0 0 1fr;
}

.main-content.view-preview-only .editor-panel,
.main-content.view-preview-only .resize-handle[data-resize="editor"] {
    display: none;
}

.main-content.view-preview-only .preview-panel {
    grid-column: 5;
}

.preview-container {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    padding: 24px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.preview-content {
    background-color: var(--bg-secondary);
    width: 100%;
    max-width: 210mm;
    min-height: 297mm;
    padding: 20mm;
    box-shadow: var(--shadow-lg);
    line-height: 1.8;
    margin-bottom: 24px;
    position: relative;
}

/* Preview Content Styling (Markdown Rendered) */
.preview-content h1 {
    font-size: 2em;
    margin-bottom: 0.5em;
    padding-bottom: 0.3em;
    border-bottom: 1px solid var(--border-color);
}

.preview-content h2 {
    font-size: 1.5em;
    margin-top: 1em;
    margin-bottom: 0.5em;
}

.preview-content h3 {
    font-size: 1.25em;
    margin-top: 1em;
    margin-bottom: 0.5em;
}

.preview-content p {
    margin-bottom: 1em;
}

.preview-content ul,
.preview-content ol {
    margin-bottom: 1em;
    padding-left: 2em;
}

.preview-content li {
    margin-bottom: 0.25em;
}

.preview-content code {
    background-color: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
    font-size: 0.9em;
}

.preview-content pre {
    background-color: var(--bg-tertiary);
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    margin-bottom: 1em;
}

.preview-content pre code {
    background: none;
    padding: 0;
}

/* Syntax highlighted code blocks */
.preview-content pre code.hljs {
    display: block;
    padding: 16px;
    border-radius: var(--radius-sm);
    overflow-x: auto;
    font-size: 0.875em;
    line-height: 1.45;
}

.preview-content pre:has(code.hljs) {
    padding: 0;
    background: transparent;
}

.preview-content blockquote {
    border-left: 4px solid var(--accent-color);
    padding-left: 16px;
    margin: 1em 0;
    color: var(--text-secondary);
}

.preview-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1em;
}

.preview-content th,
.preview-content td {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    text-align: left;
}

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

.preview-content a {
    color: var(--accent-color);
    text-decoration: none;
}

.preview-content a:hover {
    text-decoration: underline;
}

.preview-content img {
    max-width: 100%;
    height: auto;
}

.preview-content hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 2em 0;
}

/* Page Break Styling (Preview) */
.page-break {
    border-top: 2px dashed var(--accent-color);
    margin: 24px 0;
    position: relative;
    page-break-before: always;
}

.page-break::after {
    content: 'Page Break';
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-secondary);
    padding: 0 12px;
    font-size: 0.75rem;
    color: var(--accent-color);
    font-weight: 500;
}

/* Automatic Page Break Indicator */
.auto-page-break {
    position: absolute;
    left: 0;
    right: 0;
    height: 0;
    border-top: 1px dashed var(--text-muted);
    pointer-events: none;
}

.auto-page-break::before {
    content: attr(data-page-label);
    position: absolute;
    top: -10px;
    right: 0;
    background: var(--bg-secondary);
    padding: 0 8px;
    font-size: 0.7rem;
    color: var(--text-muted);
}

/* Mermaid Diagram Styling */
.mermaid-container {
    margin: 1em 0;
    text-align: center;
}

.mermaid-container .mermaid {
    background: transparent;
    padding: 0;
}

.mermaid-container svg {
    max-width: 100%;
    height: auto;
}

/* Error state for failed Mermaid diagrams */
.mermaid-container .mermaid[data-processed="true"] svg {
    display: block;
    margin: 0 auto;
}

/* Mermaid Error Display */
.mermaid-error {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 16px;
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: var(--radius-sm);
    color: var(--error-color);
}

.mermaid-error-icon {
    font-size: 1.5rem;
}

.mermaid-error-text {
    font-size: 0.875rem;
    font-weight: 500;
}

.mermaid-error-detail {
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-family: 'Menlo', 'Monaco', 'Courier New', monospace;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 100;
}

.loading-overlay[hidden] {
    display: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--bg-secondary);
    border-top-color: var(--accent-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.loading-overlay p {
    margin-top: 16px;
    color: white;
    font-size: 1rem;
    font-weight: 500;
}

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

/* Print Styles for PDF Export */
@media print {
    /* Reset */
    * {
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
    }

    body {
        background: white !important;
        margin: 0 !important;
        padding: 0 !important;
    }

    /* Hide all UI elements */
    .header,
    .sidebar,
    .editor-panel,
    .panel-title,
    .loading-overlay,
    .auto-page-break {
        display: none !important;
    }

    /* App container reset */
    .app-container {
        display: block !important;
        height: auto !important;
        overflow: visible !important;
    }

    /* Main content reset */
    .main-content {
        display: block !important;
        overflow: visible !important;
    }

    /* Preview panel - full width */
    .preview-panel {
        display: block !important;
        position: static !important;
        width: 100% !important;
        height: auto !important;
        overflow: visible !important;
        background: white !important;
    }

    .preview-container {
        display: block !important;
        padding: 0 !important;
        overflow: visible !important;
        height: auto !important;
    }

    /* Preview content - main printed area */
    .preview-content {
        width: 100% !important;
        max-width: none !important;
        min-height: auto !important;
        padding: 0 !important;
        margin: 0 !important;
        box-shadow: none !important;
        background: white !important;
    }

    /* Page break handling */
    .page-break {
        border: none !important;
        margin: 0 !important;
        padding: 0 !important;
        page-break-before: always !important;
        break-before: page !important;
    }

    .page-break::after {
        display: none !important;
    }

    /* Prevent orphans/widows */
    p, h1, h2, h3, h4, h5, h6 {
        orphans: 3;
        widows: 3;
    }

    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
        break-after: avoid;
    }

    /* Tables and images should not break across pages */
    table, img, .mermaid-container {
        page-break-inside: avoid !important;
        break-inside: avoid !important;
    }

    /* Code blocks */
    pre {
        page-break-inside: avoid !important;
        break-inside: avoid !important;
        white-space: pre-wrap !important;
        word-wrap: break-word !important;
    }

    /* Links - show URL in print */
    a[href]:after {
        content: none !important;
    }
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr 1fr;
    }

    .menu-toggle {
        display: flex;
    }

    .sidebar {
        position: fixed;
        left: -250px;
        top: 60px;
        bottom: 0;
        width: 250px;
        z-index: 20;
        transition: left 0.3s ease;
        box-shadow: var(--shadow-lg);
    }

    .sidebar.open {
        left: 0;
    }
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
        grid-template-rows: 1fr 1fr;
    }

    .preview-content {
        max-width: 100%;
        min-height: auto;
        padding: 16px;
    }

    .header {
        padding: 12px 16px;
    }

    .header-title {
        font-size: 1.25rem;
    }

    .export-btn {
        padding: 8px 16px;
        font-size: 0.875rem;
    }
}