/* Base Styles */
:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --bg-main: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-code: #282c34;
    --text-primary: #333333;
    --text-secondary: #666666;
    --border-color: #dddddd;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    --radius: 8px;
    --font-mono: 'Consolas', 'Monaco', 'Courier New', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
.app-header {
    background-color: var(--bg-main);
    border-bottom: 2px solid var(--border-color);
    box-shadow: var(--shadow);
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1800px;
    margin: 0 auto;
}

.app-header h1 {
    font-size: 1.75rem;
    color: var(--primary-color);
    font-weight: 600;
}

.header-actions {
    display: flex;
    gap: 0.5rem;
}

/* Toolbar */
.toolbar {
    background-color: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 2rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    justify-content: flex-start;
}

.toolbar-group {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.toolbar-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
}

/* Buttons */
.btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.btn:hover {
    background-color: var(--bg-secondary);
    border-color: var(--primary-color);
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(0);
}

.btn-icon {
    padding: 0.5rem;
    font-size: 1.25rem;
}

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

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

.btn-small {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--bg-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

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

.btn-small.info {
    cursor: default;
    pointer-events: none;
    font-family: var(--font-mono);
}

.select {
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: border-color 0.2s ease;
}

.select:hover {
    border-color: var(--primary-color);
}

.select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

/* Main Content */
.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
    gap: 0;
}

.pane {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-width: 0;
    background-color: var(--bg-main);
}

.editor-pane {
    border-right: 2px solid var(--border-color);
}

.pane-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.pane-header h2 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.pane-actions {
    display: flex;
    gap: 0.5rem;
}

/* Editor */
.editor {
    flex: 1;
    width: 100%;
    padding: 1.5rem;
    border: none;
    font-family: var(--font-mono);
    font-size: 16px;
    line-height: 1.6;
    resize: none;
    background-color: var(--bg-main);
    color: var(--text-primary);
}

.editor:focus {
    outline: none;
}

/* Preview */
.preview-content {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
    overflow-x: hidden;
    background-color: var(--bg-main);
}

/* Preview Markdown Styles */
.preview-content h1,
.preview-content h2,
.preview-content h3,
.preview-content h4,
.preview-content h5,
.preview-content h6 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-weight: 600;
    line-height: 1.3;
    color: var(--text-primary);
}

.preview-content h1 {
    font-size: 2.25rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.preview-content h2 {
    font-size: 1.875rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.preview-content h3 { font-size: 1.5rem; }
.preview-content h4 { font-size: 1.25rem; }
.preview-content h5 { font-size: 1.125rem; }
.preview-content h6 { font-size: 1rem; }

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

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

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

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

.preview-content li {
    margin-bottom: 0.5rem;
}

.preview-content blockquote {
    margin: 1rem 0;
    padding: 0.5rem 1rem;
    border-left: 4px solid var(--primary-color);
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
}

.preview-content code {
    padding: 0.2rem 0.4rem;
    background-color: var(--bg-secondary);
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: #e83e8c;
}

.preview-content pre {
    margin: 1rem 0;
    padding: 1rem;
    background-color: var(--bg-code);
    border-radius: var(--radius);
    overflow-x: auto;
}

.preview-content pre code {
    padding: 0;
    background-color: transparent;
    color: inherit;
    border-radius: 0;
}

.preview-content table {
    width: 100%;
    margin: 1rem 0;
    border-collapse: collapse;
    border: 1px solid var(--border-color);
}

.preview-content th,
.preview-content td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

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

.preview-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius);
    margin: 1rem 0;
}

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

/* Task lists */
.preview-content .task-list-item {
    list-style: none;
    margin-left: -2rem;
}

.preview-content .task-list-item input[type="checkbox"] {
    margin-right: 0.5rem;
}

/* Footnotes */
.preview-content .footnotes {
    margin-top: 2rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
    font-size: 0.875rem;
}

/* KaTeX */
.preview-content .katex {
    font-size: 1.1em;
}

/* Footer */
.app-footer {
    background-color: var(--bg-main);
    border-top: 1px solid var(--border-color);
    padding: 1rem 2rem;
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Fullscreen Mode */
.preview-pane.fullscreen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    border: none;
}

.preview-pane.fullscreen .pane-header {
    background-color: var(--primary-color);
    color: white;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-content {
        flex-direction: column;
    }
    
    .editor-pane {
        border-right: none;
        border-bottom: 2px solid var(--border-color);
        max-height: 50vh;
    }
    
    .toolbar {
        padding: 0.5rem 1rem;
    }
    
    .header-content {
        padding: 0.75rem 1rem;
    }
}

@media (max-width: 768px) {
    .app-header h1 {
        font-size: 1.25rem;
    }
    
    .toolbar {
        gap: 0.5rem;
    }
    
    .toolbar-group {
        flex-wrap: wrap;
    }
}

/* Print Styles */
@media print {
    * {
        -webkit-print-color-adjust: exact !important;
        print-color-adjust: exact !important;
        color-adjust: exact !important;
    }
    
    body {
        margin: 0;
        padding: 0;
    }
    
    .app-header,
    .toolbar,
    .app-footer,
    .pane-header,
    .editor-pane {
        display: none !important;
    }
    
    .main-content {
        display: block !important;
        height: auto !important;
        overflow: visible !important;
    }
    
    .preview-pane {
        border: none !important;
        flex: none !important;
        height: auto !important;
        overflow: visible !important;
        position: static !important;
    }
    
    .preview-content {
        padding: 20mm !important;
        overflow: visible !important;
        height: auto !important;
        max-height: none !important;
    }
    
    /* Allow content to flow across pages */
    .preview-content * {
        max-width: 100% !important;
        overflow: visible !important;
    }
    
    /* Better page breaks for PDF */
    .preview-content h1,
    .preview-content h2,
    .preview-content h3 {
        page-break-after: avoid;
        break-after: avoid;
        page-break-inside: avoid;
        break-inside: avoid;
    }
    
    .preview-content h4,
    .preview-content h5,
    .preview-content h6 {
        page-break-after: avoid;
        break-after: avoid;
    }
    
    /* Allow page breaks but try to keep these together */
    .preview-content pre {
        page-break-inside: avoid;
        break-inside: avoid;
        overflow: visible !important;
        white-space: pre-wrap !important;
        word-wrap: break-word !important;
    }
    
    .preview-content table {
        page-break-inside: auto;
        break-inside: auto;
    }
    
    .preview-content tr {
        page-break-inside: avoid;
        break-inside: avoid;
    }
    
    .preview-content img {
        page-break-inside: avoid;
        break-inside: avoid;
        max-height: 250mm !important;
    }
    
    .preview-content blockquote {
        page-break-inside: avoid;
        break-inside: avoid;
    }
    
    /* Lists can break */
    .preview-content ul,
    .preview-content ol {
        page-break-inside: auto;
        break-inside: auto;
    }
    
    .preview-content li {
        page-break-inside: avoid;
        break-inside: avoid;
    }
    
    /* Paragraphs */
    .preview-content p {
        orphans: 3;
        widows: 3;
    }
}