:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --error-color: #ef4444;
    --radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    transition: all 0.3s ease;
}

body[dir="rtl"] {
    text-align: right;
}

body[dir="ltr"] {
    text-align: left;
}

.header {
    background: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.header-controls {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background: var(--surface-color);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.875rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

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

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

.btn.primary:hover {
    background: #1d4ed8;
}

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

.main-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    min-height: calc(100vh - 120px);
}

.toolbar {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 0.5rem;
    margin-bottom: 1rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.toolbar-group {
    display: flex;
    gap: 0.25rem;
}

.toolbar-btn {
    padding: 0.5rem;
    border: 1px solid transparent;
    border-radius: var(--radius);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
}

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

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

.editor-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    height: 600px;
}

.editor-mode {
    height: 100%;
    transition: all 0.3s ease;
}

.editor-mode.hidden {
    display: none;
}

.markdown-textarea,
.visual-editor {
    width: 100%;
    height: 100%;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 1rem;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    line-height: 1.5;
    background: var(--surface-color);
    color: var(--text-primary);
    resize: none;
    outline: none;
    transition: border-color 0.2s ease;
}

.markdown-textarea:focus,
.visual-editor:focus {
    border-color: var(--primary-color);
}

.visual-editor {
    font-family: inherit;
    overflow-y: auto;
}

.visual-editor[contenteditable]:empty::before {
    content: attr(data-placeholder);
    color: var(--text-muted);
    font-style: italic;
}

.markdown-preview {
    height: 100%;
    overflow-y: auto;
    padding: 1rem;
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
}

.split-view {
    display: none;
    height: 600px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    overflow: hidden;
}

.split-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    height: 100%;
}

.split-pane {
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--border-color);
}

.split-pane:last-child {
    border-right: none;
}

.split-pane h3 {
    background: var(--background-color);
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.char-count,
.sync-btn {
    margin-left: auto;
    font-size: 0.75rem;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
}

.sync-btn.active {
    color: var(--primary-color);
}

.split-textarea {
    flex: 1;
    border: none;
    padding: 1rem;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 14px;
    line-height: 1.5;
    resize: none;
    outline: none;
    background: var(--surface-color);
    color: var(--text-primary);
}

.split-preview {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    background: var(--surface-color);
}

.preview-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-muted);
    font-style: italic;
}

.preview-placeholder i {
    margin-bottom: 1rem;
    opacity: 0.5;
}

.footer {
    background: var(--surface-color);
    border-top: 1px solid var(--border-color);
    padding: 0.75rem 1rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* RTL specific styles */
body[dir="rtl"] .header-content {
    flex-direction: row-reverse;
}

body[dir="rtl"] .header-controls {
    flex-direction: row-reverse;
}

body[dir="rtl"] .toolbar {
    flex-direction: row-reverse;
}

body[dir="rtl"] .toolbar-group {
    flex-direction: row-reverse;
}

body[dir="rtl"] .split-container {
    direction: rtl;
}

body[dir="rtl"] .split-pane h3 {
    flex-direction: row-reverse;
}

body[dir="rtl"] .char-count {
    margin-left: 0;
    margin-right: auto;
}

body[dir="rtl"] .sync-btn {
    margin-left: 0;
    margin-right: auto;
}

body[dir="rtl"] .footer-content {
    flex-direction: row-reverse;
}

/* Markdown styles */
.markdown-preview h1,
.markdown-preview h2,
.markdown-preview h3,
.markdown-preview h4,
.markdown-preview h5,
.markdown-preview h6 {
    margin: 1.5rem 0 0.75rem;
    font-weight: 600;
    line-height: 1.25;
}

.markdown-preview h1 { font-size: 2rem; border-bottom: 2px solid var(--border-color); padding-bottom: 0.5rem; }
.markdown-preview h2 { font-size: 1.5rem; }
.markdown-preview h3 { font-size: 1.25rem; }
.markdown-preview h4 { font-size: 1.125rem; }
.markdown-preview h5 { font-size: 1rem; }
.markdown-preview h6 { font-size: 0.875rem; }

.markdown-preview p {
    margin: 0.75rem 0;
    line-height: 1.75;
}

.markdown-preview code {
    background: var(--background-color);
    padding: 0.125rem 0.25rem;
    border-radius: 3px;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 0.875em;
}

.markdown-preview pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: var(--radius);
    overflow-x: auto;
    margin: 1rem 0;
}

.markdown-preview pre code {
    background: none;
    padding: 0;
    color: inherit;
    font-size: inherit;
}

.markdown-preview blockquote {
    border-left: 4px solid var(--primary-color);
    padding-left: 1rem;
    margin: 1rem 0;
    color: var(--text-secondary);
    font-style: italic;
}

body[dir="rtl"] .markdown-preview blockquote {
    border-left: none;
    border-right: 4px solid var(--primary-color);
    padding-left: 0;
    padding-right: 1rem;
}

.markdown-preview ul,
.markdown-preview ol {
    margin: 0.75rem 0;
    padding-left: 2rem;
}

body[dir="rtl"] .markdown-preview ul,
body[dir="rtl"] .markdown-preview ol {
    padding-left: 0;
    padding-right: 2rem;
}

.markdown-preview li {
    margin: 0.25rem 0;
}

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

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

.markdown-preview img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius);
    margin: 0.5rem 0;
}

.markdown-preview table {
    width: 100%;
    border-collapse: collapse;
    margin: 1rem 0;
}

.markdown-preview th,
.markdown-preview td {
    border: 1px solid var(--border-color);
    padding: 0.5rem;
    text-align: left;
}

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

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

/* Modal styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--surface-color);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    max-width: 400px;
    width: 90%;
}

.modal-content h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.modal-input {
    width: 100%;
    padding: 0.75rem;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
}

.modal-buttons {
    display: flex;
    gap: 0.5rem;
    justify-content: flex-end;
}

/* Responsive design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .header-controls {
        flex-wrap: wrap;
        justify-content: center;
    }

    .toolbar {
        justify-content: center;
    }

    .split-container {
        grid-template-columns: 1fr;
        grid-template-rows: 1fr 1fr;
    }

    .split-pane {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
    }

    .split-pane:last-child {
        border-bottom: none;
    }

    body[dir="rtl"] .header-content,
    body[dir="rtl"] .toolbar {
        flex-direction: column;
    }

    body[dir="rtl"] .split-container {
        direction: ltr;
    }

    body[dir="rtl"] .split-pane h3 {
        flex-direction: row;
    }

    .footer-content {
        flex-direction: column;
        gap: 0.5rem;
    }
}