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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    overflow: hidden;
    height: 100vh;
}

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

/* Tab Bar */
.tab-bar {
    display: flex;
    align-items: center;
    background: #f0f0f0;
    border-bottom: 1px solid #ddd;
    padding: 0 8px;
    min-height: 36px;
}

.tab {
    display: flex;
    align-items: center;
    padding: 6px 12px;
    background: #e8e8e8;
    border: 1px solid #ccc;
    border-bottom: none;
    border-radius: 6px 6px 0 0;
    margin-right: 2px;
    cursor: pointer;
    user-select: none;
    max-width: 200px;
    min-width: 120px;
}

.tab.active {
    background: #fff;
    border-color: #999;
    z-index: 1;
}

.tab-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 13px;
}

.tab-close {
    background: none;
    border: none;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    padding: 0;
    margin-left: 8px;
    width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 3px;
    color: #666;
}

.tab-close:hover {
    background: #ddd;
    color: #000;
}

.new-tab-button {
    background: none;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 4px 8px;
    cursor: pointer;
    font-size: 14px;
    margin-left: 8px;
    color: #666;
}

.new-tab-button:hover {
    background: #e8e8e8;
}

/* Tab Content */
.tab-content {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.tab-content:not(.active) {
    display: none;
}

/* Toolbar */
.toolbar {
    display: flex;
    align-items: center;
    padding: 8px 12px;
    background: #f5f5f5;
    border-bottom: 1px solid #ddd;
    gap: 4px;
}

.toolbar button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: 1px solid transparent;
    background: transparent;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}

.toolbar button:hover {
    background: #e0e0e0;
    border-color: #ccc;
}

.toolbar button:active {
    background: #d0d0d0;
}

.toolbar-separator {
    width: 1px;
    height: 24px;
    background: #ccc;
    margin: 0 8px;
}

/* Editor Container */
.editor-container {
    display: flex;
    flex: 1;
    overflow: hidden;
}

.pane {
    flex: 1;
    overflow: auto;
    min-width: 0;
}

.pane:first-child {
    border-right: 1px solid #ddd;
}

.editor-textarea {
    width: 100%;
    height: 100%;
    padding: 20px;
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.6;
    border: none;
    outline: none;
    resize: none;
}

.pane:last-child {
    padding: 0;
    background: #fff;
}

.preview-content {
    max-width: none;
    margin: 0;
    padding: 20px 24px 24px 24px;
    line-height: 1.6;
    font-size: 14px;
}

/* Legacy support for old selectors */
#editor-pane {
    border-right: 1px solid #ddd;
}

#editor {
    width: 100%;
    height: 100%;
    padding: 20px;
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.6;
    border: none;
    outline: none;
    resize: none;
}

#preview-pane {
    padding: 20px;
    background: #fff;
}

#preview {
    max-width: 800px;
    margin: 0 auto;
}

/* Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    padding: 4px 12px;
    background: #f5f5f5;
    border-top: 1px solid #ddd;
    font-size: 12px;
    color: #666;
}

/* Preview Styles */
#preview h1, #preview h2, #preview h3, #preview h4, #preview h5, #preview h6,
.preview-content h1, .preview-content h2, .preview-content h3, .preview-content h4, .preview-content h5, .preview-content h6 {
    margin-top: 24px;
    margin-bottom: 16px;
    font-weight: 600;
    line-height: 1.25;
}

#preview h1, .preview-content h1 {
    font-size: 2em;
    border-bottom: 1px solid #eaecef;
    padding-bottom: 0.3em;
    margin-top: 0;
}

#preview h2, .preview-content h2 {
    font-size: 1.5em;
    border-bottom: 1px solid #eaecef;
    padding-bottom: 0.3em;
}

#preview p, .preview-content p {
    margin-bottom: 16px;
    line-height: 1.6;
}

#preview code, .preview-content code {
    padding: 0.2em 0.4em;
    margin: 0;
    font-size: 85%;
    background-color: rgba(27,31,35,0.05);
    border-radius: 3px;
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
}

#preview pre, .preview-content pre {
    padding: 16px;
    overflow: auto;
    font-size: 85%;
    line-height: 1.45;
    background-color: #f6f8fa;
    border-radius: 3px;
    margin-bottom: 16px;
}

#preview pre code, .preview-content pre code {
    display: inline;
    max-width: auto;
    padding: 0;
    margin: 0;
    overflow: visible;
    line-height: inherit;
    word-wrap: normal;
    background-color: transparent;
    border: 0;
}

#preview blockquote, .preview-content blockquote {
    padding: 0 1em;
    color: #6a737d;
    border-left: 0.25em solid #dfe2e5;
    margin-bottom: 16px;
}

#preview ul, #preview ol, .preview-content ul, .preview-content ol {
    padding-left: 2em;
    margin-bottom: 16px;
}

#preview li, .preview-content li {
    margin-bottom: 4px;
}

#preview a, .preview-content a {
    color: #0366d6;
    text-decoration: none;
}

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

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

#preview table, .preview-content table {
    border-collapse: collapse;
    margin-bottom: 16px;
    width: 100%;
}

#preview table th, #preview table td,
.preview-content table th, .preview-content table td {
    padding: 6px 13px;
    border: 1px solid #dfe2e5;
}

#preview table th, .preview-content table th {
    font-weight: 600;
    background-color: #f6f8fa;
}

#preview table tr:nth-child(2n), .preview-content table tr:nth-child(2n) {
    background-color: #f6f8fa;
}

/* Theme: Dark */
body.theme-dark {
    background: #1e1e1e;
    color: #d4d4d4;
}

body.theme-dark .tab-bar {
    background: #2d2d30;
    border-bottom-color: #3e3e42;
}

body.theme-dark .tab {
    background: #3c3c3c;
    border-color: #555;
    color: #d4d4d4;
}

body.theme-dark .tab.active {
    background: #1e1e1e;
    border-color: #666;
}

body.theme-dark .tab-close {
    color: #ccc;
}

body.theme-dark .tab-close:hover {
    background: #555;
    color: #fff;
}

body.theme-dark .new-tab-button {
    border-color: #555;
    color: #ccc;
}

body.theme-dark .new-tab-button:hover {
    background: #3c3c3c;
}

body.theme-dark .toolbar {
    background: #2d2d30;
    border-bottom-color: #3e3e42;
}

body.theme-dark .toolbar button {
    color: #cccccc;
}

body.theme-dark .toolbar button:hover {
    background: #3e3e42;
    border-color: #464647;
}

body.theme-dark .toolbar-separator {
    background: #3e3e42;
}

body.theme-dark .pane:first-child {
    border-right-color: #3e3e42;
}

body.theme-dark .editor-textarea {
    background: #1e1e1e;
    color: #d4d4d4;
}

body.theme-dark .pane:last-child {
    background: #1e1e1e;
}

/* Legacy support */
body.theme-dark #editor-pane {
    border-right-color: #3e3e42;
}

body.theme-dark #editor {
    background: #1e1e1e;
    color: #d4d4d4;
}

body.theme-dark #preview-pane {
    background: #252526;
}

body.theme-dark #preview, body.theme-dark .preview-content {
    color: #d4d4d4;
}

body.theme-dark #preview h1, body.theme-dark #preview h2,
body.theme-dark .preview-content h1, body.theme-dark .preview-content h2 {
    border-bottom-color: #3e3e42;
}

body.theme-dark #preview code, body.theme-dark .preview-content code {
    background-color: rgba(255,255,255,0.1);
}

body.theme-dark #preview pre, body.theme-dark .preview-content pre {
    background-color: #2d2d30;
}

body.theme-dark #preview blockquote, body.theme-dark .preview-content blockquote {
    color: #808080;
    border-left-color: #3e3e42;
}

body.theme-dark #preview a, body.theme-dark .preview-content a {
    color: #569cd6;
}

body.theme-dark #preview table th, body.theme-dark #preview table td,
body.theme-dark .preview-content table th, body.theme-dark .preview-content table td {
    border-color: #3e3e42;
}

body.theme-dark #preview table th, body.theme-dark .preview-content table th {
    background-color: #2d2d30;
}

body.theme-dark #preview table tr:nth-child(2n), body.theme-dark .preview-content table tr:nth-child(2n) {
    background-color: #2d2d30;
}

body.theme-dark .status-bar {
    background: #2d2d30;
    border-top-color: #3e3e42;
    color: #969696;
}

/* Theme: Solarized */
body.theme-solarized {
    background: #fdf6e3;
    color: #657b83;
}

body.theme-solarized .toolbar {
    background: #eee8d5;
    border-bottom-color: #93a1a1;
}

body.theme-solarized .toolbar button {
    color: #586e75;
}

body.theme-solarized .toolbar button:hover {
    background: #fdf6e3;
    border-color: #93a1a1;
}

body.theme-solarized #editor {
    background: #fdf6e3;
    color: #657b83;
}

body.theme-solarized #preview, body.theme-solarized .preview-content {
    color: #586e75;
}

body.theme-solarized #preview code, body.theme-solarized .preview-content code {
    background-color: #eee8d5;
}

body.theme-solarized #preview pre, body.theme-solarized .preview-content pre {
    background-color: #eee8d5;
}

body.theme-solarized #preview a, body.theme-solarized .preview-content a {
    color: #268bd2;
}

/* Theme: Monokai */
body.theme-monokai {
    background: #272822;
    color: #f8f8f2;
}

body.theme-monokai .toolbar {
    background: #3e3d32;
    border-bottom-color: #75715e;
}

body.theme-monokai .toolbar button {
    color: #f8f8f2;
}

body.theme-monokai .toolbar button:hover {
    background: #49483e;
    border-color: #75715e;
}

body.theme-monokai #editor {
    background: #272822;
    color: #f8f8f2;
}

body.theme-monokai #preview-pane {
    background: #272822;
}

body.theme-monokai #preview, body.theme-monokai .preview-content {
    color: #f8f8f2;
}

body.theme-monokai #preview h1, body.theme-monokai #preview h2,
body.theme-monokai .preview-content h1, body.theme-monokai .preview-content h2 {
    border-bottom-color: #75715e;
}

body.theme-monokai #preview code, body.theme-monokai .preview-content code {
    background-color: #3e3d32;
}

body.theme-monokai #preview pre, body.theme-monokai .preview-content pre {
    background-color: #3e3d32;
}

body.theme-monokai #preview blockquote, body.theme-monokai .preview-content blockquote {
    color: #75715e;
    border-left-color: #75715e;
}

body.theme-monokai #preview a, body.theme-monokai .preview-content a {
    color: #66d9ef;
}

body.theme-monokai .status-bar {
    background: #3e3d32;
    border-top-color: #75715e;
    color: #75715e;
}

/* Theme: GitHub */
body.theme-github {
    background: #fff;
    color: #24292e;
}

body.theme-github .toolbar {
    background: #fafbfc;
    border-bottom-color: #e1e4e8;
}

body.theme-github .toolbar button {
    color: #586069;
}

body.theme-github .toolbar button:hover {
    background: #f6f8fa;
    border-color: #e1e4e8;
}

body.theme-github #editor {
    background: #fff;
    color: #24292e;
}

body.theme-github #preview, body.theme-github .preview-content {
    color: #24292e;
}

body.theme-github #preview h1, body.theme-github #preview h2,
body.theme-github .preview-content h1, body.theme-github .preview-content h2 {
    border-bottom-color: #eaecef;
}

body.theme-github #preview code, body.theme-github .preview-content code {
    background-color: rgba(27,31,35,0.05);
}

body.theme-github #preview pre, body.theme-github .preview-content pre {
    background-color: #f6f8fa;
}

body.theme-github #preview blockquote, body.theme-github .preview-content blockquote {
    color: #6a737d;
    border-left-color: #dfe2e5;
}

body.theme-github #preview a, body.theme-github .preview-content a {
    color: #0366d6;
}

body.theme-github .status-bar {
    background: #fafbfc;
    border-top-color: #e1e4e8;
    color: #586069;
}

/* Hide preview pane by default */
.pane.hidden {
    display: none;
}

.pane.full-width {
    border-right: none;
}

/* Legacy support */
#preview-pane.hidden {
    display: none;
}

#editor-pane.full-width {
    border-right: none;
}

/* Find & Replace Dialog */
.find-dialog {
    position: absolute;
    top: 60px;
    right: 20px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 6px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 1000;
    min-width: 400px;
    padding: 12px;
}

.find-dialog.hidden {
    display: none;
}

.find-controls {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 8px;
}

.find-controls input {
    flex: 1;
    padding: 6px 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 13px;
}

.find-controls button {
    padding: 6px 10px;
    border: 1px solid #ddd;
    background: #f5f5f5;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    white-space: nowrap;
}

.find-controls button:hover {
    background: #e5e5e5;
}

.find-info {
    font-size: 12px;
    color: #666;
    text-align: right;
}

/* Editor Wrapper with Line Numbers */
.editor-wrapper {
    position: relative;
    display: flex;
    height: 100%;
}

.line-numbers {
    min-width: 40px;
    padding: 8px 4px;
    background: #f8f8f8;
    border-right: 1px solid #ddd;
    font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
    font-size: 13px;
    line-height: 1.4;
    color: #666;
    text-align: right;
    user-select: none;
    overflow: hidden;
}

.line-numbers.hidden {
    display: none;
}

.line-numbers .line-number {
    display: block;
    white-space: nowrap;
}

/* Adjust editor when line numbers are shown */
.editor-wrapper #editor {
    flex: 1;
}

/* Theme support for find dialog */
body.theme-dark .find-dialog {
    background: #2d2d2d;
    border-color: #555;
    color: #f0f0f0;
}

body.theme-dark .find-controls input {
    background: #333;
    border-color: #555;
    color: #f0f0f0;
}

body.theme-dark .find-controls button {
    background: #404040;
    border-color: #555;
    color: #f0f0f0;
}

body.theme-dark .find-controls button:hover {
    background: #4a4a4a;
}

body.theme-dark .line-numbers {
    background: #2a2a2a;
    border-right-color: #555;
    color: #888;
}

/* Additional theme support for line numbers */
body.theme-solarized .line-numbers {
    background: #fdf6e3;
    border-right-color: #eee8d5;
    color: #93a1a1;
}

body.theme-monokai .line-numbers {
    background: #2f2f2f;
    border-right-color: #555;
    color: #75715e;
}

body.theme-github .line-numbers {
    background: #fafbfc;
    border-right-color: #e1e4e8;
    color: #586069;
}