* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        :root {
            --bg: #f5f7fa;
            --panel-bg: #ffffff;
            --text: #2d3748;
            --text-light: #718096;
            --border: #e2e8f0;
            --primary: #4a5568;
            --primary-hover: #2d3748;
            --accent: #4299e1;
            --accent-hover: #3182ce;
            --code-bg: #f7fafc;
            --shadow: 0 1px 3px rgba(0,0,0,0.1);
            --shadow-lg: 0 4px 6px rgba(0,0,0,0.07);
        }
        
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            background: var(--bg);
            color: var(--text);
            line-height: 1.6;
        }
        
        /* Header */
        .header {
            background: var(--panel-bg);
            border-bottom: 1px solid var(--border);
            padding: 0 32px;
            height: 60px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            position: sticky;
            top: 0;
            z-index: 100;
            box-shadow: var(--shadow);
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 12px;
            text-decoration: none;
            color: var(--text);
        }
        
        .logo-text h1 {
            font-size: 18px;
            font-weight: 600;
            margin: 0;
            line-height: 1.2;
        }
        
        .logo-text span {
            font-size: 12px;
            color: var(--text-light);
        }
        
        .header-actions {
            display: flex;
            gap: 10px;
            align-items: center;
        }
        
        .btn {
            padding: 8px 16px;
            border: 1px solid var(--border);
            background: var(--panel-bg);
            border-radius: 6px;
            cursor: pointer;
            font-size: 14px;
            color: var(--text);
            transition: all 0.2s;
            display: flex;
            align-items: center;
            gap: 6px;
        }
        
        .btn:hover {
            background: var(--bg);
            border-color: var(--primary);
        }
        
        .btn-primary {
            background: var(--accent);
            color: white;
            border-color: var(--accent);
        }
        
        .btn-primary:hover {
            background: var(--accent-hover);
            border-color: var(--accent-hover);
        }
        
        .btn svg {
            width: 16px;
            height: 16px;
        }
        
        .status {
            font-size: 12px;
            color: var(--text-light);
            margin-right: 12px;
        }
        
        /* Toolbar */
        .toolbar {
            background: var(--panel-bg);
            border-bottom: 1px solid var(--border);
            padding: 8px 32px;
            display: flex;
            gap: 6px;
            align-items: center;
            overflow-x: auto;
            white-space: nowrap;
        }
        
        .toolbar-group {
            display: flex;
            gap: 4px;
            padding-right: 12px;
            margin-right: 12px;
            border-right: 1px solid var(--border);
            flex-shrink: 0;
        }
        
        .toolbar-group:last-child {
            border-right: none;
            margin-left: auto;
            padding-right: 0;
        }
        
        .tool-btn {
                min-width: 32px;
    width: auto;
    padding: 0 10px;
            height: 32px;
            border: 1px solid transparent;
            background: transparent;
            border-radius: 4px;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--text-light);
            transition: all 0.15s;
            font-size: 14px;
            font-weight: 600;
            font-family: inherit;
            white-space: nowrap;
        }
        
        .tool-btn:hover {
            background: var(--bg);
            color: var(--text);
            border-color: var(--border);
        }
        
        .tool-btn.active {
            background: var(--accent);
            color: white;
        }
        
        /* Editor Layout */
        .editor-container {
            display: flex;
            height: calc(100vh - 108px);
            min-height: 600px;
        }
        
        .editor-pane {
            flex: 1;
            display: flex;
            flex-direction: column;
            background: var(--panel-bg);
            border-right: 1px solid var(--border);
            min-width: 400px;
        }
        
        .pane-header {
            padding: 10px 20px;
            background: #fafbfc;
            border-bottom: 1px solid var(--border);
            font-size: 13px;
            font-weight: 500;
            color: var(--text-light);
            display: flex;
            justify-content: space-between;
            align-items: center;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }
        
        .pane-header .word-count {
            font-size: 12px;
            text-transform: none;
            letter-spacing: 0;
        }
        
        #editor {
            flex: 1;
            width: 100%;
            padding: 24px;
            border: none;
            outline: none;
            font-family: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New", monospace;
            font-size: 15px;
            line-height: 1.8;
            color: var(--text);
            background: var(--panel-bg);
            resize: none;
            tab-size: 4;
        }
        
        .preview-pane {
            flex: 1;
            display: flex;
            flex-direction: column;
            background: var(--panel-bg);
            min-width: 400px;
        }
        
        #preview {
            flex: 1;
            padding: 32px 40px;
            overflow-y: auto;
            font-size: 16px;
            line-height: 1.8;
        }
        
        /* Markdown Preview Styles */
        #preview h1 { font-size: 2em; border-bottom: 2px solid var(--border); padding-bottom: 0.3em; margin: 0.67em 0; }
        #preview h2 { font-size: 1.5em; border-bottom: 1px solid var(--border); padding-bottom: 0.3em; margin: 0.83em 0; }
        #preview h3 { font-size: 1.25em; margin: 1em 0; }
        #preview h4 { font-size: 1em; margin: 1.33em 0; }
        #preview p { margin: 1em 0; }
        #preview a { color: var(--accent); text-decoration: none; }
        #preview a:hover { text-decoration: underline; }
        #preview ul, #preview ol { margin: 1em 0; padding-left: 2em; }
        #preview li { margin: 0.3em 0; }
        #preview blockquote { 
            margin: 1em 0; 
            padding: 0.5em 1em; 
            border-left: 4px solid var(--accent); 
            background: var(--code-bg);
            color: var(--text-light);
        }
        #preview code { 
            background: var(--code-bg); 
            padding: 0.2em 0.4em; 
            border-radius: 3px; 
            font-family: monospace; 
            font-size: 0.9em;
            color: #e53e3e;
        }
        #preview pre { 
            background: #2d3748; 
            color: #e2e8f0; 
            padding: 16px; 
            border-radius: 6px; 
            overflow-x: auto; 
            margin: 1em 0;
        }
        #preview pre code { 
            background: transparent; 
            color: inherit; 
            padding: 0; 
            font-size: 14px;
        }
        #preview table { 
            border-collapse: collapse; 
            margin: 1em 0; 
            width: 100%;
        }
        #preview th, #preview td { 
            border: 1px solid var(--border); 
            padding: 8px 12px; 
            text-align: left;
        }
        #preview th { background: var(--bg); font-weight: 600; }
        #preview tr:nth-child(even) { background: var(--code-bg); }
        #preview img { max-width: 100%; border-radius: 4px; margin: 1em 0; }
        #preview hr { border: none; border-top: 2px solid var(--border); margin: 2em 0; }
        
        /* Content Section */
        .content-section {
            background: var(--panel-bg);
            border-top: 1px solid var(--border);
            padding: 60px 32px;
        }
        
        .content-wrapper {
            max-width: 1100px;
            margin: 0 auto;
        }
        
        .content-section h2 {
            font-size: 28px;
            margin-bottom: 24px;
            color: var(--text);
            font-weight: 600;
        }
        
        .content-section h3 {
            font-size: 20px;
            margin: 32px 0 16px;
            color: var(--text);
            font-weight: 600;
        }
        
        .content-section p {
            margin-bottom: 16px;
            color: var(--text-light);
            line-height: 1.8;
        }
        
        .content-section ul {
            margin-bottom: 16px;
            padding-left: 24px;
            color: var(--text-light);
        }
        
        .content-section li {
            margin-bottom: 8px;
            line-height: 1.8;
        }
        
        .feature-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 24px;
            margin-top: 32px;
        }
        
        .feature-card {
            padding: 24px;
            border: 1px solid var(--border);
            border-radius: 8px;
            background: var(--bg);
        }
        
        .feature-card h3 {
            font-size: 16px;
            margin-bottom: 8px;
            color: var(--text);
        }
        
        .feature-card p {
            font-size: 14px;
            margin: 0;
        }
        
        .syntax-table {
            width: 100%;
            border-collapse: collapse;
            margin: 24px 0;
            font-size: 14px;
        }
        
        .syntax-table th, .syntax-table td {
            border: 1px solid var(--border);
            padding: 12px 16px;
            text-align: left;
        }
        
        .syntax-table th {
            background: var(--bg);
            font-weight: 600;
            color: var(--text);
        }
        
        .syntax-table td code {
            background: var(--code-bg);
            padding: 2px 6px;
            border-radius: 3px;
            font-family: monospace;
            color: #e53e3e;
        }
        
        .faq-item {
            margin-bottom: 24px;
            padding-bottom: 24px;
            border-bottom: 1px solid var(--border);
        }
        
        .faq-item:last-child {
            border-bottom: none;
        }
        
        .faq-item h3 {
            font-size: 16px;
            margin-bottom: 8px;
            color: var(--text);
            font-weight: 600;
        }
        
        .faq-item p {
            margin: 0;
            font-size: 15px;
        }
        
        .footer {
            background: #2d3748;
            color: #a0aec0;
            padding: 40px 32px;
            text-align: center;
            font-size: 14px;
        }
        
        .footer a {
            color: #cbd5e0;
            text-decoration: none;
            margin: 0 12px;
        }
        
        .footer a:hover {
            color: white;
        }
        
        /* Toast */
        .toast {
            position: fixed;
            bottom: 24px;
            right: 24px;
            background: var(--text);
            color: white;
            padding: 12px 20px;
            border-radius: 6px;
            font-size: 14px;
            opacity: 0;
            transform: translateY(10px);
            transition: all 0.3s;
            z-index: 1000;
            pointer-events: none;
        }
        
        .toast.show {
            opacity: 1;
            transform: translateY(0);
        }
@media (max-width: 768px) {
  .header {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 16px;
  }
  .header-actions {
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 8px;
  }
  .toolbar {
    flex-wrap: wrap;
    padding: 8px 12px;
    gap: 4px;
  }
  .toolbar-group {
    border-right: none;
    margin-right: 0;
    padding-right: 0;
  }
  .editor-container {
    flex-direction: column;
    height: auto;
    min-height: 100vh;
  }
  .editor-pane,
  .preview-pane {
    min-width: 100%;
    min-height: 50vh;
  }
  .feature-grid {
    grid-template-columns: 1fr;
  }
  .content-section {
    padding: 40px 16px;
  }
  #preview {
    padding: 20px;
  }
}