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

:root {
    --bg-primary: #f5f7fa;
    --bg-secondary: #e8ecf0;
    --bg-tertiary: #d9dee4;
    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #6c757d;
    --border-color: #cdd1d5;
    --accent-color: #007bff;
    --accent-hover: #0056b3;
    --error-color: #dc3545;
    --error-bg: #f8d7da;
    --success-color: #28a745;
    --success-bg: #d4edda;
}

body.dark {
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --bg-tertiary: #3d3d3d;
    --text-primary: #f8f9fa;
    --text-secondary: #e9ecef;
    --text-tertiary: #adb5bd;
    --border-color: #495057;
    --accent-color: #6c757d;
    --accent-hover: #868e96;
    --error-color: #f8d7da;
    --error-bg: #721c24;
    --success-color: #d4edda;
    --success-bg: #155724;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    padding: 20px;
    transition: all 0.3s ease;
}

.container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    background: var(--bg-primary);
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    height: calc(100vh - 40px);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.sidebar {
    width: 300px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: all 0.3s ease;
}

.sidebar-header {
    padding: 20px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    transition: all 0.3s ease;
}

.sidebar-header h2 {
    font-size: 18px;
    color: var(--text-primary);
    margin: 0;
    font-weight: 600;
}

.subtitle {
    font-size: 12px;
    color: var(--text-tertiary);
    margin: 0;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 6px 12px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: translateY(-1px);
}

.file-tree {
    flex: 1;
    overflow-y: auto;
    padding: 10px;
    transition: all 0.3s ease;
}

.file-tree::-webkit-scrollbar {
    width: 6px;
}

.file-tree::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

.file-tree::-webkit-scrollbar-thumb {
    background: var(--text-tertiary);
    border-radius: 3px;
}

.placeholder {
    color: var(--text-tertiary);
    text-align: center;
    padding: 20px;
    font-size: 14px;
}

.error {
    color: var(--error-color);
    text-align: center;
    padding: 20px;
    font-size: 14px;
}

.error-message {
    color: var(--error-color);
    padding: 20px;
    background: var(--error-bg);
    border: 1px solid var(--error-color);
    border-radius: 6px;
    margin: 20px;
}

.project-list-header {
    padding: 15px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.project-list-header h3 {
    font-size: 14px;
    color: var(--text-primary);
    font-weight: 600;
    margin: 0;
}

.project-list {
    padding: 10px;
}

.project-item {
    display: flex;
    align-items: flex-start;
    padding: 12px;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s ease;
    margin-bottom: 8px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
}

.project-item:hover {
    background: var(--bg-tertiary);
    transform: translateY(-1px);
}

.project-icon {
    margin-right: 10px;
    font-size: 24px;
    flex-shrink: 0;
    color: var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.project-info {
    flex: 1;
    min-width: 0;
}

.project-label {
    font-size: 14px;
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 2px;
}

.project-desc {
    font-size: 12px;
    color: var(--text-tertiary);
    line-height: 1.4;
}

.file-node {
    display: flex;
    align-items: center;
    padding: 6px 10px;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.2s ease;
    margin-bottom: 2px;
}

.file-node:hover {
    background: var(--bg-tertiary);
}

.file-node.active {
    background: var(--accent-color);
    color: white;
}

.file-node.active .file-label {
    color: white;
}

.file-icon {
    margin-right: 8px;
    font-size: 18px;
    flex-shrink: 0;
    color: var(--text-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.file-node.active .file-icon {
    color: white;
}

.file-label {
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 400;
}

.project-header {
    padding: 15px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.project-header h3 {
    font-size: 14px;
    color: var(--text-primary);
    margin-top: 8px;
    font-weight: 600;
}

.back-btn {
    padding: 6px 12px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 500;
    transition: all 0.2s ease;
}

.back-btn:hover {
    background: var(--bg-tertiary);
    transform: translateY(-1px);
}

.content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: all 0.3s ease;
}

.file-tree-container {
    padding: 10px;
}

.tree-node {
    margin-bottom: 2px;
}

.tree-header {
    display: flex;
    align-items: center;
    padding: 6px 10px;
    cursor: pointer;
    border-radius: 4px;
    transition: background 0.2s ease;
}

.tree-header:hover {
    background: var(--bg-tertiary);
}

.folder-icon {
    margin-right: 6px;
    font-size: 16px;
    color: var(--accent-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.folder-label {
    font-size: 13px;
    color: var(--text-primary);
    font-weight: 500;
}

.tree-children {
    margin-left: 20px;
    padding-left: 10px;
    border-left: 2px solid var(--border-color);
}

.content-header {
    padding: 15px 20px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
}

.content-header h3 {
    font-size: 14px;
    color: var(--text-primary);
    margin: 0;
}

.markdown-content {
    flex: 1;
    padding: 25px;
    overflow-y: auto;
    line-height: 1.6;
    background: var(--bg-primary);
    transition: all 0.3s ease;
}

.markdown-content::-webkit-scrollbar {
    width: 6px;
}

.markdown-content::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

.markdown-content::-webkit-scrollbar-thumb {
    background: var(--text-tertiary);
    border-radius: 3px;
}

.markdown-content h1 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
}

.markdown-content h2 {
    font-size: 20px;
    margin-top: 25px;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.markdown-content h3 {
    font-size: 18px;
    margin-top: 20px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.markdown-content p {
    margin-bottom: 15px;
    color: var(--text-secondary);
}

.markdown-content code {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: Consolas, 'Courier New', monospace;
    font-size: 13px;
    color: var(--text-primary);
}

.markdown-content pre code .hljs-comment,
.markdown-content pre code.hljs-comment {
    color: #6a9955;
}

body.dark .markdown-content pre code .hljs-comment,
body.dark .markdown-content pre code.hljs-comment {
    color: #7ee787;
}

.markdown-content pre {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 15px;
    border-radius: 6px;
    overflow-x: auto;
    margin-bottom: 20px;
    font-family: Consolas, 'Courier New', monospace;
    font-size: 12px;
    line-height: 1.5;
    border: 1px solid var(--border-color);
}

.markdown-content pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.markdown-content ul,
.markdown-content ol {
    margin-left: 25px;
    margin-bottom: 15px;
    color: var(--text-secondary);
}

.markdown-content li {
    margin-bottom: 6px;
}

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

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

.markdown-content blockquote {
    border-left: 3px solid var(--accent-color);
    padding-left: 15px;
    margin: 15px 0;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: 12px;
    border-radius: 0 4px 4px 0;
}

.markdown-content table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 20px;
}

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

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

.markdown-content img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
    margin: 15px 0;
    border: 1px solid var(--border-color);
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
        height: auto;
    }

    .sidebar {
        width: 100%;
        max-height: 300px;
    }

    .content {
        min-height: 500px;
    }
}