diff --git a/markbase-core/src/category_view.html b/markbase-core/src/category_view.html
new file mode 100644
index 0000000..3815326
--- /dev/null
+++ b/markbase-core/src/category_view.html
@@ -0,0 +1,351 @@
+<!DOCTYPE html>
+<html lang="zh-TW">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>MarkBase Download Service</title>
+    <style>
+        * { box-sizing: border-box; }
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+            max-width: 1200px;
+            margin: 0 auto;
+            padding: 20px;
+            background: #f5f5f7;
+        }
+        h1 { color: #1d1d1f; font-size: 28px; margin-bottom: 20px; }
+        
+        .search-box {
+            display: flex;
+            gap: 10px;
+            margin-bottom: 20px;
+        }
+        .search-input {
+            flex: 1;
+            padding: 12px 16px;
+            border: 1px solid #d2d2d7;
+            border-radius: 8px;
+            font-size: 16px;
+        }
+        .search-btn {
+            padding: 12px 24px;
+            background: #0071e3;
+            color: white;
+            border: none;
+            border-radius: 8px;
+            cursor: pointer;
+            font-size: 16px;
+        }
+        .search-btn:hover { background: #0077ed; }
+        
+        .tabs {
+            display: flex;
+            gap: 0;
+            margin-bottom: 20px;
+            background: white;
+            border-radius: 12px;
+            padding: 4px;
+            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
+        }
+        .tab {
+            padding: 12px 24px;
+            border-radius: 8px;
+            cursor: pointer;
+            font-weight: 500;
+            color: #86868b;
+            transition: all 0.2s;
+        }
+        .tab.active {
+            background: #0071e3;
+            color: white;
+        }
+        .tab:hover:not(.active) {
+            background: #f5f5f7;
+        }
+        
+        .stats {
+            display: flex;
+            gap: 20px;
+            margin-bottom: 30px;
+        }
+        .stat-box {
+            background: white;
+            padding: 20px;
+            border-radius: 12px;
+            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
+            flex: 1;
+        }
+        .stat-number { font-size: 24px; font-weight: bold; color: #0071e3; }
+        .stat-label { font-size: 14px; color: #86868b; margin-top: 5px; }
+        
+        .content-panel {
+            background: white;
+            border-radius: 12px;
+            box-shadow: 0 2px 8px rgba(0,0,0,0.1);
+            padding: 20px;
+        }
+        
+        .item-list { display: grid; gap: 16px; }
+        .item-card {
+            display: flex;
+            align-items: center;
+            padding: 16px;
+            border: 1px solid #d2d2d7;
+            border-radius: 8px;
+            cursor: pointer;
+            transition: all 0.2s;
+        }
+        .item-card:hover {
+            border-color: #0071e3;
+            background: #f5f5f7;
+        }
+        .item-icon {
+            width: 48px;
+            height: 48px;
+            background: #0071e3;
+            border-radius: 8px;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            color: white;
+            font-size: 20px;
+            margin-right: 16px;
+        }
+        .item-info { flex: 1; }
+        .item-name { font-weight: 600; color: #1d1d1f; margin-bottom: 4px; }
+        .item-count { font-size: 14px; color: #86868b; }
+        
+        .file-list { display: grid; gap: 12px; }
+        .file-item {
+            display: flex;
+            align-items: center;
+            padding: 12px;
+            border: 1px solid #d2d2d7;
+            border-radius: 8px;
+        }
+        .file-name { flex: 1; color: #0071e3; font-weight: 500; }
+        .file-size { color: #86868b; font-size: 14px; }
+        .download-link {
+            padding: 8px 16px;
+            background: #0071e3;
+            color: white;
+            border-radius: 6px;
+            text-decoration: none;
+            font-size: 14px;
+        }
+        .download-link:hover { background: #0077ed; }
+        
+        .loading { text-align: center; padding: 40px; color: #86868b; }
+        .empty { text-align: center; padding: 40px; color: #86868b; }
+        .back-btn {
+            padding: 8px 16px;
+            background: #f5f5f7;
+            border: 1px solid #d2d2d7;
+            border-radius: 6px;
+            cursor: pointer;
+            margin-bottom: 20px;
+        }
+        .back-btn:hover { background: #e8e8ed; }
+    </style>
+</head>
+<body>
+    <h1>MarkBase Download Service</h1>
+    
+    <div class="search-box">
+        <input type="text" class="search-input" id="search-input" placeholder="Search files...">
+        <button class="search-btn" onclick="searchFiles()">Search</button>
+    </div>
+    
+    <div class="tabs">
+        <div class="tab active" data-view="category" onclick="switchTab('category')">By Category</div>
+        <div class="tab" data-view="series" onclick="switchTab('series')">By Series</div>
+    </div>
+    
+    <div class="stats">
+        <div class="stat-box">
+            <div class="stat-number" id="total-items">-</div>
+            <div class="stat-label" id="items-label">Categories</div>
+        </div>
+        <div class="stat-box">
+            <div class="stat-number" id="total-files">-</div>
+            <div class="stat-label">Total Files</div>
+        </div>
+    </div>
+    
+    <div class="content-panel">
+        <button class="back-btn" id="back-btn" onclick="goBack()" style="display: none;">← Back</button>
+        <div id="content">
+            <div class="loading">Loading...</div>
+        </div>
+    </div>
+
+    <script>
+        const apiBase = window.location.protocol + '//' + window.location.host;
+        let currentView = 'category';
+        let currentItem = null;
+        let navigationStack = [];
+
+        function formatSize(bytes) {
+            if (bytes === 0) return '0 B';
+            const k = 1024;
+            const sizes = ['B', 'KB', 'MB', 'GB'];
+            const i = Math.floor(Math.log(bytes) / Math.log(k));
+            return (bytes / Math.pow(k, i)).toFixed(1) + ' ' + sizes[i];
+        }
+
+        function switchTab(view) {
+            currentView = view;
+            currentItem = null;
+            navigationStack = [];
+            
+            document.querySelectorAll('.tab').forEach(t => t.classList.remove('active'));
+            document.querySelector(`.tab[data-view="${view}"]`).classList.add('active');
+            document.getElementById('back-btn').style.display = 'none';
+            document.getElementById('items-label').textContent = view === 'category' ? 'Categories' : 'Series';
+            
+            loadItems();
+        }
+
+        async function loadItems() {
+            const content = document.getElementById('content');
+            content.innerHTML = '<div class="loading">Loading...</div>';
+            
+            try {
+                const endpoint = currentView === 'category' ? '/api/v2/categories' : '/api/v2/series';
+                const response = await fetch(apiBase + endpoint);
+                const data = await response.json();
+                
+                document.getElementById('total-items').textContent = data.length;
+                const totalFiles = data.reduce((sum, item) => sum + (item.file_count || 0), 0);
+                document.getElementById('total-files').textContent = totalFiles;
+                
+                if (data.length === 0) {
+                    content.innerHTML = '<div class="empty">No items found</div>';
+                    return;
+                }
+                
+                let html = '<div class="item-list">';
+                data.forEach(item => {
+                    const name = currentView === 'category' ? item.category : item.series;
+                    const count = item.file_count || 0;
+                    html += `
+                        <div class="item-card" onclick="loadItemDetail('${name}')">
+                            <div class="item-icon">${currentView === 'category' ? '📁' : '📦'}</div>
+                            <div class="item-info">
+                                <div class="item-name">${name}</div>
+                                <div class="item-count">${count} files</div>
+                            </div>
+                        </div>`;
+                });
+                html += '</div>';
+                content.innerHTML = html;
+            } catch (err) {
+                content.innerHTML = '<div class="empty">Error loading data</div>';
+            }
+        }
+
+        async function loadItemDetail(name) {
+            navigationStack.push({ view: currentView, item: currentItem });
+            currentItem = name;
+            
+            const content = document.getElementById('content');
+            content.innerHTML = '<div class="loading">Loading...</div>';
+            document.getElementById('back-btn').style.display = 'inline-block';
+            
+            try {
+                const endpoint = currentView === 'category' 
+                    ? `/api/v2/categories/${encodeURIComponent(name)}`
+                    : `/api/v2/series/${encodeURIComponent(name)}`;
+                const response = await fetch(apiBase + endpoint);
+                const data = await response.json();
+                
+                document.getElementById('total-items').textContent = '1';
+                document.getElementById('total-files').textContent = data.files?.length || 0;
+                
+                if (!data.files || data.files.length === 0) {
+                    content.innerHTML = '<div class="empty">No files in this ' + currentView + '</div>';
+                    return;
+                }
+                
+                let html = '<div class="file-list">';
+                data.files.forEach(file => {
+                    const downloadUrl = file.download_url || '';
+                    const size = file.file_size || 0;
+                    html += `
+                        <div class="file-item">
+                            <div class="file-name">${file.filename}</div>
+                            <div class="file-size">${formatSize(size)}</div>
+                            ${downloadUrl ? `<a class="download-link" href="${downloadUrl}" target="_blank">Download</a>` : ''}
+                        </div>`;
+                });
+                html += '</div>';
+                content.innerHTML = html;
+            } catch (err) {
+                content.innerHTML = '<div class="empty">Error loading files</div>';
+            }
+        }
+
+        async function searchFiles() {
+            const query = document.getElementById('search-input').value.trim();
+            if (!query) {
+                loadItems();
+                return;
+            }
+            
+            const content = document.getElementById('content');
+            content.innerHTML = '<div class="loading">Searching...</div>';
+            document.getElementById('back-btn').style.display = 'inline-block';
+            navigationStack.push({ view: currentView, item: currentItem });
+            
+            try {
+                const response = await fetch(`${apiBase}/api/v2/files/search?q=${encodeURIComponent(query)}&view=${currentView}`);
+                const data = await response.json();
+                
+                document.getElementById('total-items').textContent = '-';
+                document.getElementById('total-files').textContent = data.files?.length || 0;
+                
+                if (!data.files || data.files.length === 0) {
+                    content.innerHTML = '<div class="empty">No files found matching "' + query + '"</div>';
+                    return;
+                }
+                
+                let html = '<div class="file-list">';
+                data.files.forEach(file => {
+                    html += `
+                        <div class="file-item">
+                            <div class="file-name">${file.filename}</div>
+                            <div class="file-size">${formatSize(file.file_size || 0)}</div>
+                            ${file.download_url ? `<a class="download-link" href="${file.download_url}" target="_blank">Download</a>` : ''}
+                        </div>`;
+                });
+                html += '</div>';
+                content.innerHTML = html;
+            } catch (err) {
+                content.innerHTML = '<div class="empty">Error searching files</div>';
+            }
+        }
+
+        function goBack() {
+            if (navigationStack.length === 0) {
+                currentItem = null;
+                document.getElementById('back-btn').style.display = 'none';
+                loadItems();
+                return;
+            }
+            
+            const prev = navigationStack.pop();
+            if (prev.item === null) {
+                currentItem = null;
+                document.getElementById('back-btn').style.display = 'none';
+                loadItems();
+            } else {
+                currentItem = prev.item;
+                loadItemDetail(currentItem);
+            }
+        }
+
+        // Initialize
+        loadItems();
+    </script>
+</body>
+</html>
\ No newline at end of file
diff --git a/markbase-core/src/server.rs b/markbase-core/src/server.rs
index 51e7bc4..6ff3c77 100644
--- a/markbase-core/src/server.rs
+++ b/markbase-core/src/server.rs
@@ -232,6 +232,8 @@ pub async fn run(port: u16, file: Option<String>) -> anyhow::Result<()> {
         .route("/upload", get(|| async { Html(include_str!("upload.html")) }))
         .route("/files", get(|| async { Html(include_str!("file_list.html")) }))
         .route("/products", get(|| async { Html(include_str!("product_manager.html")) }))
+        .route("/downloads", get(|| async { Html(include_str!("category_view.html")) }))
+        .route("/", get(|| async { Html(include_str!("category_view.html")) }))
         .layer(DefaultBodyLimit::disable()) // Disable body size limit for large file uploads
         .with_state(state);
 

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