diff --git a/web/app.js b/web/app.js
new file mode 100644
index 0000000..941c812
--- /dev/null
+++ b/web/app.js
@@ -0,0 +1,454 @@
+// Global state
+let map;
+let osmLayer;
+let diffLayer;
+let countyLayer;
+let osmData = null;
+let diffData = null;
+let countyData = null;
+let selectedFeature = null;
+let selectedLayer = null;
+let acceptedFeatures = new Set();
+let rejectedFeatures = new Set();
+let featurePopup = null;
+
+// Initialize map
+function initMap() {
+    map = L.map('map').setView([28.7, -81.7], 12);
+
+    L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png', {
+        attribution: '© OpenStreetMap contributors © CARTO',
+        subdomains: 'abcd',
+        maxZoom: 20
+    }).addTo(map);
+}
+
+// Calculate bounds for all loaded layers
+function calculateBounds() {
+    const bounds = L.latLngBounds([]);
+    let hasData = false;
+
+    if (osmData && osmData.features.length > 0) {
+        L.geoJSON(osmData).eachLayer(layer => {
+            if (layer.getBounds) {
+                bounds.extend(layer.getBounds());
+            } else if (layer.getLatLng) {
+                bounds.extend(layer.getLatLng());
+            }
+        });
+        hasData = true;
+    }
+
+    if (diffData && diffData.features.length > 0) {
+        L.geoJSON(diffData).eachLayer(layer => {
+            if (layer.getBounds) {
+                bounds.extend(layer.getBounds());
+            } else if (layer.getLatLng) {
+                bounds.extend(layer.getLatLng());
+            }
+        });
+        hasData = true;
+    }
+
+    if (countyData && countyData.features.length > 0) {
+        L.geoJSON(countyData).eachLayer(layer => {
+            if (layer.getBounds) {
+                bounds.extend(layer.getBounds());
+            } else if (layer.getLatLng) {
+                bounds.extend(layer.getLatLng());
+            }
+        });
+        hasData = true;
+    }
+
+    if (hasData && bounds.isValid()) {
+        map.fitBounds(bounds, { padding: [50, 50] });
+    }
+}
+
+// Style functions
+function osmStyle(feature) {
+    return {
+        color: '#8B4513',
+        weight: 3,
+        opacity: 0.7
+    };
+}
+
+function diffStyle(feature) {
+    // Check if feature is accepted or rejected
+    if (acceptedFeatures.has(feature)) {
+        return {
+            color: '#007bff',
+            weight: 3,
+            opacity: 0.8
+        };
+    }
+
+    if (rejectedFeatures.has(feature)) {
+        return {
+            color: '#4a4a4a',
+            weight: 3,
+            opacity: 0.8
+        };
+    }
+
+    const isRemoved = feature.properties && feature.properties.removed === true;
+    return {
+        color: isRemoved ? '#dc3545' : '#28a745',
+        weight: 3,
+        opacity: 0.8
+    };
+}
+
+function countyStyle(feature) {
+    return {
+        color: '#800080',
+        weight: 3,
+        opacity: 0.7
+    };
+}
+
+// Create layer for OSM data
+function createOsmLayer() {
+    if (osmLayer) {
+        map.removeLayer(osmLayer);
+    }
+
+    if (!osmData) return;
+
+    osmLayer = L.geoJSON(osmData, {
+        style: osmStyle
+    }).addTo(map);
+}
+
+// Create layer for diff data with click handlers
+function createDiffLayer() {
+    if (diffLayer) {
+        map.removeLayer(diffLayer);
+    }
+
+    if (!diffData) return;
+
+    diffLayer = L.geoJSON(diffData, {
+        style: diffStyle,
+        onEachFeature: function(feature, layer) {
+            layer.on('click', function(e) {
+                L.DomEvent.stopPropagation(e);
+                selectFeature(feature, layer, e);
+            });
+
+            layer.on('mouseover', function(e) {
+                if (selectedLayer !== layer) {
+                    layer.setStyle({
+                        weight: 5,
+                        opacity: 1
+                    });
+                }
+            });
+
+            layer.on('mouseout', function(e) {
+                if (selectedLayer !== layer) {
+                    layer.setStyle(diffStyle(feature));
+                }
+            });
+        }
+    }).addTo(map);
+}
+
+// Create layer for county data
+function createCountyLayer() {
+    if (countyLayer) {
+        map.removeLayer(countyLayer);
+    }
+
+    if (!countyData) return;
+
+    countyLayer = L.geoJSON(countyData, {
+        style: countyStyle
+    });
+
+    // County layer is hidden by default
+    if (document.getElementById('countyToggle').checked) {
+        countyLayer.addTo(map);
+    }
+}
+
+// Select a feature from diff layer
+function selectFeature(feature, layer, e) {
+    // Deselect previous feature
+    if (selectedLayer) {
+        selectedLayer.setStyle(diffStyle(selectedLayer.feature));
+    }
+
+    selectedFeature = feature;
+    selectedLayer = layer;
+    layer.setStyle({
+        weight: 6,
+        opacity: 1,
+        color: '#ffc107'
+    });
+
+    // Create popup near the clicked location
+    const props = feature.properties || {};
+    const isRemoved = props.removed === true;
+    const isAccepted = acceptedFeatures.has(feature);
+    const isRejected = rejectedFeatures.has(feature);
+
+    let html = '<div style="font-size: 12px;">';
+    html += `<div><strong>Status:</strong> ${isRemoved ? 'Removed' : 'Added/Modified'}</div>`;
+
+    if (props.name) {
+        html += `<div><strong>Name:</strong> ${props.name}</div>`;
+    }
+    if (props.highway) {
+        html += `<div><strong>Highway:</strong> ${props.highway}</div>`;
+    }
+    if (props.service) {
+        html += `<div><strong>Service:</strong> ${props.service}</div>`;
+    }
+
+    if (isAccepted) {
+        html += '<div style="margin-top: 8px; color: #007bff; font-weight: bold;">✓ Accepted</div>';
+    } else if (isRejected) {
+        html += '<div style="margin-top: 8px; color: #4a4a4a; font-weight: bold;">✗ Rejected</div>';
+    }
+
+    html += '<div style="margin-top: 10px; display: flex; gap: 5px;">';
+    html += '<button onclick="acceptFeature()" style="flex: 1; padding: 5px; background: #007bff; color: white; border: none; border-radius: 3px; cursor: pointer;">Accept</button>';
+    html += '<button onclick="rejectFeature()" style="flex: 1; padding: 5px; background: #6c757d; color: white; border: none; border-radius: 3px; cursor: pointer;">Reject</button>';
+    html += '</div>';
+    html += '</div>';
+
+    // Remove old popup if exists
+    if (featurePopup) {
+        map.closePopup(featurePopup);
+    }
+
+    // Create popup at click location
+    featurePopup = L.popup({
+        maxWidth: 300,
+        closeButton: true,
+        autoClose: false,
+        closeOnClick: false
+    })
+    .setLatLng(e.latlng)
+    .setContent(html)
+    .openOn(map);
+
+    // Handle popup close
+    featurePopup.on('remove', function() {
+        if (selectedLayer) {
+            selectedLayer.setStyle(diffStyle(selectedLayer.feature));
+            selectedLayer = null;
+            selectedFeature = null;
+        }
+    });
+}
+
+// Accept a feature
+function acceptFeature() {
+    if (!selectedFeature) return;
+
+    // Remove from rejected if present
+    rejectedFeatures.delete(selectedFeature);
+
+    // Add to accepted
+    acceptedFeatures.add(selectedFeature);
+
+    // Update layer style
+    if (selectedLayer) {
+        selectedLayer.setStyle(diffStyle(selectedFeature));
+    }
+
+    // Close popup
+    if (featurePopup) {
+        map.closePopup(featurePopup);
+    }
+
+    // Enable save button
+    updateSaveButton();
+
+    showStatus(`${acceptedFeatures.size} accepted, ${rejectedFeatures.size} rejected`, 'success');
+}
+
+// Reject a feature
+function rejectFeature() {
+    if (!selectedFeature) return;
+
+    // Remove from accepted if present
+    acceptedFeatures.delete(selectedFeature);
+
+    // Add to rejected
+    rejectedFeatures.add(selectedFeature);
+
+    // Update layer style
+    if (selectedLayer) {
+        selectedLayer.setStyle(diffStyle(selectedFeature));
+    }
+
+    // Close popup
+    if (featurePopup) {
+        map.closePopup(featurePopup);
+    }
+
+    // Enable save button
+    updateSaveButton();
+
+    showStatus(`${acceptedFeatures.size} accepted, ${rejectedFeatures.size} rejected`, 'success');
+}
+
+// Update save button state
+function updateSaveButton() {
+    document.getElementById('saveButton').disabled =
+        acceptedFeatures.size === 0 && rejectedFeatures.size === 0;
+}
+
+// Load file from input
+function loadFile(input) {
+    return new Promise((resolve, reject) => {
+        const file = input.files[0];
+        if (!file) {
+            resolve(null);
+            return;
+        }
+
+        const reader = new FileReader();
+        reader.onload = (e) => {
+            try {
+                const data = JSON.parse(e.target.result);
+                resolve(data);
+            } catch (error) {
+                reject(new Error(`Failed to parse ${file.name}: ${error.message}`));
+            }
+        };
+        reader.onerror = () => reject(new Error(`Failed to read ${file.name}`));
+        reader.readAsText(file);
+    });
+}
+
+// Load all files
+async function loadFiles() {
+    try {
+        showStatus('Loading files...', 'success');
+
+        const osmInput = document.getElementById('osmFile');
+        const diffInput = document.getElementById('diffFile');
+        const countyInput = document.getElementById('countyFile');
+
+        // Load files
+        osmData = await loadFile(osmInput);
+        diffData = await loadFile(diffInput);
+        countyData = await loadFile(countyInput);
+
+        if (!osmData && !diffData && !countyData) {
+            showStatus('Please select at least one file', 'error');
+            return;
+        }
+
+        // Create layers
+        createOsmLayer();
+        createDiffLayer();
+        createCountyLayer();
+
+        // Fit bounds to smallest layer
+        calculateBounds();
+
+        showStatus('Files loaded successfully!', 'success');
+
+        // Enable save button if we have diff data
+        document.getElementById('saveButton').disabled = !diffData;
+
+    } catch (error) {
+        showStatus(error.message, 'error');
+        console.error(error);
+    }
+}
+
+// Save accepted and rejected items to original diff file
+async function saveAcceptedItems() {
+    if (!diffData || (acceptedFeatures.size === 0 && rejectedFeatures.size === 0)) {
+        showStatus('No features to save', 'error');
+        return;
+    }
+
+    try {
+        // Add accepted=true or accepted=false property to features
+        diffData.features.forEach(feature => {
+            if (acceptedFeatures.has(feature)) {
+                feature.properties.accepted = true;
+            } else if (rejectedFeatures.has(feature)) {
+                feature.properties.accepted = false;
+            }
+        });
+
+        // Create download
+        const dataStr = JSON.stringify(diffData, null, 2);
+        const dataBlob = new Blob([dataStr], { type: 'application/json' });
+        const url = URL.createObjectURL(dataBlob);
+
+        const link = document.createElement('a');
+        link.href = url;
+        link.download = 'diff-updated.geojson';
+        document.body.appendChild(link);
+        link.click();
+        document.body.removeChild(link);
+        URL.revokeObjectURL(url);
+
+        showStatus(`Saved ${acceptedFeatures.size} accepted, ${rejectedFeatures.size} rejected`, 'success');
+
+    } catch (error) {
+        showStatus(`Save failed: ${error.message}`, 'error');
+        console.error(error);
+    }
+}
+
+// Show status message
+function showStatus(message, type) {
+    const status = document.getElementById('status');
+    status.textContent = message;
+    status.className = `status ${type}`;
+
+    setTimeout(() => {
+        status.classList.add('hidden');
+    }, 3000);
+}
+
+// Toggle layer visibility
+function toggleLayer(layerId, layer) {
+    const checkbox = document.getElementById(layerId);
+
+    if (checkbox.checked && layer) {
+        if (!map.hasLayer(layer)) {
+            map.addLayer(layer);
+        }
+    } else if (layer) {
+        if (map.hasLayer(layer)) {
+            map.removeLayer(layer);
+        }
+    }
+}
+
+// Event listeners
+document.addEventListener('DOMContentLoaded', function() {
+    initMap();
+
+    // Layer toggles
+    document.getElementById('osmToggle').addEventListener('change', function() {
+        toggleLayer('osmToggle', osmLayer);
+    });
+
+    document.getElementById('diffToggle').addEventListener('change', function() {
+        toggleLayer('diffToggle', diffLayer);
+    });
+
+    document.getElementById('countyToggle').addEventListener('change', function() {
+        toggleLayer('countyToggle', countyLayer);
+    });
+
+    // Load button
+    document.getElementById('loadButton').addEventListener('click', loadFiles);
+
+    // Save button
+    document.getElementById('saveButton').addEventListener('click', saveAcceptedItems);
+});
diff --git a/web/index.html b/web/index.html
new file mode 100644
index 0000000..b0f2d88
--- /dev/null
+++ b/web/index.html
@@ -0,0 +1,172 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>GeoJSON Map Viewer</title>
+    <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
+    <style>
+        * {
+            margin: 0;
+            padding: 0;
+            box-sizing: border-box;
+        }
+
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+            height: 100vh;
+            display: flex;
+            flex-direction: column;
+        }
+
+        #map {
+            flex: 1;
+            width: 100%;
+        }
+
+        .controls {
+            position: absolute;
+            top: 10px;
+            right: 10px;
+            z-index: 1000;
+            background: white;
+            padding: 15px;
+            border-radius: 8px;
+            box-shadow: 0 2px 10px rgba(0,0,0,0.2);
+            min-width: 200px;
+        }
+
+        .controls h3 {
+            margin: 0 0 10px 0;
+            font-size: 14px;
+            color: #333;
+        }
+
+        .controls label {
+            display: flex;
+            align-items: center;
+            margin: 8px 0;
+            cursor: pointer;
+            font-size: 13px;
+        }
+
+        .controls input[type="checkbox"] {
+            margin-right: 8px;
+        }
+
+        .controls button {
+            width: 100%;
+            padding: 10px;
+            margin-top: 10px;
+            background: #007bff;
+            color: white;
+            border: none;
+            border-radius: 4px;
+            cursor: pointer;
+            font-size: 13px;
+            font-weight: 500;
+        }
+
+        .controls button:hover {
+            background: #0056b3;
+        }
+
+        .controls button:disabled {
+            background: #ccc;
+            cursor: not-allowed;
+        }
+
+        .status {
+            margin-top: 10px;
+            padding: 8px;
+            border-radius: 4px;
+            font-size: 12px;
+            text-align: center;
+        }
+
+        .status.success {
+            background: #d4edda;
+            color: #155724;
+        }
+
+        .status.error {
+            background: #f8d7da;
+            color: #721c24;
+        }
+
+        .status.hidden {
+            display: none;
+        }
+
+        .file-input-group {
+            margin-bottom: 15px;
+            padding-bottom: 15px;
+            border-bottom: 1px solid #eee;
+        }
+
+        .file-input-group:last-of-type {
+            border-bottom: none;
+        }
+
+        .file-input-group label {
+            display: block;
+            margin-bottom: 5px;
+            font-weight: 500;
+        }
+
+        .file-input-group input[type="file"] {
+            width: 100%;
+            font-size: 11px;
+        }
+
+        .load-button {
+            background: #28a745 !important;
+        }
+
+        .load-button:hover {
+            background: #218838 !important;
+        }
+    </style>
+</head>
+<body>
+    <div id="map"></div>
+
+    <div class="controls">
+        <h3>Layer Controls</h3>
+        <label>
+            <input type="checkbox" id="osmToggle" checked>
+            OSM Roads (Brown)
+        </label>
+        <label>
+            <input type="checkbox" id="diffToggle" checked>
+            Diff Layer
+        </label>
+        <label>
+            <input type="checkbox" id="countyToggle">
+            County Layer (Purple)
+        </label>
+
+        <h3 style="margin-top: 15px;">Load Files</h3>
+        <div class="file-input-group">
+            <label for="osmFile">OSM File:</label>
+            <input type="file" id="osmFile" accept=".geojson,.json">
+        </div>
+        <div class="file-input-group">
+            <label for="diffFile">Diff File:</label>
+            <input type="file" id="diffFile" accept=".geojson,.json">
+        </div>
+        <div class="file-input-group">
+            <label for="countyFile">County File:</label>
+            <input type="file" id="countyFile" accept=".geojson,.json">
+        </div>
+
+        <button id="loadButton" class="load-button">Load Files</button>
+        <button id="saveButton" disabled>Save Accepted Items</button>
+
+        <div id="status" class="status hidden"></div>
+    </div>
+
+    <script src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js"></script>
+    <script src="app.js"></script>
+</body>
+</html>