Merge branch 'feature/7-nav-theme-modernization' into development

- Add floating pill-shaped sidebar with navigation icons
- Implement dark/light theme toggle with localStorage persistence
- Update all figure factories for transparent backgrounds
- Use carto-darkmatter map style for choropleths
- Add methodology link button to Toronto dashboard header
- Add back to dashboard button on methodology page
- Remove social links from home page (now in sidebar)
- Update CLAUDE.md to Sprint 7

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.pre-commit-config.yaml

@@ -7,7 +7,7 @@ repos:
       - id: check-yaml
       - id: check-added-large-files
         args: ['--maxkb=1000']
-        exclude: ^data/raw/
+        exclude: ^data/(raw/|toronto/raw/geo/)
       - id: check-merge-conflict
 
   - repo: https://github.com/astral-sh/ruff-pre-commit

CLAUDE.md

@@ -6,7 +6,7 @@ Working context for Claude Code on the Analytics Portfolio project.
 
 ## Project Status
 
-**Current Sprint**: 1 (Project Bootstrap)
+**Current Sprint**: 7 (Navigation & Theme Modernization)
 **Phase**: 1 - Toronto Housing Dashboard
 **Branch**: `development` (feature branches merge here)
 
@@ -254,4 +254,4 @@ All scripts in `scripts/`:
 
 ---
 
-*Last Updated: Sprint 1*
+*Last Updated: Sprint 7*

portfolio_app/app.py

@@ -2,7 +2,9 @@
 
 import dash
 import dash_mantine_components as dmc
+from dash import dcc, html
 
+from .components import create_sidebar
 from .config import get_settings
 
 
@@ -17,14 +19,31 @@ def create_app() -> dash.Dash:
     )
 
     app.layout = dmc.MantineProvider(
+        id="mantine-provider",
+        children=[
+            dcc.Location(id="url", refresh=False),
+            dcc.Store(id="theme-store", storage_type="local", data="dark"),
+            dcc.Store(id="theme-init-dummy"),  # Dummy store for theme init callback
+            html.Div(
+                [
+                    create_sidebar(),
+                    html.Div(
                         dash.page_container,
+                        className="page-content-wrapper",
+                    ),
+                ],
+            ),
+        ],
         theme={
             "primaryColor": "blue",
             "fontFamily": "'Inter', sans-serif",
         },
-        forceColorScheme="light",
+        defaultColorScheme="dark",
     )
 
+    # Import callbacks to register them
+    from . import callbacks  # noqa: F401
+
     return app
 
 

portfolio_app/assets/sidebar.css

@@ -0,0 +1,139 @@
+/* Floating sidebar navigation styles */
+
+/* Sidebar container */
+.floating-sidebar {
+    position: fixed;
+    left: 16px;
+    top: 50%;
+    transform: translateY(-50%);
+    width: 60px;
+    padding: 16px 8px;
+    border-radius: 32px;
+    z-index: 1000;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 8px;
+    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
+    transition: background-color 0.2s ease;
+}
+
+/* Page content offset to prevent sidebar overlap */
+.page-content-wrapper {
+    margin-left: 92px; /* sidebar width (60px) + left margin (16px) + gap (16px) */
+    min-height: 100vh;
+}
+
+/* Dark theme (default) */
+[data-mantine-color-scheme="dark"] .floating-sidebar {
+    background-color: #141414;
+}
+
+[data-mantine-color-scheme="dark"] body {
+    background-color: #000000;
+}
+
+/* Light theme */
+[data-mantine-color-scheme="light"] .floating-sidebar {
+    background-color: #f0f0f0;
+}
+
+[data-mantine-color-scheme="light"] body {
+    background-color: #ffffff;
+}
+
+/* Brand initials styling */
+.sidebar-brand {
+    width: 40px;
+    height: 40px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    border-radius: 50%;
+    background-color: var(--mantine-color-blue-filled);
+    margin-bottom: 4px;
+    transition: transform 0.2s ease;
+}
+
+.sidebar-brand:hover {
+    transform: scale(1.05);
+}
+
+.sidebar-brand-link {
+    font-weight: 700;
+    font-size: 16px;
+    color: white;
+    text-decoration: none;
+    line-height: 1;
+}
+
+/* Divider between sections */
+.sidebar-divider {
+    width: 32px;
+    height: 1px;
+    background-color: var(--mantine-color-dimmed);
+    margin: 4px 0;
+    opacity: 0.3;
+}
+
+/* Active nav icon indicator */
+.nav-icon-active {
+    background-color: var(--mantine-color-blue-filled) !important;
+}
+
+/* Navigation icon hover effects */
+.floating-sidebar .mantine-ActionIcon-root {
+    transition: transform 0.15s ease, background-color 0.15s ease;
+}
+
+.floating-sidebar .mantine-ActionIcon-root:hover {
+    transform: scale(1.1);
+}
+
+/* Ensure links don't have underlines */
+.floating-sidebar a {
+    text-decoration: none;
+}
+
+/* Theme toggle specific styling */
+#theme-toggle {
+    transition: transform 0.3s ease;
+}
+
+#theme-toggle:hover {
+    transform: rotate(15deg) scale(1.1);
+}
+
+/* Responsive adjustments for smaller screens */
+@media (max-width: 768px) {
+    .floating-sidebar {
+        left: 8px;
+        width: 50px;
+        padding: 12px 6px;
+        border-radius: 25px;
+    }
+
+    .page-content-wrapper {
+        margin-left: 70px;
+    }
+
+    .sidebar-brand {
+        width: 34px;
+        height: 34px;
+    }
+
+    .sidebar-brand-link {
+        font-size: 14px;
+    }
+}
+
+/* Very small screens - hide sidebar, show minimal navigation */
+@media (max-width: 480px) {
+    .floating-sidebar {
+        display: none;
+    }
+
+    .page-content-wrapper {
+        margin-left: 0;
+    }
+}

portfolio_app/callbacks/__init__.py

@@ -0,0 +1,5 @@
+"""Application-level callbacks for the portfolio app."""
+
+from . import theme
+
+__all__ = ["theme"]

portfolio_app/callbacks/theme.py

@@ -0,0 +1,38 @@
+"""Theme toggle callbacks using clientside JavaScript."""
+
+from dash import Input, Output, State, clientside_callback
+
+# Toggle theme on button click
+# Stores new theme value and updates the DOM attribute
+clientside_callback(
+    """
+    function(n_clicks, currentTheme) {
+        if (n_clicks === undefined || n_clicks === null) {
+            return window.dash_clientside.no_update;
+        }
+        const newTheme = currentTheme === 'dark' ? 'light' : 'dark';
+        document.documentElement.setAttribute('data-mantine-color-scheme', newTheme);
+        return newTheme;
+    }
+    """,
+    Output("theme-store", "data"),
+    Input("theme-toggle", "n_clicks"),
+    State("theme-store", "data"),
+    prevent_initial_call=True,
+)
+
+# Initialize theme from localStorage on page load
+# Uses a dummy output since we only need the side effect of setting the DOM attribute
+clientside_callback(
+    """
+    function(theme) {
+        if (theme) {
+            document.documentElement.setAttribute('data-mantine-color-scheme', theme);
+        }
+        return theme;
+    }
+    """,
+    Output("theme-init-dummy", "data"),
+    Input("theme-store", "data"),
+    prevent_initial_call=False,
+)

portfolio_app/components/__init__.py

@@ -2,11 +2,13 @@
 
 from .map_controls import create_map_controls, create_metric_selector
 from .metric_card import MetricCard, create_metric_cards_row
+from .sidebar import create_sidebar
 from .time_slider import create_time_slider, create_year_selector
 
 __all__ = [
     "create_map_controls",
     "create_metric_selector",
+    "create_sidebar",
     "create_time_slider",
     "create_year_selector",
     "MetricCard",

portfolio_app/components/sidebar.py

@@ -0,0 +1,179 @@
+"""Floating sidebar navigation component."""
+
+import dash_mantine_components as dmc
+from dash import dcc, html
+from dash_iconify import DashIconify
+
+# Navigation items configuration
+NAV_ITEMS = [
+    {"path": "/", "icon": "tabler:home", "label": "Home"},
+    {"path": "/toronto", "icon": "tabler:map-2", "label": "Toronto Housing"},
+]
+
+# External links configuration
+EXTERNAL_LINKS = [
+    {
+        "url": "https://github.com/leomiranda",
+        "icon": "tabler:brand-github",
+        "label": "GitHub",
+    },
+    {
+        "url": "https://linkedin.com/in/leobmiranda",
+        "icon": "tabler:brand-linkedin",
+        "label": "LinkedIn",
+    },
+]
+
+
+def create_brand_logo() -> html.Div:
+    """Create the brand initials logo."""
+    return html.Div(
+        dcc.Link(
+            "LM",
+            href="/",
+            className="sidebar-brand-link",
+        ),
+        className="sidebar-brand",
+    )
+
+
+def create_nav_icon(
+    icon: str,
+    label: str,
+    path: str,
+    current_path: str,
+) -> dmc.Tooltip:
+    """Create a navigation icon with tooltip.
+
+    Args:
+        icon: Iconify icon string.
+        label: Tooltip label.
+        path: Navigation path.
+        current_path: Current page path for active state.
+
+    Returns:
+        Tooltip-wrapped navigation icon.
+    """
+    is_active = current_path == path or (path != "/" and current_path.startswith(path))
+
+    return dmc.Tooltip(
+        dcc.Link(
+            dmc.ActionIcon(
+                DashIconify(icon=icon, width=20),
+                variant="subtle" if not is_active else "filled",
+                size="lg",
+                radius="xl",
+                color="blue" if is_active else "gray",
+                className="nav-icon-active" if is_active else "",
+            ),
+            href=path,
+        ),
+        label=label,
+        position="right",
+        withArrow=True,
+    )
+
+
+def create_theme_toggle(current_theme: str = "dark") -> dmc.Tooltip:
+    """Create the theme toggle button.
+
+    Args:
+        current_theme: Current theme ('dark' or 'light').
+
+    Returns:
+        Tooltip-wrapped theme toggle icon.
+    """
+    icon = "tabler:sun" if current_theme == "dark" else "tabler:moon"
+    label = "Switch to light mode" if current_theme == "dark" else "Switch to dark mode"
+
+    return dmc.Tooltip(
+        dmc.ActionIcon(
+            DashIconify(icon=icon, width=20, id="theme-toggle-icon"),
+            id="theme-toggle",
+            variant="subtle",
+            size="lg",
+            radius="xl",
+            color="gray",
+        ),
+        label=label,
+        position="right",
+        withArrow=True,
+    )
+
+
+def create_external_link(url: str, icon: str, label: str) -> dmc.Tooltip:
+    """Create an external link icon with tooltip.
+
+    Args:
+        url: External URL.
+        icon: Iconify icon string.
+        label: Tooltip label.
+
+    Returns:
+        Tooltip-wrapped external link icon.
+    """
+    return dmc.Tooltip(
+        dmc.Anchor(
+            dmc.ActionIcon(
+                DashIconify(icon=icon, width=20),
+                variant="subtle",
+                size="lg",
+                radius="xl",
+                color="gray",
+            ),
+            href=url,
+            target="_blank",
+        ),
+        label=label,
+        position="right",
+        withArrow=True,
+    )
+
+
+def create_sidebar_divider() -> html.Div:
+    """Create a horizontal divider for the sidebar."""
+    return html.Div(className="sidebar-divider")
+
+
+def create_sidebar(current_path: str = "/", current_theme: str = "dark") -> html.Div:
+    """Create the floating sidebar navigation.
+
+    Args:
+        current_path: Current page path for active state highlighting.
+        current_theme: Current theme for toggle icon state.
+
+    Returns:
+        Complete sidebar component.
+    """
+    return html.Div(
+        [
+            # Brand logo
+            create_brand_logo(),
+            create_sidebar_divider(),
+            # Navigation icons
+            *[
+                create_nav_icon(
+                    icon=item["icon"],
+                    label=item["label"],
+                    path=item["path"],
+                    current_path=current_path,
+                )
+                for item in NAV_ITEMS
+            ],
+            create_sidebar_divider(),
+            # Theme toggle
+            create_theme_toggle(current_theme),
+            create_sidebar_divider(),
+            # External links
+            *[
+                create_external_link(
+                    url=link["url"],
+                    icon=link["icon"],
+                    label=link["label"],
+                )
+                for link in EXTERNAL_LINKS
+            ],
+        ],
+        className="floating-sidebar",
+        id="floating-sidebar",
+    )

portfolio_app/figures/choropleth.py

@@ -39,6 +39,10 @@ def create_choropleth_figure(
     if center is None:
         center = {"lat": 43.7, "lon": -79.4}
 
+    # Use dark-mode friendly map style by default
+    if map_style == "carto-positron":
+        map_style = "carto-darkmatter"
+
     # If no geojson provided, create a placeholder map
     if geojson is None or not data:
         fig = go.Figure(go.Scattermapbox())
@@ -51,6 +55,9 @@ def create_choropleth_figure(
             margin={"l": 0, "r": 0, "t": 40, "b": 0},
             title=title or "Toronto Housing Map",
             height=500,
+            paper_bgcolor="rgba(0,0,0,0)",
+            plot_bgcolor="rgba(0,0,0,0)",
+            font_color="#c9c9c9",
         )
         fig.add_annotation(
             text="No geometry data available. Complete QGIS digitization to enable map.",
@@ -59,7 +66,7 @@ def create_choropleth_figure(
             x=0.5,
             y=0.5,
             showarrow=False,
-            font={"size": 14, "color": "gray"},
+            font={"size": 14, "color": "#888888"},
         )
         return fig
 
@@ -68,6 +75,11 @@ def create_choropleth_figure(
 
     df = pd.DataFrame(data)
 
+    # Use dark-mode friendly map style
+    effective_map_style = (
+        "carto-darkmatter" if map_style == "carto-positron" else map_style
+    )
+
     fig = px.choropleth_mapbox(
         df,
         geojson=geojson,
@@ -76,7 +88,7 @@ def create_choropleth_figure(
         color=color_column,
         color_continuous_scale=color_scale,
         hover_data=hover_data,
-        mapbox_style=map_style,
+        mapbox_style=effective_map_style,
         center=center,
         zoom=zoom,
         opacity=0.7,
@@ -86,10 +98,17 @@ def create_choropleth_figure(
         margin={"l": 0, "r": 0, "t": 40, "b": 0},
         title=title,
         height=500,
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color="#c9c9c9",
         coloraxis_colorbar={
-            "title": color_column.replace("_", " ").title(),
+            "title": {
+                "text": color_column.replace("_", " ").title(),
+                "font": {"color": "#c9c9c9"},
+            },
             "thickness": 15,
             "len": 0.7,
+            "tickfont": {"color": "#c9c9c9"},
         },
     )
 

portfolio_app/figures/summary_cards.py

@@ -69,7 +69,8 @@ def create_metric_card_figure(
         height=120,
         margin={"l": 20, "r": 20, "t": 40, "b": 20},
         paper_bgcolor="rgba(0,0,0,0)",
-        font={"family": "Inter, sans-serif"},
+        plot_bgcolor="rgba(0,0,0,0)",
+        font={"family": "Inter, sans-serif", "color": "#c9c9c9"},
     )
 
     return fig

portfolio_app/figures/time_series.py

@@ -38,8 +38,15 @@ def create_price_time_series(
             x=0.5,
             y=0.5,
             showarrow=False,
+            font={"color": "#888888"},
+        )
+        fig.update_layout(
+            title=title,
+            height=350,
+            paper_bgcolor="rgba(0,0,0,0)",
+            plot_bgcolor="rgba(0,0,0,0)",
+            font_color="#c9c9c9",
         )
-        fig.update_layout(title=title, height=350)
         return fig
 
     df = pd.DataFrame(data)
@@ -69,6 +76,11 @@ def create_price_time_series(
         yaxis_tickprefix="$",
         yaxis_tickformat=",",
         hovermode="x unified",
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color="#c9c9c9",
+        xaxis={"gridcolor": "#333333", "linecolor": "#444444"},
+        yaxis={"gridcolor": "#333333", "linecolor": "#444444"},
     )
 
     return fig
@@ -106,8 +118,15 @@ def create_volume_time_series(
             x=0.5,
             y=0.5,
             showarrow=False,
+            font={"color": "#888888"},
+        )
+        fig.update_layout(
+            title=title,
+            height=350,
+            paper_bgcolor="rgba(0,0,0,0)",
+            plot_bgcolor="rgba(0,0,0,0)",
+            font_color="#c9c9c9",
         )
-        fig.update_layout(title=title, height=350)
         return fig
 
     df = pd.DataFrame(data)
@@ -153,6 +172,11 @@ def create_volume_time_series(
         yaxis_title=volume_column.replace("_", " ").title(),
         yaxis_tickformat=",",
         hovermode="x unified",
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color="#c9c9c9",
+        xaxis={"gridcolor": "#333333", "linecolor": "#444444"},
+        yaxis={"gridcolor": "#333333", "linecolor": "#444444"},
     )
 
     return fig
@@ -187,8 +211,15 @@ def create_market_comparison_chart(
             x=0.5,
             y=0.5,
             showarrow=False,
+            font={"color": "#888888"},
+        )
+        fig.update_layout(
+            title=title,
+            height=400,
+            paper_bgcolor="rgba(0,0,0,0)",
+            plot_bgcolor="rgba(0,0,0,0)",
+            font_color="#c9c9c9",
         )
-        fig.update_layout(title=title, height=400)
         return fig
 
     if metrics is None:
@@ -221,12 +252,18 @@ def create_market_comparison_chart(
         height=400,
         margin={"l": 40, "r": 40, "t": 50, "b": 40},
         hovermode="x unified",
+        paper_bgcolor="rgba(0,0,0,0)",
+        plot_bgcolor="rgba(0,0,0,0)",
+        font_color="#c9c9c9",
+        xaxis={"gridcolor": "#333333", "linecolor": "#444444"},
+        yaxis={"gridcolor": "#333333", "linecolor": "#444444"},
         legend={
             "orientation": "h",
             "yanchor": "bottom",
             "y": 1.02,
             "xanchor": "right",
             "x": 1,
+            "font": {"color": "#c9c9c9"},
         },
     )
 

portfolio_app/pages/home.py

@@ -2,7 +2,6 @@
 
 import dash
 import dash_mantine_components as dmc
-from dash_iconify import DashIconify
 
 dash.register_page(__name__, path="/", name="Home")
 
@@ -52,19 +51,6 @@ PROJECTS = [
     },
 ]
 
-SOCIAL_LINKS = [
-    {
-        "platform": "LinkedIn",
-        "url": "https://linkedin.com/in/leobmiranda",
-        "icon": "mdi:linkedin",
-    },
-    {
-        "platform": "GitHub",
-        "url": "https://github.com/leomiranda",
-        "icon": "mdi:github",
-    },
-]
-
 AVAILABILITY = "Open to Senior Data Analyst, Analytics Engineer, and BI Developer opportunities in Toronto or remote."
 
 
@@ -160,27 +146,6 @@ def create_projects_section() -> dmc.Paper:
     )
 
 
-def create_social_links() -> dmc.Group:
-    """Create social media links."""
-    return dmc.Group(
-        [
-            dmc.Anchor(
-                dmc.Button(
-                    link["platform"],
-                    leftSection=DashIconify(icon=link["icon"], width=20),
-                    variant="outline",
-                    size="md",
-                ),
-                href=link["url"],
-                target="_blank",
-            )
-            for link in SOCIAL_LINKS
-        ],
-        justify="center",
-        gap="md",
-    )
-
-
 def create_availability_section() -> dmc.Text:
     """Create the availability statement."""
     return dmc.Text(AVAILABILITY, size="sm", c="dimmed", ta="center", fs="italic")
@@ -193,7 +158,6 @@ layout = dmc.Container(
             create_summary_section(),
             create_tech_stack_section(),
             create_projects_section(),
-            create_social_links(),
             dmc.Divider(my="lg"),
             create_availability_section(),
             dmc.Space(h=40),

portfolio_app/pages/toronto/dashboard.py

@@ -3,6 +3,7 @@
 import dash
 import dash_mantine_components as dmc
 from dash import dcc, html
+from dash_iconify import DashIconify
 
 from portfolio_app.components import (
     create_map_controls,
@@ -76,6 +77,17 @@ def create_header() -> dmc.Group:
             ),
             dmc.Group(
                 [
+                    dcc.Link(
+                        dmc.Button(
+                            "Methodology",
+                            leftSection=DashIconify(
+                                icon="tabler:info-circle", width=18
+                            ),
+                            variant="subtle",
+                            color="gray",
+                        ),
+                        href="/toronto/methodology",
+                    ),
                     create_year_selector(
                         id_prefix="toronto",
                         min_year=2020,

portfolio_app/pages/toronto/methodology.py

@@ -2,7 +2,8 @@
 
 import dash
 import dash_mantine_components as dmc
-from dash import html
+from dash import dcc, html
+from dash_iconify import DashIconify
 
 dash.register_page(
     __name__,
@@ -18,8 +19,18 @@ def layout() -> dmc.Container:
         size="md",
         py="xl",
         children=[
+            # Back to Dashboard button
+            dcc.Link(
+                dmc.Button(
+                    "Back to Dashboard",
+                    leftSection=DashIconify(icon="tabler:arrow-left", width=18),
+                    variant="subtle",
+                    color="gray",
+                ),
+                href="/toronto",
+            ),
             # Header
-            dmc.Title("Methodology", order=1, mb="lg"),
+            dmc.Title("Methodology", order=1, mb="lg", mt="md"),
             dmc.Text(
                 "This page documents the data sources, processing methodology, "
                 "and known limitations of the Toronto Housing Dashboard.",

portfolio_app/toronto/parsers/__init__.py

@@ -1,9 +1,20 @@
 """Parsers for Toronto housing data sources."""
 
 from .cmhc import CMHCParser
+from .geo import (
+    CMHCZoneParser,
+    NeighbourhoodParser,
+    TRREBDistrictParser,
+    load_geojson,
+)
 from .trreb import TRREBParser
 
 __all__ = [
     "TRREBParser",
     "CMHCParser",
+    # GeoJSON parsers
+    "CMHCZoneParser",
+    "TRREBDistrictParser",
+    "NeighbourhoodParser",
+    "load_geojson",
 ]

portfolio_app/toronto/parsers/geo.py

@@ -0,0 +1,463 @@
+"""GeoJSON parser for geographic boundary files.
+
+This module provides parsers for loading geographic boundary files
+(GeoJSON format) and converting them to Pydantic schemas for database
+loading or direct use in Plotly choropleth maps.
+"""
+
+import json
+from pathlib import Path
+from typing import Any
+
+from pyproj import Transformer
+from shapely.geometry import mapping, shape
+from shapely.ops import transform
+
+from portfolio_app.toronto.schemas import CMHCZone, Neighbourhood, TRREBDistrict
+from portfolio_app.toronto.schemas.dimensions import AreaType
+
+# Transformer for reprojecting from Web Mercator to WGS84
+_TRANSFORMER_3857_TO_4326 = Transformer.from_crs(
+    "EPSG:3857", "EPSG:4326", always_xy=True
+)
+
+
+def load_geojson(path: Path) -> dict[str, Any]:
+    """Load a GeoJSON file and return as dictionary.
+
+    Args:
+        path: Path to the GeoJSON file.
+
+    Returns:
+        GeoJSON as dictionary (FeatureCollection).
+
+    Raises:
+        FileNotFoundError: If file does not exist.
+        ValueError: If file is not valid GeoJSON.
+    """
+    if not path.exists():
+        raise FileNotFoundError(f"GeoJSON file not found: {path}")
+
+    if path.suffix.lower() not in (".geojson", ".json"):
+        raise ValueError(f"Expected GeoJSON file, got: {path.suffix}")
+
+    with open(path, encoding="utf-8") as f:
+        data = json.load(f)
+
+    if data.get("type") != "FeatureCollection":
+        raise ValueError("GeoJSON must be a FeatureCollection")
+
+    return dict(data)
+
+
+def geometry_to_wkt(geometry: dict[str, Any]) -> str:
+    """Convert GeoJSON geometry to WKT string.
+
+    Args:
+        geometry: GeoJSON geometry dictionary.
+
+    Returns:
+        WKT representation of the geometry.
+    """
+    return str(shape(geometry).wkt)
+
+
+def reproject_geometry(
+    geometry: dict[str, Any], source_crs: str = "EPSG:3857"
+) -> dict[str, Any]:
+    """Reproject a GeoJSON geometry to WGS84 (EPSG:4326).
+
+    Args:
+        geometry: GeoJSON geometry dictionary.
+        source_crs: Source CRS (default EPSG:3857 Web Mercator).
+
+    Returns:
+        GeoJSON geometry in WGS84 coordinates.
+    """
+    if source_crs == "EPSG:3857":
+        transformer = _TRANSFORMER_3857_TO_4326
+    else:
+        transformer = Transformer.from_crs(source_crs, "EPSG:4326", always_xy=True)
+
+    geom = shape(geometry)
+    reprojected = transform(transformer.transform, geom)
+    return dict(mapping(reprojected))
+
+
+class CMHCZoneParser:
+    """Parser for CMHC zone boundary GeoJSON files.
+
+    CMHC zone boundaries are extracted from the R `cmhc` package using
+    `get_cmhc_geography(geography_type="ZONE", cma="Toronto")`.
+
+    Expected GeoJSON properties:
+        - zone_code or Zone_Code: Zone identifier
+        - zone_name or Zone_Name: Zone name
+    """
+
+    # Property name mappings for different GeoJSON formats
+    CODE_PROPERTIES = ["zone_code", "Zone_Code", "ZONE_CODE", "zonecode", "code"]
+    NAME_PROPERTIES = [
+        "zone_name",
+        "Zone_Name",
+        "ZONE_NAME",
+        "ZONE_NAME_EN",
+        "NAME_EN",
+        "zonename",
+        "name",
+        "NAME",
+    ]
+
+    def __init__(self, geojson_path: Path) -> None:
+        """Initialize parser with path to GeoJSON file.
+
+        Args:
+            geojson_path: Path to the CMHC zones GeoJSON file.
+        """
+        self.geojson_path = geojson_path
+        self._geojson: dict[str, Any] | None = None
+
+    @property
+    def geojson(self) -> dict[str, Any]:
+        """Lazy-load and return raw GeoJSON data."""
+        if self._geojson is None:
+            self._geojson = load_geojson(self.geojson_path)
+        return self._geojson
+
+    def _find_property(
+        self, properties: dict[str, Any], candidates: list[str]
+    ) -> str | None:
+        """Find a property value by checking multiple candidate names."""
+        for name in candidates:
+            if name in properties and properties[name] is not None:
+                return str(properties[name])
+        return None
+
+    def parse(self) -> list[CMHCZone]:
+        """Parse GeoJSON and return list of CMHCZone schemas.
+
+        Returns:
+            List of validated CMHCZone objects.
+
+        Raises:
+            ValueError: If required properties are missing.
+        """
+        zones = []
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            geom = feature.get("geometry")
+
+            zone_code = self._find_property(props, self.CODE_PROPERTIES)
+            zone_name = self._find_property(props, self.NAME_PROPERTIES)
+
+            if not zone_code:
+                raise ValueError(
+                    f"Zone code not found in properties: {list(props.keys())}"
+                )
+            if not zone_name:
+                zone_name = zone_code  # Fallback to code if name missing
+
+            geometry_wkt = geometry_to_wkt(geom) if geom else None
+
+            zones.append(
+                CMHCZone(
+                    zone_code=zone_code,
+                    zone_name=zone_name,
+                    geometry_wkt=geometry_wkt,
+                )
+            )
+
+        return zones
+
+    def _needs_reprojection(self) -> bool:
+        """Check if GeoJSON needs reprojection to WGS84."""
+        crs = self.geojson.get("crs", {})
+        crs_name = crs.get("properties", {}).get("name", "")
+        # EPSG:3857 or Web Mercator needs reprojection
+        return "3857" in crs_name or "900913" in crs_name
+
+    def get_geojson_for_choropleth(
+        self, key_property: str = "zone_code"
+    ) -> dict[str, Any]:
+        """Get GeoJSON formatted for Plotly choropleth maps.
+
+        Ensures the feature properties include a standardized key for
+        joining with data. Automatically reprojects from EPSG:3857 to
+        WGS84 if needed.
+
+        Args:
+            key_property: Property name to use as feature identifier.
+
+        Returns:
+            GeoJSON FeatureCollection with standardized properties in WGS84.
+        """
+        needs_reproject = self._needs_reprojection()
+        features = []
+
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            new_props = dict(props)
+
+            # Ensure standardized property names exist
+            zone_code = self._find_property(props, self.CODE_PROPERTIES)
+            zone_name = self._find_property(props, self.NAME_PROPERTIES)
+
+            new_props["zone_code"] = zone_code
+            new_props["zone_name"] = zone_name or zone_code
+
+            # Reproject geometry if needed
+            geometry = feature.get("geometry")
+            if needs_reproject and geometry:
+                geometry = reproject_geometry(geometry)
+
+            features.append(
+                {
+                    "type": "Feature",
+                    "properties": new_props,
+                    "geometry": geometry,
+                }
+            )
+
+        return {"type": "FeatureCollection", "features": features}
+
+
+class TRREBDistrictParser:
+    """Parser for TRREB district boundary GeoJSON files.
+
+    TRREB district boundaries are manually digitized from the TRREB PDF map
+    using QGIS.
+
+    Expected GeoJSON properties:
+        - district_code: District code (W01, C01, E01, etc.)
+        - district_name: District name
+        - area_type: West, Central, East, or North
+    """
+
+    CODE_PROPERTIES = [
+        "district_code",
+        "District_Code",
+        "DISTRICT_CODE",
+        "districtcode",
+        "code",
+    ]
+    NAME_PROPERTIES = [
+        "district_name",
+        "District_Name",
+        "DISTRICT_NAME",
+        "districtname",
+        "name",
+        "NAME",
+    ]
+    AREA_PROPERTIES = [
+        "area_type",
+        "Area_Type",
+        "AREA_TYPE",
+        "areatype",
+        "area",
+        "type",
+    ]
+
+    def __init__(self, geojson_path: Path) -> None:
+        """Initialize parser with path to GeoJSON file."""
+        self.geojson_path = geojson_path
+        self._geojson: dict[str, Any] | None = None
+
+    @property
+    def geojson(self) -> dict[str, Any]:
+        """Lazy-load and return raw GeoJSON data."""
+        if self._geojson is None:
+            self._geojson = load_geojson(self.geojson_path)
+        return self._geojson
+
+    def _find_property(
+        self, properties: dict[str, Any], candidates: list[str]
+    ) -> str | None:
+        """Find a property value by checking multiple candidate names."""
+        for name in candidates:
+            if name in properties and properties[name] is not None:
+                return str(properties[name])
+        return None
+
+    def _infer_area_type(self, district_code: str) -> AreaType:
+        """Infer area type from district code prefix."""
+        prefix = district_code[0].upper()
+        mapping = {"W": AreaType.WEST, "C": AreaType.CENTRAL, "E": AreaType.EAST}
+        return mapping.get(prefix, AreaType.NORTH)
+
+    def parse(self) -> list[TRREBDistrict]:
+        """Parse GeoJSON and return list of TRREBDistrict schemas."""
+        districts = []
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            geom = feature.get("geometry")
+
+            district_code = self._find_property(props, self.CODE_PROPERTIES)
+            district_name = self._find_property(props, self.NAME_PROPERTIES)
+            area_type_str = self._find_property(props, self.AREA_PROPERTIES)
+
+            if not district_code:
+                raise ValueError(
+                    f"District code not found in properties: {list(props.keys())}"
+                )
+            if not district_name:
+                district_name = district_code
+
+            # Infer or parse area type
+            if area_type_str:
+                try:
+                    area_type = AreaType(area_type_str)
+                except ValueError:
+                    area_type = self._infer_area_type(district_code)
+            else:
+                area_type = self._infer_area_type(district_code)
+
+            geometry_wkt = geometry_to_wkt(geom) if geom else None
+
+            districts.append(
+                TRREBDistrict(
+                    district_code=district_code,
+                    district_name=district_name,
+                    area_type=area_type,
+                    geometry_wkt=geometry_wkt,
+                )
+            )
+
+        return districts
+
+    def get_geojson_for_choropleth(
+        self, key_property: str = "district_code"
+    ) -> dict[str, Any]:
+        """Get GeoJSON formatted for Plotly choropleth maps."""
+        features = []
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            new_props = dict(props)
+
+            district_code = self._find_property(props, self.CODE_PROPERTIES)
+            district_name = self._find_property(props, self.NAME_PROPERTIES)
+
+            new_props["district_code"] = district_code
+            new_props["district_name"] = district_name or district_code
+
+            features.append(
+                {
+                    "type": "Feature",
+                    "properties": new_props,
+                    "geometry": feature.get("geometry"),
+                }
+            )
+
+        return {"type": "FeatureCollection", "features": features}
+
+
+class NeighbourhoodParser:
+    """Parser for City of Toronto neighbourhood boundary GeoJSON files.
+
+    Neighbourhood boundaries are from the City of Toronto Open Data portal.
+
+    Expected GeoJSON properties:
+        - neighbourhood_id or AREA_ID: Neighbourhood ID (1-158)
+        - name or AREA_NAME: Neighbourhood name
+    """
+
+    ID_PROPERTIES = [
+        "neighbourhood_id",
+        "AREA_SHORT_CODE",  # City of Toronto 158 neighbourhoods
+        "AREA_LONG_CODE",
+        "AREA_ID",
+        "area_id",
+        "id",
+        "ID",
+        "HOOD_ID",
+    ]
+    NAME_PROPERTIES = [
+        "AREA_NAME",  # City of Toronto 158 neighbourhoods
+        "name",
+        "NAME",
+        "area_name",
+        "neighbourhood_name",
+    ]
+
+    def __init__(self, geojson_path: Path) -> None:
+        """Initialize parser with path to GeoJSON file."""
+        self.geojson_path = geojson_path
+        self._geojson: dict[str, Any] | None = None
+
+    @property
+    def geojson(self) -> dict[str, Any]:
+        """Lazy-load and return raw GeoJSON data."""
+        if self._geojson is None:
+            self._geojson = load_geojson(self.geojson_path)
+        return self._geojson
+
+    def _find_property(
+        self, properties: dict[str, Any], candidates: list[str]
+    ) -> str | None:
+        """Find a property value by checking multiple candidate names."""
+        for name in candidates:
+            if name in properties and properties[name] is not None:
+                return str(properties[name])
+        return None
+
+    def parse(self) -> list[Neighbourhood]:
+        """Parse GeoJSON and return list of Neighbourhood schemas.
+
+        Note: This parser only extracts ID, name, and geometry.
+        Census enrichment data (population, income, etc.) should be
+        loaded separately and merged.
+        """
+        neighbourhoods = []
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            geom = feature.get("geometry")
+
+            neighbourhood_id_str = self._find_property(props, self.ID_PROPERTIES)
+            name = self._find_property(props, self.NAME_PROPERTIES)
+
+            if not neighbourhood_id_str:
+                raise ValueError(
+                    f"Neighbourhood ID not found in properties: {list(props.keys())}"
+                )
+
+            neighbourhood_id = int(neighbourhood_id_str)
+            if not name:
+                name = f"Neighbourhood {neighbourhood_id}"
+
+            geometry_wkt = geometry_to_wkt(geom) if geom else None
+
+            neighbourhoods.append(
+                Neighbourhood(
+                    neighbourhood_id=neighbourhood_id,
+                    name=name,
+                    geometry_wkt=geometry_wkt,
+                )
+            )
+
+        return neighbourhoods
+
+    def get_geojson_for_choropleth(
+        self, key_property: str = "neighbourhood_id"
+    ) -> dict[str, Any]:
+        """Get GeoJSON formatted for Plotly choropleth maps."""
+        features = []
+        for feature in self.geojson.get("features", []):
+            props = feature.get("properties", {})
+            new_props = dict(props)
+
+            neighbourhood_id = self._find_property(props, self.ID_PROPERTIES)
+            name = self._find_property(props, self.NAME_PROPERTIES)
+
+            new_props["neighbourhood_id"] = (
+                int(neighbourhood_id) if neighbourhood_id else None
+            )
+            new_props["name"] = name
+
+            features.append(
+                {
+                    "type": "Feature",
+                    "properties": new_props,
+                    "geometry": feature.get("geometry"),
+                }
+            )
+
+        return {"type": "FeatureCollection", "features": features}

tests/test_placeholder.py

@@ -0,0 +1,6 @@
+"""Placeholder test to ensure pytest collection succeeds."""
+
+
+def test_placeholder():
+    """Remove this once real tests are added."""
+    assert True