Add Timepoll availability polling application and image

2026-09-09 19:39:40 +00:00
parent cb80d420c0
commit 4cc2e8fc80
21 changed files with 3519 additions and 2 deletions
@@ -100,6 +100,24 @@ jobs:
            fingerprint_command: |
              { dpkg-query -W -f='${binary:Package}=${Version}\n' | LC_ALL=C sort; pip freeze | LC_ALL=C sort; }

+          - name: timepoll
+            context: timepoll
+            base_image: python:3.12-slim
+            primary_tag: git.ajpanton.se/ajp_anton/timepoll:1
+            oci_labels: |
+              org.opencontainers.image.title=Timepoll
+              org.opencontainers.image.description=Self-hosted availability polls with timezone-aware voting and live updates.
+              org.opencontainers.image.documentation=https://git.ajpanton.se/ajp_anton/docker-images/src/branch/main/timepoll/README.md
+              org.opencontainers.image.source=https://git.ajpanton.se/ajp_anton/docker-images
+              org.opencontainers.image.url=https://git.ajpanton.se/ajp_anton/-/packages/container/timepoll
+            tags: |
+              git.ajpanton.se/ajp_anton/timepoll:1
+              git.ajpanton.se/ajp_anton/timepoll:latest
+            build_args: |
+              PYTHON_VERSION=3.12-slim
+            fingerprint_command: |
+              { dpkg-query -W -f='${binary:Package}=${Version}\n' | LC_ALL=C sort; pip freeze | LC_ALL=C sort; }
+
    steps:
      - name: Check out repository
        uses: actions/checkout@v4
@@ -107,6 +125,12 @@ jobs:
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

+      - name: Test Timepoll
+        if: matrix.image.name == 'timepoll'
+        run: |
+          tar -C timepoll -cf - . | docker run --rm -i --workdir /app python:3.12-slim \
+            sh -c 'tar -xf - && pip install --no-cache-dir -r requirements.txt pytest httpx && PYTHONDONTWRITEBYTECODE=1 pytest -q -p no:cacheprovider'
+
      - name: Log in to Gitea container registry
        run: |
          printf '%s' "$REGISTRY_TOKEN" | docker login "$REGISTRY" --username "$REGISTRY_USERNAME" --password-stdin
@@ -2,3 +2,4 @@ local/
 python-tools/tasks/
 __pycache__/
 *.py[cod]
+timepoll/data/
@@ -3,8 +3,8 @@
 This repository builds a small set of OCI/container images published at
 `git.ajpanton.se`.

-The images are intended to stay close to their upstream base images while adding
-a few commonly useful database/runtime extensions.
+The images include extended database/runtime images and standalone self-hosted
+applications. Each image has its own build context and documentation.

 ## Images

@@ -14,6 +14,7 @@ a few commonly useful database/runtime extensions.
 | `git.ajpanton.se/ajp_anton/php8-pgsql:8` | PHP 8 FPM on Alpine with PostgreSQL client runtime support and the `pdo_pgsql` PHP extension enabled. |
 | `git.ajpanton.se/ajp_anton/python-tools:3` | Python 3 task runner with ExifTool and a web control panel for mounted task scripts. |
 | `git.ajpanton.se/ajp_anton/linkki-tiedotus:1` | Web editor and scheduler for multilingual Telegram channel broadcasts. |
+| `git.ajpanton.se/ajp_anton/timepoll:1` | Timezone-aware availability polls with a live voting grid. |

 ## Included Components

@@ -119,6 +120,19 @@ Included application:
 The image contains no configuration or broadcast data. Mount `/data` from a
 persistent host directory and create its configuration from `linkki-tiedotus/config-examples/`.

+### `timepoll`
+
+Base image: `python:3.12-slim`, following Python 3.12 patch releases.
+
+- Standalone FastAPI application with SQLite persistence and live browser updates.
+- UTC-based yes/maybe voting, IANA timezones, optional blackouts, and private
+  poll administration links. No accounts required.
+- FastAPI and Uvicorn follow releases below version 1; `tzdata` follows available
+  releases. Lucide browser icons are bundled at version 0.468.0.
+- Persistent data is stored in `/data`; the application listens on port `8080`.
+
+See [Timepoll's README](timepoll/README.md) for setup, voting rules and testing.
+
 ## Tags

 Moving deployment tags:
@@ -127,6 +141,7 @@ Moving deployment tags:
 - `git.ajpanton.se/ajp_anton/php8-pgsql:8`
 - `git.ajpanton.se/ajp_anton/python-tools:3`
 - `git.ajpanton.se/ajp_anton/linkki-tiedotus:1`
+- `git.ajpanton.se/ajp_anton/timepoll:1`

 Descriptive tags:

@@ -139,6 +154,7 @@ Convenience tags:
 - `git.ajpanton.se/ajp_anton/php8-pgsql:latest`
 - `git.ajpanton.se/ajp_anton/python-tools:latest`
 - `git.ajpanton.se/ajp_anton/linkki-tiedotus:latest`
+- `git.ajpanton.se/ajp_anton/timepoll:latest`

 Tags are mutable. A weekly candidate build only repoints a deployment tag when
 its content fingerprint changed: base image, build context, build arguments,
@@ -0,0 +1,7 @@
+__pycache__
+.pytest_cache
+tests
+data
+*.md
+pytest.ini
+compose.example.yaml
@@ -0,0 +1,22 @@
+ARG PYTHON_VERSION=3.12-slim
+FROM python:${PYTHON_VERSION}
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    TIMEPOLL_DATA_DIR=/data
+
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt \
+    && groupadd --gid 10001 timepoll \
+    && useradd --uid 10001 --gid 10001 --create-home timepoll \
+    && mkdir /data && chown timepoll:timepoll /data
+
+COPY server.py domain.py ./
+COPY static ./static
+USER timepoll
+EXPOSE 8080
+VOLUME ["/data"]
+HEALTHCHECK --interval=30s --timeout=5s --start-period=10s \
+    CMD python -c "import urllib.request; urllib.request.urlopen('http://127.0.0.1:8080/healthz', timeout=3)"
+CMD ["uvicorn", "server:create_app", "--factory", "--host", "0.0.0.0", "--port", "8080", "--no-access-log", "--timeout-graceful-shutdown", "10"]
@@ -0,0 +1,34 @@
+# Timepoll Implementation
+
+- [x] Poll model, SQLite persistence, timezone-aware schedules and vote conversion.
+- [x] Public/admin API, edit conflicts, live updates and basic abuse limits.
+- [x] Poll creation, administration, voting grid and overlap summaries.
+- [x] Responsive light/dark UI, touch interactions and accessibility.
+- [x] Backend and browser tests, Docker image definition, build workflow and documentation.
+
+Public codes use nine Crockford Base32 characters (3-3-3); private admin
+codes use twelve (4-4-4). Participant editing is intentionally trust-based.
+There are no accounts, calendar integrations, notifications or meeting durations.
+All persisted voting intervals are UTC instants; IANA timezones control display
+and conversion of the creator's local daily schedule.
+
+## Verification
+
+- 24 backend tests pass, including DST transitions, half-hour transitions,
+  vote conversion, edit conflicts, code collisions and restart persistence.
+- Chromium desktop and touch/mobile tests pass in light/dark modes, including
+  live updates and a 320-pixel-wide editing viewport.
+- Ruff, workflow/Compose YAML validation and whitespace checks pass.
+- The build workflow runs the backend tests before building and publishing the
+  Docker image. Publishing an image does not deploy a running service.
+
+## Usability Follow-Up
+
+- [x] Explicit added-date collection and pending-date validation.
+- [x] Matching time dropdowns and outward rounding on slot-size changes.
+- [x] Root-level public/private links; old preview routes removed.
+- [x] Direct clipboard copying, tested against the actual clipboard over HTTP.
+- [x] Dismiss hover details on pointer exit and page/grid scrolling.
+- [x] Other participants' availability and boundaries remain visible through draft selections; combined view after saving or cancelling.
+- [x] Compact 15-minute rows on desktop and mobile.
+- [x] Emphasized hour labels and rules for 15- and 30-minute grids.
@@ -0,0 +1,184 @@
+# Timepoll
+
+A small self-hosted availability poll. Create an event, share its public link,
+and vote **Yes**, **Maybe**, or leave times unavailable. No accounts are needed.
+Anyone with the public link can edit or remove any participant's votes; this is
+deliberately trust-based, not suitable for confidential or adversarial voting.
+
+## Run
+
+Use [compose.example.yaml](compose.example.yaml). The only persistent mount is
+`/data`, containing the SQLite database and its WAL files. The image runs as UID
+and GID `10001`; create the bind-mount directory with that ownership first:
+
+```sh
+mkdir -p timepoll-data
+sudo chown 10001:10001 timepoll-data
+docker compose -f compose.example.yaml up -d
+```
+
+Open port `8080`, or put an HTTPS reverse proxy in front of it. No external
+database, broker, login provider or browser CDN is required. `/healthz` is the
+container health endpoint. `TIMEPOLL_DATA_DIR` defaults to `/data` and normally
+does not need configuring. Deploy a single application instance; keep SQLite
+on a local filesystem, not an NFS/SMB share.
+
+The registry tags `:1` and `:latest` move together for this application series.
+The repository checks for rebuilds weekly on Monday at 03:27 UTC and on pushes
+to `main`. It publishes a changed image only when the build fingerprint changes.
+This includes base-image, application and installed-dependency changes.
+
+### Reverse Proxy
+
+Forward the original `Host` header and scheme. For TLS termination, configure
+Uvicorn's standard `FORWARDED_ALLOW_IPS` with the proxy's IP so that it trusts
+the proxy's forwarded scheme/client headers. Do not trust arbitrary clients or
+use `*` on a directly reachable backend. Cross-origin writes are rejected.
+
+Disable buffering and caching for `/api/polls/*/events`. These are long-lived
+server-sent event connections with a heartbeat every two seconds. Permit at
+least a 60-second read timeout. Open pages reconnect automatically after an
+outage and fetch the current revision, without discarding an active vote draft.
+
+Public links are bearer access, not a login. Use HTTPS. Add perimeter access
+control if the application itself must be private. Basic per-client request and
+creation limits are included, but do not replace a proxy's abuse protection.
+
+## Creating and Editing
+
+- Set an event name, location timezone and 15-, 30- or 60-minute slots (default 30).
+- Add an inclusive date range, individual dates, or both. **Add dates** moves the
+  chosen range into **Dates in this poll**, which lists all added dates and their
+  count. Dates left in the entry fields must be added or cleared before saving.
+  Remove dates individually from this list.
+- Apply a common daily start/end range, then optionally paint blocked times.
+  `00:00` begins a day; `24:00` ends that day. Overnight availability can be
+  represented by adjoining dates and blocking the unwanted hours.
+- After creation, save the private admin link and share the public voting link.
+  The admin is also a participant only after saving votes through the public link.
+
+Public codes use nine random Crockford Base32 characters, displayed `ABC-123-XYZ`.
+Private codes use twelve characters, displayed `ABCD-1234-WXYZ`. `0` and `1`
+are retained; digits are colored blue. Codes accept lowercase, spaces and hyphens;
+`O` aliases `0`, and `I` or `L` aliases `1`. Database uniqueness checks handle
+collisions. See the [alphabet specification](https://www.crockford.com/base32.html).
+
+Public links are `https://example.com/ABC-123-XYZ`; private links are
+`https://example.com/ABCD-1234-WXYZ`, with no public code in the private link.
+The API resolves the private token through its SHA-256 digest and never includes
+it in public poll data. API authorization uses a header, not a query parameter.
+Only these root-level links are supported.
+
+The private token is now part of the URL path: exclude these paths from reverse
+proxy access logs, analytics and caches. The application disables access logging
+and sends `Referrer-Policy: no-referrer`. Use HTTPS and keep the private link safe;
+losing it means losing normal admin access.
+
+Copy buttons include the current browser origin (scheme, domain and any port),
+so links automatically use the domain on which the application is hosted.
+HTTPS uses the browser's Clipboard
+API; plain HTTP uses a user-initiated legacy copy command where supported. If
+browser policy blocks both, the link is selected or shown for manual copying.
+
+### Timezones and Existing Votes
+
+Timepoll stores slot starts as UTC seconds and a slot duration. IANA location
+timezones, not current fixed offsets, convert each date independently. Missing
+spring-forward times are skipped; repeated fall-back times remain distinct.
+Slots are fitted into the resulting continuous UTC ranges. A remaining fragment
+shorter than a whole slot, including at a half-hour DST change, is omitted.
+Viewers can choose their timezone unless the creator fixed the display zone.
+Times crossing local midnight appear on separate dates, with `24:00` denoting
+the preceding day's end. Disconnected daily ranges have a visual gap.
+
+Changing the admin timezone immediately converts the displayed grid, selected
+dates and editable start/end controls without moving existing UTC intervals.
+Both time controls are dropdowns with steps matching the slot length. They
+reflect the first displayed day's range, rounded outward to those steps;
+converted days may have different ranges. **Apply dates and times** replaces the schedule
+with the selected common daily range in the newly selected timezone.
+
+Resizing slots preserves a full new slot as Yes only if Yes covered all of it.
+Any partial Yes or Maybe coverage becomes Maybe. On slot-length changes, starts
+round down and ends round up in the editor timezone. Existing contiguous ranges
+are expanded outward before fitting the new slots; a partial slot at an unusual
+DST transition is still omitted. Removing dates/times or adding blackouts removes affected votes,
+with a confirmation before saving if any existing voted intervals are lost.
+
+## Voting
+
+Enter a unique name to start a draft, then paint Yes, Maybe or Unavailable.
+Save or cancel explicitly; an empty saved vote still counts as a participant.
+During editing, the background shows everyone else's saved availability,
+excluding the edited participant. Your selections use a translucent gray layer
+and check/minus marks; lines preserve changes in other participants' votes.
+Saving or cancelling returns to the combined view.
+Use the participant list or the names in a slot's hover/tap popup to filter one
+person. Select them again to return to everyone. The filtered view offers edit
+and removal actions. Participant editing does not require an admin link.
+
+Green intensity counts Yes + Maybe. Blue means everyone is available, possibly
+with Maybes. Diagonal stripes mark Maybes, becoming denser with their proportion.
+Individual views use gray. Lines separate different voting subsets even when
+their total counts are equal. Light/dark appearance follows the browser setting.
+15-minute rows are compact; hour labels and rules stand out in both 15- and
+30-minute grids. Hover popups close when leaving the slot/popup or
+scrolling the page or grid; touch popups remain open until dismissed or scrolling.
+
+The longest-overlap lists treat Maybe separately as unavailable and available.
+They show everyone, then all but one/two/three, limited to at most 25% absent.
+Each stretch keeps the same participating set. Equal longest stretches show the
+earliest first, with the other ties expandable. Empty saved participants count
+in these thresholds; unsaved drafts do not.
+
+Changes arrive live, including other participants' edits. Saving rejects a stale
+draft if that same participant or the actual schedule changed. Other people's
+votes, title changes and display timezone changes do not invalidate it. The
+browser warns before leaving an unsaved draft or unsaved admin changes.
+
+## Data and Limits
+
+SQLite uses WAL transactions and persists immediately, including participant and
+schedule revisions. Back up with SQLite's online backup API or stop the container
+before copying the entire data directory. Copying only the live `.sqlite3` file
+can miss committed data still in the WAL.
+
+Polls do not expire automatically. There is a per-poll limit of 12,000 slots and
+200 participants; generated schedules accept up to 366 dates. Creation is limited
+to 20 polls per client IP per hour and other API requests to 240 per minute.
+These in-memory abuse limits reset on restart. This is a small-group application,
+not a multi-tenant scheduling service.
+
+## Development
+
+Python 3.12 or newer:
+
+```sh
+python -m venv /tmp/timepoll-venv
+/tmp/timepoll-venv/bin/pip install -r requirements.txt pytest httpx
+TIMEPOLL_DATA_DIR=./data /tmp/timepoll-venv/bin/uvicorn server:create_app --factory --host 0.0.0.0 --port 8080
+```
+
+`data/` is gitignored. The app consists of `domain.py` (interval rules), `server.py`
+(API and SQLite) and `static/` (plain browser JavaScript/CSS). No frontend build
+step. FastAPI supplies request validation, Uvicorn handles HTTP and asynchronous
+live streams, and `tzdata` supplies IANA data even on minimal container hosts.
+
+```sh
+/tmp/timepoll-venv/bin/pytest -q
+```
+
+For browser tests, install Playwright into a temporary directory, install its
+Chromium browser, start Timepoll against a **disposable** database, and run:
+
+```sh
+npm install --prefix /tmp/timepoll-browser playwright
+/tmp/timepoll-browser/node_modules/.bin/playwright install chromium
+NODE_PATH=/tmp/timepoll-browser/node_modules TIMEPOLL_TEST_URL=http://127.0.0.1:8080 node tests/browser.cjs
+```
+
+The browser suite creates test polls and writes screenshots under `/tmp`.
+It covers desktop/mobile voting, real-time updates, same-person conflicts,
+admin timezone conversion and horizontal overflow. Backend tests cover SQLite
+restart persistence, DST, interval conversion, collisions/conflicts and validation.
+Asset attribution is in [static/vendor/README.md](static/vendor/README.md).
@@ -0,0 +1,16 @@
+services:
+  timepoll:
+    image: git.ajpanton.se/ajp_anton/timepoll:1
+    restart: unless-stopped
+    ports:
+      - "8080:8080"
+    volumes:
+      - ./timepoll-data:/data
+    security_opt:
+      - no-new-privileges:true
+    cap_drop:
+      - ALL
+    read_only: true
+    tmpfs:
+      - /tmp
+    stop_grace_period: 15s
@@ -0,0 +1,142 @@
+"""UTC intervals and availability rules, independent of HTTP and storage."""
+
+from datetime import date, datetime, time, timedelta
+from zoneinfo import ZoneInfo
+
+
+def make_slots(
+    dates: list[str], start: str, end: str, minutes: int, zone: str
+) -> list[int]:
+    tz = ZoneInfo(zone)
+    start_time = time.fromisoformat(start)
+    end_time = time.min if end == "24:00" else time.fromisoformat(end)
+    if any(t.second or t.microsecond or t.tzinfo for t in (start_time, end_time)):
+        raise ValueError("Use local times with minute precision.")
+    if end != "24:00" and end_time <= start_time:
+        raise ValueError("The end must be after the start; use 24:00 for midnight.")
+    slots = set()
+    for day in sorted(set(dates)):
+        first = datetime.combine(date.fromisoformat(day), start_time)
+        last = datetime.combine(first.date(), end_time)
+        if end == "24:00":
+            last += timedelta(days=1)
+        if (last - first).total_seconds() % (minutes * 60):
+            raise ValueError("The daily range must contain whole slots.")
+        current = first
+        valid_minutes = set()
+        while current < last:
+            # Build valid UTC ranges first, then fit whole slots. This also handles
+            # half-hour DST changes without producing overlapping hour-long slots.
+            for fold in (0, 1):
+                instant = int(current.replace(tzinfo=tz, fold=fold).timestamp())
+                if datetime.fromtimestamp(instant, tz).replace(tzinfo=None) == current:
+                    valid_minutes.add(instant)
+            current += timedelta(minutes=1)
+        step = minutes * 60
+        for first_utc, last_utc in intervals(sorted(valid_minutes), 60):
+            slots.update(range(first_utc, last_utc - step + 1, step))
+    return sorted(slots)
+
+
+def intervals(slots: list[int], seconds: int) -> list[tuple[int, int]]:
+    result = []
+    for slot in sorted(slots):
+        if result and result[-1][1] == slot:
+            result[-1] = (result[-1][0], slot + seconds)
+        else:
+            result.append((slot, slot + seconds))
+    return result
+
+
+def resize_slots(
+    slots: list[int], old_minutes: int, new_minutes: int, zone: str = "UTC"
+) -> list[int]:
+    step = new_minutes * 60
+    ranges = []
+    tz = ZoneInfo(zone)
+    for first, last in intervals(slots, old_minutes * 60):
+        start_clock, end_clock = (
+            datetime.fromtimestamp(first, tz),
+            datetime.fromtimestamp(last, tz),
+        )
+        first -= (start_clock.minute % new_minutes) * 60
+        last += (-end_clock.minute % new_minutes) * 60
+        if ranges and first <= ranges[-1][1]:
+            ranges[-1] = (ranges[-1][0], max(last, ranges[-1][1]))
+        else:
+            ranges.append((first, last))
+    return [s for first, last in ranges for s in range(first, last - step + 1, step)]
+
+
+def remap_votes(
+    votes: dict[str, str], old_minutes: int, slots: list[int], new_minutes: int
+) -> dict[str, str]:
+    old = sorted(
+        (int(start), int(start) + old_minutes * 60, value)
+        for start, value in votes.items()
+    )
+    result = {}
+    index = 0
+    for start in slots:
+        end = start + new_minutes * 60
+        while index < len(old) and old[index][1] <= start:
+            index += 1
+        yes_seconds = 0
+        overlaps = False
+        for old_index in range(index, len(old)):
+            a, b, value = old[old_index]
+            if a >= end:
+                break
+            overlap = min(end, b) - max(start, a)
+            if overlap > 0:
+                overlaps = True
+                if value == "yes":
+                    yes_seconds += overlap
+        if overlaps:
+            result[str(start)] = "yes" if yes_seconds == end - start else "maybe"
+    return result
+
+
+def votes_lost(
+    votes: dict[str, str], old_minutes: int, slots: list[int], minutes: int
+) -> bool:
+    ranges = intervals(slots, minutes * 60)
+    return any(
+        not any(a <= int(slot) and b >= int(slot) + old_minutes * 60 for a, b in ranges)
+        for slot in votes
+    )
+
+
+def summaries(slots: list[int], minutes: int, people: list[dict]) -> dict:
+    """Longest runs retain the exact participating set, not just its count."""
+    result = {"yes": [], "inclusive": []}
+    if not people:
+        return result
+    for mode, groups in result.items():
+        runs = []
+        for start in slots:
+            ids = tuple(
+                p["id"]
+                for p in people
+                if p["votes"].get(str(start))
+                in (("yes",) if mode == "yes" else ("yes", "maybe"))
+            )
+            if runs and runs[-1]["end"] == start and runs[-1]["people"] == ids:
+                runs[-1]["end"] += minutes * 60
+            else:
+                runs.append(
+                    {"start": start, "end": start + minutes * 60, "people": ids}
+                )
+        for missing in range(min(3, len(people) // 4) + 1):
+            eligible = [r for r in runs if len(r["people"]) >= len(people) - missing]
+            longest = max((r["end"] - r["start"] for r in eligible), default=0)
+            groups.append(
+                {
+                    "missing": missing,
+                    "seconds": longest,
+                    "stretches": [
+                        r for r in eligible if r["end"] - r["start"] == longest
+                    ],
+                }
+            )
+    return result
@@ -0,0 +1,3 @@
+[pytest]
+pythonpath = .
+testpaths = tests
@@ -0,0 +1,3 @@
+fastapi>=0.115,<1
+uvicorn>=0.30,<1
+tzdata
@@ -0,0 +1,501 @@
+import asyncio
+import hashlib
+import json
+import os
+import secrets
+import sqlite3
+import time
+import unicodedata
+from collections import defaultdict, deque
+from contextlib import contextmanager
+from itertools import pairwise
+from pathlib import Path
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError, available_timezones
+
+from domain import make_slots, remap_votes, resize_slots, summaries, votes_lost
+from fastapi import FastAPI, HTTPException, Request
+from fastapi.responses import FileResponse, JSONResponse, StreamingResponse
+from fastapi.staticfiles import StaticFiles
+from pydantic import BaseModel, Field, field_validator
+
+ALPHABET = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"
+ROOT = Path(__file__).parent
+
+
+def normalize_code(value):
+    return (
+        "".join(value.upper().split())
+        .replace("-", "")
+        .translate(str.maketrans("OIL", "011"))
+    )
+
+
+def new_code(length):
+    return "".join(secrets.choice(ALPHABET) for _ in range(length))
+
+
+class Schedule(BaseModel):
+    dates: list[str] = Field(max_length=366)
+    start: str = "09:00"
+    end: str = "17:00"
+    minutes: int = 30
+    timezone: str
+
+    @field_validator("minutes")
+    @classmethod
+    def slot_size(cls, value):
+        if value not in (15, 30, 60):
+            raise ValueError("Choose 15, 30 or 60 minutes.")
+        return value
+
+    @field_validator("timezone")
+    @classmethod
+    def zone(cls, value):
+        try:
+            ZoneInfo(value)
+        except (ZoneInfoNotFoundError, ValueError):
+            raise ValueError("Choose an IANA location timezone.") from None
+        return value
+
+
+class PollSettings(BaseModel):
+    title: str = Field(min_length=1, max_length=120)
+    timezone: str
+    fixed_timezone: bool = False
+    minutes: int = 30
+    slots: list[int] = Field(min_length=1, max_length=12000)
+    blocked: list[int] = Field(default_factory=list, max_length=12000)
+    settings_revision: int = 0
+    confirm_loss: bool = False
+
+    _size = field_validator("minutes")(Schedule.slot_size.__func__)
+    _zone = field_validator("timezone")(Schedule.zone.__func__)
+
+    @field_validator("title")
+    @classmethod
+    def title_valid(cls, value):
+        value = value.strip()
+        if not value:
+            raise ValueError("Enter an event name.")
+        return value
+
+
+class Votes(BaseModel):
+    name: str = Field(min_length=1, max_length=80)
+    votes: dict[str, str] = Field(default_factory=dict, max_length=12000)
+    revision: int = 0
+    schedule_revision: int
+
+
+def create_app(data_dir=None):
+    app = FastAPI(docs_url=None, redoc_url=None, openapi_url=None)
+    data = Path(data_dir or os.environ.get("TIMEPOLL_DATA_DIR", "/data"))
+    data.mkdir(parents=True, exist_ok=True)
+    database = data / "timepoll.sqlite3"
+
+    @contextmanager
+    def db(write=False):
+        con = sqlite3.connect(database, timeout=10, isolation_level=None)
+        con.row_factory = sqlite3.Row
+        con.execute("PRAGMA foreign_keys=ON")
+        try:
+            con.execute("BEGIN IMMEDIATE" if write else "BEGIN")
+            yield con
+            con.commit()
+        except BaseException:
+            con.rollback()
+            raise
+        finally:
+            con.close()
+
+    with sqlite3.connect(database) as con:
+        con.execute("PRAGMA journal_mode=WAL")
+        con.executescript("""
+            CREATE TABLE IF NOT EXISTS polls (
+                code TEXT PRIMARY KEY, admin_hash TEXT NOT NULL UNIQUE,
+                title TEXT NOT NULL, timezone TEXT NOT NULL, fixed_timezone INTEGER NOT NULL,
+                minutes INTEGER NOT NULL, slots TEXT NOT NULL, blocked TEXT NOT NULL,
+                revision INTEGER NOT NULL DEFAULT 1, schedule_revision INTEGER NOT NULL DEFAULT 1,
+                settings_revision INTEGER NOT NULL DEFAULT 1);
+            CREATE TABLE IF NOT EXISTS people (
+                id INTEGER PRIMARY KEY, poll TEXT NOT NULL REFERENCES polls(code) ON DELETE CASCADE,
+                name TEXT NOT NULL, name_key TEXT NOT NULL, votes TEXT NOT NULL,
+                revision INTEGER NOT NULL DEFAULT 1, UNIQUE(poll, name_key));
+        """)
+
+    limits = defaultdict(deque)
+
+    @app.middleware("http")
+    async def guards(request, call_next):
+        if request.method in ("POST", "PUT", "DELETE"):
+            origin = request.headers.get("origin")
+            if origin and origin != str(request.base_url).rstrip("/"):
+                return JSONResponse(
+                    {"detail": "Cross-origin writes are not allowed."}, 403
+                )
+            # Limit actual bytes, including chunked requests without Content-Length.
+            body = bytearray()
+            async for chunk in request.stream():
+                body.extend(chunk)
+                if len(body) > 1024 * 1024:
+                    return JSONResponse({"detail": "Request too large."}, 413)
+            request._body = bytes(body)
+        if request.url.path.startswith("/api/") and not request.url.path.endswith(
+            "/events"
+        ):
+            now = time.monotonic()
+            # Bound memory and expire idle addresses, including rate-limit keys.
+            for key in list(limits):
+                if not limits[key] or limits[key][-1] < now - 3600:
+                    del limits[key]
+            creating = request.method == "POST" and request.url.path == "/api/polls"
+            key = (request.client.host, creating)
+            window, maximum = (3600, 20) if creating else (60, 240)
+            queue = limits[key]
+            while queue and queue[0] <= now - window:
+                queue.popleft()
+            if len(queue) >= maximum:
+                return JSONResponse(
+                    {"detail": "Too many requests. Please try again later."},
+                    429,
+                    headers={"Retry-After": str(window)},
+                )
+            queue.append(now)
+        response = await call_next(request)
+        response.headers.update(
+            {
+                "X-Content-Type-Options": "nosniff",
+                "Referrer-Policy": "no-referrer",
+                "X-Frame-Options": "DENY",
+                "Content-Security-Policy": "default-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'self'; frame-ancestors 'none'; base-uri 'none'; form-action 'self'",
+            }
+        )
+        if request.url.path.startswith("/api/"):
+            response.headers["Cache-Control"] = "no-store"
+        return response
+
+    def load(con, code):
+        row = con.execute(
+            "SELECT * FROM polls WHERE code=?", (normalize_code(code),)
+        ).fetchone()
+        if row is None:
+            raise HTTPException(404, "Poll not found. Check the event code.")
+        poll = dict(row)
+        poll["slots"] = json.loads(poll["slots"])
+        poll["blocked"] = json.loads(poll["blocked"])
+        poll["fixed_timezone"] = bool(poll["fixed_timezone"])
+        return poll
+
+    def people(con, code):
+        return [
+            {
+                "id": r["id"],
+                "name": r["name"],
+                "votes": json.loads(r["votes"]),
+                "revision": r["revision"],
+            }
+            for r in con.execute(
+                "SELECT * FROM people WHERE poll=? ORDER BY id", (code,)
+            )
+        ]
+
+    def authorize(request, poll):
+        token = normalize_code(
+            request.headers.get("Authorization", "").removeprefix("Bearer ")
+        )
+        if not secrets.compare_digest(
+            hashlib.sha256(token.encode()).hexdigest(), poll["admin_hash"]
+        ):
+            raise HTTPException(403, "The private admin link is required.")
+
+    def check_settings(settings):
+        slots = sorted(set(settings.slots))
+        if any(s < 0 or s > 4102444800 or s % 60 for s in slots):
+            raise HTTPException(
+                422, "Slots must be minute-aligned dates between 1970 and 2100."
+            )
+        if any(b - a < settings.minutes * 60 for a, b in pairwise(slots)):
+            raise HTTPException(422, "Time slots cannot overlap.")
+        if not set(settings.blocked) <= set(slots):
+            raise HTTPException(422, "Blocked times must belong to the schedule.")
+        return slots, sorted(set(settings.blocked))
+
+    @app.get("/healthz")
+    def health():
+        with db() as con:
+            con.execute("SELECT 1 FROM polls LIMIT 1").fetchone()
+        return {"status": "ok"}
+
+    @app.get("/api/timezones")
+    def zones():
+        return sorted(available_timezones())
+
+    @app.post("/api/schedule")
+    def preview(schedule: Schedule):
+        try:
+            slots = make_slots(
+                schedule.dates,
+                schedule.start,
+                schedule.end,
+                schedule.minutes,
+                schedule.timezone,
+            )
+        except ValueError as exc:
+            raise HTTPException(422, str(exc)) from exc
+        if not slots or len(slots) > 12000:
+            raise HTTPException(422, "Choose between 1 and 12,000 slots.")
+        return {"slots": slots}
+
+    @app.post("/api/resize")
+    def resize(settings: PollSettings, old_minutes: int):
+        if old_minutes not in (15, 30, 60):
+            raise HTTPException(422, "Invalid previous slot size.")
+        slots = resize_slots(
+            sorted(set(settings.slots)),
+            old_minutes,
+            settings.minutes,
+            settings.timezone,
+        )
+        blocked = remap_votes(
+            {str(s): "yes" for s in settings.blocked},
+            old_minutes,
+            slots,
+            settings.minutes,
+        )
+        return {"slots": slots, "blocked": [int(s) for s in blocked]}
+
+    @app.post("/api/polls", status_code=201)
+    def create(settings: PollSettings):
+        slots, blocked = check_settings(settings)
+        with db(True) as con:
+            while True:
+                code, token = new_code(9), new_code(12)
+                digest = hashlib.sha256(token.encode()).hexdigest()
+                try:
+                    con.execute(
+                        "INSERT INTO polls(code,admin_hash,title,timezone,fixed_timezone,minutes,slots,blocked) VALUES(?,?,?,?,?,?,?,?)",
+                        (
+                            code,
+                            digest,
+                            settings.title,
+                            settings.timezone,
+                            settings.fixed_timezone,
+                            settings.minutes,
+                            json.dumps(slots),
+                            json.dumps(blocked),
+                        ),
+                    )
+                    break
+                except sqlite3.IntegrityError:
+                    if (
+                        con.execute(
+                            "SELECT 1 FROM polls WHERE code=? OR admin_hash=?",
+                            (code, digest),
+                        ).fetchone()
+                        is None
+                    ):
+                        raise
+        return {"code": code, "admin_token": token}
+
+    @app.get("/api/polls/{code}")
+    def get_poll(code: str):
+        with db() as con:
+            poll = load(con, code)
+            poll.pop("admin_hash")
+            poll["people"] = people(con, poll["code"])
+        active = sorted(set(poll["slots"]) - set(poll["blocked"]))
+        poll["summaries"] = summaries(active, poll["minutes"], poll["people"])
+        return poll
+
+    @app.get("/api/polls/{code}/admin")
+    def admin(code: str, request: Request):
+        with db() as con:
+            authorize(request, load(con, code))
+        return {"authorized": True}
+
+    @app.post("/api/admin/resolve")
+    def resolve_admin(request: Request):
+        token = normalize_code(
+            request.headers.get("Authorization", "").removeprefix("Bearer ")
+        )
+        with db() as con:
+            row = con.execute(
+                "SELECT code FROM polls WHERE admin_hash=?",
+                (hashlib.sha256(token.encode()).hexdigest(),),
+            ).fetchone()
+        if row is None:
+            raise HTTPException(403, "The private admin link is invalid.")
+        return {"code": row["code"]}
+
+    @app.put("/api/polls/{code}")
+    def update(code: str, settings: PollSettings, request: Request):
+        slots, blocked = check_settings(settings)
+        with db(True) as con:
+            poll = load(con, code)
+            authorize(request, poll)
+            if settings.settings_revision != poll["settings_revision"]:
+                raise HTTPException(
+                    409, "This poll was edited elsewhere. Reload before saving."
+                )
+            active = sorted(set(slots) - set(blocked))
+            participants = people(con, poll["code"])
+            if not settings.confirm_loss and any(
+                votes_lost(p["votes"], poll["minutes"], active, settings.minutes)
+                for p in participants
+            ):
+                raise HTTPException(
+                    409,
+                    {
+                        "code": "vote_loss",
+                        "message": "Some existing votes will be lost. Save these changes?",
+                    },
+                )
+            changed = (
+                slots != poll["slots"]
+                or blocked != poll["blocked"]
+                or settings.minutes != poll["minutes"]
+            )
+            if changed:
+                for person in participants:
+                    votes = remap_votes(
+                        person["votes"], poll["minutes"], active, settings.minutes
+                    )
+                    con.execute(
+                        "UPDATE people SET votes=?, revision=revision+1 WHERE id=?",
+                        (json.dumps(votes), person["id"]),
+                    )
+            con.execute(
+                "UPDATE polls SET title=?, timezone=?, fixed_timezone=?, minutes=?, slots=?, blocked=?, revision=revision+1, settings_revision=settings_revision+1, schedule_revision=schedule_revision+? WHERE code=?",
+                (
+                    settings.title,
+                    settings.timezone,
+                    settings.fixed_timezone,
+                    settings.minutes,
+                    json.dumps(slots),
+                    json.dumps(blocked),
+                    int(changed),
+                    poll["code"],
+                ),
+            )
+        return {"saved": True}
+
+    def save_person(code, body, person_id=None):
+        name = " ".join(body.name.split())
+        if not name:
+            raise HTTPException(422, "Enter your name.")
+        name_key = unicodedata.normalize("NFKC", name).casefold()
+        with db(True) as con:
+            poll = load(con, code)
+            if body.schedule_revision != poll["schedule_revision"]:
+                raise HTTPException(
+                    409,
+                    "The available times changed. Cancel and review the new schedule before saving.",
+                )
+            active = {str(s) for s in set(poll["slots"]) - set(poll["blocked"])}
+            if not set(body.votes) <= active or any(
+                v not in ("yes", "maybe") for v in body.votes.values()
+            ):
+                raise HTTPException(
+                    422, "Votes must refer to available slots and use yes or maybe."
+                )
+            if person_id is not None:
+                person = con.execute(
+                    "SELECT * FROM people WHERE id=? AND poll=?",
+                    (person_id, poll["code"]),
+                ).fetchone()
+                if person is None or person["revision"] != body.revision:
+                    raise HTTPException(
+                        409,
+                        "This participant was changed or removed elsewhere. Cancel and reload their votes.",
+                    )
+            elif (
+                con.execute(
+                    "SELECT count(*) FROM people WHERE poll=?", (poll["code"],)
+                ).fetchone()[0]
+                >= 200
+            ):
+                raise HTTPException(
+                    422, "This poll has reached its limit of 200 participants."
+                )
+            try:
+                if person_id is None:
+                    person_id = con.execute(
+                        "INSERT INTO people(poll,name,name_key,votes) VALUES(?,?,?,?)",
+                        (poll["code"], name, name_key, json.dumps(body.votes)),
+                    ).lastrowid
+                else:
+                    con.execute(
+                        "UPDATE people SET name=?, name_key=?, votes=?, revision=revision+1 WHERE id=?",
+                        (name, name_key, json.dumps(body.votes), person_id),
+                    )
+            except sqlite3.IntegrityError as exc:
+                raise HTTPException(
+                    409, "That name is already in this poll. Choose a different name."
+                ) from exc
+            con.execute(
+                "UPDATE polls SET revision=revision+1 WHERE code=?", (poll["code"],)
+            )
+        return {"id": person_id}
+
+    @app.post("/api/polls/{code}/people", status_code=201)
+    def add_person(code: str, body: Votes):
+        return save_person(code, body)
+
+    @app.put("/api/polls/{code}/people/{person_id}")
+    def edit_person(code: str, person_id: int, body: Votes):
+        return save_person(code, body, person_id)
+
+    @app.delete("/api/polls/{code}/people/{person_id}")
+    def delete_person(code: str, person_id: int, revision: int):
+        with db(True) as con:
+            poll = load(con, code)
+            cursor = con.execute(
+                "DELETE FROM people WHERE poll=? AND id=? AND revision=?",
+                (poll["code"], person_id, revision),
+            )
+            if not cursor.rowcount:
+                raise HTTPException(
+                    409,
+                    "This participant was changed or removed elsewhere. Reload before removing them.",
+                )
+            con.execute(
+                "UPDATE polls SET revision=revision+1 WHERE code=?", (poll["code"],)
+            )
+        return {"removed": True}
+
+    @app.get("/api/polls/{code}/events")
+    async def events(code: str, request: Request):
+        def revision():
+            with db() as con:
+                return load(con, code)["revision"]
+
+        await asyncio.to_thread(revision)
+
+        async def stream():
+            previous = None
+            while not await request.is_disconnected():
+                current = await asyncio.to_thread(revision)
+                if current != previous:
+                    yield f"data: {current}\n\n"
+                    previous = current
+                else:
+                    yield ": heartbeat\n\n"
+                await asyncio.sleep(2)
+
+        return StreamingResponse(
+            stream(),
+            media_type="text/event-stream",
+            headers={"X-Accel-Buffering": "no", "Cache-Control": "no-cache"},
+        )
+
+    app.mount("/static", StaticFiles(directory=ROOT / "static"), name="static")
+
+    @app.get("/")
+    @app.get("/new")
+    @app.get("/{link_code}")
+    def page():
+        return FileResponse(
+            ROOT / "static" / "index.html", headers={"Cache-Control": "no-cache"}
+        )
+
+    return app
@@ -0,0 +1,23 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <meta name="color-scheme" content="light dark" />
+    <title>Timepoll</title>
+    <link rel="icon" href="/static/icon.png" type="image/png" />
+    <link rel="stylesheet" href="/static/style.css" />
+    <script src="/static/vendor/lucide.min.js" defer></script>
+    <script src="/static/app.js" defer></script>
+  </head>
+  <body>
+    <header class="site-header">
+      <a href="/" class="brand"
+        ><img src="/static/icon.png" width="30" height="30" alt="" />Timepoll</a
+      ><span id="connection"></span>
+    </header>
+    <main id="app"><p class="muted">Loading...</p></main>
+    <div id="notice" role="alert" hidden></div>
+    <div id="popover" role="dialog" aria-label="Slot availability" hidden></div>
+  </body>
+</html>
@@ -0,0 +1,859 @@
+:root {
+  color-scheme: light dark;
+  --bg: #fafcfb;
+  --surface: #fff;
+  --ink: #182a24;
+  --muted: #63736d;
+  --line: #d5dfd9;
+  --soft: #eef3ef;
+  --green: #166548;
+  --blue: #1254ad;
+  --selected: #dcece4;
+  --shadow: 0 8px 30px #18342625;
+  --slot-empty: #f1f4f2;
+  --stripe: #13241d75;
+  --gray: #68717c;
+}
+@media (prefers-color-scheme: dark) {
+  :root {
+    --bg: #131817;
+    --surface: #1b2320;
+    --ink: #ebf1ed;
+    --muted: #a4b3ac;
+    --line: #3a4841;
+    --soft: #222e27;
+    --green: #82d5ac;
+    --blue: #91c5ff;
+    --selected: #294237;
+    --shadow: 0 8px 30px #0007;
+    --slot-empty: #202c25;
+    --stripe: #e9fff39c;
+    --gray: #afb9c1;
+  }
+}
+* {
+  box-sizing: border-box;
+  letter-spacing: 0;
+}
+body {
+  margin: 0;
+  background: var(--bg);
+  color: var(--ink);
+  font:
+    15px/1.5 system-ui,
+    sans-serif;
+}
+button,
+input,
+select {
+  font: inherit;
+}
+button,
+a,
+input,
+select {
+  touch-action: manipulation;
+}
+a {
+  color: var(--blue);
+  text-underline-offset: 3px;
+}
+button {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: 7px;
+  min-height: 40px;
+  padding: 7px 13px;
+  border: 1px solid var(--line);
+  border-radius: 6px;
+  color: var(--ink);
+  background: var(--surface);
+  cursor: pointer;
+}
+button:hover {
+  background: var(--soft);
+}
+button:disabled {
+  cursor: default;
+  opacity: 0.5;
+}
+.primary {
+  background: #196b4c;
+  color: #fff;
+  border-color: #196b4c;
+}
+.primary:hover {
+  background: #13583e;
+}
+.button-link {
+  display: inline-flex;
+  align-items: center;
+  gap: 7px;
+  padding: 7px 13px;
+  min-height: 40px;
+  border-radius: 6px;
+  text-decoration: none;
+}
+.danger {
+  color: #ba3838;
+}
+.icon-button {
+  width: 40px;
+  padding: 8px;
+  flex: none;
+}
+svg.lucide {
+  width: 18px;
+  height: 18px;
+  flex: none;
+}
+input,
+select {
+  min-height: 40px;
+  max-width: 100%;
+  padding: 7px 10px;
+  border: 1px solid var(--line);
+  border-radius: 5px;
+  background: var(--surface);
+  color: var(--ink);
+}
+input[type="checkbox"] {
+  min-height: auto;
+  accent-color: var(--green);
+  width: 17px;
+  height: 17px;
+}
+input[type="time"],
+input[type="date"] {
+  width: auto;
+}
+input:focus,
+select:focus,
+button:focus-visible,
+a:focus-visible {
+  outline: 2px solid var(--blue);
+  outline-offset: 3px;
+}
+label {
+  max-width: 100%;
+  min-width: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 5px;
+  font-size: 14px;
+  font-weight: 550;
+}
+.check {
+  flex-direction: row;
+  align-items: center;
+  gap: 9px;
+  font-weight: 400;
+}
+.site-header {
+  height: 66px;
+  border-bottom: 1px solid var(--line);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 28px;
+}
+.brand {
+  display: inline-flex;
+  align-items: center;
+  gap: 10px;
+  font-size: 21px;
+  font-weight: 700;
+  text-decoration: none;
+  color: var(--ink);
+}
+.brand img {
+  border-radius: 6px;
+}
+#connection {
+  color: var(--muted);
+  font-size: 13px;
+}
+main {
+  max-width: 1420px;
+  margin: auto;
+  padding: 26px 28px 60px;
+}
+h1 {
+  font-size: 28px;
+  line-height: 1.25;
+  margin: 0 0 12px;
+  overflow-wrap: anywhere;
+}
+h2 {
+  font-size: 19px;
+  line-height: 1.35;
+  margin: 0 0 14px;
+}
+h3 {
+  font-size: 16px;
+  margin: 0 0 10px;
+}
+p {
+  margin: 8px 0 16px;
+}
+.muted {
+  color: var(--muted);
+}
+.home {
+  max-width: 800px;
+  margin: 40px auto;
+}
+.home h1 {
+  font-size: 36px;
+}
+.home-actions {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  margin-top: 32px;
+  gap: 40px;
+  border-top: 1px solid var(--line);
+  padding-top: 28px;
+}
+.home-actions section + section {
+  border-left: 1px solid var(--line);
+  padding-left: 40px;
+}
+.home-actions form {
+  display: flex;
+  gap: 8px;
+  align-items: end;
+  flex-wrap: wrap;
+}
+.home-actions input {
+  width: 170px;
+}
+.heading {
+  display: flex;
+  justify-content: space-between;
+  align-items: start;
+  gap: 16px;
+  margin-bottom: 22px;
+}
+.heading h1 {
+  margin-bottom: 6px;
+}
+.row {
+  display: flex;
+  gap: 12px;
+  align-items: center;
+  flex-wrap: wrap;
+}
+.between {
+  justify-content: space-between;
+}
+.toolbar {
+  display: flex;
+  gap: 12px;
+  align-items: end;
+  flex-wrap: wrap;
+  margin: 18px 0;
+}
+.toolbar label {
+  font-weight: 400;
+}
+.fields {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 18px;
+  align-items: end;
+}
+.fields .wide {
+  width: 320px;
+  max-width: 100%;
+}
+.editor {
+  max-width: 1150px;
+  margin: auto;
+}
+.band {
+  border-top: 1px solid var(--line);
+  padding: 22px 0;
+}
+.dates {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 6px;
+  max-height: 150px;
+  overflow: auto;
+  margin-top: 16px;
+}
+.date-chip {
+  min-height: 32px;
+  padding: 3px 9px;
+  font-size: 13px;
+}
+.date-chip svg {
+  width: 13px;
+  height: 13px;
+}
+.date-entry {
+  display: flex;
+  align-items: end;
+  gap: 18px 30px;
+  flex-wrap: wrap;
+}
+.date-range-entry,
+.single-date-entry {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: end;
+  gap: 8px;
+}
+.date-bucket {
+  margin: 22px 0 0;
+  padding: 12px 14px 16px;
+  border: 1px solid var(--line);
+  border-radius: 5px;
+  min-width: 0;
+  background: var(--soft);
+}
+.date-bucket legend {
+  padding: 0 7px;
+  font-weight: 600;
+}
+.date-bucket .dates {
+  min-height: 38px;
+  margin: 0;
+  align-items: center;
+}
+#date-count {
+  margin-left: 8px;
+  font-size: 13px;
+  font-weight: 400;
+}
+.clipboard-buffer {
+  position: fixed;
+  left: -9999px;
+  top: 0;
+}
+.code {
+  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
+  white-space: nowrap;
+  font-size: 16px;
+  font-weight: 650;
+}
+.code .digit {
+  color: var(--blue);
+}
+.links {
+  max-width: 820px;
+  margin: auto;
+}
+.link-row {
+  display: flex;
+  gap: 8px;
+  align-items: center;
+  margin: 12px 0;
+}
+.link-row input {
+  flex: 1;
+  min-width: 0;
+}
+.links section {
+  padding: 22px 0;
+  border-top: 1px solid var(--line);
+}
+.links a.primary {
+  display: inline-flex;
+  border-radius: 6px;
+  padding: 10px 16px;
+  text-decoration: none;
+}
+.people {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 7px;
+  margin: 16px 0;
+}
+.person {
+  max-width: 100%;
+  overflow-wrap: anywhere;
+  min-height: 34px;
+  font-size: 14px;
+}
+.person.active {
+  background: var(--selected);
+  border-color: var(--green);
+}
+.person.filtered {
+  border-color: var(--gray);
+  background: var(--soft);
+}
+.new-person {
+  display: flex;
+  gap: 8px;
+  align-items: end;
+  flex-wrap: wrap;
+}
+.new-person input {
+  width: 240px;
+}
+.editbar {
+  display: flex;
+  align-items: center;
+  gap: 15px;
+  flex-wrap: wrap;
+  padding: 13px 0;
+  border-top: 1px solid var(--line);
+  border-bottom: 1px solid var(--line);
+  margin: 16px 0;
+}
+.editbar .save-actions {
+  margin-left: auto;
+  display: flex;
+  gap: 8px;
+}
+.editbar strong {
+  max-width: 100%;
+  overflow-wrap: anywhere;
+}
+#vote-actions {
+  margin-bottom: 18px;
+}
+.segmented {
+  display: inline-flex;
+  max-width: 100%;
+  flex-wrap: wrap;
+}
+.segmented button {
+  border-radius: 0;
+  margin-left: -1px;
+}
+.segmented button:first-child {
+  border-radius: 6px 0 0 6px;
+  margin-left: 0;
+}
+.segmented button:last-child {
+  border-radius: 0 6px 6px 0;
+}
+.segmented button[aria-pressed="true"] {
+  background: var(--selected);
+  border-color: var(--green);
+  position: relative;
+}
+.legend {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 16px;
+  font-size: 13px;
+  color: var(--muted);
+  align-items: center;
+}
+.swatch {
+  display: inline-block;
+  width: 13px;
+  height: 13px;
+  margin-right: 5px;
+  border-radius: 2px;
+  vertical-align: -2px;
+  background: #399368;
+}
+.swatch.blue {
+  background: #478aca;
+}
+.swatch.maybe {
+  background:
+    repeating-linear-gradient(135deg, transparent 0 3px, #405e5070 3px 4px),
+    #8ac5a8;
+}
+.swatch.gray {
+  background: #949fa4;
+}
+.grid-scroll {
+  overflow: auto;
+  max-height: 72vh;
+  border: 1px solid var(--line);
+  border-radius: 5px;
+  background: var(--surface);
+  overscroll-behavior: contain;
+  position: relative;
+  scrollbar-gutter: stable;
+}
+.grid {
+  --day-width: 112px;
+  --time-width: 83px;
+  border-spacing: 0;
+  table-layout: fixed;
+  min-width: calc(var(--time-width) + var(--columns) * var(--day-width));
+  width: 100%;
+  border-collapse: separate;
+}
+.grid .time-column {
+  width: var(--time-width);
+}
+.grid th {
+  position: sticky;
+  top: 0;
+  z-index: 2;
+  background: var(--surface);
+  font-size: 13px;
+  text-align: center;
+  padding: 10px 8px;
+  border-bottom: 1px solid var(--line);
+  min-width: 112px;
+}
+.grid th small {
+  display: block;
+  color: var(--muted);
+  font-weight: 400;
+}
+.grid .time {
+  left: 0;
+  z-index: 1;
+  position: sticky;
+  background: var(--surface);
+  width: 83px;
+  min-width: 83px;
+  text-align: right;
+  padding: 3px 10px 3px 6px;
+  font-size: 12px;
+  color: var(--muted);
+  font-weight: 400;
+  border-right: 1px solid var(--line);
+}
+.grid thead .time {
+  z-index: 3;
+  top: 0;
+}
+.grid td {
+  padding: 0;
+  min-width: 112px;
+  height: 32px;
+  border-right: 1px solid var(--surface);
+  border-bottom: 1px solid var(--line);
+}
+.grid td.empty {
+  background: var(--bg);
+}
+.grid button.slot {
+  width: 100%;
+  height: 32px;
+  min-height: 32px;
+  padding: 0 4px;
+  border: 0;
+  border-radius: 0;
+  font-size: 12px;
+  background-color: var(--cell, var(--slot-empty));
+  color: var(--ink);
+  display: block;
+  position: relative;
+  user-select: none;
+}
+.grid button.slot:hover {
+  box-shadow: inset 0 0 0 2px var(--blue);
+}
+.grid button.slot.stripes {
+  background-image: repeating-linear-gradient(
+    135deg,
+    transparent 0 calc(var(--spacing) - 1px),
+    var(--stripe) calc(var(--spacing) - 1px) var(--spacing)
+  );
+}
+.grid button.slot.blocked {
+  background: var(--soft);
+  color: var(--muted);
+  opacity: 0.8;
+}
+.grid button.slot.boundary {
+  border-top: 2px solid var(--ink);
+}
+.grid .hour-mark > .time {
+  font-weight: 700;
+  color: var(--ink);
+  background: var(--soft);
+  border-top: 1px solid var(--muted);
+}
+.grid .hour-mark > td {
+  border-top: 1px solid var(--muted);
+}
+.grid button.slot.peer-boundary {
+  border-top: 2px solid var(--green);
+}
+.vote-mark {
+  position: relative;
+  z-index: 1;
+}
+.grid button.draft-slot {
+  background-color: var(--slot-empty);
+  background-image: none;
+}
+.draft-slot::before,
+.draft-slot::after {
+  content: "";
+  position: absolute;
+  inset: 0;
+  pointer-events: none;
+}
+.draft-slot::before {
+  background-color: var(--peer-cell, transparent);
+  opacity: 0.75;
+}
+.draft-slot.peer-stripes::before {
+  background-image: repeating-linear-gradient(
+    135deg,
+    transparent 0 calc(var(--peer-spacing) - 1px),
+    var(--stripe) calc(var(--peer-spacing) - 1px) var(--peer-spacing)
+  );
+}
+.draft-slot::after {
+  background-color: var(--cell, transparent);
+  opacity: 0.35;
+}
+.draft-slot.stripes::after {
+  background-image: repeating-linear-gradient(
+    135deg,
+    transparent 0 calc(var(--spacing) - 1px),
+    var(--stripe) calc(var(--spacing) - 1px) var(--spacing)
+  );
+}
+.grid .gap td,
+.grid .gap th {
+  height: 11px;
+  min-height: 11px;
+  background: var(--bg);
+  padding: 0;
+}
+.grid.editing .slot {
+  touch-action: none;
+}
+.slot svg {
+  width: 14px;
+  height: 14px;
+  margin: auto;
+}
+.grid-foot {
+  padding: 8px 0;
+  display: flex;
+  gap: 16px;
+  align-items: center;
+  justify-content: space-between;
+  flex-wrap: wrap;
+  font-size: 13px;
+  color: var(--muted);
+}
+.summary-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 35px;
+  padding-top: 26px;
+}
+.summary-list {
+  padding: 0;
+  margin: 0;
+  list-style: none;
+}
+.summary-list > li {
+  border-top: 1px solid var(--line);
+  padding: 13px 0;
+}
+.summary-list strong {
+  display: block;
+}
+.summary-list .muted {
+  font-size: 13px;
+}
+.summary-list details {
+  margin-top: 6px;
+  font-size: 13px;
+}
+.summary-list details summary {
+  cursor: pointer;
+  color: var(--blue);
+}
+#popover {
+  position: fixed;
+  z-index: 20;
+  width: 290px;
+  max-width: calc(100vw - 24px);
+  max-height: 65vh;
+  overflow: auto;
+  padding: 14px;
+  border: 1px solid var(--line);
+  border-radius: 6px;
+  background: var(--surface);
+  box-shadow: var(--shadow);
+}
+#popover h3 {
+  font-size: 14px;
+  padding-right: 28px;
+}
+#popover .close {
+  position: absolute;
+  right: 5px;
+  top: 5px;
+  min-height: 28px;
+  width: 28px;
+  padding: 4px;
+}
+#popover .voter {
+  display: flex;
+  width: 100%;
+  justify-content: space-between;
+  text-align: left;
+  border: 0;
+  min-height: 35px;
+  background: transparent;
+  overflow-wrap: anywhere;
+}
+#popover .voter.absent .name {
+  text-decoration: line-through;
+  color: var(--muted);
+}
+#popover .voter small {
+  color: var(--muted);
+  margin-left: 10px;
+}
+#notice {
+  position: fixed;
+  bottom: 18px;
+  left: 50%;
+  transform: translateX(-50%);
+  max-width: calc(100vw - 28px);
+  width: max-content;
+  background: var(--ink);
+  color: var(--bg);
+  padding: 14px 18px;
+  border-radius: 6px;
+  box-shadow: var(--shadow);
+  z-index: 40;
+  font-size: 14px;
+}
+#notice button {
+  margin-left: 12px;
+  color: inherit;
+  background: transparent;
+  border: 0;
+  min-height: 22px;
+  padding: 0;
+}
+.busy svg {
+  animation: spin 1s linear infinite;
+}
+@keyframes spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+[hidden] {
+  display: none !important;
+}
+.sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  overflow: hidden;
+  clip-path: inset(50%);
+}
+.grid.compact td,
+.grid.compact button.slot {
+  height: 20px;
+  min-height: 20px;
+  line-height: 16px;
+}
+.grid.compact tbody .time {
+  padding-top: 0;
+  padding-bottom: 0;
+  line-height: 16px;
+}
+.grid.compact .gap td {
+  height: 11px;
+  min-height: 11px;
+}
+@media (prefers-reduced-motion: reduce) {
+  .busy svg {
+    animation: none;
+  }
+}
+@media (max-width: 700px) {
+  .segmented button {
+    font-size: 14px;
+    padding: 7px 8px;
+    gap: 5px;
+  }
+  .grid {
+    --day-width: 95px;
+    --time-width: 69px;
+  }
+  .site-header {
+    padding: 0 16px;
+    height: 58px;
+  }
+  main {
+    padding: 20px 14px 45px;
+  }
+  h1 {
+    font-size: 25px;
+  }
+  .home {
+    margin: 18px auto;
+  }
+  .home h1 {
+    font-size: 30px;
+  }
+  .home-actions {
+    grid-template-columns: 1fr;
+    gap: 28px;
+  }
+  .home-actions section + section {
+    padding: 24px 0 0;
+    border-left: 0;
+    border-top: 1px solid var(--line);
+  }
+  .heading {
+    flex-wrap: wrap;
+  }
+  .summary-grid {
+    grid-template-columns: 1fr;
+    gap: 18px;
+  }
+  .fields {
+    gap: 12px;
+  }
+  .fields .wide {
+    width: 100%;
+  }
+  .editbar {
+    gap: 12px;
+  }
+  .editbar .save-actions {
+    margin-left: 0;
+  }
+  .grid th,
+  .grid td {
+    min-width: 95px;
+  }
+  .grid .time {
+    min-width: 69px;
+    width: 69px;
+    padding-right: 7px;
+  }
+  .grid-scroll {
+    max-height: 68vh;
+  }
+  .date-entry {
+    gap: 6px;
+  }
+  .date-entry input {
+    font-size: 14px;
+  }
+  #connection {
+    font-size: 12px;
+  }
+  .grid button.slot,
+  .grid td {
+    height: 36px;
+  }
+  .grid button.slot {
+    min-height: 36px;
+  }
+  .new-person input {
+    width: 190px;
+  }
+}
@@ -0,0 +1,9 @@
+# Bundled Assets
+
+- `lucide.min.js`: Lucide 0.468.0, ISC license in `lucide.LICENSE`.
+  Source: https://unpkg.com/lucide@0.468.0/dist/umd/lucide.min.js
+- `../icon.png`: Spiral Calendar (U+1F5D3), Twitter Twemoji 14.0.2.
+  Graphics licensed under CC BY 4.0: https://creativecommons.org/licenses/by/4.0/
+  Source: https://github.com/twitter/twemoji/tree/v14.0.2/assets/72x72
+
+Assets are served locally; the browser does not contact any third-party service.
@@ -0,0 +1,15 @@
+ISC License
+
+Copyright (c) for portions of Lucide are held by Cole Bemis 2013-2022 as part of Feather (MIT). All other copyright (c) for Lucide are held by Lucide Contributors 2022.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
@@ -0,0 +1,310 @@
+// Run against an isolated local database, not an existing production instance.
+const { chromium } = require("playwright");
+const assert = require("node:assert/strict");
+const base = process.env.TIMEPOLL_TEST_URL || "http://127.0.0.1:8094";
+
+(async () => {
+  const browser = await chromium.launch({
+    headless: true,
+    executablePath: process.env.CHROMIUM_PATH,
+  });
+  const desktop = await browser.newContext({
+    viewport: { width: 1440, height: 1050 },
+    timezoneId: "Europe/Helsinki",
+  });
+  const errors = [];
+  desktop.on("page", (p) =>
+    p.on("pageerror", (error) => errors.push(error.message)),
+  );
+  const page = await desktop.newPage();
+  const clipboardContext = await browser.newContext({
+    permissions: ["clipboard-read", "clipboard-write"],
+  });
+  const clipboardPage = await clipboardContext.newPage();
+  const clipboardOrigin = new URL(base);
+  clipboardOrigin.hostname = "127.0.0.1";
+  await clipboardPage.goto(clipboardOrigin.origin + "/healthz");
+  async function checkCopy(button, expected) {
+    await page.bringToFront();
+    if (await page.locator("#notice").isVisible())
+      await page.getByRole("button", { name: "Dismiss" }).click();
+    await button.click();
+    await page.getByRole("alert").filter({ hasText: "Link copied." }).waitFor();
+    await clipboardPage.bringToFront();
+    assert.equal(
+      await clipboardPage.evaluate(() => navigator.clipboard.readText()),
+      expected,
+    );
+    await page.bringToFront();
+  }
+  await page.goto(base + "/");
+  await page.getByRole("heading", { name: "Timepoll", exact: true }).waitFor();
+  await page.screenshot({ path: "/tmp/timepoll-home.png", fullPage: true });
+  await page.getByRole("link", { name: "Create poll", exact: true }).click();
+  await page.getByLabel("Event name").fill("Autumn weekend");
+  assert.equal(
+    await page.locator("#event-zone").inputValue(),
+    "Europe/Helsinki",
+  );
+  await page.locator("#date-from").fill("2026-10-23");
+  await page.locator("#date-to").fill("2026-10-26");
+  assert.equal(await page.locator("#date-count").textContent(), "0 added");
+  await page.getByRole("button", { name: "Apply dates and times" }).click();
+  await page
+    .getByRole("alert")
+    .filter({ hasText: "Add the pending dates" })
+    .waitFor();
+  assert.equal(await page.locator(".slot").count(), 0);
+  await page.getByRole("button", { name: "Dismiss" }).click();
+  await page.getByRole("button", { name: "Add dates", exact: true }).click();
+  assert.equal(await page.locator("#date-count").textContent(), "4 added");
+  assert.equal(await page.locator("#date-from").inputValue(), "");
+  assert.equal(await page.locator("#start-time option").count(), 48);
+  assert.equal(await page.locator("#end-time option").count(), 48);
+  await page.locator("#slot-size").selectOption("15");
+  await page.locator("#start-time").selectOption("09:15");
+  await page.locator("#end-time").selectOption("16:45");
+  await page.locator("#slot-size").selectOption("30");
+  assert.equal(await page.locator("#start-time").inputValue(), "09:00");
+  assert.equal(await page.locator("#end-time").inputValue(), "17:00");
+  await page.getByRole("button", { name: "Apply dates and times" }).click();
+  await page.locator(".slot").first().waitFor();
+  assert.equal(await page.locator(".slot").count(), 64);
+  assert.equal(await page.locator("tr.hour-mark").count(), 8);
+  assert.equal(
+    await page
+      .locator("tr.hour-mark .time")
+      .first()
+      .evaluate((e) => getComputedStyle(e).fontWeight),
+    "700",
+  );
+  await page.locator(".slot").first().click();
+  assert.equal(await page.locator(".slot.blocked").count(), 1);
+  await page.screenshot({ path: "/tmp/timepoll-editor.png", fullPage: true });
+  await page.getByRole("button", { name: "Create poll", exact: true }).click();
+  const publicLink = await page.getByLabel("Public voting link").inputValue();
+  const adminLink = await page.getByLabel("Private admin link").inputValue();
+  assert.match(
+    new URL(publicLink).pathname,
+    /^\/[A-Z0-9]{3}-[A-Z0-9]{3}-[A-Z0-9]{3}$/,
+  );
+  assert.match(
+    new URL(adminLink).pathname,
+    /^\/[A-Z0-9]{4}-[A-Z0-9]{4}-[A-Z0-9]{4}$/,
+  );
+  assert.equal(new URL(adminLink).hash, "");
+  await checkCopy(
+    page.getByRole("button", { name: "Copy private link" }),
+    adminLink,
+  );
+  await checkCopy(
+    page.getByRole("button", { name: "Copy public link" }),
+    publicLink,
+  );
+  await page.getByRole("link", { name: "Open poll" }).click();
+  await checkCopy(
+    page.getByRole("button", { name: "Copy public link" }),
+    publicLink,
+  );
+  await page.getByLabel("Your name").fill("Alice");
+  await page.getByRole("button", { name: "Add availability" }).click();
+  // Drag one contiguous day, without replacing the DOM mid-gesture.
+  const available = page.locator(".slot:not([disabled])");
+  const a = await available.nth(0).boundingBox();
+  const b = await available.nth(8).boundingBox();
+  await page.mouse.move(a.x + a.width / 2, a.y + a.height / 2);
+  await page.mouse.down();
+  await page.mouse.move(b.x + b.width / 2, b.y + b.height / 2, { steps: 15 });
+  await page.mouse.up();
+  await page.getByRole("button", { name: "Maybe", exact: true }).click();
+  await available.nth(3).click();
+  await page.getByRole("button", { name: "Save votes" }).click();
+  await page.getByRole("button", { name: "Add availability" }).waitFor();
+  assert.equal(
+    await page.locator("#everyone").getAttribute("class"),
+    "person active",
+  );
+  await page.getByRole("button", { name: "Everyone", exact: true }).click();
+  await page.getByLabel("Your name").fill("alice");
+  await page.getByRole("button", { name: "Add availability" }).click();
+  await page
+    .getByRole("alert")
+    .filter({ hasText: "already in this poll" })
+    .waitFor();
+  await page.getByRole("button", { name: "Dismiss" }).click();
+
+  const other = await desktop.newPage();
+  await other.goto(publicLink);
+  await other.getByLabel("Your name").fill("Bob");
+  await other.getByRole("button", { name: "Add availability" }).click();
+  const shadow = other.locator(".slot:not([disabled])").first();
+  assert.match(
+    await shadow.getAttribute("aria-label"),
+    /Other participants: 1 yes, 0 maybe out of 1/,
+  );
+  assert.ok(
+    await shadow.evaluate((e) => e.style.getPropertyValue("--peer-cell")),
+  );
+  const boundarySlot = Number(
+    await other
+      .locator(".peer-boundary:not([disabled])")
+      .first()
+      .getAttribute("data-slot"),
+  );
+  await other.locator(`[data-slot="${boundarySlot - 1800}"]`).click();
+  await other.locator(`[data-slot="${boundarySlot}"]`).click();
+  const peerBoundary = other.locator(`[data-slot="${boundarySlot}"]`);
+  assert.ok(
+    (await peerBoundary.getAttribute("class")).includes("peer-boundary"),
+  );
+  assert.equal(
+    await peerBoundary.evaluate((e) => getComputedStyle(e).borderTopWidth),
+    "2px",
+  );
+  assert.equal(
+    await peerBoundary.evaluate((e) => getComputedStyle(e, "::after").opacity),
+    "0.35",
+  );
+  await other.screenshot({
+    path: "/tmp/timepoll-vote-shadow.png",
+    fullPage: true,
+  });
+  await other.emulateMedia({ colorScheme: "dark" });
+  await other.screenshot({
+    path: "/tmp/timepoll-vote-shadow-dark.png",
+    fullPage: true,
+  });
+  await other.emulateMedia({ colorScheme: "light" });
+  await other.locator(".slot:not([disabled])").first().click();
+  await other.getByRole("button", { name: "Save votes" }).click();
+  await page
+    .getByRole("button", { name: "Bob", exact: true })
+    .waitFor({ timeout: 10000 });
+  await page.getByRole("button", { name: "Everyone", exact: true }).click();
+  await page.locator(".slot:not([disabled])").first().hover();
+  await page.locator("#popover").waitFor({ state: "visible" });
+  await page.locator("#poll-title").hover();
+  await page.locator("#popover").waitFor({ state: "hidden" });
+  await page.locator(".slot:not([disabled])").first().hover();
+  await page.locator("#popover").waitFor({ state: "visible" });
+  await page.evaluate(() => window.scrollBy(0, 100));
+  await page.locator("#popover").waitFor({ state: "hidden" });
+  await page.locator(".slot:not([disabled])").first().click();
+  await page.locator("#popover").waitFor({ state: "visible" });
+  assert.equal(await page.locator("#popover .voter").count(), 2);
+  await page.locator("#popover .voter").filter({ hasText: "Bob" }).click();
+  await page.getByRole("button", { name: "Edit votes" }).click();
+  assert.match(
+    await page
+      .locator(".slot:not([disabled])")
+      .first()
+      .getAttribute("aria-label"),
+    /Other participants: 1 yes, 0 maybe out of 1/,
+  );
+  // Another editor updates the same participant. This draft must not win.
+  await other.getByRole("button", { name: "Bob", exact: true }).click();
+  await other.getByRole("button", { name: "Edit votes" }).click();
+  await other.getByRole("button", { name: "Save votes" }).click();
+  await page
+    .getByRole("alert")
+    .filter({ hasText: "changed elsewhere" })
+    .waitFor({ timeout: 10000 });
+  await page.getByRole("button", { name: "Save votes" }).click();
+  await page
+    .getByRole("alert")
+    .filter({ hasText: "changed or removed elsewhere" })
+    .waitFor();
+  await page.getByRole("button", { name: "Cancel", exact: true }).click();
+  assert.equal(
+    await page.locator("#everyone").getAttribute("class"),
+    "person active",
+  );
+  await page.getByRole("button", { name: "Add availability" }).waitFor();
+  await page.getByRole("button", { name: "Dismiss" }).click();
+  await page.screenshot({ path: "/tmp/timepoll-desktop.png", fullPage: true });
+
+  // Admin timezone change must retain UTC slots and update editable clocks.
+  const admin = await desktop.newPage();
+  await admin.goto(adminLink);
+  const initial = await admin
+    .locator(".slot")
+    .first()
+    .getAttribute("data-slot");
+  await admin.locator("#event-zone").selectOption("America/New_York");
+  assert.equal(
+    await admin.locator(".slot").first().getAttribute("data-slot"),
+    initial,
+  );
+  assert.equal(await admin.locator("#start-time").inputValue(), "02:00");
+  await admin.getByRole("button", { name: "Save changes" }).click();
+  await admin.getByRole("alert").filter({ hasText: "Poll saved" }).waitFor();
+  await admin.locator("#slot-size").selectOption("15");
+  await admin.locator(".grid.compact").waitFor();
+  assert.ok((await admin.locator("tr.hour-mark").count()) > 0);
+  assert.ok((await admin.locator(".slot").first().boundingBox()).height <= 21);
+  await admin.getByRole("button", { name: "Save changes" }).click();
+  await admin.getByRole("alert").filter({ hasText: "Poll saved" }).waitFor();
+
+  const mobileContext = await browser.newContext({
+    viewport: { width: 390, height: 844 },
+    isMobile: true,
+    hasTouch: true,
+    colorScheme: "dark",
+    timezoneId: "America/Los_Angeles",
+  });
+  mobileContext.on("page", (p) =>
+    p.on("pageerror", (error) => errors.push(error.message)),
+  );
+  const mobile = await mobileContext.newPage();
+  await mobile.goto(publicLink);
+  await mobile.locator(".slot").first().waitFor();
+  assert.equal(
+    await mobile.evaluate(
+      () => document.documentElement.scrollWidth <= innerWidth,
+    ),
+    true,
+  );
+  await mobile.locator(".slot:not([disabled])").first().tap();
+  await mobile.locator("#popover").waitFor({ state: "visible" });
+  await mobile.getByRole("button", { name: "Close", exact: true }).tap();
+  await mobile.screenshot({
+    path: "/tmp/timepoll-mobile-dark.png",
+    fullPage: true,
+  });
+  await mobile.getByLabel("Your name").fill("Casey");
+  await mobile.getByRole("button", { name: "Add availability" }).tap();
+  await mobile.locator(".slot:not([disabled])").first().tap();
+  await mobile.getByRole("button", { name: "Save votes" }).tap();
+  await mobile.getByRole("button", { name: "Add availability" }).waitFor();
+  await page
+    .getByRole("button", { name: "Casey", exact: true })
+    .waitFor({ timeout: 10000 });
+  await mobile.setViewportSize({ width: 320, height: 800 });
+  await mobile.getByRole("button", { name: "Casey", exact: true }).tap();
+  await mobile.getByRole("button", { name: "Edit votes" }).tap();
+  assert.equal(
+    await mobile.evaluate(() => document.documentElement.scrollWidth),
+    320,
+  );
+  await mobile.getByRole("button", { name: "Pan grid" }).tap();
+  assert.equal(await mobile.locator(".grid.editing").count(), 0);
+  await mobile.getByRole("button", { name: "Cancel", exact: true }).tap();
+  assert.equal(
+    await mobile.locator("#everyone").getAttribute("class"),
+    "person active",
+  );
+  await mobileContext.close();
+  assert.deepEqual(errors, []);
+  console.log(
+    JSON.stringify({
+      publicLink,
+      adminLink: "[private]",
+      screenshots: "/tmp/timepoll-*.png",
+      browserErrors: errors,
+    }),
+  );
+  await browser.close();
+})().catch((error) => {
+  console.error(error);
+  process.exit(1);
+});
@@ -0,0 +1,319 @@
+import sqlite3
+from datetime import datetime, timezone
+from itertools import pairwise
+
+import pytest
+from domain import make_slots, remap_votes, resize_slots, summaries, votes_lost
+from fastapi.testclient import TestClient
+from server import create_app, normalize_code
+
+
+def stamp(value):
+    return int(datetime.fromisoformat(value).replace(tzinfo=timezone.utc).timestamp())
+
+
+def test_dst_spring_skips_nonexistent_hour():
+    slots = make_slots(["2026-03-29"], "02:00", "05:00", 30, "Europe/Helsinki")
+    assert len(slots) == 4
+    assert all(b - a == 1800 for a, b in pairwise(slots))
+
+
+def test_dst_fall_keeps_both_repeated_hours():
+    slots = make_slots(["2026-10-25"], "02:00", "05:00", 30, "Europe/Helsinki")
+    assert len(slots) == 8
+    assert len(set(slots)) == 8
+    assert all(b - a == 1800 for a, b in pairwise(slots))
+
+
+def test_slot_ending_at_spring_transition_is_not_lost():
+    assert len(make_slots(["2026-03-29"], "02:00", "03:00", 30, "Europe/Helsinki")) == 2
+
+
+def test_half_hour_dst_change_never_overlaps_slots_or_escapes_range():
+    slots = make_slots(["2026-04-05"], "01:30", "03:30", 60, "Australia/Lord_Howe")
+    assert len(slots) == 2
+    assert all(b - a >= 3600 for a, b in pairwise(slots))
+    # The first repeated 01:45 precedes a reset to 01:30, outside this range.
+    slots = make_slots(["2026-04-05"], "01:45", "02:45", 60, "Australia/Lord_Howe")
+    assert slots == [stamp("2026-04-04T15:15")]
+
+
+def test_timezone_uses_date_not_current_offset():
+    winter = make_slots(["2026-01-05"], "09:00", "10:00", 60, "Europe/Helsinki")
+    summer = make_slots(["2026-07-05"], "09:00", "10:00", 60, "Europe/Helsinki")
+    assert datetime.fromtimestamp(winter[0], timezone.utc).hour == 7
+    assert datetime.fromtimestamp(summer[0], timezone.utc).hour == 6
+
+
+def test_midnight_and_quarter_hour_zone():
+    slots = make_slots(["2026-01-05"], "23:00", "24:00", 30, "Asia/Kathmandu")
+    assert slots == [stamp("2026-01-05T17:15"), stamp("2026-01-05T17:45")]
+
+
+@pytest.mark.parametrize(
+    "start,end", [("17:00", "09:00"), ("09:00", "09:00"), ("09:00", "10:15")]
+)
+def test_invalid_ranges(start, end):
+    with pytest.raises(ValueError):
+        make_slots(["2026-01-01"], start, end, 30, "UTC")
+
+
+def test_vote_resize():
+    assert remap_votes({"0": "yes", "1800": "yes"}, 30, [0], 60) == {"0": "yes"}
+    assert remap_votes({"0": "yes"}, 30, [0], 60) == {"0": "maybe"}
+    assert remap_votes({"0": "maybe"}, 30, [0], 60) == {"0": "maybe"}
+    assert remap_votes({"0": "yes", "1800": "maybe"}, 30, [0], 60) == {"0": "maybe"}
+    assert remap_votes({"0": "yes"}, 60, [0, 1800], 30) == {"0": "yes", "1800": "yes"}
+    assert resize_slots([0, 1800, 7200, 9000], 30, 60) == [0, 7200]
+    assert votes_lost({"0": "yes"}, 60, [0], 30)
+    assert not votes_lost({"0": "yes"}, 60, [0, 1800], 30)
+
+
+def test_overlap_requires_same_people_and_counts_empty_voters():
+    people = [
+        {"id": 1, "votes": {"0": "yes", "1800": "yes"}},
+        {"id": 2, "votes": {"0": "yes"}},
+        {"id": 3, "votes": {"1800": "maybe"}},
+        {"id": 4, "votes": {"0": "yes", "1800": "yes"}},
+    ]
+    result = summaries([0, 1800], 30, people)
+    assert result["yes"][0]["seconds"] == 0
+    assert result["yes"][1]["seconds"] == 1800
+    assert len(result["inclusive"][1]["stretches"]) == 2
+    assert (
+        result["inclusive"][1]["stretches"][0]["people"]
+        != result["inclusive"][1]["stretches"][1]["people"]
+    )
+
+
+def test_overlap_gap_and_midnight():
+    people = [{"id": 1, "votes": {"84600": "yes", "86400": "yes", "91800": "yes"}}]
+    result = summaries([84600, 86400, 91800], 30, people)
+    assert result["yes"][0]["seconds"] == 3600
+
+
+@pytest.fixture
+def client(tmp_path):
+    with TestClient(create_app(tmp_path)) as client:
+        yield client
+
+
+def settings(**kwargs):
+    return dict(
+        title="Weekend",
+        timezone="Europe/Helsinki",
+        fixed_timezone=False,
+        minutes=30,
+        slots=[1800000000, 1800001800, 1800003600, 1800005400],
+        blocked=[],
+        **kwargs,
+    )
+
+
+def create(client):
+    response = client.post("/api/polls", json=settings())
+    assert response.status_code == 201, response.text
+    result = response.json()
+    return result["code"], {"Authorization": "Bearer " + result["admin_token"]}
+
+
+def add(client, code, name="Alice", votes=None):
+    response = client.post(
+        f"/api/polls/{code}/people",
+        json={"name": name, "votes": votes or {}, "schedule_revision": 1},
+    )
+    assert response.status_code == 201, response.text
+    return response.json()["id"]
+
+
+def test_codes_and_private_token_are_not_public(client, tmp_path):
+    code, headers = create(client)
+    assert len(code) == 9 and len(headers["Authorization"].split()[1]) == 12
+    assert normalize_code("ab-oil xyz") == "AB011XYZ"
+    response = client.get(f"/api/polls/{code.lower()}")
+    assert response.status_code == 200
+    assert "admin" not in response.text
+    with sqlite3.connect(tmp_path / "timepoll.sqlite3") as db:
+        assert headers["Authorization"].split()[1] not in str(
+            db.execute("SELECT * FROM polls").fetchall()
+        )
+    assert client.get(f"/api/polls/{code}/admin").status_code == 403
+    assert client.get(f"/api/polls/{code}/admin", headers=headers).status_code == 200
+
+
+def test_empty_duplicate_and_unavailable_votes(client):
+    code, _ = create(client)
+    add(client, code)
+    duplicate = client.post(
+        f"/api/polls/{code}/people",
+        json={"name": " ALICE ", "votes": {}, "schedule_revision": 1},
+    )
+    assert duplicate.status_code == 409
+    invalid = client.post(
+        f"/api/polls/{code}/people",
+        json={"name": "Bob", "votes": {"123": "yes"}, "schedule_revision": 1},
+    )
+    assert invalid.status_code == 422
+    assert len(client.get(f"/api/polls/{code}").json()["people"]) == 1
+
+
+def test_conflicts_and_unrelated_edits(client):
+    code, headers = create(client)
+    alice = add(client, code)
+    add(client, code, "Bob")
+    body = {
+        "name": "Alice",
+        "votes": {"1800000000": "yes"},
+        "schedule_revision": 1,
+        "revision": 1,
+    }
+    assert client.put(f"/api/polls/{code}/people/{alice}", json=body).status_code == 200
+    assert client.put(f"/api/polls/{code}/people/{alice}", json=body).status_code == 409
+    edit = settings(settings_revision=1)
+    edit.update(title="Renamed", timezone="America/New_York")
+    assert (
+        client.put(f"/api/polls/{code}", json=edit, headers=headers).status_code == 200
+    )
+    assert client.get(f"/api/polls/{code}").json()["schedule_revision"] == 1
+    body["revision"] = 2
+    assert client.put(f"/api/polls/{code}/people/{alice}", json=body).status_code == 200
+    assert (
+        client.delete(f"/api/polls/{code}/people/{alice}?revision=2").status_code == 409
+    )
+    assert (
+        client.delete(f"/api/polls/{code}/people/{alice}?revision=3").status_code == 200
+    )
+
+
+def test_admin_vote_loss_confirmation_and_conversion(client):
+    code, headers = create(client)
+    add(
+        client,
+        code,
+        votes={"1800000000": "yes", "1800001800": "yes", "1800003600": "yes"},
+    )
+    edit = settings(settings_revision=1)
+    edit.update(minutes=60, slots=[1800000000, 1800003600])
+    response = client.put(f"/api/polls/{code}", json=edit, headers=headers)
+    assert response.status_code == 200, response.text
+    poll = client.get(f"/api/polls/{code}").json()
+    assert poll["people"][0]["votes"] == {"1800000000": "yes", "1800003600": "maybe"}
+    edit.update(settings_revision=2, blocked=[1800000000])
+    response = client.put(f"/api/polls/{code}", json=edit, headers=headers)
+    assert (
+        response.status_code == 409 and response.json()["detail"]["code"] == "vote_loss"
+    )
+    assert client.get(f"/api/polls/{code}").json()["revision"] == poll["revision"]
+    edit["confirm_loss"] = True
+    assert (
+        client.put(f"/api/polls/{code}", json=edit, headers=headers).status_code == 200
+    )
+    assert client.get(f"/api/polls/{code}").json()["people"][0]["votes"] == {
+        "1800003600": "maybe"
+    }
+
+
+def test_blocked_votes_and_changed_schedule_conflict(client):
+    code, headers = create(client)
+    edit = settings(settings_revision=1)
+    edit["blocked"] = [1800000000]
+    client.put(f"/api/polls/{code}", json=edit, headers=headers)
+    body = {"name": "Alice", "votes": {"1800000000": "yes"}, "schedule_revision": 1}
+    assert client.post(f"/api/polls/{code}/people", json=body).status_code == 409
+    body["schedule_revision"] = 2
+    assert client.post(f"/api/polls/{code}/people", json=body).status_code == 422
+
+
+def test_persistence(tmp_path):
+    with TestClient(create_app(tmp_path)) as client:
+        code, _ = create(client)
+        add(client, code)
+    with TestClient(create_app(tmp_path)) as restarted:
+        assert (
+            restarted.get(f"/api/polls/{code}").json()["people"][0]["name"] == "Alice"
+        )
+
+
+def test_security_validation_and_health(client):
+    assert client.get("/healthz").json() == {"status": "ok"}
+    assert client.get("/").headers["x-frame-options"] == "DENY"
+    assert (
+        client.post(
+            "/api/polls",
+            json=settings(),
+            headers={"Origin": "https://elsewhere.invalid"},
+        ).status_code
+        == 403
+    )
+    assert (
+        client.post("/api/polls", content=b"x" * (1024 * 1024 + 1)).status_code == 413
+    )
+    invalid = settings()
+    invalid["slots"] = [1800000000, 1800000060]
+    assert client.post("/api/polls", json=invalid).status_code == 422
+    invalid.update(timezone="../etc/passwd")
+    assert client.post("/api/polls", json=invalid).status_code == 422
+
+
+def test_schedule_preview_and_resize(client):
+    response = client.post(
+        "/api/schedule",
+        json={
+            "dates": ["2026-10-25"],
+            "start": "02:00",
+            "end": "05:00",
+            "minutes": 30,
+            "timezone": "Europe/Helsinki",
+        },
+    )
+    assert response.status_code == 200
+    assert len(response.json()["slots"]) == 8
+    body = settings()
+    body["minutes"] = 60
+    response = client.post("/api/resize?old_minutes=30", json=body)
+    assert response.json()["slots"] == [1800000000, 1800003600]
+
+
+def test_random_code_collision_is_retried(client, monkeypatch):
+    code, headers = create(client)
+    token = headers["Authorization"].split()[1]
+    values = iter([code, token, "123456789", "123456789ABC"])
+    monkeypatch.setattr("server.new_code", lambda length: next(values))
+    response = client.post("/api/polls", json=settings())
+    assert response.status_code == 201
+    assert response.json()["code"] == "123456789"
+
+
+def test_root_public_and_private_links(client):
+    code, headers = create(client)
+    token = headers["Authorization"].split()[1]
+    assert client.get(f"/{code}").status_code == 200
+    assert client.get(f"/{token}").status_code == 200
+    response = client.post("/api/admin/resolve", headers=headers)
+    assert response.json() == {"code": code}
+    assert client.post("/api/admin/resolve").status_code == 403
+    assert (
+        client.post(
+            "/api/admin/resolve", headers={"Authorization": "Bearer " + code}
+        ).status_code
+        == 403
+    )
+    assert client.get(f"/p/{code}").status_code == 404
+    assert client.get(f"/admin/{code}").status_code == 404
+    assert token not in client.get(f"/api/polls/{code}").text
+
+
+def test_resizing_rounds_local_range_outward():
+    slots = make_slots(["2026-09-15"], "09:15", "10:45", 15, "Europe/Helsinki")
+    assert resize_slots(slots, 15, 30, "Europe/Helsinki") == make_slots(
+        ["2026-09-15"], "09:00", "11:00", 30, "Europe/Helsinki"
+    )
+    # A non-whole-hour UTC offset must not change the local rounding origin.
+    slots = make_slots(["2026-09-15"], "09:15", "10:45", 15, "Asia/Kathmandu")
+    assert resize_slots(slots, 15, 60, "Asia/Kathmandu") == make_slots(
+        ["2026-09-15"], "09:00", "11:00", 60, "Asia/Kathmandu"
+    )
+
+
+def test_resizing_merges_ranges_that_round_into_one_another():
+    assert resize_slots([900, 2700], 15, 60) == [0]