diff --git a/public/app.js b/public/app.js
new file mode 100644
index 0000000..a151310
--- /dev/null
+++ b/public/app.js
@@ -0,0 +1,238 @@
+import {
+  f1, fInt, fmm, markerPos, barHeights, wmoIcon, trendLabel,
+  formatDate, formatTime, dayAbbr, monthName, isOlderThan, msUntil,
+} from './format.js';
+import { icon } from './icons.js';
+
+const CANVAS_W = 1133;
+const CANVAS_H = 744;
+const API_URL = 'api/data.php';
+const REFRESH_MS = 5 * 60 * 1000;
+const FETCH_TIMEOUT_MS = 10000;
+const STALE_MINUTES = 30;
+const RELOAD_HOUR = 4;
+const FALLBACK_TZ = 'Europe/Berlin';
+
+const $ = (id) => document.getElementById(id);
+const stage = $('stage');
+const viewport = $('viewport');
+
+const state = {
+  data: null,        // laatste payload, ook als die uit de SW-cache komt
+  tz: FALLBACK_TZ,
+  lastOk: null,      // Date van de laatste geslaagde live-fetch
+  offlineSince: null // Date vanaf wanneer er geen verbinding is
+};
+
+/* ---------- schaal ---------- */
+
+function fit() {
+  const w = viewport.clientWidth;
+  const h = viewport.clientHeight;
+  const s = Math.min(w / CANVAS_W, h / CANVAS_H);
+  const x = Math.round((w - CANVAS_W * s) / 2);
+  const y = Math.round((h - CANVAS_H * s) / 2);
+  stage.style.transform = `translate(${x}px, ${y}px) scale(${s})`;
+}
+
+/* ---------- render ---------- */
+
+function setText(id, text) {
+  $(id).textContent = text;
+}
+
+function renderHeader(now) {
+  setText('date', formatDate(now, state.tz));
+  setText('clock', formatTime(now, state.tz));
+}
+
+function renderMeasurement(now) {
+  const d = state.data;
+  const upd = $('upd');
+  if (!d) return;
+  const stale = d.station.stale || isOlderThan(d.station.measured_at, now, STALE_MINUTES);
+  upd.textContent = `meting ${formatTime(d.station.measured_at, state.tz)}${stale ? ' · verouderd' : ''}`;
+  upd.classList.toggle('stale', stale);
+}
+
+function renderOutdoor(o) {
+  setText('trend', trendLabel(o.trend));
+  setText('temp', `${f1(o.temp)}°`);
+  $('mark').style.left = `${markerPos(o.temp, o.min, o.max).toFixed(1)}%`;
+  setText('min', `${f1(o.min)}°`);
+  setText('min-at', `laagst om ${formatTime(o.min_at, state.tz)}`);
+  setText('max', `${f1(o.max)}°`);
+  setText('max-at', `hoogst om ${formatTime(o.max_at, state.tz)}`);
+}
+
+function renderRooms(rooms) {
+  const html = rooms.map((r) => {
+    const off = !r.reachable || r.temp === null;
+    return `<div class="a-room${off ? ' off' : ''}">
+      <p class="a-rname">${esc(r.name)}</p>
+      <p class="a-rtemp num">${off ? '–' : f1(r.temp) + '°'}</p>
+      <p class="a-rmm num"><span class="cold">↓ ${off ? '–' : f1(r.min) + '°'}</span><span class="warm">↑ ${off ? '–' : f1(r.max) + '°'}</span></p>
+    </div>`;
+  });
+  $('rooms').innerHTML = html.join('');
+}
+
+function renderRain(rain, now) {
+  setText('rain-today', f1(rain.today));
+  setText('month-name', monthName(now, state.tz));
+  setText('month-total', `${f1(rain.month_total)} mm`);
+
+  const bars = rain.previous_days.map((p) => ({ label: dayAbbr(p.date, state.tz), mm: p.mm }));
+  bars.push({ label: 'Vandaag', mm: rain.today, now: true });
+  const heights = barHeights(bars.map((b) => b.mm));
+  $('bars').innerHTML = bars.map((b, i) => `<div class="a-bar${b.now ? ' now' : ''}">
+      <span class="num">${f1(b.mm)}</span><i style="height:${heights[i].toFixed(1)}px"></i><span>${b.label}</span>
+    </div>`).join('');
+}
+
+function renderForecast(days) {
+  $('forecast').innerHTML = days.map((d) => `<div class="a-day">
+      <p class="a-dname">${dayAbbr(d.date, state.tz)}</p>
+      <div class="a-icon">${icon(wmoIcon(d.weather_code))}</div>
+      <p class="a-hl num">${fInt(d.temp_max)}°<span>${fInt(d.temp_min)}°</span></p>
+      <p class="a-fr num">${fmm(d.precip_mm)}<span>${d.precip_prob === null ? '–' : d.precip_prob + '%'}</span></p>
+    </div>`).join('');
+}
+
+function renderBanner() {
+  const banner = $('banner');
+  const errors = state.data ? state.data.errors : [];
+  if (errors.includes('netatmo_auth')) {
+    banner.innerHTML = 'Netatmo-koppeling verlopen<small>Voer <code>bin/netatmo-init.php</code> opnieuw uit met een nieuwe refresh token.</small>';
+    banner.hidden = false;
+  } else if (!state.data) {
+    banner.hidden = false;
+  } else {
+    banner.hidden = true;
+  }
+}
+
+function renderStatus() {
+  const el = $('status');
+  if (state.offlineSince) {
+    el.textContent = `geen verbinding sinds ${formatTime(state.offlineSince, state.tz)}`;
+    el.hidden = false;
+  } else {
+    el.hidden = true;
+  }
+}
+
+function render() {
+  const now = new Date();
+  const d = state.data;
+  renderHeader(now);
+  if (d) {
+    renderMeasurement(now);
+    renderOutdoor(d.outdoor);
+    renderRooms(d.indoor);
+    renderRain(d.rain, now);
+    renderForecast(d.forecast);
+  }
+  renderBanner();
+  renderStatus();
+}
+
+function esc(s) {
+  return String(s).replace(/[&<>"]/g, (c) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;' }[c]));
+}
+
+/* ---------- data ---------- */
+
+async function fetchData() {
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), FETCH_TIMEOUT_MS);
+  try {
+    const res = await fetch(API_URL, { cache: 'no-store', signal: controller.signal });
+    if (!res.ok) throw new Error(`HTTP ${res.status}`);
+    const json = await res.json();
+    if (!json || !json.station) throw new Error('onvolledig antwoord');
+    return { json, fromCache: res.headers.get('X-From-Cache') === '1' };
+  } finally {
+    clearTimeout(timer);
+  }
+}
+
+let refreshing = false;
+
+async function refresh() {
+  if (refreshing) return;
+  refreshing = true;
+  try {
+    const { json, fromCache } = await fetchData();
+    state.data = json;
+    state.tz = json.timezone || FALLBACK_TZ;
+    if (fromCache) {
+      state.offlineSince = state.offlineSince || state.lastOk || new Date();
+    } else {
+      state.lastOk = new Date();
+      state.offlineSince = null;
+    }
+  } catch (err) {
+    console.warn('weerscherm: ophalen mislukt', err);
+    if (!state.offlineSince) state.offlineSince = state.lastOk || new Date();
+    if (!state.data) {
+      $('banner').innerHTML = 'Geen verbinding met de server<small>Er wordt elke 5 minuten opnieuw geprobeerd.</small>';
+    }
+  } finally {
+    refreshing = false;
+    render();
+  }
+}
+
+/* ---------- timers ---------- */
+
+function scheduleClock() {
+  const now = new Date();
+  const wait = 60000 - (now.getSeconds() * 1000 + now.getMilliseconds());
+  setTimeout(() => {
+    renderHeader(new Date());
+    renderMeasurement(new Date());
+    scheduleClock();
+  }, wait);
+}
+
+function scheduleMidnight() {
+  setTimeout(() => {
+    refresh();
+    scheduleMidnight();
+  }, msUntil(new Date(), state.tz, 0));
+}
+
+function scheduleReload() {
+  setTimeout(() => location.reload(), msUntil(new Date(), state.tz, RELOAD_HOUR));
+}
+
+async function requestWakeLock() {
+  if (!('wakeLock' in navigator)) return;
+  try {
+    await navigator.wakeLock.request('screen');
+  } catch (err) {
+    // Niet beschikbaar of geweigerd; Automatisch vergrendelen op "Nooit" is de primaire oplossing.
+  }
+}
+
+/* ---------- start ---------- */
+
+window.addEventListener('resize', fit);
+window.addEventListener('orientationchange', () => setTimeout(fit, 50));
+document.addEventListener('visibilitychange', () => {
+  if (document.visibilityState === 'visible') {
+    fit();
+    refresh();
+    requestWakeLock();
+  }
+});
+
+fit();
+render();
+refresh();
+setInterval(refresh, REFRESH_MS);
+scheduleClock();
+scheduleMidnight();
+scheduleReload();
+requestWakeLock();
diff --git a/public/index.html b/public/index.html
new file mode 100644
index 0000000..1f2c674
--- /dev/null
+++ b/public/index.html
@@ -0,0 +1,63 @@
+<!doctype html>
+<html lang="nl">
+<head>
+<meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover, user-scalable=no">
+<title>Weerscherm</title>
+<meta name="apple-mobile-web-app-capable" content="yes">
+<meta name="apple-mobile-web-app-status-bar-style" content="default">
+<meta name="apple-mobile-web-app-title" content="Weer">
+<meta name="theme-color" content="#E8EDF1">
+<link rel="manifest" href="manifest.webmanifest">
+<link rel="apple-touch-icon" href="icons/icon-180.png">
+<link rel="icon" href="icons/icon.svg" type="image/svg+xml">
+<link rel="stylesheet" href="styles.css">
+</head>
+<body>
+<div id="viewport">
+  <main id="stage" class="da" aria-live="polite">
+    <header class="a-top">
+      <span class="a-date" id="date">&nbsp;</span>
+      <span class="a-right">
+        <span class="a-status" id="status" hidden></span>
+        <span class="a-upd" id="upd">meting –</span>
+        <span class="a-clock num" id="clock">–:–</span>
+      </span>
+    </header>
+
+    <section class="a-hero">
+      <p class="a-label">Buiten <span class="a-trend" id="trend"></span></p>
+      <p class="a-temp num" id="temp">–</p>
+      <div class="a-range">
+        <div class="a-track"><span class="a-mark" id="mark" style="left:50%"></span></div>
+        <div class="a-ends num">
+          <span><b class="cold" id="min">–</b><span id="min-at">laagst om –</span></span>
+          <span><b class="warm" id="max">–</b><span id="max-at">hoogst om –</span></span>
+        </div>
+      </div>
+    </section>
+
+    <section class="a-inside" id="rooms"></section>
+
+    <section class="a-bottom">
+      <div>
+        <p class="a-sub">Regen</p>
+        <div class="a-rainrow">
+          <div>
+            <p class="a-rbig"><span class="num" id="rain-today">–</span> mm</p>
+            <p class="a-rsm">vandaag</p>
+            <p class="a-month"><span id="month-name">–</span><b class="num" id="month-total">–</b></p>
+          </div>
+          <div class="a-bars" id="bars"></div>
+        </div>
+      </div>
+      <div class="a-fc" id="forecast"></div>
+    </section>
+
+    <div class="banner" id="banner">Gegevens laden…</div>
+  </main>
+</div>
+<div id="rotate">Draai de iPad een kwartslag</div>
+<script type="module" src="app.js"></script>
+</body>
+</html>
diff --git a/public/styles.css b/public/styles.css
new file mode 100644
index 0000000..d2745f7
--- /dev/null
+++ b/public/styles.css
@@ -0,0 +1,158 @@
+/* Weerscherm, ontwerp A. Vast canvas van 1133 × 744 dat via JS geschaald en gecentreerd wordt. */
+
+:root {
+  --bg: #E8EDF1;
+  --ink: #1B2A35;
+  --muted: #5F707C;
+  --line: #C6D0D8;
+  --warm: #B8761C;
+  --cold: #3A75A3;
+  --rain: #2E6A99;
+  --sun: #D39A2C;
+  --iconfill: #E8EDF1;
+  --w: 1133px;
+  --h: 744px;
+}
+
+* { box-sizing: border-box; margin: 0; padding: 0; }
+
+html, body {
+  height: 100%;
+  overflow: hidden;
+  background: var(--bg);
+  color: var(--ink);
+  font-family: -apple-system, "SF Pro Display", system-ui, "Segoe UI", Roboto, sans-serif;
+  font-variant-numeric: tabular-nums;
+  -webkit-text-size-adjust: none;
+  -webkit-user-select: none;
+  user-select: none;
+  -webkit-touch-callout: none;
+}
+
+[hidden] { display: none !important; }
+
+#viewport {
+  position: fixed;
+  top: env(safe-area-inset-top, 0px);
+  right: env(safe-area-inset-right, 0px);
+  bottom: env(safe-area-inset-bottom, 0px);
+  left: env(safe-area-inset-left, 0px);
+  overflow: hidden;
+}
+
+#stage {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: var(--w);
+  height: var(--h);
+  transform-origin: top left;
+  display: grid;
+  padding: 30px 44px;
+  grid-template-columns: 1fr 330px;
+  grid-template-rows: 40px 1fr 232px;
+  column-gap: 56px;
+  background: var(--bg);
+}
+
+.num { font-variant-numeric: tabular-nums; }
+.cold { color: var(--cold); }
+.warm { color: var(--warm); }
+.muted { color: var(--muted); }
+
+.ic { fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; width: 100%; height: 100%; display: block; }
+.i-sun { stroke: var(--sun); }
+.i-drop { stroke: var(--rain); }
+.i-cloud { fill: var(--iconfill); }
+
+/* Kopregel */
+.a-top { grid-column: 1 / -1; display: flex; justify-content: space-between; align-items: baseline; }
+.a-date { font-size: 22px; font-weight: 500; }
+.a-right { display: flex; gap: 18px; align-items: baseline; }
+.a-status { font-size: 15px; color: var(--warm); }
+.a-upd { font-size: 15px; color: var(--muted); }
+.a-upd.stale { color: var(--warm); }
+.a-clock { font-size: 26px; font-weight: 300; }
+
+/* Buiten */
+.a-hero { align-self: center; }
+.a-label { font-size: 22px; color: var(--muted); font-weight: 500; display: flex; gap: 14px; align-items: baseline; }
+.a-trend { font-size: 17px; font-weight: 400; }
+.a-temp { font-size: 200px; font-weight: 200; letter-spacing: -.045em; line-height: .95; margin: 4px 0 24px -8px; }
+.a-range { width: 560px; }
+.a-track { position: relative; height: 12px; border-radius: 6px; background: linear-gradient(90deg, var(--cold), var(--warm)); }
+.a-mark { position: absolute; top: 50%; width: 28px; height: 28px; border-radius: 50%; background: var(--bg); border: 5px solid var(--ink); transform: translate(-50%, -50%); transition: left .6s ease; }
+.a-ends { display: flex; justify-content: space-between; margin-top: 14px; font-size: 17px; color: var(--muted); }
+.a-ends b { font-size: 24px; font-weight: 600; margin-right: 6px; }
+
+/* Binnen */
+.a-inside { align-self: center; }
+.a-room { padding: 12px 0; border-top: 1px solid var(--line); }
+.a-room:first-child { border-top: 0; }
+.a-rname { font-size: 19px; color: var(--muted); }
+.a-rtemp { font-size: 50px; font-weight: 300; line-height: 1.05; }
+.a-room.off .a-rtemp { color: var(--muted); }
+.a-rmm { font-size: 17px; display: flex; gap: 18px; }
+
+/* Onderste strook */
+.a-bottom { grid-column: 1 / -1; border-top: 1px solid var(--line); padding-top: 22px; display: grid; grid-template-columns: 390px 1fr; column-gap: 36px; }
+.a-sub { font-size: 19px; color: var(--muted); font-weight: 500; margin-bottom: 10px; }
+.a-rainrow { display: flex; justify-content: space-between; align-items: flex-end; }
+.a-rbig { font-size: 22px; color: var(--rain); }
+.a-rbig span { font-size: 60px; font-weight: 300; line-height: 1; }
+.a-rsm { font-size: 17px; color: var(--muted); }
+.a-month { font-size: 17px; margin-top: 18px; color: var(--muted); white-space: nowrap; }
+.a-month b { color: var(--ink); font-weight: 600; font-size: 20px; margin-left: 4px; }
+.a-bars { display: flex; gap: 6px; align-items: flex-end; }
+.a-bar { display: flex; flex-direction: column; align-items: center; gap: 5px; font-size: 14px; color: var(--muted); min-width: 38px; }
+.a-bar i { display: block; width: 24px; border-radius: 4px 4px 0 0; background: var(--rain); opacity: .4; transition: height .6s ease; }
+.a-bar.now i { opacity: 1; }
+.a-bar.now span { color: var(--ink); font-weight: 600; }
+
+/* Verwachting */
+.a-fc { display: grid; grid-template-columns: repeat(5, 1fr); text-align: center; }
+.a-day { display: flex; flex-direction: column; align-items: center; gap: 6px; border-left: 1px solid var(--line); }
+.a-day:first-child { border-left: 0; }
+.a-dname { font-size: 19px; font-weight: 600; }
+.a-icon { width: 58px; height: 58px; }
+.a-hl { font-size: 28px; font-weight: 500; }
+.a-hl span { font-size: 22px; color: var(--muted); font-weight: 400; margin-left: 6px; }
+.a-fr { font-size: 16px; color: var(--rain); }
+.a-fr span { color: var(--muted); margin-left: 6px; }
+
+/* Meldingen */
+.banner {
+  position: absolute;
+  left: 44px;
+  right: 44px;
+  top: 86px;
+  height: 396px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  text-align: center;
+  padding: 40px 60px;
+  font-size: 30px;
+  line-height: 1.4;
+  color: var(--ink);
+  background: var(--bg);
+  border: 1px solid var(--line);
+  border-radius: 18px;
+  z-index: 2;
+}
+.banner small { display: block; margin-top: 16px; font-size: 20px; color: var(--muted); }
+
+#rotate {
+  display: none;
+  position: fixed;
+  top: 0; right: 0; bottom: 0; left: 0;
+  align-items: center;
+  justify-content: center;
+  font-size: 30px;
+  color: var(--muted);
+  background: var(--bg);
+  z-index: 10;
+}
+@media (orientation: portrait) {
+  #rotate { display: flex; }
+}