diff --git a/public/monatsvorhersage.php b/public/monatsvorhersage.php
index f26f87d..5f35993 100644
--- a/public/monatsvorhersage.php
+++ b/public/monatsvorhersage.php
@@ -2502,6 +2502,11 @@ $observationTipCalendarFilenameJson = json_encode(sprintf('astrotools-monatserei
             <?= htmlspecialchars($chartLocationName, ENT_QUOTES, 'UTF-8') ?>
           </p>
         </div>
+        <div class="monatskarte-export">
+          <button type="button" class="monatskarte-export-button" id="downloadMonatskartePng">
+            PNG herunterladen
+          </button>
+        </div>
       </div>
 
       <div class="monatskarte-stage">
@@ -2522,6 +2527,11 @@ $observationTipCalendarFilenameJson = json_encode(sprintf('astrotools-monatserei
             <?= htmlspecialchars($chartLocationName, ENT_QUOTES, 'UTF-8') ?>
           </p>
         </div>
+        <div class="monatskarte-export">
+          <button type="button" class="monatskarte-export-button" id="downloadMonatskarteSouthPng">
+            PNG herunterladen
+          </button>
+        </div>
       </div>
 
       <div class="monatskarte-stage monatskarte-stage-south">
@@ -2875,9 +2885,11 @@ const MONTH_PHASE_EVENTS = <?= $moonPhaseEventsJson ?: '[]' ?>;
 const MONTH_CHART_ERROR = <?= $starDataErrorJson ?: 'null' ?>;
 const OBSERVATION_TIP_ICAL = <?= $observationTipCalendarIcsJson ?: '""' ?>;
 const OBSERVATION_TIP_ICAL_FILENAME = <?= $observationTipCalendarFilenameJson ?: '"astrotools-monatsereignisse.ics"' ?>;
+const MONTH_CHART_EXPORT_LOGO_SRC = <?= json_encode($publicBasePath . 'images/logoAM_ws.png', JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) ?>;
 
 const MONTH_CHART_COMET_K = 0.01720209895;
 const MONTH_CHART_COMET_OBLIQ = 23.439279444444445 * Math.PI / 180;
+const MONTH_CHART_EXPORT_WIDTH = 2000;
 
 function isoWeekCount(year) {
   const dec28 = new Date(Date.UTC(year, 11, 28));
@@ -2895,6 +2907,168 @@ function isoWeekMonday(year, week) {
   return monday;
 }
 
+function downloadCanvasAsPng(sourceCanvas, filename, outputWidth) {
+  if (!sourceCanvas || !sourceCanvas.width || !sourceCanvas.height) {
+    return false;
+  }
+
+  const exportCanvas = document.createElement('canvas');
+  const aspectRatio = sourceCanvas.height / sourceCanvas.width;
+  exportCanvas.width = outputWidth;
+  exportCanvas.height = Math.max(1, Math.round(outputWidth * aspectRatio));
+
+  const exportCtx = exportCanvas.getContext('2d');
+  if (!exportCtx) {
+    return false;
+  }
+
+  exportCtx.fillStyle = '#000000';
+  exportCtx.fillRect(0, 0, exportCanvas.width, exportCanvas.height);
+  exportCtx.drawImage(sourceCanvas, 0, 0, exportCanvas.width, exportCanvas.height);
+
+  const link = document.createElement('a');
+  link.href = exportCanvas.toDataURL('image/png');
+  link.download = filename;
+  document.body.appendChild(link);
+  link.click();
+  document.body.removeChild(link);
+  return true;
+}
+
+let monthChartExportLogoPromise = null;
+
+function loadImage(src) {
+  return new Promise(function (resolve, reject) {
+    const image = new Image();
+    image.onload = function () {
+      resolve(image);
+    };
+    image.onerror = function () {
+      reject(new Error('Bild konnte nicht geladen werden: ' + src));
+    };
+    image.src = src;
+  });
+}
+
+function getMonthChartExportLogo() {
+  if (!MONTH_CHART_EXPORT_LOGO_SRC) {
+    return Promise.resolve(null);
+  }
+
+  if (!monthChartExportLogoPromise) {
+    monthChartExportLogoPromise = loadImage(MONTH_CHART_EXPORT_LOGO_SRC).catch(function () {
+      return null;
+    });
+  }
+
+  return monthChartExportLogoPromise;
+}
+
+async function composeExportCanvas(sourceCanvas, logoPosition) {
+  const exportCanvas = document.createElement('canvas');
+  exportCanvas.width = sourceCanvas.width;
+  exportCanvas.height = sourceCanvas.height;
+
+  const exportCtx = exportCanvas.getContext('2d');
+  if (!exportCtx) {
+    return null;
+  }
+
+  exportCtx.fillStyle = '#000000';
+  exportCtx.fillRect(0, 0, exportCanvas.width, exportCanvas.height);
+  exportCtx.drawImage(sourceCanvas, 0, 0);
+
+  const logo = await getMonthChartExportLogo();
+  if (logo) {
+    const padding = Math.round(exportCanvas.width * 0.024);
+    const targetWidth = Math.max(180, Math.min(320, Math.round(exportCanvas.width * 0.14)));
+    const targetHeight = Math.round(targetWidth * (logo.naturalHeight / Math.max(1, logo.naturalWidth)));
+    const drawX = padding;
+    const drawY = logoPosition === 'bottom-left'
+      ? exportCanvas.height - padding - targetHeight
+      : padding;
+    exportCtx.drawImage(logo, drawX, drawY, targetWidth, targetHeight);
+  }
+
+  const caption = monthChartExportCaption();
+  if (caption !== '') {
+    const padding = Math.round(exportCanvas.width * 0.024);
+    const fontSize = Math.max(26, Math.round(exportCanvas.width * 0.022));
+    exportCtx.save();
+    exportCtx.font = '600 ' + fontSize + 'px Rajdhani, sans-serif';
+    exportCtx.textAlign = 'right';
+    exportCtx.textBaseline = 'bottom';
+
+    const metrics = exportCtx.measureText(caption);
+    const textWidth = metrics.width;
+    const ascent = metrics.actualBoundingBoxAscent || fontSize * 0.8;
+    const descent = metrics.actualBoundingBoxDescent || fontSize * 0.2;
+    const boxPadX = Math.round(fontSize * 0.45);
+    const boxPadY = Math.round(fontSize * 0.3);
+    const boxWidth = textWidth + boxPadX * 2;
+    const boxHeight = ascent + descent + boxPadY * 2;
+    const boxX = exportCanvas.width - padding - boxWidth;
+    const boxY = exportCanvas.height - padding - boxHeight;
+    const radius = Math.round(fontSize * 0.28);
+
+    exportCtx.fillStyle = 'rgba(3, 7, 14, 0.7)';
+    exportCtx.beginPath();
+    exportCtx.moveTo(boxX + radius, boxY);
+    exportCtx.lineTo(boxX + boxWidth - radius, boxY);
+    exportCtx.quadraticCurveTo(boxX + boxWidth, boxY, boxX + boxWidth, boxY + radius);
+    exportCtx.lineTo(boxX + boxWidth, boxY + boxHeight - radius);
+    exportCtx.quadraticCurveTo(boxX + boxWidth, boxY + boxHeight, boxX + boxWidth - radius, boxY + boxHeight);
+    exportCtx.lineTo(boxX + radius, boxY + boxHeight);
+    exportCtx.quadraticCurveTo(boxX, boxY + boxHeight, boxX, boxY + boxHeight - radius);
+    exportCtx.lineTo(boxX, boxY + radius);
+    exportCtx.quadraticCurveTo(boxX, boxY, boxX + radius, boxY);
+    exportCtx.closePath();
+    exportCtx.fill();
+
+    exportCtx.fillStyle = 'rgba(235, 242, 255, 0.96)';
+    exportCtx.fillText(caption, exportCanvas.width - padding - boxPadX, exportCanvas.height - padding - boxPadY);
+    exportCtx.restore();
+  }
+
+  return exportCanvas;
+}
+
+function triggerCanvasDownload(sourceCanvas, filename) {
+  const link = document.createElement('a');
+  link.href = sourceCanvas.toDataURL('image/png');
+  link.download = filename;
+  document.body.appendChild(link);
+  link.click();
+  document.body.removeChild(link);
+}
+
+function monthChartExportFilename(viewMode) {
+  if (!MONTH_CHART_CONFIG) {
+    return 'Himmelsanblick_' + viewMode + '.png';
+  }
+
+  const month = String(MONTH_CHART_CONFIG.monthNumber || MONTH_CHART_CONFIG.month || '').padStart(2, '0');
+  const year = String(MONTH_CHART_CONFIG.year || '');
+  const hour = String(Number(MONTH_CHART_CONFIG.monthSkyHour ?? 0)).padStart(2, '0');
+  const minute = String(Number(MONTH_CHART_CONFIG.monthSkyMinute ?? 0)).padStart(2, '0');
+  const safeMode = viewMode === 'sued' ? 'sued' : 'polar';
+  return 'Himmelsanblick_' + safeMode + '_' + year + '_' + month + '_' + hour + '-' + minute + '.png';
+}
+
+function monthChartExportCaption() {
+  if (!MONTH_CHART_CONFIG) {
+    return '';
+  }
+
+  const hour = Number(MONTH_CHART_CONFIG.monthSkyHour ?? NaN);
+  const minute = Number(MONTH_CHART_CONFIG.monthSkyMinute ?? NaN);
+  if (!Number.isFinite(hour) || !Number.isFinite(minute)) {
+    return '';
+  }
+
+  return 'Sternhimmel fuer ' + String(hour).padStart(2, '0') + ':' + String(minute).padStart(2, '0') + ' Uhr';
+}
+
 function formatGermanDate(date) {
   const day = String(date.getUTCDate()).padStart(2, '0');
   const month = String(date.getUTCMonth() + 1).padStart(2, '0');
@@ -3213,7 +3387,7 @@ function monthChartCometRaDec(comet, date) {
     ctx.restore();
 
     ctx.strokeStyle = 'rgba(255, 255, 255, 0.16)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
     ctx.beginPath();
     ctx.arc(x, y, radius, 0, Math.PI * 2);
     ctx.stroke();
@@ -3301,6 +3475,7 @@ function monthChartCometRaDec(comet, date) {
 })();
 
 (function () {
+  const downloadButton = document.getElementById('downloadMonatskartePng');
   const canvas = document.getElementById('monatskarteCanvas');
   const statusEl = document.getElementById('monatskarteStatus');
 
@@ -3335,9 +3510,25 @@ function monthChartCometRaDec(comet, date) {
   const displayStarMap = new Map();
   let labelPlacer = null;
   let projectionLayout = null;
+  let viewportWidth = 900;
+  let viewportHeight = 900;
+  let renderScale = 1;
+  let exportRenderMode = false;
   const projCenterAzDeg = 180;
   const projCenterAltDeg = 45;
 
+  function uiScale() {
+    return (viewportWidth / 900) * 1.22;
+  }
+
+  function scalePx(value) {
+    return value * uiScale();
+  }
+
+  function scaleFont(sizePx, weight = '600', family = 'Rajdhani, sans-serif') {
+    return weight + ' ' + scalePx(sizePx) + 'px ' + family;
+  }
+
   for (const star of MONTH_CHART_LINE_STARS) {
     if (Number.isFinite(Number(star.hip))) {
       starByHip.set(Number(star.hip), star);
@@ -3395,8 +3586,8 @@ function monthChartCometRaDec(comet, date) {
     function insideStage(box) {
       return box.x >= 0 &&
         box.y >= 0 &&
-        box.x + box.width <= canvas.clientWidth &&
-        box.y + box.height <= canvas.clientHeight;
+        box.x + box.width <= viewportWidth &&
+        box.y + box.height <= viewportHeight;
     }
 
     return {
@@ -3408,11 +3599,11 @@ function monthChartCometRaDec(comet, date) {
           text,
           x,
           y,
-          font = '12px Georgia, serif',
+          font = scaleFont(12, '400', 'Georgia, serif'),
           color = 'rgba(232, 239, 255, 0.82)',
           align = 'left',
           baseline = 'middle',
-          padding = 2,
+          padding = scalePx(2),
         } = options;
 
         if (!text) {
@@ -3465,25 +3656,25 @@ function monthChartCometRaDec(comet, date) {
 
   function placePlanetLabel(text, x, y, radius) {
     const attempts = [
-      { x: x + radius + 6, y: y - 1, align: 'left', baseline: 'middle' },
-      { x: x - radius - 6, y: y - 1, align: 'right', baseline: 'middle' },
-      { x, y: y - radius - 7, align: 'center', baseline: 'bottom' },
-      { x, y: y + radius + 7, align: 'center', baseline: 'top' },
-      { x: x + radius + 6, y: y - radius - 5, align: 'left', baseline: 'bottom' },
-      { x: x - radius - 6, y: y - radius - 5, align: 'right', baseline: 'bottom' },
-      { x: x + radius + 6, y: y + radius + 5, align: 'left', baseline: 'top' },
-      { x: x - radius - 6, y: y + radius + 5, align: 'right', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - scalePx(1), align: 'left', baseline: 'middle' },
+      { x: x - radius - scalePx(6), y: y - scalePx(1), align: 'right', baseline: 'middle' },
+      { x, y: y - radius - scalePx(7), align: 'center', baseline: 'bottom' },
+      { x, y: y + radius + scalePx(7), align: 'center', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - radius - scalePx(5), align: 'left', baseline: 'bottom' },
+      { x: x - radius - scalePx(6), y: y - radius - scalePx(5), align: 'right', baseline: 'bottom' },
+      { x: x + radius + scalePx(6), y: y + radius + scalePx(5), align: 'left', baseline: 'top' },
+      { x: x - radius - scalePx(6), y: y + radius + scalePx(5), align: 'right', baseline: 'top' },
     ];
 
     function drawLabelBackdrop(drawX, drawY, align, baseline) {
       ctx.save();
-      ctx.font = '600 11px Rajdhani, sans-serif';
+      ctx.font = scaleFont(11);
       const metrics = ctx.measureText(text);
       const textWidth = metrics.width;
       const ascent = metrics.actualBoundingBoxAscent || 8;
       const descent = metrics.actualBoundingBoxDescent || 4;
-      const padX = 5;
-      const padY = 3;
+      const padX = scalePx(5);
+      const padY = scalePx(3);
 
       let boxX = drawX;
       if (align === 'center') boxX = drawX - textWidth / 2;
@@ -3497,7 +3688,7 @@ function monthChartCometRaDec(comet, date) {
       const rectY = boxY - padY;
       const rectW = textWidth + padX * 2;
       const rectH = ascent + descent + padY * 2;
-      const radiusPx = 6;
+      const radiusPx = scalePx(6);
 
       ctx.fillStyle = 'rgba(3, 6, 12, 0.52)';
       ctx.beginPath();
@@ -3520,15 +3711,15 @@ function monthChartCometRaDec(comet, date) {
         text,
         x: attempt.x,
         y: attempt.y,
-        font: '600 11px Rajdhani, sans-serif',
+        font: scaleFont(11),
         color: 'rgba(246, 235, 214, 0.84)',
         align: attempt.align,
         baseline: attempt.baseline,
-        padding: 2,
+        padding: scalePx(2),
       })) {
         drawLabelBackdrop(attempt.x, attempt.y, attempt.align, attempt.baseline);
         ctx.save();
-        ctx.font = '600 11px Rajdhani, sans-serif';
+        ctx.font = scaleFont(11);
         ctx.textAlign = attempt.align;
         ctx.textBaseline = attempt.baseline;
         ctx.fillStyle = 'rgba(246, 235, 214, 0.84)';
@@ -3543,25 +3734,25 @@ function monthChartCometRaDec(comet, date) {
 
   function placePlanetLabel(text, x, y, radius) {
     const attempts = [
-      { x: x + radius + 6, y: y - 1, align: 'left', baseline: 'middle' },
-      { x: x - radius - 6, y: y - 1, align: 'right', baseline: 'middle' },
-      { x, y: y - radius - 7, align: 'center', baseline: 'bottom' },
-      { x, y: y + radius + 7, align: 'center', baseline: 'top' },
-      { x: x + radius + 6, y: y - radius - 5, align: 'left', baseline: 'bottom' },
-      { x: x - radius - 6, y: y - radius - 5, align: 'right', baseline: 'bottom' },
-      { x: x + radius + 6, y: y + radius + 5, align: 'left', baseline: 'top' },
-      { x: x - radius - 6, y: y + radius + 5, align: 'right', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - scalePx(1), align: 'left', baseline: 'middle' },
+      { x: x - radius - scalePx(6), y: y - scalePx(1), align: 'right', baseline: 'middle' },
+      { x, y: y - radius - scalePx(7), align: 'center', baseline: 'bottom' },
+      { x, y: y + radius + scalePx(7), align: 'center', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - radius - scalePx(5), align: 'left', baseline: 'bottom' },
+      { x: x - radius - scalePx(6), y: y - radius - scalePx(5), align: 'right', baseline: 'bottom' },
+      { x: x + radius + scalePx(6), y: y + radius + scalePx(5), align: 'left', baseline: 'top' },
+      { x: x - radius - scalePx(6), y: y + radius + scalePx(5), align: 'right', baseline: 'top' },
     ];
 
     function drawLabelBackdrop(drawX, drawY, align, baseline) {
       ctx.save();
-      ctx.font = '600 11px Rajdhani, sans-serif';
+      ctx.font = scaleFont(11);
       const metrics = ctx.measureText(text);
       const textWidth = metrics.width;
       const ascent = metrics.actualBoundingBoxAscent || 8;
       const descent = metrics.actualBoundingBoxDescent || 4;
-      const padX = 5;
-      const padY = 3;
+      const padX = scalePx(5);
+      const padY = scalePx(3);
 
       let boxX = drawX;
       if (align === 'center') boxX = drawX - textWidth / 2;
@@ -3575,7 +3766,7 @@ function monthChartCometRaDec(comet, date) {
       const rectY = boxY - padY;
       const rectW = textWidth + padX * 2;
       const rectH = ascent + descent + padY * 2;
-      const radiusPx = 6;
+      const radiusPx = scalePx(6);
 
       ctx.fillStyle = 'rgba(3, 6, 12, 0.52)';
       ctx.beginPath();
@@ -3598,15 +3789,15 @@ function monthChartCometRaDec(comet, date) {
         text,
         x: attempt.x,
         y: attempt.y,
-        font: '600 11px Rajdhani, sans-serif',
+        font: scaleFont(11),
         color: 'rgba(246, 235, 214, 0.84)',
         align: attempt.align,
         baseline: attempt.baseline,
-        padding: 2,
+        padding: scalePx(2),
       })) {
         drawLabelBackdrop(attempt.x, attempt.y, attempt.align, attempt.baseline);
         ctx.save();
-        ctx.font = '600 11px Rajdhani, sans-serif';
+        ctx.font = scaleFont(11);
         ctx.textAlign = attempt.align;
         ctx.textBaseline = attempt.baseline;
         ctx.fillStyle = 'rgba(246, 235, 214, 0.84)';
@@ -3622,12 +3813,15 @@ function monthChartCometRaDec(comet, date) {
   function resizeCanvas() {
     const cssSize = Math.max(320, Math.min(canvas.parentElement.clientWidth, 900));
     const ratio = Math.min(window.devicePixelRatio || 1, 2);
-    canvas.width = Math.round(cssSize * ratio);
-    canvas.height = Math.round(cssSize * ratio);
+    viewportWidth = cssSize;
+    viewportHeight = cssSize;
+    renderScale = ratio;
+    canvas.width = Math.round(viewportWidth * renderScale);
+    canvas.height = Math.round(viewportHeight * renderScale);
     canvas.style.width = cssSize + 'px';
     canvas.style.height = cssSize + 'px';
     ctx.setTransform(1, 0, 0, 1, 0, 0);
-    ctx.scale(ratio, ratio);
+    ctx.scale(renderScale, renderScale);
     labelPlacer = createLabelPlacer(ctx);
     draw();
   }
@@ -3709,13 +3903,13 @@ function monthChartCometRaDec(comet, date) {
     horizonGlow.addColorStop(0.9, 'rgba(118, 170, 255, 0.09)');
     horizonGlow.addColorStop(1, 'rgba(168, 208, 255, 0.14)');
     ctx.strokeStyle = horizonGlow;
-    ctx.lineWidth = Math.max(8, radius * 0.035);
+    ctx.lineWidth = Math.max(scalePx(8), radius * 0.035);
     ctx.beginPath();
     ctx.arc(cx, cy, radius * 0.97, 0, Math.PI * 2);
     ctx.stroke();
 
     ctx.strokeStyle = 'rgba(183, 205, 255, 0.28)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
     ctx.beginPath();
     ctx.arc(cx, cy, radius, 0, Math.PI * 2);
     ctx.stroke();
@@ -3723,7 +3917,7 @@ function monthChartCometRaDec(comet, date) {
 
   function drawGuides(cx, cy, radius) {
     ctx.strokeStyle = 'rgba(140, 165, 220, 0.18)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
 
     for (const frac of [0.33, 0.66]) {
       ctx.beginPath();
@@ -3760,20 +3954,20 @@ function monthChartCometRaDec(comet, date) {
       ctx.restore();
     }
 
-    drawDirectionLabel(0, 'Norden', 18, '600 13px Rajdhani, sans-serif', 0.78);
-    drawDirectionLabel(90, 'Westen', 22, '600 13px Rajdhani, sans-serif', 0.78);
-    drawDirectionLabel(180, 'Süden', 18, '600 13px Rajdhani, sans-serif', 0.78);
-    drawDirectionLabel(270, 'Osten', 22, '600 13px Rajdhani, sans-serif', 0.78);
+    drawDirectionLabel(0, 'Norden', scalePx(18), scaleFont(13), 0.78);
+    drawDirectionLabel(90, 'Westen', scalePx(22), scaleFont(13), 0.78);
+    drawDirectionLabel(180, 'Süden', scalePx(18), scaleFont(13), 0.78);
+    drawDirectionLabel(270, 'Osten', scalePx(22), scaleFont(13), 0.78);
 
-    drawDirectionLabel(45, 'Nordosten', 18, '600 11px Rajdhani, sans-serif', 0.64);
-    drawDirectionLabel(315, 'Nordwesten', 18, '600 11px Rajdhani, sans-serif', 0.64);
-    drawDirectionLabel(135, 'Südosten', 18, '600 11px Rajdhani, sans-serif', 0.64);
-    drawDirectionLabel(225, 'Südwesten', 18, '600 11px Rajdhani, sans-serif', 0.64);
+    drawDirectionLabel(45, 'Nordosten', scalePx(18), scaleFont(11), 0.64);
+    drawDirectionLabel(315, 'Nordwesten', scalePx(18), scaleFont(11), 0.64);
+    drawDirectionLabel(135, 'Südosten', scalePx(18), scaleFont(11), 0.64);
+    drawDirectionLabel(225, 'Südwesten', scalePx(18), scaleFont(11), 0.64);
 
     ctx.fillStyle = 'rgba(214, 226, 255, 0.62)';
-    ctx.font = '600 11px Rajdhani, sans-serif';
-    ctx.fillText('60°', cx, cy - radius * 0.66 - 6);
-    ctx.fillText('30°', cx, cy - radius * 0.33 - 6);
+    ctx.font = scaleFont(11);
+    ctx.fillText('60°', cx, cy - radius * 0.66 - scalePx(6));
+    ctx.fillText('30°', cx, cy - radius * 0.33 - scalePx(6));
     ctx.fillText('Zenit', cx, cy);
   }
 
@@ -3817,7 +4011,7 @@ function monthChartCometRaDec(comet, date) {
         ctx.lineJoin = 'round';
 
         ctx.strokeStyle = 'rgba(210, 214, 224, 0.16)';
-        ctx.lineWidth = 2.1;
+        ctx.lineWidth = scalePx(2.1);
         ctx.beginPath();
         ctx.moveTo(points[0].x, points[0].y);
         for (let i = 1; i < points.length; i++) {
@@ -3826,12 +4020,12 @@ function monthChartCometRaDec(comet, date) {
         ctx.stroke();
 
         ctx.strokeStyle = 'rgba(36, 40, 48, 0.34)';
-        ctx.lineWidth = 0.95;
+        ctx.lineWidth = scalePx(0.95);
         ctx.beginPath();
-        ctx.moveTo(points[0].x + 0.18, points[0].y - 0.12);
+        ctx.moveTo(points[0].x + scalePx(0.18), points[0].y - scalePx(0.12));
         for (let i = 1; i < points.length; i++) {
-          const jitterX = (i % 2 === 0 ? 0.22 : -0.12);
-          const jitterY = (i % 2 === 0 ? -0.14 : 0.2);
+          const jitterX = (i % 2 === 0 ? scalePx(0.22) : -scalePx(0.12));
+          const jitterY = (i % 2 === 0 ? -scalePx(0.14) : scalePx(0.2));
           ctx.lineTo(points[i].x + jitterX, points[i].y + jitterY);
         }
         ctx.stroke();
@@ -3870,11 +4064,11 @@ function monthChartCometRaDec(comet, date) {
           text: label,
           x: pt.x,
           y: pt.y,
-          font: '600 11px Rajdhani, sans-serif',
+          font: scaleFont(11),
           color: 'rgba(198, 214, 255, 0.54)',
           align: 'center',
           baseline: 'middle',
-          padding: 3,
+          padding: scalePx(3),
         });
 
         if (placed) {
@@ -3955,7 +4149,7 @@ function monthChartCometRaDec(comet, date) {
 
     const phaseFraction = clamp01(Number(MONTH_CHART_MOON.phaseFraction ?? 0.5));
     const waxing = Boolean(MONTH_CHART_MOON.waxing);
-    const moonRadius = 10.5;
+    const moonRadius = scalePx(10.5);
     const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, moonRadius * 2.1);
     glow.addColorStop(0, 'rgba(220, 226, 238, 0.28)');
     glow.addColorStop(0.5, 'rgba(220, 226, 238, 0.08)');
@@ -3990,7 +4184,7 @@ function monthChartCometRaDec(comet, date) {
     ctx.restore();
 
     ctx.strokeStyle = 'rgba(255, 255, 255, 0.3)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
     ctx.beginPath();
     ctx.arc(pt.x, pt.y, moonRadius, 0, Math.PI * 2);
     ctx.stroke();
@@ -4012,8 +4206,8 @@ function monthChartCometRaDec(comet, date) {
       const style = getPlanetStyle(planet);
       const mag = Number(planet.mag);
       const baseRadius = Number.isFinite(mag)
-        ? Math.max(3.8, Math.min(8.6, 6.7 - mag * 0.72))
-        : 5.4;
+        ? Math.max(scalePx(3.8), Math.min(scalePx(8.6), scalePx(6.7 - mag * 0.72)))
+        : scalePx(5.4);
       const glowRadius = baseRadius * 2.2;
 
       const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, glowRadius);
@@ -4031,7 +4225,7 @@ function monthChartCometRaDec(comet, date) {
       ctx.fill();
 
       ctx.strokeStyle = 'rgba(255, 255, 255, 0.26)';
-      ctx.lineWidth = 1;
+      ctx.lineWidth = scalePx(1);
       ctx.beginPath();
       ctx.arc(pt.x, pt.y, baseRadius, 0, Math.PI * 2);
       ctx.stroke();
@@ -4040,11 +4234,11 @@ function monthChartCometRaDec(comet, date) {
         ctx.save();
         ctx.translate(pt.x, pt.y);
         ctx.beginPath();
-        ctx.arc(0, 0, baseRadius - 0.3, 0, Math.PI * 2);
+        ctx.arc(0, 0, baseRadius - scalePx(0.3), 0, Math.PI * 2);
         ctx.clip();
 
         ctx.strokeStyle = 'rgba(116, 84, 54, 0.78)';
-        ctx.lineWidth = Math.max(1, baseRadius * 0.34);
+        ctx.lineWidth = Math.max(scalePx(1), baseRadius * 0.34);
         ctx.beginPath();
         ctx.moveTo(-baseRadius * 0.95, -baseRadius * 0.34);
         ctx.lineTo(baseRadius * 0.95, -baseRadius * 0.34);
@@ -4064,7 +4258,7 @@ function monthChartCometRaDec(comet, date) {
         ctx.translate(pt.x, pt.y);
         ctx.rotate(-0.35);
         ctx.strokeStyle = 'rgba(232, 221, 170, 0.72)';
-        ctx.lineWidth = 1;
+        ctx.lineWidth = scalePx(1);
         ctx.beginPath();
         ctx.ellipse(0, 0, baseRadius * 1.7, baseRadius * 0.72, 0, 0, Math.PI * 2);
         ctx.stroke();
@@ -4115,7 +4309,7 @@ function monthChartCometRaDec(comet, date) {
         tailAngle = Math.atan2(pt.y - sunPt.y, pt.x - sunPt.x);
       }
 
-      const tailLen = pos.rH > 0 ? Math.max(8, Math.min(28, 18 / pos.rH)) : 12;
+      const tailLen = pos.rH > 0 ? Math.max(scalePx(8), Math.min(scalePx(28), scalePx(18) / pos.rH)) : scalePx(12);
       const tx = pt.x + Math.cos(tailAngle) * tailLen;
       const ty = pt.y + Math.sin(tailAngle) * tailLen;
 
@@ -4127,11 +4321,11 @@ function monthChartCometRaDec(comet, date) {
       ctx.moveTo(pt.x, pt.y);
       ctx.lineTo(tx, ty);
       ctx.strokeStyle = grd;
-      ctx.lineWidth = 2.2;
+      ctx.lineWidth = scalePx(2.2);
       ctx.lineCap = 'round';
       ctx.stroke();
 
-      const comaR = 4.2;
+      const comaR = scalePx(4.2);
       const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, comaR * 2.6);
       glow.addColorStop(0, 'rgba(255, 245, 200, 0.94)');
       glow.addColorStop(0.45, 'rgba(201, 168, 76, 0.54)');
@@ -4170,10 +4364,10 @@ function monthChartCometRaDec(comet, date) {
       }
 
       const style = getMessierStyle(String(obj.type || 'As'));
-      const symbolRadius = Math.max(3.4, Math.min(6.8, 3.2 + Math.max(0, 6.5 - Number(obj.mag)) * 0.5));
+      const symbolRadius = Math.max(scalePx(3.4), Math.min(scalePx(6.8), scalePx(3.2 + Math.max(0, 6.5 - Number(obj.mag)) * 0.5)));
       ctx.strokeStyle = style.stroke;
       ctx.fillStyle = style.fill;
-      ctx.lineWidth = 1;
+      ctx.lineWidth = scalePx(1);
 
       if (obj.type === 'Gc') {
         ctx.beginPath();
@@ -4187,7 +4381,7 @@ function monthChartCometRaDec(comet, date) {
         ctx.lineTo(pt.x, pt.y + symbolRadius * 0.8);
         ctx.stroke();
       } else if (obj.type === 'Oc') {
-        ctx.setLineDash([2, 2]);
+        ctx.setLineDash([scalePx(2), scalePx(2)]);
         ctx.beginPath();
         ctx.arc(pt.x, pt.y, symbolRadius, 0, Math.PI * 2);
         ctx.stroke();
@@ -4222,13 +4416,13 @@ function monthChartCometRaDec(comet, date) {
       if (label !== '') {
         labelPlacer.drawText({
           text: label,
-          x: pt.x + symbolRadius + 5,
+          x: pt.x + symbolRadius + scalePx(5),
           y: pt.y,
-          font: '600 11px Rajdhani, sans-serif',
+          font: scaleFont(11),
           color: 'rgba(210, 224, 255, 0.78)',
           align: 'left',
           baseline: 'middle',
-          padding: 2,
+          padding: scalePx(2),
         });
       }
     }
@@ -4258,7 +4452,7 @@ function monthChartCometRaDec(comet, date) {
         ? Math.min(Number(star.mag), Number(MONTH_CHART_CONFIG.starLimit) + 0.35)
         : Number(star.mag);
       const brightness = clamp01((Number(MONTH_CHART_CONFIG.starLimit) - effectiveMagnitude + 1.6) / magRange);
-      const starRadius = (isConstellationStar ? 0.85 : 0.65) + Math.pow(brightness, 1.9) * 5.2;
+      const starRadius = ((isConstellationStar ? 0.85 : 0.65) + Math.pow(brightness, 1.9) * 5.2) * (exportRenderMode ? 2.0 : 1);
       const glowRadius = starRadius * (effectiveMagnitude <= 1 ? 2.8 : 1.9);
       const color = starColor(star);
 
@@ -4278,7 +4472,7 @@ function monthChartCometRaDec(comet, date) {
 
       if (star.mag <= 0.8) {
         ctx.strokeStyle = color + '44';
-        ctx.lineWidth = 1;
+        ctx.lineWidth = scalePx(1);
         ctx.beginPath();
         ctx.moveTo(pt.x - starRadius * 1.35, pt.y);
         ctx.lineTo(pt.x + starRadius * 1.35, pt.y);
@@ -4292,13 +4486,13 @@ function monthChartCometRaDec(comet, date) {
         if (label !== '') {
           labelPlacer.drawText({
             text: label,
-            x: pt.x + starRadius + 5,
-            y: pt.y - 1,
-            font: '600 11px Rajdhani, sans-serif',
+            x: pt.x + starRadius + scalePx(5),
+            y: pt.y - scalePx(1),
+            font: scaleFont(11),
             color: 'rgba(232, 239, 255, 0.82)',
             align: 'left',
             baseline: 'middle',
-            padding: 2,
+            padding: scalePx(2),
           });
         }
       }
@@ -4306,8 +4500,8 @@ function monthChartCometRaDec(comet, date) {
   }
 
   function draw() {
-    const width = canvas.clientWidth;
-    const height = canvas.clientHeight;
+    const width = viewportWidth;
+    const height = viewportHeight;
     const cx = width / 2;
     const cy = height / 2;
     const radius = Math.min(width, height) * 0.44;
@@ -4327,11 +4521,64 @@ function monthChartCometRaDec(comet, date) {
     statusEl.textContent = 'Sternkarte für ' + MONTH_CHART_CONFIG.localTimeLabel;
   }
 
+  if (downloadButton) {
+    downloadButton.addEventListener('click', async function () {
+      const previous = {
+        width: canvas.width,
+        height: canvas.height,
+        styleWidth: canvas.style.width,
+        styleHeight: canvas.style.height,
+        viewportWidth,
+        viewportHeight,
+        renderScale,
+      };
+
+      try {
+        statusEl.textContent = 'PNG wird in 2000 px neu gerendert...';
+        downloadButton.disabled = true;
+
+        exportRenderMode = true;
+        viewportWidth = MONTH_CHART_EXPORT_WIDTH;
+        viewportHeight = MONTH_CHART_EXPORT_WIDTH;
+        renderScale = 1;
+        canvas.width = viewportWidth;
+        canvas.height = viewportHeight;
+        ctx.setTransform(1, 0, 0, 1, 0, 0);
+        labelPlacer = createLabelPlacer(ctx);
+        draw();
+
+        const exportCanvas = await composeExportCanvas(canvas, 'bottom-left');
+        if (!exportCanvas) {
+          throw new Error('Export-Canvas konnte nicht erzeugt werden.');
+        }
+
+        triggerCanvasDownload(exportCanvas, monthChartExportFilename('polar'));
+      } catch (error) {
+        statusEl.textContent = 'PNG-Download konnte nicht erstellt werden.';
+      } finally {
+        exportRenderMode = false;
+        viewportWidth = previous.viewportWidth;
+        viewportHeight = previous.viewportHeight;
+        renderScale = previous.renderScale;
+        canvas.width = previous.width;
+        canvas.height = previous.height;
+        canvas.style.width = previous.styleWidth;
+        canvas.style.height = previous.styleHeight;
+        ctx.setTransform(1, 0, 0, 1, 0, 0);
+        ctx.scale(renderScale, renderScale);
+        labelPlacer = createLabelPlacer(ctx);
+        draw();
+        downloadButton.disabled = false;
+      }
+    });
+  }
+
   resizeCanvas();
   window.addEventListener('resize', resizeCanvas);
 })();
 
 (function () {
+  const downloadButton = document.getElementById('downloadMonatskarteSouthPng');
   const canvas = document.getElementById('monatskarteSouthCanvas');
   const statusEl = document.getElementById('monatskarteSouthStatus');
 
@@ -4351,9 +4598,25 @@ function monthChartCometRaDec(comet, date) {
   const displayStarMap = new Map();
   let labelPlacer = null;
   let projectionLayout = null;
+  let viewportWidth = 1200;
+  let viewportHeight = 720;
+  let renderScale = 1;
+  let exportRenderMode = false;
   const projCenterAzDeg = 180;
   const projCenterAltDeg = 45;
 
+  function uiScale() {
+    return (viewportWidth / 1100) * 1.22;
+  }
+
+  function scalePx(value) {
+    return value * uiScale();
+  }
+
+  function scaleFont(sizePx, weight = '600', family = 'Rajdhani, sans-serif') {
+    return weight + ' ' + scalePx(sizePx) + 'px ' + family;
+  }
+
   for (const star of MONTH_CHART_LINE_STARS) {
     if (Number.isFinite(Number(star.hip))) {
       starByHip.set(Number(star.hip), star);
@@ -4409,8 +4672,8 @@ function monthChartCometRaDec(comet, date) {
     function insideStage(box) {
       return box.x >= 0 &&
         box.y >= 0 &&
-        box.x + box.width <= canvas.clientWidth &&
-        box.y + box.height <= canvas.clientHeight;
+        box.x + box.width <= viewportWidth &&
+        box.y + box.height <= viewportHeight;
     }
 
     return {
@@ -4422,11 +4685,11 @@ function monthChartCometRaDec(comet, date) {
           text,
           x,
           y,
-          font = '600 11px Rajdhani, sans-serif',
+          font = scaleFont(11),
           color = 'rgba(232, 239, 255, 0.82)',
           align = 'left',
           baseline = 'middle',
-          padding = 2,
+          padding = scalePx(2),
         } = options;
 
         if (!text) {
@@ -4473,14 +4736,14 @@ function monthChartCometRaDec(comet, date) {
 
   function placePlanetLabel(text, x, y, radius) {
     const attempts = [
-      { x: x + radius + 6, y: y - 1, align: 'left', baseline: 'middle' },
-      { x: x - radius - 6, y: y - 1, align: 'right', baseline: 'middle' },
-      { x, y: y - radius - 7, align: 'center', baseline: 'bottom' },
-      { x, y: y + radius + 7, align: 'center', baseline: 'top' },
-      { x: x + radius + 6, y: y - radius - 5, align: 'left', baseline: 'bottom' },
-      { x: x - radius - 6, y: y - radius - 5, align: 'right', baseline: 'bottom' },
-      { x: x + radius + 6, y: y + radius + 5, align: 'left', baseline: 'top' },
-      { x: x - radius - 6, y: y + radius + 5, align: 'right', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - scalePx(1), align: 'left', baseline: 'middle' },
+      { x: x - radius - scalePx(6), y: y - scalePx(1), align: 'right', baseline: 'middle' },
+      { x, y: y - radius - scalePx(7), align: 'center', baseline: 'bottom' },
+      { x, y: y + radius + scalePx(7), align: 'center', baseline: 'top' },
+      { x: x + radius + scalePx(6), y: y - radius - scalePx(5), align: 'left', baseline: 'bottom' },
+      { x: x - radius - scalePx(6), y: y - radius - scalePx(5), align: 'right', baseline: 'bottom' },
+      { x: x + radius + scalePx(6), y: y + radius + scalePx(5), align: 'left', baseline: 'top' },
+      { x: x - radius - scalePx(6), y: y + radius + scalePx(5), align: 'right', baseline: 'top' },
     ];
 
     for (const attempt of attempts) {
@@ -4488,11 +4751,11 @@ function monthChartCometRaDec(comet, date) {
         text,
         x: attempt.x,
         y: attempt.y,
-        font: '600 11px Rajdhani, sans-serif',
+        font: scaleFont(11),
         color: 'rgba(246, 235, 214, 0.84)',
         align: attempt.align,
         baseline: attempt.baseline,
-        padding: 2,
+        padding: scalePx(2),
       })) {
         return true;
       }
@@ -4505,12 +4768,15 @@ function monthChartCometRaDec(comet, date) {
     const cssWidth = Math.max(420, Math.min(canvas.parentElement.clientWidth, 1100));
     const cssHeight = Math.round(cssWidth * 0.6);
     const ratio = Math.min(window.devicePixelRatio || 1, 2);
-    canvas.width = Math.round(cssWidth * ratio);
-    canvas.height = Math.round(cssHeight * ratio);
+    viewportWidth = cssWidth;
+    viewportHeight = cssHeight;
+    renderScale = ratio;
+    canvas.width = Math.round(viewportWidth * renderScale);
+    canvas.height = Math.round(viewportHeight * renderScale);
     canvas.style.width = cssWidth + 'px';
     canvas.style.height = cssHeight + 'px';
     ctx.setTransform(1, 0, 0, 1, 0, 0);
-    ctx.scale(ratio, ratio);
+    ctx.scale(renderScale, renderScale);
     labelPlacer = createLabelPlacer(ctx);
     draw();
   }
@@ -4700,7 +4966,7 @@ function monthChartCometRaDec(comet, date) {
 
     const phaseFraction = clamp01(Number(MONTH_CHART_MOON.phaseFraction ?? 0.5));
     const waxing = Boolean(MONTH_CHART_MOON.waxing);
-    const moonRadius = 10.5;
+    const moonRadius = scalePx(10.5);
     const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, moonRadius * 2.1);
     glow.addColorStop(0, 'rgba(220, 226, 238, 0.28)');
     glow.addColorStop(0.5, 'rgba(220, 226, 238, 0.08)');
@@ -4735,7 +5001,7 @@ function monthChartCometRaDec(comet, date) {
     ctx.restore();
 
     ctx.strokeStyle = 'rgba(255, 255, 255, 0.3)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
     ctx.beginPath();
     ctx.arc(pt.x, pt.y, moonRadius, 0, Math.PI * 2);
     ctx.stroke();
@@ -4753,8 +5019,8 @@ function monthChartCometRaDec(comet, date) {
       const style = getPlanetStyle(planet);
       const mag = Number(planet.mag);
       const baseRadius = Number.isFinite(mag)
-        ? Math.max(3.8, Math.min(8.6, 6.7 - mag * 0.72))
-        : 5.4;
+        ? Math.max(scalePx(3.8), Math.min(scalePx(8.6), scalePx(6.7 - mag * 0.72)))
+        : scalePx(5.4);
       const glowRadius = baseRadius * 2.2;
 
       const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, glowRadius);
@@ -4772,7 +5038,7 @@ function monthChartCometRaDec(comet, date) {
       ctx.fill();
 
       ctx.strokeStyle = 'rgba(255, 255, 255, 0.26)';
-      ctx.lineWidth = 1;
+      ctx.lineWidth = scalePx(1);
       ctx.beginPath();
       ctx.arc(pt.x, pt.y, baseRadius, 0, Math.PI * 2);
       ctx.stroke();
@@ -4781,11 +5047,11 @@ function monthChartCometRaDec(comet, date) {
         ctx.save();
         ctx.translate(pt.x, pt.y);
         ctx.beginPath();
-        ctx.arc(0, 0, baseRadius - 0.3, 0, Math.PI * 2);
+        ctx.arc(0, 0, baseRadius - scalePx(0.3), 0, Math.PI * 2);
         ctx.clip();
 
         ctx.strokeStyle = 'rgba(116, 84, 54, 0.78)';
-        ctx.lineWidth = Math.max(1, baseRadius * 0.34);
+        ctx.lineWidth = Math.max(scalePx(1), baseRadius * 0.34);
         ctx.beginPath();
         ctx.moveTo(-baseRadius * 0.95, -baseRadius * 0.34);
         ctx.lineTo(baseRadius * 0.95, -baseRadius * 0.34);
@@ -4805,7 +5071,7 @@ function monthChartCometRaDec(comet, date) {
         ctx.translate(pt.x, pt.y);
         ctx.rotate(-0.35);
         ctx.strokeStyle = 'rgba(232, 221, 170, 0.72)';
-        ctx.lineWidth = 1;
+        ctx.lineWidth = scalePx(1);
         ctx.beginPath();
         ctx.ellipse(0, 0, baseRadius * 1.7, baseRadius * 0.72, 0, 0, Math.PI * 2);
         ctx.stroke();
@@ -4856,7 +5122,7 @@ function monthChartCometRaDec(comet, date) {
         tailAngle = Math.atan2(pt.y - sunPt.y, pt.x - sunPt.x);
       }
 
-      const tailLen = pos.rH > 0 ? Math.max(8, Math.min(28, 18 / pos.rH)) : 12;
+      const tailLen = pos.rH > 0 ? Math.max(scalePx(8), Math.min(scalePx(28), scalePx(18) / pos.rH)) : scalePx(12);
       const tx = pt.x + Math.cos(tailAngle) * tailLen;
       const ty = pt.y + Math.sin(tailAngle) * tailLen;
 
@@ -4868,11 +5134,11 @@ function monthChartCometRaDec(comet, date) {
       ctx.moveTo(pt.x, pt.y);
       ctx.lineTo(tx, ty);
       ctx.strokeStyle = grd;
-      ctx.lineWidth = 2.2;
+      ctx.lineWidth = scalePx(2.2);
       ctx.lineCap = 'round';
       ctx.stroke();
 
-      const comaR = 4.2;
+      const comaR = scalePx(4.2);
       const glow = ctx.createRadialGradient(pt.x, pt.y, 0, pt.x, pt.y, comaR * 2.6);
       glow.addColorStop(0, 'rgba(255, 245, 200, 0.94)');
       glow.addColorStop(0.45, 'rgba(201, 168, 76, 0.54)');
@@ -4953,14 +5219,14 @@ function monthChartCometRaDec(comet, date) {
 
   function drawGuides(width, height) {
     ctx.strokeStyle = 'rgba(140, 165, 220, 0.14)';
-    ctx.lineWidth = 1;
+    ctx.lineWidth = scalePx(1);
 
     for (const alt of [0, 30, 60]) {
       const samples = [];
       for (let az = 90; az <= 270; az += 2) {
         samples.push({ alt, az });
       }
-      strokeProjectedCurve(samples, alt === 0 ? 'rgba(183, 205, 255, 0.18)' : 'rgba(140, 165, 220, 0.14)', 1);
+      strokeProjectedCurve(samples, alt === 0 ? 'rgba(183, 205, 255, 0.18)' : 'rgba(140, 165, 220, 0.14)', scalePx(1));
     }
 
     for (const az of [90, 135, 180, 225, 270]) {
@@ -4968,7 +5234,7 @@ function monthChartCometRaDec(comet, date) {
       for (let alt = 0; alt <= 90; alt += 2) {
         samples.push({ alt, az });
       }
-      strokeProjectedCurve(samples, 'rgba(140, 165, 220, 0.12)', 1);
+      strokeProjectedCurve(samples, 'rgba(140, 165, 220, 0.12)', scalePx(1));
     }
 
     function drawDirectionLabelOutside(azDeg, text, offset = 18) {
@@ -4995,7 +5261,7 @@ function monthChartCometRaDec(comet, date) {
       ctx.translate(horizonPt.x + nx * offset, horizonPt.y + ny * offset);
       ctx.rotate(angle);
       ctx.fillStyle = 'rgba(214, 226, 255, 0.72)';
-      ctx.font = '600 12px Rajdhani, sans-serif';
+      ctx.font = scaleFont(12);
       ctx.textAlign = 'center';
       ctx.textBaseline = 'middle';
       ctx.fillText(text, 0, 0);
@@ -5011,16 +5277,16 @@ function monthChartCometRaDec(comet, date) {
     ];
 
     for (const label of directionLabels) {
-      drawDirectionLabelOutside(label.az, label.text, label.az === 180 ? 22 : 18);
+      drawDirectionLabelOutside(label.az, label.text, label.az === 180 ? scalePx(22) : scalePx(18));
     }
 
     const zenitPt = southProject(88, 180);
     if (zenitPt) {
       ctx.fillStyle = 'rgba(214, 226, 255, 0.72)';
-      ctx.font = '600 12px Rajdhani, sans-serif';
+      ctx.font = scaleFont(12);
       ctx.textAlign = 'center';
       ctx.textBaseline = 'bottom';
-      ctx.fillText('Zenit', zenitPt.x, zenitPt.y - 8);
+      ctx.fillText('Zenit', zenitPt.x, zenitPt.y - scalePx(8));
     }
 
     for (const alt of [30, 60]) {
@@ -5029,10 +5295,10 @@ function monthChartCometRaDec(comet, date) {
         continue;
       }
       ctx.fillStyle = 'rgba(214, 226, 255, 0.58)';
-      ctx.font = '600 11px Rajdhani, sans-serif';
+      ctx.font = scaleFont(11);
       ctx.textAlign = 'left';
       ctx.textBaseline = 'middle';
-      ctx.fillText(`${alt}°`, pt.x + 8, pt.y);
+      ctx.fillText(`${alt}°`, pt.x + scalePx(8), pt.y);
     }
   }
 
@@ -5055,19 +5321,19 @@ function monthChartCometRaDec(comet, date) {
         ctx.lineCap = 'round';
         ctx.lineJoin = 'round';
         ctx.strokeStyle = 'rgba(210, 214, 224, 0.16)';
-        ctx.lineWidth = 2.1;
+        ctx.lineWidth = scalePx(2.1);
         ctx.beginPath();
         ctx.moveTo(points[0].x, points[0].y);
         for (let i = 1; i < points.length; i++) ctx.lineTo(points[i].x, points[i].y);
         ctx.stroke();
 
         ctx.strokeStyle = 'rgba(36, 40, 48, 0.34)';
-        ctx.lineWidth = 0.95;
+        ctx.lineWidth = scalePx(0.95);
         ctx.beginPath();
-        ctx.moveTo(points[0].x + 0.18, points[0].y - 0.12);
+        ctx.moveTo(points[0].x + scalePx(0.18), points[0].y - scalePx(0.12));
         for (let i = 1; i < points.length; i++) {
-          const jitterX = (i % 2 === 0 ? 0.22 : -0.12);
-          const jitterY = (i % 2 === 0 ? -0.14 : 0.2);
+          const jitterX = (i % 2 === 0 ? scalePx(0.22) : -scalePx(0.12));
+          const jitterY = (i % 2 === 0 ? -scalePx(0.14) : scalePx(0.2));
           ctx.lineTo(points[i].x + jitterX, points[i].y + jitterY);
         }
         ctx.stroke();
@@ -5092,11 +5358,11 @@ function monthChartCometRaDec(comet, date) {
           text: label,
           x: pt.x,
           y: pt.y,
-          font: '600 11px Rajdhani, sans-serif',
+          font: scaleFont(11),
           color: 'rgba(198, 214, 255, 0.54)',
           align: 'center',
           baseline: 'middle',
-          padding: 3,
+          padding: scalePx(3),
         })) break;
       }
     }
@@ -5109,10 +5375,10 @@ function monthChartCometRaDec(comet, date) {
       const pt = southProject(hor.altitude, hor.azimuth);
       if (!pt) continue;
       const style = getMessierStyle(String(obj.type || 'As'));
-      const symbolRadius = Math.max(3.4, Math.min(6.8, 3.2 + Math.max(0, 6.5 - Number(obj.mag)) * 0.5));
+      const symbolRadius = Math.max(scalePx(3.4), Math.min(scalePx(6.8), scalePx(3.2 + Math.max(0, 6.5 - Number(obj.mag)) * 0.5)));
       ctx.strokeStyle = style.stroke;
       ctx.fillStyle = style.fill;
-      ctx.lineWidth = 1;
+      ctx.lineWidth = scalePx(1);
 
       if (obj.type === 'Gc') {
         ctx.beginPath(); ctx.arc(pt.x, pt.y, symbolRadius, 0, Math.PI * 2); ctx.fill(); ctx.stroke();
@@ -5121,7 +5387,7 @@ function monthChartCometRaDec(comet, date) {
         ctx.moveTo(pt.x, pt.y - symbolRadius * 0.8); ctx.lineTo(pt.x, pt.y + symbolRadius * 0.8);
         ctx.stroke();
       } else if (obj.type === 'Oc') {
-        ctx.setLineDash([2, 2]); ctx.beginPath(); ctx.arc(pt.x, pt.y, symbolRadius, 0, Math.PI * 2); ctx.stroke(); ctx.setLineDash([]);
+        ctx.setLineDash([scalePx(2), scalePx(2)]); ctx.beginPath(); ctx.arc(pt.x, pt.y, symbolRadius, 0, Math.PI * 2); ctx.stroke(); ctx.setLineDash([]);
       } else if (obj.type === 'Gx') {
         ctx.save(); ctx.translate(pt.x, pt.y); ctx.rotate(Math.PI / 5); ctx.beginPath(); ctx.ellipse(0, 0, symbolRadius, symbolRadius * 0.58, 0, 0, Math.PI * 2); ctx.fill(); ctx.stroke(); ctx.restore();
       } else if (obj.type === 'Nb' || obj.type === 'Sc') {
@@ -5136,13 +5402,13 @@ function monthChartCometRaDec(comet, date) {
       if (label) {
         labelPlacer.drawText({
           text: label,
-          x: pt.x + symbolRadius + 5,
+          x: pt.x + symbolRadius + scalePx(5),
           y: pt.y,
-          font: '600 11px Rajdhani, sans-serif',
+          font: scaleFont(11),
           color: 'rgba(210, 224, 255, 0.78)',
           align: 'left',
           baseline: 'middle',
-          padding: 2,
+          padding: scalePx(2),
         });
       }
     }
@@ -5162,7 +5428,7 @@ function monthChartCometRaDec(comet, date) {
         ? Math.min(Number(star.mag), Number(MONTH_CHART_CONFIG.starLimit) + 0.35)
         : Number(star.mag);
       const brightness = clamp01((Number(MONTH_CHART_CONFIG.starLimit) - effectiveMagnitude + 1.6) / magRange);
-      const starRadius = (isConstellationStar ? 0.85 : 0.65) + Math.pow(brightness, 1.9) * 5.2;
+      const starRadius = ((isConstellationStar ? 0.85 : 0.65) + Math.pow(brightness, 1.9) * 5.2) * (exportRenderMode ? 2.0 : 1);
       const glowRadius = starRadius * (effectiveMagnitude <= 1 ? 2.8 : 1.9);
       const color = starColor(star);
 
@@ -5178,7 +5444,7 @@ function monthChartCometRaDec(comet, date) {
 
       if (star.mag <= 0.8) {
         ctx.strokeStyle = color + '44';
-        ctx.lineWidth = 1;
+        ctx.lineWidth = scalePx(1);
         ctx.beginPath();
         ctx.moveTo(pt.x - starRadius * 1.35, pt.y); ctx.lineTo(pt.x + starRadius * 1.35, pt.y);
         ctx.moveTo(pt.x, pt.y - starRadius * 1.35); ctx.lineTo(pt.x, pt.y + starRadius * 1.35);
@@ -5190,13 +5456,13 @@ function monthChartCometRaDec(comet, date) {
         if (label) {
           labelPlacer.drawText({
             text: label,
-            x: pt.x + starRadius + 5,
-            y: pt.y - 1,
-            font: '600 11px Rajdhani, sans-serif',
+            x: pt.x + starRadius + scalePx(5),
+            y: pt.y - scalePx(1),
+            font: scaleFont(11),
             color: 'rgba(232, 239, 255, 0.82)',
             align: 'left',
             baseline: 'middle',
-            padding: 2,
+            padding: scalePx(2),
           });
         }
       }
@@ -5204,8 +5470,8 @@ function monthChartCometRaDec(comet, date) {
   }
 
   function draw() {
-    const width = canvas.clientWidth;
-    const height = canvas.clientHeight;
+    const width = viewportWidth;
+    const height = viewportHeight;
     projectionLayout = computeProjectionLayout(width, height);
     ctx.clearRect(0, 0, width, height);
     labelPlacer.reset();
@@ -5221,6 +5487,58 @@ function monthChartCometRaDec(comet, date) {
     statusEl.textContent = 'Südhimmel für ' + MONTH_CHART_CONFIG.localTimeLabel;
   }
 
+  if (downloadButton) {
+    downloadButton.addEventListener('click', async function () {
+      const previous = {
+        width: canvas.width,
+        height: canvas.height,
+        styleWidth: canvas.style.width,
+        styleHeight: canvas.style.height,
+        viewportWidth,
+        viewportHeight,
+        renderScale,
+      };
+
+      try {
+        statusEl.textContent = 'PNG wird in 2000 px neu gerendert...';
+        downloadButton.disabled = true;
+
+        exportRenderMode = true;
+        viewportWidth = MONTH_CHART_EXPORT_WIDTH;
+        viewportHeight = Math.round(MONTH_CHART_EXPORT_WIDTH * 0.6);
+        renderScale = 1;
+        canvas.width = viewportWidth;
+        canvas.height = viewportHeight;
+        ctx.setTransform(1, 0, 0, 1, 0, 0);
+        labelPlacer = createLabelPlacer(ctx);
+        draw();
+
+        const exportCanvas = await composeExportCanvas(canvas, 'bottom-left');
+        if (!exportCanvas) {
+          throw new Error('Export-Canvas konnte nicht erzeugt werden.');
+        }
+
+        triggerCanvasDownload(exportCanvas, monthChartExportFilename('sued'));
+      } catch (error) {
+        statusEl.textContent = 'PNG-Download konnte nicht erstellt werden.';
+      } finally {
+        exportRenderMode = false;
+        viewportWidth = previous.viewportWidth;
+        viewportHeight = previous.viewportHeight;
+        renderScale = previous.renderScale;
+        canvas.width = previous.width;
+        canvas.height = previous.height;
+        canvas.style.width = previous.styleWidth;
+        canvas.style.height = previous.styleHeight;
+        ctx.setTransform(1, 0, 0, 1, 0, 0);
+        ctx.scale(renderScale, renderScale);
+        labelPlacer = createLabelPlacer(ctx);
+        draw();
+        downloadButton.disabled = false;
+      }
+    });
+  }
+
   resizeCanvas();
   window.addEventListener('resize', resizeCanvas);
 })();