diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 6bbfeb6..1bae8f9 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1 +1 @@
-{".":"0.5.0"}
+{".":"0.5.1"}
diff --git a/docker-compose.yml b/docker-compose.yml
index b038711..61e92d0 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -7,11 +7,18 @@ services:
     container_name: cashflow
     ports:
       - "8080:80"
+    # Skip entrypoint template processing (fails on read-only root)
+    entrypoint: ["nginx", "-g", "daemon off;"]
+    # Mount local sources for live debugging without rebuild
+    volumes:
+      - ./index.html:/usr/share/nginx/html/index.html:ro
+      - ./src:/usr/share/nginx/html/src:ro
     read_only: true
     tmpfs:
-      - /tmp
-      - /var/cache/nginx
-      - /var/run
+      # nginx user (uid/gid 101) must own cache/run dirs
+      - /tmp:uid=101,gid=101,mode=1777
+      - /var/cache/nginx:uid=101,gid=101,mode=1777
+      - /var/run:uid=101,gid=101,mode=1777
     security_opt:
       - no-new-privileges:true
     deploy:
diff --git a/index.html b/index.html
index abdbc31..4c4482c 100644
--- a/index.html
+++ b/index.html
@@ -43,7 +43,7 @@ <h1 class="text-2xl font-bold">Cashflow Simulator</h1>
           </p>
         </div>
         <div class="flex items-center gap-3">
-          <span class="text-sm text-blue-200">v0.5.0</span>
+          <span class="text-sm text-blue-200">v0.5.1</span>
           <button
             @click="toggleTheme"
             class="text-white hover:text-blue-200 text-2xl"
@@ -1049,6 +1049,32 @@ <h2 class="text-lg font-semibold text-gray-700 dark:text-gray-200">
             const expenseData = chartData.map(r => (r.cashflow < 0 ? r.cashflow : null));
             const balanceData = chartData.map(r => r.balance);
 
+            const AXIS_ORANGE = '#FF4F00';
+            // Must be attached via config.plugins (array); options.plugins only configures registered plugins.
+            // Attach after JSON clones — stringify strips functions.
+            const axisHighlightPlugin = {
+              id: 'axisHighlight',
+              afterDraw(chart) {
+                const yScale = chart.scales.y;
+                const ctx = chart.ctx;
+                const { left, right, top, bottom } = chart.chartArea;
+                // Only highlight y=0 — not the chart-area baseline (scale min)
+                const zeroY = yScale.getPixelForValue(0);
+                if (zeroY < top || zeroY > bottom) {
+                  return;
+                }
+                ctx.save();
+                ctx.strokeStyle = AXIS_ORANGE;
+                ctx.lineWidth = 2.5;
+                ctx.setLineDash([]);
+                ctx.beginPath();
+                ctx.moveTo(left, zeroY);
+                ctx.lineTo(right, zeroY);
+                ctx.stroke();
+                ctx.restore();
+              },
+            };
+
             const chartOptions = {
               responsive: true,
               maintainAspectRatio: false,
@@ -1061,45 +1087,6 @@ <h2 class="text-lg font-semibold text-gray-700 dark:text-gray-200">
                   display: true,
                   position: 'top',
                 },
-                // Draw a stronger/brighter horizontal line at y=0
-                zeroLine: {
-                  afterDraw: chart => {
-                    const yScale = chart.scales.y;
-                    const ctx = chart.ctx;
-                    const { top, bottom } = chart.chartArea;
-                    const xLeft = chart.chartArea.left;
-                    const xRight = chart.chartArea.right;
-                    const zeroY = yScale.getPixelForValue(0);
-                    if (zeroY >= top && zeroY <= bottom) {
-                      ctx.save();
-                      ctx.strokeStyle = darkMode.value ? '#e5e7eb' : '#374151';
-                      ctx.lineWidth = 2.5;
-                      ctx.setLineDash([]);
-                      ctx.beginPath();
-                      ctx.moveTo(xLeft, zeroY);
-                      ctx.lineTo(xRight, zeroY);
-                      ctx.stroke();
-                      ctx.restore();
-                    }
-                  },
-                },
-                // Draw a stronger x-axis baseline
-                xAxisLine: {
-                  afterDraw: chart => {
-                    const ctx = chart.ctx;
-                    const { left, right, bottom } = chart.chartArea;
-                    const xBottomY = bottom;
-                    ctx.save();
-                    ctx.strokeStyle = darkMode.value ? '#e5e7eb' : '#374151';
-                    ctx.lineWidth = 2.5;
-                    ctx.setLineDash([]);
-                    ctx.beginPath();
-                    ctx.moveTo(left, xBottomY);
-                    ctx.lineTo(right, xBottomY);
-                    ctx.stroke();
-                    ctx.restore();
-                  },
-                },
               },
               scales: {
                 x: {
@@ -1156,6 +1143,7 @@ <h2 class="text-lg font-semibold text-gray-700 dark:text-gray-200">
               inlineConfig.data.datasets[0].categoryPercentage = 0.5;
               inlineConfig.data.datasets[1].barPercentage = 1.0;
               inlineConfig.data.datasets[1].categoryPercentage = 0.5;
+              inlineConfig.plugins = [axisHighlightPlugin];
               cashflowChartInstance = new Chart(cashflowChart.value, inlineConfig);
             }
             if (cashflowChartFullscreen.value) {
@@ -1180,8 +1168,6 @@ <h2 class="text-lg font-semibold text-gray-700 dark:text-gray-200">
                   position: 'top',
                   labels: { color: textColor },
                 },
-                zeroLine: chartOptions.plugins.zeroLine,
-                xAxisLine: chartOptions.plugins.xAxisLine,
               };
               const fullscreenConfig = JSON.parse(JSON.stringify(chartConfig));
               // Set bar spacing per dataset for fullscreen
@@ -1190,6 +1176,7 @@ <h2 class="text-lg font-semibold text-gray-700 dark:text-gray-200">
               fullscreenConfig.data.datasets[1].barPercentage = 1.0;
               fullscreenConfig.data.datasets[1].categoryPercentage = 0.5;
               fullscreenConfig.options = fullscreenOptions;
+              fullscreenConfig.plugins = [axisHighlightPlugin];
               cashflowChartFullscreenInstance = new Chart(
                 cashflowChartFullscreen.value,
                 fullscreenConfig
diff --git a/package.json b/package.json
index e5e5c0c..7c6ad2c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cf-sim",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "Visualize your income, expenses, and balance over time",
   "type": "module",
   "scripts": {
diff --git a/src/style.css b/src/style.css
index a9dbe74..f631447 100644
--- a/src/style.css
+++ b/src/style.css
@@ -31,16 +31,6 @@
   color: inherit;
 }
 
-/* Page background — desk photo from aloisio.dev */
-body {
-  background-color: #226e93;
-  background-image: url('../assets/bg-desk.jpg');
-  background-size: cover;
-  background-position: center center;
-  background-repeat: no-repeat;
-  background-attachment: fixed;
-}
-
 /* CSS custom properties for theming — dark mode via .dark class */
 :root {
   --color-bg: #f3f4f6;
@@ -102,14 +92,8 @@ html.dark {
 
 /* Apply CSS variables to all relevant elements in dark mode */
 html.dark body {
+  background-color: var(--color-bg) !important;
   color: var(--color-text) !important;
-  background-color: #226e93 !important;
-  background-image:
-    linear-gradient(rgba(17, 24, 39, 0.55), rgba(17, 24, 39, 0.55)), url('../assets/bg-desk.jpg') !important;
-  background-size: cover !important;
-  background-position: center center !important;
-  background-repeat: no-repeat !important;
-  background-attachment: fixed !important;
 }
 html.dark header {
   background-color: var(--color-header-bg) !important;
@@ -136,9 +120,19 @@ html.dark .bg-gray-800 {
 html.dark .bg-blue-50 {
   background-color: var(--color-hover-bg) !important;
 }
+html.dark .bg-blue-100 {
+  background-color: var(--color-hover-bg) !important;
+}
 html.dark .bg-blue-900 {
   background-color: var(--color-hover-bg) !important;
 }
+/* Tailwind hover:bg-blue-100 stays light unless overridden — washes out green/red values */
+html.dark .hover\:bg-blue-100:hover {
+  background-color: var(--color-hover-bg) !important;
+}
+html.dark .hover\:bg-gray-200:hover {
+  background-color: #374151 !important;
+}
 html.dark .bg-red-50 {
   background-color: var(--color-error-bg) !important;
 }