diff --git a/app/routes/home.tsx b/app/routes/home.tsx
index 2e4b69f..9c00c95 100644
--- a/app/routes/home.tsx
+++ b/app/routes/home.tsx
@@ -14,6 +14,41 @@ type Row = Record<string, number>;
 
 type PlotType = "scatter" | "surface";
 
+type ThemeScheme = "light" | "dark" | "transparent";
+
+const THEME_SCHEMES: Record<
+  ThemeScheme,
+  {
+    paperBg: string;
+    plotBg: string;
+    fontColor: string;
+    gridColor: string;
+    mainClass: string;
+  }
+> = {
+  dark: {
+    paperBg: "#0b0d12",
+    plotBg: "#0b0d12",
+    fontColor: "#cfd3ff",
+    gridColor: "rgba(148, 163, 184, 0.25)",
+    mainClass: "bg-[#0b0d12]",
+  },
+  light: {
+    paperBg: "#f8fafc",
+    plotBg: "#f8fafc",
+    fontColor: "#1e293b",
+    gridColor: "rgba(148, 163, 184, 0.5)",
+    mainClass: "bg-slate-100",
+  },
+  transparent: {
+    paperBg: "rgba(0,0,0,0)",
+    plotBg: "rgba(0,0,0,0)",
+    fontColor: "#475569",
+    gridColor: "rgba(100, 116, 139, 0.4)",
+    mainClass: "bg-transparent",
+  },
+};
+
 const COLORSCALES = [
   "Viridis",
   "Plasma",
@@ -41,6 +76,7 @@ export default function Home() {
   const [z, setZ] = useState("");
   const [plotType, setPlotType] = useState<PlotType>("scatter");
   const [colorscale, setColorscale] = useState<string>(COLORSCALES[0]);
+  const [themeScheme, setThemeScheme] = useState<ThemeScheme>("dark");
 
   // First row after header = axis sizes (X max, Y max, Z max); rest = plot data.
   const plotData = rows.length > 1 ? rows.slice(1) : rows;
@@ -118,14 +154,44 @@ export default function Home() {
           },
         };
 
+      const theme = THEME_SCHEMES[themeScheme];
       const sceneLayout: {
-        xaxis: { title: { text: string }; range?: [number, number] };
-        yaxis: { title: { text: string }; range?: [number, number] };
-        zaxis: { title: { text: string }; range?: [number, number] };
+        bgcolor?: string;
+        xaxis: {
+          title: { text: string };
+          range?: [number, number];
+          gridcolor?: string;
+          tickfont?: { color: string };
+        };
+        yaxis: {
+          title: { text: string };
+          range?: [number, number];
+          gridcolor?: string;
+          tickfont?: { color: string };
+        };
+        zaxis: {
+          title: { text: string };
+          range?: [number, number];
+          gridcolor?: string;
+          tickfont?: { color: string };
+        };
       } = {
-        xaxis: { title: { text: x } },
-        yaxis: { title: { text: y } },
-        zaxis: { title: { text: z } },
+        bgcolor: theme.plotBg,
+        xaxis: {
+          title: { text: x },
+          gridcolor: theme.gridColor,
+          tickfont: { color: theme.fontColor },
+        },
+        yaxis: {
+          title: { text: y },
+          gridcolor: theme.gridColor,
+          tickfont: { color: theme.fontColor },
+        },
+        zaxis: {
+          title: { text: z },
+          gridcolor: theme.gridColor,
+          tickfont: { color: theme.fontColor },
+        },
       };
       if (axisSizes) {
         sceneLayout.xaxis.range = [0, axisSizes.x];
@@ -137,9 +203,9 @@ export default function Home() {
         plotRef.current!,
         [trace],
         {
-          paper_bgcolor: "#0b0d12",
-          plot_bgcolor: "#0b0d12",
-          font: { color: "#cfd3ff" },
+          paper_bgcolor: theme.paperBg,
+          plot_bgcolor: theme.plotBg,
+          font: { color: theme.fontColor },
           scene: sceneLayout,
           margin: { l: 0, r: 0, t: 0, b: 0 },
         },
@@ -150,7 +216,7 @@ export default function Home() {
     return () => {
       cancelled = true;
     };
-  }, [rows, x, y, z, plotType, colorscale]);
+  }, [rows, x, y, z, plotType, colorscale, themeScheme]);
 
 
   function onFile(file: File) {
@@ -204,9 +270,9 @@ export default function Home() {
   }
 
   return (
-    <div className="h-screen grid grid-cols-[280px_1fr]">
+    <div className="h-screen grid grid-cols-[280px_1fr] overflow-y-hidden">
       {/* Sidebar */}
-      <aside className="bg-panel p-4 space-y-4">
+      <aside className="bg-panel p-4 space-y-4 overflow-y-scroll">
         <div className="text-lg font-semibold">
           3dplot-gen
           <div className="text-xs text-muted">CSV → 3D Plot</div>
@@ -300,6 +366,18 @@ export default function Home() {
           </select>
         </Control>
 
+        <Control label="Background">
+          <select
+            className="w-full bg-neutral-900 border border-slate-700 rounded px-2 py-1"
+            value={themeScheme}
+            onChange={(e) => setThemeScheme(e.target.value as ThemeScheme)}
+          >
+            <option value="dark">Dark</option>
+            <option value="light">Light</option>
+            <option value="transparent">Transparent</option>
+          </select>
+        </Control>
+
         {plotType === "surface" &&
           plotData.length > 0 &&
           buildSurfaceGrid() === null && (
@@ -317,7 +395,7 @@ export default function Home() {
       </aside>
 
       {/* Plot */}
-      <main className="bg-plot">
+      <main className={THEME_SCHEMES[themeScheme].mainClass}>
         <div ref={plotRef} className="w-full h-full" />
       </main>
     </div>