diff --git a/frontend/src/components/editor/EditorPane.tsx b/frontend/src/components/editor/EditorPane.tsx
index 9ac4e3a..dc3e65a 100644
--- a/frontend/src/components/editor/EditorPane.tsx
+++ b/frontend/src/components/editor/EditorPane.tsx
@@ -1,11 +1,55 @@
 import { useEffect, useRef } from "react";
-import { EditorView, keymap } from "@codemirror/view";
-import { EditorState } from "@codemirror/state";
+import { EditorView, keymap, lineNumbers, highlightActiveLine, Decoration, ViewPlugin } from "@codemirror/view";
+import { EditorState, RangeSetBuilder } from "@codemirror/state";
 import type { Extension } from "@codemirror/state";
+import type { DecorationSet } from "@codemirror/view";
 import { defaultKeymap, history, historyKeymap } from "@codemirror/commands";
 import { searchKeymap } from "@codemirror/search";
 import { oneDark } from "./oneDarkTheme";
 
+function toRoman(n: number): string {
+  const vals = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
+  const syms = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"];
+  let result = "";
+  for (let i = 0; i < vals.length; i++) {
+    while (n >= vals[i]) {
+      result += syms[i];
+      n -= vals[i];
+    }
+  }
+  return result;
+}
+
+const dotDeco = Decoration.mark({ class: "cm-dot-space" });
+
+function buildSpaceDeco(view: EditorView): DecorationSet {
+  const builder = new RangeSetBuilder<Decoration>();
+  for (const { from, to } of view.visibleRanges) {
+    const text = view.state.sliceDoc(from, to);
+    for (let i = 0; i < text.length; i++) {
+      if (text[i] === " ") {
+        builder.add(from + i, from + i + 1, dotDeco);
+      }
+    }
+  }
+  return builder.finish();
+}
+
+const subtleWhitespace = ViewPlugin.fromClass(
+  class {
+    decorations: DecorationSet;
+    constructor(view: EditorView) {
+      this.decorations = buildSpaceDeco(view);
+    }
+    update(update: { docChanged: boolean; viewportChanged: boolean; view: EditorView }) {
+      if (update.docChanged || update.viewportChanged) {
+        this.decorations = buildSpaceDeco(update.view);
+      }
+    }
+  },
+  { decorations: (v) => v.decorations },
+);
+
 interface Props {
   value: string;
   onChange: (value: string) => void;
@@ -25,6 +69,9 @@ export default function EditorPane({ value, onChange, extensions = [] }: Props)
       doc: value,
       extensions: [
         history(),
+        lineNumbers({ formatNumber: toRoman }),
+        highlightActiveLine(),
+        subtleWhitespace,
         keymap.of([...defaultKeymap, ...historyKeymap, ...searchKeymap]),
         oneDark,
         EditorView.updateListener.of((update) => {
@@ -49,6 +96,20 @@ export default function EditorPane({ value, onChange, extensions = [] }: Props)
             borderLeftColor: "var(--primary)",
             borderLeftWidth: "0.5em",
           },
+          ".cm-dot-space": {
+            color: "transparent",
+            position: "relative",
+          },
+          ".cm-dot-space:before": {
+            content: '"\\22C5"',
+            position: "absolute",
+            left: "0",
+            right: "0",
+            textAlign: "center",
+            color: "var(--muted-foreground)",
+            opacity: "0.5",
+            pointerEvents: "none",
+          },
         }),
         ...extensions,
       ],
diff --git a/frontend/src/components/editor/oneDarkTheme.ts b/frontend/src/components/editor/oneDarkTheme.ts
index ee7dbc6..ca7ac10 100644
--- a/frontend/src/components/editor/oneDarkTheme.ts
+++ b/frontend/src/components/editor/oneDarkTheme.ts
@@ -3,26 +3,27 @@ import { EditorView } from "@codemirror/view";
 export const oneDark = EditorView.theme(
   {
     "&": {
-      backgroundColor: "#0d1117",
-      color: "#c9d1d9",
+      backgroundColor: "var(--background)",
+      color: "var(--foreground)",
     },
     ".cm-cursor, .cm-cursor-primary": {
       borderLeftColor: "var(--primary)",
       borderLeftWidth: "0.5em",
     },
     ".cm-selectionBackground, &.cm-focused .cm-selectionBackground": {
-      backgroundColor: "#264f78",
+      backgroundColor: "color-mix(in oklch, var(--primary) 25%, transparent)",
     },
     ".cm-activeLine": {
-      backgroundColor: "#161b2266",
+      backgroundColor: "color-mix(in oklch, var(--primary) 8%, transparent)",
     },
     ".cm-gutters": {
-      backgroundColor: "#0d1117",
-      color: "#484f58",
-      borderRight: "1px solid #21262d",
+      backgroundColor: "var(--background)",
+      color: "var(--muted-foreground)",
+      borderRight: "1px solid var(--border)",
     },
     ".cm-activeLineGutter": {
-      backgroundColor: "#161b2266",
+      backgroundColor: "color-mix(in oklch, var(--primary) 8%, transparent)",
+      color: "var(--primary)",
     },
   },
   { dark: true }