diff --git a/Dockerfile b/Dockerfile
index e243da4..8222dfd 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -37,24 +37,9 @@ RUN --mount=type=bind,source=src,target=src \
 
 FROM docker.io/library/alpine:3.18 AS final
 
-# Create a non-privileged user (recommended best practice)
-ARG UID=10001
-RUN adduser \
-    --disabled-password \
-    --gecos "" \
-    --home "/nonexistent" \
-    --shell "/sbin/nologin" \
-    --no-create-home \
-    --uid "${UID}" \
-    imnyang
-
 RUN mkdir -p /app
 RUN chmod -R 755 /app
 RUN mkdir -p /app/uploads
-RUN chown -R imnyang:imnyang /app
-
-# Drop privileges for runtime.
-USER imnyang
 
 WORKDIR /app
 
diff --git a/src/assets/editor.html b/src/assets/editor.html
index 21e9e77..9e19173 100644
--- a/src/assets/editor.html
+++ b/src/assets/editor.html
@@ -8,6 +8,10 @@
     <style>
         @import url("https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,100..800;1,100..800&display=swap");
 
+        :root {
+            --editor-font-size: 14px;
+        }
+
         body {
             font-family: "JetBrains Mono", monospace;
             font-optical-sizing: auto;
@@ -27,6 +31,7 @@
 
         .cm-editor {
             height: 100%;
+            font-size: var(--editor-font-size);
         }
 
         header {
@@ -125,6 +130,13 @@
                     <input id="extension-input" type="text" inputmode="text" autocomplete="off" spellcheck="false"
                         placeholder="txt" />
                 </li>
+                <li>
+                    <span>[</span>
+                    <button id="increase-size-button" type="button">+</button>
+                    <button id="reset-size-button" type="button">|</button>
+                    <button id="decrease-size-button" type="button">-</button>
+                    <span>]</span>
+                </li>
             </ul>
         </header>
         <div id="editor"></div>
@@ -158,8 +170,15 @@
         const extensionInput = document.getElementById("extension-input");
         const saveButton = document.getElementById("save-button");
         const newButton = document.getElementById("new-button");
+        const decreaseSizeButton = document.getElementById("decrease-size-button");
+        const resetSizeButton = document.getElementById("reset-size-button");
+        const increaseSizeButton = document.getElementById("increase-size-button");
 
         const languageCompartment = new Compartment();
+        const DEFAULT_EDITOR_FONT_SIZE = 14;
+        const MIN_EDITOR_FONT_SIZE = 10;
+        const MAX_EDITOR_FONT_SIZE = 28;
+        const EDITOR_FONT_SIZE_STEP = 1;
 
         const LANGUAGE_PRESETS = {
             plain: {
@@ -233,6 +252,7 @@
         let initialDoc = initialData.textContent;
         let initialExtension = ".txt";
         let lastSuggestedExtension = ".txt";
+        let editorFontSize = DEFAULT_EDITOR_FONT_SIZE;
 
         function normalizeExtension(value, fallback = ".txt") {
             const cleaned = value
@@ -266,6 +286,13 @@
             saveButton.disabled = !isDirty();
         }
 
+        function updateEditorSize() {
+            document.documentElement.style.setProperty("--editor-font-size", `${editorFontSize}px`);
+            decreaseSizeButton.disabled = editorFontSize <= MIN_EDITOR_FONT_SIZE;
+            increaseSizeButton.disabled = editorFontSize >= MAX_EDITOR_FONT_SIZE;
+            resetSizeButton.disabled = editorFontSize === DEFAULT_EDITOR_FONT_SIZE;
+        }
+
         function applyLanguagePreset(languageKey) {
             const preset = LANGUAGE_PRESETS[languageKey] ?? LANGUAGE_PRESETS.plain;
             const currentExtension = normalizeExtension(extensionInput.value, "");
@@ -341,6 +368,18 @@
 
         saveButton.onclick = saveFile;
         newButton.onclick = () => (window.location.href = "/");
+        decreaseSizeButton.onclick = () => {
+            editorFontSize = Math.max(MIN_EDITOR_FONT_SIZE, editorFontSize - EDITOR_FONT_SIZE_STEP);
+            updateEditorSize();
+        };
+        resetSizeButton.onclick = () => {
+            editorFontSize = DEFAULT_EDITOR_FONT_SIZE;
+            updateEditorSize();
+        };
+        increaseSizeButton.onclick = () => {
+            editorFontSize = Math.min(MAX_EDITOR_FONT_SIZE, editorFontSize + EDITOR_FONT_SIZE_STEP);
+            updateEditorSize();
+        };
 
         languageSelect.addEventListener("change", (event) => {
             applyLanguagePreset(event.target.value);
@@ -365,6 +404,7 @@
             saveFile();
         });
 
+        updateEditorSize();
         refreshSaveState();
     </script>
 </body>