Add Note Width setting to cap editor content width (#137)

src-tauri/src/commands.rs

@@ -122,6 +122,14 @@ pub fn set_ui_scale(state: State<'_, AppState>, scale: f64) -> Result<(), String
     Ok(())
 }
 
+#[tauri::command]
+pub fn set_content_width(state: State<'_, AppState>, width: Option<u32>) -> Result<(), String> {
+    let mut config = state.config.lock().map_err(|e| e.to_string())?;
+    config.content_width = width;
+    save_app_config(&config)?;
+    Ok(())
+}
+
 // ── Notebooks ──
 
 #[tauri::command]

src-tauri/src/lib.rs

@@ -106,6 +106,7 @@ pub fn run() {
             commands::set_font_family,
             commands::set_line_height,
             commands::set_ui_scale,
+            commands::set_content_width,
             commands::get_notebooks,
             commands::count_root_notes,
             commands::create_notebook,

src-tauri/src/types.rs

@@ -72,6 +72,8 @@ pub struct AppConfig {
     #[serde(default)]
     pub ui_scale: Option<f64>,
     #[serde(default)]
+    pub content_width: Option<u32>,
+    #[serde(default)]
     pub compact_notes: bool,
     #[serde(default = "default_true")]
     pub show_note_dates: bool,
@@ -205,6 +207,7 @@ impl Default for AppConfig {
             font_family: None,
             line_height: None,
             ui_scale: None,
+            content_width: None,
             compact_notes: false,
             show_note_dates: true,
             time_format: "relative".to_string(),

src/lib/api.ts

@@ -52,6 +52,10 @@ export async function setUiScale(scale: number): Promise<void> {
   return invoke("set_ui_scale", { scale });
 }
 
+export async function setContentWidth(width: number | null): Promise<void> {
+  return invoke("set_content_width", { width });
+}
+
 export async function getNotebooks(): Promise<NotebookEntry[]> {
   return invoke("get_notebooks");
 }

src/lib/components/Editor.svelte

@@ -7433,7 +7433,8 @@
 		resize: none;
 		outline: none;
 		padding: 0 0 var(--editor-scroll-past-end, 65vh);
-		margin: 0;
+		margin: 0 auto;
+		max-width: var(--editor-content-width, none);
 		user-select: text;
 		/* Wrap long lines instead of horizontal-scrolling (matches mobile). (issue #100) */
 		white-space: pre-wrap;
@@ -7447,6 +7448,9 @@
 		   Keep no-wrap (horizontal scroll) whenever line numbers are on. (issue #100) */
 		white-space: pre;
 		overflow-x: auto;
+		/* The line-number gutter is pinned to the left edge, so don't center/cap here. (#137) */
+		max-width: none;
+		margin: 0;
 	}
 
 	.line-numbers-clip {
@@ -7479,6 +7483,12 @@
 	.tiptap-wrapper {
 		height: 100%;
 		user-select: text;
+		/* Optional reading-width cap (Settings > Styling > Note Width). Default `none` = full
+		   width; when set, the text column is capped and centered. Scrollbar stays at the
+		   panel edge because only the inner content is constrained, not .editor-body. (#137) */
+		max-width: var(--editor-content-width, none);
+		margin-left: auto;
+		margin-right: auto;
 	}
 
 	:global(.tiptap-wrapper .tiptap) {

src/lib/components/SettingsPanel.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 	import { showSettings, theme, appConfig, updateAvailable as globalUpdateAvailable, updateObj as globalUpdateObj, installType, settingsTab, vaultReady, androidApkUrl, checkForUpdateMobile, notebookSortMode, isManagedInstall } from '$lib/stores/app';
-	import { setTheme, setAccentColor, setFontSize, setFontFamily, setLineHeight, setUiScale, setGeneralSettings, importObsidian, createBackup, listBackups, restoreBackup, deleteBackup, setBackupSettings, setAiSettings, testAiConnection, setSyncSettings, testSyncConnection, syncNow } from '$lib/api';
+	import { setTheme, setAccentColor, setFontSize, setFontFamily, setLineHeight, setUiScale, setContentWidth, setGeneralSettings, importObsidian, createBackup, listBackups, restoreBackup, deleteBackup, setBackupSettings, setAiSettings, testAiConnection, setSyncSettings, testSyncConnection, syncNow } from '$lib/api';
 	import { darkThemes } from '$lib/platform';
 	import { open as openDialog } from '@tauri-apps/plugin-dialog';
 	import { listen } from '@tauri-apps/api/event';
@@ -477,12 +477,20 @@
 		{ label: '200%', value: 2 },
 	];
 
+	const contentWidthPresets: { label: string; value: number | null }[] = [
+		{ label: 'Narrow', value: 600 },
+		{ label: 'Medium', value: 760 },
+		{ label: 'Wide', value: 960 },
+		{ label: 'Full', value: null },
+	];
+
 	let activeAccent = $state($appConfig?.accent_color ?? 'Indigo');
 	let customAccentColor = $state(($appConfig?.accent_color?.startsWith('#') ? $appConfig.accent_color : null) ?? '#5b6abf');
 	let activeFontSize = $state($appConfig?.font_size ?? 14);
 	let activeFontFamily = $state($appConfig?.font_family ?? 'system');
 	let activeLineHeight = $state($appConfig?.line_height ?? 1.6);
 	let activeUiScale = $state($appConfig?.ui_scale ?? 1);
+	let activeContentWidth = $state<number | null>($appConfig?.content_width ?? null);
 	let themeDropdownOpen = $state(false);
 	let accentDropdownOpen = $state(false);
 	let activeThemePreset = $derived(themePresets.find(p => p.id === $theme) ?? themePresets[0]);
@@ -681,6 +689,17 @@
 		}
 	}
 
+	function selectContentWidth(value: number | null) {
+		activeContentWidth = value;
+		applyContentWidth(value);
+		if ($appConfig) $appConfig.content_width = value;
+		setContentWidth(value).catch((e) => console.error('Failed to save content width:', e));
+	}
+
+	function applyContentWidth(value: number | null) {
+		document.documentElement.style.setProperty('--editor-content-width', value ? `${value}px` : 'none');
+	}
+
 	function clickOutside(node: HTMLElement, callback: () => void) {
 		function handle(e: MouseEvent) {
 			if (!node.contains(e.target as Node)) callback();
@@ -732,6 +751,11 @@
 			activeLineHeight = savedLineHeight;
 			applyLineHeight(savedLineHeight);
 		}
+		const savedContentWidth = $appConfig?.content_width;
+		if (savedContentWidth) {
+			activeContentWidth = savedContentWidth;
+			applyContentWidth(savedContentWidth);
+		}
 		// Sync general settings
 		if ($appConfig) {
 			compactNotes = $appConfig.compact_notes ?? false;
@@ -1185,6 +1209,24 @@
 								</div>
 							{/if}
 
+							{#if !isMobile}
+								<div class="settings-section">
+									<h3>Note Width</h3>
+									<div class="font-size-options">
+										{#each contentWidthPresets as preset}
+											<button
+												class="font-size-btn"
+												class:active={activeContentWidth === preset.value}
+												onclick={() => selectContentWidth(preset.value)}
+											>
+												<span class="font-size-label">{preset.label}</span>
+											</button>
+										{/each}
+									</div>
+									<p class="setting-hint">Caps the width of the note text for easier reading on wide screens; the column stays centered. Most noticeable in Focus Mode. "Full" uses the entire width.</p>
+								</div>
+							{/if}
+
 							<div class="settings-section">
 								<h3>Line Height</h3>
 								<div class="font-size-options">

src/lib/types.ts

@@ -55,6 +55,7 @@ export interface AppConfig {
   font_family: string | null;
   line_height: number | null;
   ui_scale: number | null;
+  content_width: number | null;
   compact_notes: boolean;
   show_note_dates: boolean;
   time_format: string;

src/routes/+page.svelte

@@ -138,6 +138,9 @@
 			if (config.line_height) {
 				document.documentElement.style.setProperty('--editor-line-height', String(config.line_height));
 			}
+			if (config.content_width) {
+				document.documentElement.style.setProperty('--editor-content-width', `${config.content_width}px`);
+			}
 			if (config.font_family) {
 				const fontStacks: Record<string, string> = {
 					system: '-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif',