diff --git a/app/containers/aboutPage/index.js b/app/containers/aboutPage/index.js
index 2c7c7a04..8845f27f 100644
--- a/app/containers/aboutPage/index.js
+++ b/app/containers/aboutPage/index.js
@@ -1,6 +1,6 @@
 import { bindActionCreators } from 'redux'
 import { connect } from 'react-redux'
-import { Image } from 'react-bootstrap'
+import { Button, Image } from 'react-bootstrap'
 import electronBridge from '../../utilities/electronBridge'
 import Modal from '../compatModal'
 import { updateAboutModalStatus } from '../../actions'
@@ -11,15 +11,273 @@ import ContributorInfo from '../../../.all-contributorsrc'
 import logoDarkImage from './logo-dark.webp'
 import logoLightImage from './logo-light.webp'
 import React, { Component } from 'react'
-import { isDarkTheme } from '../../utilities/themeManager'
-import { t } from '../../utilities/i18n'
+import ThemeManager, { isDarkTheme } from '../../utilities/themeManager'
+import { getSupportedLocales, t } from '../../utilities/i18n'
+import { preferenceRequiresRestart } from '../../utilities/config/preferences'
 
 import './index.scss'
 
 const conf = electronBridge.config
 const { configFilePath, logFilePath } = electronBridge.globals.getPaths()
+const themeManager = new ThemeManager()
+
+const preferenceGroups = [
+  {
+    title: 'Appearance',
+    fields: [
+      {
+        key: 'theme',
+        label: 'Theme',
+        type: 'select',
+        options: [
+          ['light', 'Light'], ['dark', 'Dark'], ['one-dark', 'One Dark'], ['atom-one-dark', 'Atom One Dark'],
+          ['github-light', 'GitHub Light'], ['github-dark', 'GitHub Dark'],
+          ['catppuccin-latte', 'Catppuccin Latte'], ['catppuccin-mocha', 'Catppuccin Mocha'],
+          ['solarized-light', 'Solarized Light'], ['solarized-dark', 'Solarized Dark'],
+          ['dracula', 'Dracula'], ['material-theme', 'Material'], ['ayu', 'Ayu']
+        ]
+      },
+      { key: 'i18n:locale', label: 'Language', type: 'select', options: getSupportedLocales().map(locale => [locale.code, locale.name]) }
+    ]
+  },
+  {
+    title: 'Behavior',
+    fields: [
+      { key: 'autoUpdate', label: 'Automatically check for updates', type: 'checkbox' },
+      { key: 'startAtLogin', label: 'Start Lepton at login', type: 'checkbox' },
+      { key: 'window:closeToTray', label: 'Close window to tray', type: 'checkbox' },
+      { key: 'window:minimizeToTray', label: 'Minimize window to tray', type: 'checkbox' }
+    ]
+  },
+  {
+    title: 'Profile',
+    fields: [
+      { key: 'avatar:type', label: 'Avatar', type: 'select', options: [['github', 'GitHub'], ['boring', 'Generated']] },
+      { key: 'avatar:boringAvatarVariant', label: 'Generated avatar style', type: 'select', options: [['beam', 'Beam'], ['marble', 'Marble'], ['pixel', 'Pixel'], ['sunset', 'Sunset'], ['ring', 'Ring'], ['bauhaus', 'Bauhaus']] },
+      { key: 'userPanel:hideProfilePhoto', label: 'Hide profile photo', type: 'checkbox' }
+    ]
+  },
+  {
+    title: 'Snippets and Tags',
+    fields: [
+      { key: 'snippet:sorting', label: 'Sort by', type: 'select', options: [['updated_at', 'Updated'], ['created_at', 'Created'], ['description', 'Description']] },
+      { key: 'snippet:sortingReverse', label: 'Reverse sort order', type: 'checkbox' },
+      { key: 'snippet:expanded', label: 'Expand snippets by default', type: 'checkbox' },
+      { key: 'snippet:newSnippetPrivate', label: 'Create secret snippets by default', type: 'checkbox' },
+      { key: 'snippet:downloadAll', label: 'Download all snippets for content search', type: 'checkbox' },
+      { key: 'tag:showInSnippetList', label: 'Show tags in the snippet list', type: 'checkbox' },
+      { key: 'tag:colored', label: 'Use colored tag badges', type: 'checkbox' }
+    ]
+  },
+  {
+    title: 'Editor',
+    fields: [
+      { key: 'editor:tabSize', label: 'Tab size', type: 'select', numeric: true, options: [[2, '2'], [4, '4'], [8, '8']] },
+      { key: 'editor:validateFilename', label: 'Validate filenames', type: 'checkbox' }
+    ]
+  },
+  {
+    title: 'Notifications',
+    fields: [
+      { key: 'notifications:success', label: 'Show success notifications', type: 'checkbox' },
+      { key: 'notifications:failure', label: 'Show failure notifications', type: 'checkbox' }
+    ]
+  },
+  {
+    title: 'Network',
+    fields: [
+      { key: 'proxy:enable', label: 'Use proxy', type: 'checkbox' },
+      { key: 'proxy:address', label: 'Proxy address', type: 'text', placeholder: 'socks://localhost:1080' }
+    ]
+  },
+  {
+    title: 'GitHub Enterprise',
+    fields: [
+      { key: 'enterprise:enable', label: 'Enable GitHub Enterprise', type: 'checkbox' },
+      { key: 'enterprise:host', label: 'Host', type: 'text', placeholder: 'github.example.com' },
+      { key: 'enterprise:token', label: 'Personal access token', type: 'password' },
+      { key: 'enterprise:avatarUrl', label: 'Avatar URL', type: 'text' }
+    ]
+  },
+  {
+    title: 'Advanced',
+    fields: [
+      { key: 'zoom:percent', label: 'Default zoom', type: 'number', numeric: true, min: 50, max: 300 },
+      { key: 'logger:level', label: 'Log level', type: 'select', options: [['info', 'Info'], ['debug', 'Debug'], ['warn', 'Warning'], ['error', 'Error']] },
+      { key: 'security:cachedAccessTokenStorage', label: 'Cached token storage', type: 'select', options: [['auto', 'Automatic'], ['encrypted', 'Encrypted'], ['file', 'File']] }
+    ]
+  },
+  {
+    title: 'Keyboard Shortcuts',
+    fields: [
+      { key: 'shortcuts:keyShortcutForSearch', label: 'Search', type: 'text' },
+      { key: 'shortcuts:keyNewGist', label: 'New snippet', type: 'text' },
+      { key: 'shortcuts:keyEditGist', label: 'Edit snippet', type: 'text' },
+      { key: 'shortcuts:keyDeleteGist', label: 'Delete snippet', type: 'text' },
+      { key: 'shortcuts:keySubmitGist', label: 'Save snippet', type: 'text' },
+      { key: 'shortcuts:keyImmersiveMode', label: 'Immersive mode', type: 'text' },
+      { key: 'shortcuts:keyAboutPage', label: 'Settings', type: 'text' },
+      { key: 'shortcuts:keyDashboard', label: 'Dashboard', type: 'text' },
+      { key: 'shortcuts:keySyncGists', label: 'Sync snippets', type: 'text' }
+    ]
+  }
+]
 
 class AboutPage extends Component {
+  constructor (props) {
+    super(props)
+    const values = this.loadPreferences()
+    this.state = {
+      activeTab: 'preferences',
+      error: '',
+      initialValues: values,
+      restartNotice: '',
+      saveNotice: '',
+      saving: false,
+      values
+    }
+  }
+
+  componentDidUpdate (previousProps) {
+    if (previousProps.aboutModalStatus !== 'ON' && this.props.aboutModalStatus === 'ON') {
+      const values = this.loadPreferences()
+      this.setState({
+        activeTab: 'preferences',
+        error: '',
+        initialValues: values,
+        restartNotice: '',
+        saveNotice: '',
+        saving: false,
+        values
+      })
+    }
+  }
+
+  loadPreferences () {
+    return preferenceGroups.reduce((values, group) => {
+      group.fields.forEach(field => { values[field.key] = conf.get(field.key) })
+      return values
+    }, {})
+  }
+
+  updatePreference (field, event) {
+    const value = field.type === 'checkbox'
+      ? event.target.checked
+      : field.numeric ? Number(event.target.value) : event.target.value
+
+    this.setState(state => ({
+      error: '',
+      restartNotice: '',
+      saveNotice: '',
+      values: Object.assign({}, state.values, { [field.key]: value })
+    }))
+  }
+
+  getChangedPreferenceKeys () {
+    return Object.keys(this.state.values).filter(key => this.state.values[key] !== this.state.initialValues[key])
+  }
+
+  applyPreferences (closeAfterSave) {
+    const changedKeys = this.getChangedPreferenceKeys()
+    if (changedKeys.length === 0) {
+      if (closeAfterSave) this.handleCloseButtonClicked()
+      return
+    }
+
+    this.setState({ error: '', restartNotice: '', saveNotice: '', saving: true })
+    Promise.all(changedKeys.map(key => electronBridge.config.set(key, this.state.values[key])))
+      .then(persistedValues => {
+        if (persistedValues.some(value => value === undefined)) throw new Error('Preference was rejected')
+
+        if (changedKeys.includes('theme')) themeManager.setTheme(this.state.values.theme)
+        const restartFields = preferenceGroups
+          .flatMap(group => group.fields)
+          .filter(field => changedKeys.includes(field.key) && preferenceRequiresRestart(field.key))
+        const restartRequired = restartFields.length > 0
+        const restartNotice = restartRequired
+          ? `Saved. Restart Lepton to apply: ${restartFields.map(field => field.label).join(', ')}.`
+          : ''
+        const saveNotice = restartRequired ? '' : 'Changes applied.'
+        const values = Object.assign({}, this.state.values)
+        this.setState({ initialValues: values, restartNotice, saveNotice, saving: false })
+
+        if (closeAfterSave && restartRequired) {
+          electronBridge.dialog.showMessage({
+            title: 'Restart required',
+            message: restartNotice
+          }).catch(() => {})
+        }
+        if (closeAfterSave) this.handleCloseButtonClicked()
+      })
+      .catch(() => {
+        this.setState({
+          error: 'Could not save preferences to .leptonrc.',
+          saveNotice: '',
+          saving: false
+        })
+      })
+  }
+
+  cancelPreferences () {
+    this.setState(state => ({
+      error: '',
+      restartNotice: '',
+      saveNotice: '',
+      values: Object.assign({}, state.initialValues)
+    }))
+    this.handleCloseButtonClicked()
+  }
+
+  renderPreferenceField (field) {
+    const value = this.state.values[field.key]
+    if (field.type === 'checkbox') {
+      return (
+        <label className='preference-checkbox' key={ field.key }>
+          <input type='checkbox' checked={ Boolean(value) } onChange={ this.updatePreference.bind(this, field) } />
+          <span>{ field.label }</span>
+        </label>
+      )
+    }
+
+    if (field.type === 'select') {
+      return (
+        <label className='preference-row' key={ field.key }>
+          <span>{ field.label }</span>
+          <select value={ value } onChange={ this.updatePreference.bind(this, field) }>
+            { field.options.map(option => <option key={ option[0] } value={ option[0] }>{ option[1] }</option>) }
+          </select>
+        </label>
+      )
+    }
+
+    return (
+      <label className='preference-row' key={ field.key }>
+        <span>{ field.label }</span>
+        <input
+          max={ field.max }
+          min={ field.min }
+          placeholder={ field.placeholder }
+          type={ field.type }
+          value={ value === undefined ? '' : value }
+          onChange={ this.updatePreference.bind(this, field) } />
+      </label>
+    )
+  }
+
+  renderPreferencesSection () {
+    return (
+      <div className='preferences-section'>
+        { preferenceGroups.map(group => (
+          <section className='preference-group' key={ group.title }>
+            <h4>{ group.title }</h4>
+            { group.fields.map(this.renderPreferenceField.bind(this)) }
+          </section>
+        )) }
+        <div className='preference-save-note'>Save or Apply writes these changes to <code>.leptonrc</code>.</div>
+      </div>
+    )
+  }
+
   openFileInEditor (filePath) {
     if (filePath === configFilePath) {
       electronBridge.files.ensureConfigFile(defaultConfig)
@@ -100,8 +358,14 @@ class AboutPage extends Component {
 
   renderSettingModalBody () {
     return (
-      <div>
-        { this.renderAboutSection() }
+      <div className='settings-layout'>
+        <nav className='settings-tabs' aria-label='Settings sections'>
+          <button className={ this.state.activeTab === 'preferences' ? 'active' : '' } onClick={ () => this.setState({ activeTab: 'preferences' }) }>Preferences</button>
+          <button className={ this.state.activeTab === 'about' ? 'active' : '' } onClick={ () => this.setState({ activeTab: 'about' }) }>About</button>
+        </nav>
+        <div className='settings-content'>
+          { this.state.activeTab === 'preferences' ? this.renderPreferencesSection() : this.renderAboutSection() }
+        </div>
       </div>
     )
   }
@@ -111,19 +375,50 @@ class AboutPage extends Component {
     updateAboutModalStatus('OFF')
   }
 
+  renderFooter () {
+    if (this.state.activeTab === 'about') {
+      return <Button onClick={ this.handleCloseButtonClicked.bind(this) }>Close</Button>
+    }
+
+    const disabled = this.state.saving
+    const hasChanges = this.getChangedPreferenceKeys().length > 0
+    const applied = !hasChanges && !disabled && Boolean(this.state.saveNotice || this.state.restartNotice)
+    return (
+      <div className='preferences-footer'>
+        <div className='preference-status' aria-live='polite'>
+          { this.state.saving ? 'Applying changes…' : null }
+          { !this.state.saving && this.state.error ? <span className='preference-error'>{ this.state.error }</span> : null }
+          { !this.state.saving && this.state.restartNotice ? <span className='preference-restart-notice'>{ this.state.restartNotice }</span> : null }
+          { !this.state.saving && this.state.saveNotice ? this.state.saveNotice : null }
+        </div>
+        <div className='preference-actions'>
+          { applied
+            ? <Button bsStyle='primary' onClick={ this.handleCloseButtonClicked.bind(this) }>Close</Button>
+            : <div>
+              <Button disabled={ disabled } onClick={ this.cancelPreferences.bind(this) }>Cancel</Button>
+              <Button disabled={ disabled || !hasChanges } onClick={ this.applyPreferences.bind(this, false) }>Apply</Button>
+              <Button bsStyle='primary' disabled={ disabled || !hasChanges } onClick={ this.applyPreferences.bind(this, true) }>Save</Button>
+            </div> }
+        </div>
+      </div>
+    )
+  }
+
   render () {
     return (
       <Modal
         className='about-modal'
-        bsSize='small'
         show={ this.props.aboutModalStatus === 'ON' }
         onHide={ this.handleCloseButtonClicked.bind(this) }>
         <Modal.Header closeButton>
-          <Modal.Title>{ t('about.title') }</Modal.Title>
+          <Modal.Title>Settings</Modal.Title>
         </Modal.Header>
         <Modal.Body>
           { this.renderSettingModalBody() }
         </Modal.Body>
+        <Modal.Footer>
+          { this.renderFooter() }
+        </Modal.Footer>
       </Modal>
     )
   }
diff --git a/app/containers/aboutPage/index.scss b/app/containers/aboutPage/index.scss
index fdb8fbbd..8c43e008 100644
--- a/app/containers/aboutPage/index.scss
+++ b/app/containers/aboutPage/index.scss
@@ -6,19 +6,181 @@
     color: var(--text-secondary);
   }
 
-  .section-base {
-    height: 80vh;
+  .about-section {
+    display: flex;
+    flex-direction: column;
+    min-height: 100%;
+    color: var(--text-secondary);
   }
 
-  .general-section {
-    @extend .section-base;
+  .modal-dialog {
+    width: min(780px, calc(100vw - 32px));
   }
 
-  .about-section {
-    @extend .section-base;
+  .modal-content {
     display: flex;
+    max-height: calc(100vh - 40px);
     flex-direction: column;
+  }
+
+  .modal-body {
+    min-height: 0;
+    padding: 0;
+    overflow: hidden;
+  }
+
+  .settings-layout {
+    display: flex;
+    height: min(68vh, 540px);
+    min-height: 0;
+  }
+
+  .settings-tabs {
+    width: 145px;
+    flex: 0 0 145px;
+    padding: 16px 9px;
+    border-right: 1px solid var(--border-color);
+    background: var(--bg-secondary);
+  }
+
+  .settings-tabs button {
+    width: 100%;
+    padding: 7px 9px;
+    border: 0;
+    background: transparent;
+    color: var(--text-secondary);
+    text-align: left;
+  }
+
+  .settings-tabs button:hover,
+  .settings-tabs button.active {
+    color: var(--text-primary);
+  }
+
+  .settings-tabs button.active {
+    font-weight: bold;
+  }
+
+  .settings-content {
+    min-width: 0;
+    min-height: 0;
+    flex: 1;
+    padding: 16px 20px;
+    overflow-x: hidden;
+    overflow-y: scroll;
+    scrollbar-color: color-mix(in srgb, var(--text-secondary) 48%, transparent) var(--bg-secondary);
+    scrollbar-gutter: stable;
+    scrollbar-width: thin;
+  }
+
+  .settings-content::-webkit-scrollbar {
+    width: 10px;
+  }
+
+  .settings-content::-webkit-scrollbar-track {
+    background: var(--bg-secondary);
+  }
+
+  .settings-content::-webkit-scrollbar-thumb {
+    border: 2px solid var(--bg-secondary);
+    border-radius: 999px;
+    background: color-mix(in srgb, var(--text-secondary) 48%, transparent);
+  }
+
+  .preferences-section {
+    color: var(--text-secondary);
+  }
+
+  .preference-group {
+    margin-bottom: 12px;
+  }
+
+  .preference-group h4 {
+    margin: 0 0 4px;
+    padding-bottom: 4px;
+    border-bottom: 1px solid var(--border-color);
     color: var(--text-secondary);
+    font-size: 12px;
+    font-weight: bold;
+    letter-spacing: .08em;
+    text-transform: uppercase;
+  }
+
+  .preference-row,
+  .preference-checkbox {
+    display: flex;
+    min-height: 29px;
+    margin: 0;
+    align-items: center;
+    font-weight: normal;
+  }
+
+  .preference-row {
+    justify-content: space-between;
+  }
+
+  .preference-row select,
+  .preference-row > input {
+    width: 280px;
+    height: 26px;
+    padding: 2px 7px;
+    border: 1px solid var(--border-color);
+    border-radius: 4px;
+    background: var(--bg-primary);
+    color: var(--text-primary);
+  }
+
+  .preference-row select {
+    padding-right: 34px;
+    appearance: none;
+    background-image:
+      linear-gradient(45deg, transparent 50%, var(--text-secondary) 50%),
+      linear-gradient(135deg, var(--text-secondary) 50%, transparent 50%);
+    background-position:
+      calc(100% - 17px) 50%,
+      calc(100% - 12px) 50%;
+    background-repeat: no-repeat;
+    background-size: 5px 5px, 5px 5px;
+  }
+
+  .preference-checkbox input {
+    margin: 0 9px 0 0;
+  }
+
+  .preference-save-note {
+    padding-top: 10px;
+    border-top: 1px solid var(--border-color);
+    font-size: 12px;
+  }
+
+  .preference-error {
+    color: var(--accent-warning);
+  }
+
+  .preference-restart-notice {
+    color: var(--accent-warning);
+  }
+
+  .preferences-footer {
+    display: flex;
+    width: 100%;
+    align-items: center;
+    justify-content: space-between;
+  }
+
+  .preference-status {
+    padding-right: 14px;
+    color: var(--text-secondary);
+    font-size: 12px;
+    text-align: left;
+  }
+
+  .preference-actions {
+    flex: none;
+  }
+
+  .modal-footer .btn + .btn {
+    margin-left: 7px;
   }
 
   .logo-section {
@@ -34,7 +196,7 @@
   }
 
   .contributor-section {
-    overflow: auto;
+    overflow: visible;
     min-height: 150px;
     border-radius: 5px;
     padding: 0 20px;
@@ -43,8 +205,8 @@
   }
 
   .license-section {
-    overflow: auto;
-    flex: auto;
+    overflow: visible;
+    flex: none;
     margin-bottom: 20px;
     border-radius: 5px;
     padding: 0 20px;
@@ -91,10 +253,6 @@
     cursor: pointer;
   }
 
-  .modal-sm {
-    width: 375px;
-  }
-
   .logo-sub {
     margin: 0 5px;
   }
diff --git a/app/utilities/config/preferences.js b/app/utilities/config/preferences.js
new file mode 100644
index 00000000..c9926e16
--- /dev/null
+++ b/app/utilities/config/preferences.js
@@ -0,0 +1,118 @@
+const { getSupportedLocales } = require('../i18n')
+
+const THEMES = [
+  'light',
+  'dark',
+  'one-dark',
+  'atom-one-dark',
+  'github-light',
+  'github-dark',
+  'catppuccin-latte',
+  'catppuccin-mocha',
+  'solarized-light',
+  'solarized-dark',
+  'dracula',
+  'material-theme',
+  'ayu'
+]
+
+const booleanKeys = new Set([
+  'autoUpdate',
+  'startAtLogin',
+  'window:closeToTray',
+  'window:minimizeToTray',
+  'userPanel:hideProfilePhoto',
+  'proxy:enable',
+  'snippet:sortingReverse',
+  'snippet:expanded',
+  'snippet:newSnippetPrivate',
+  'snippet:downloadAll',
+  'tag:showInSnippetList',
+  'tag:colored',
+  'editor:validateFilename',
+  'enterprise:enable',
+  'notifications:success',
+  'notifications:failure'
+])
+
+const shortcutKeys = [
+  'keyShortcutForSearch', 'keyNewGist', 'keyEditGist', 'keyDeleteGist',
+  'keySubmitGist', 'keyImmersiveMode', 'keyAboutPage', 'keyDashboard', 'keySyncGists'
+].map(key => `shortcuts:${key}`)
+
+const stringKeys = new Set([
+  'proxy:address',
+  'enterprise:host',
+  'enterprise:token',
+  'enterprise:avatarUrl',
+  ...shortcutKeys
+])
+
+const APPLY_MODES = {
+  IMMEDIATE: 'immediate',
+  NEXT_USE: 'next-use',
+  RESTART: 'restart'
+}
+
+function metadataForKeys (keys, applyMode) {
+  return keys.reduce((metadata, key) => {
+    metadata[key] = { applyMode }
+    return metadata
+  }, {})
+}
+
+const preferenceMetadata = {
+  ...metadataForKeys([
+    'theme', 'autoUpdate', 'startAtLogin', 'zoom:percent', 'logger:level', ...shortcutKeys
+  ], APPLY_MODES.IMMEDIATE),
+  ...metadataForKeys([
+    'window:closeToTray', 'window:minimizeToTray', 'security:cachedAccessTokenStorage',
+    'snippet:sorting', 'snippet:sortingReverse', 'snippet:downloadAll',
+    'tag:showInSnippetList', 'tag:colored', 'editor:validateFilename',
+    'notifications:success', 'notifications:failure'
+  ], APPLY_MODES.NEXT_USE),
+  ...metadataForKeys([
+    'i18n:locale', 'avatar:type', 'avatar:boringAvatarVariant', 'userPanel:hideProfilePhoto',
+    'proxy:enable', 'proxy:address', 'snippet:expanded', 'snippet:newSnippetPrivate',
+    'editor:tabSize', 'enterprise:enable', 'enterprise:host', 'enterprise:token',
+    'enterprise:avatarUrl'
+  ], APPLY_MODES.RESTART)
+}
+
+const writableConfigKeys = new Set(Object.keys(preferenceMetadata))
+
+function preferenceRequiresRestart (key) {
+  return Boolean(preferenceMetadata[key] && preferenceMetadata[key].applyMode === APPLY_MODES.RESTART)
+}
+
+function isValidPreferenceValue (key, value) {
+  if (!writableConfigKeys.has(key)) return false
+  if (booleanKeys.has(key)) return typeof value === 'boolean'
+  if (stringKeys.has(key)) {
+    if (typeof value !== 'string' || value.length > 500) return false
+    return !key.startsWith('shortcuts:') || value.trim().length > 0
+  }
+  if (key === 'theme') return THEMES.includes(value)
+  if (key === 'i18n:locale') {
+    return getSupportedLocales().some(locale => locale.code === value)
+  }
+  if (key === 'editor:tabSize') {
+    return Number.isInteger(value) && [2, 4, 8].includes(value)
+  }
+  if (key === 'zoom:percent') return Number.isInteger(value) && value >= 50 && value <= 300
+  if (key === 'avatar:type') return ['github', 'boring'].includes(value)
+  if (key === 'avatar:boringAvatarVariant') return ['beam', 'marble', 'pixel', 'sunset', 'ring', 'bauhaus'].includes(value)
+  if (key === 'logger:level') return ['debug', 'info', 'warn', 'error'].includes(value)
+  if (key === 'security:cachedAccessTokenStorage') return ['auto', 'encrypted', 'file'].includes(value)
+  if (key === 'snippet:sorting') return ['updated_at', 'created_at', 'description'].includes(value)
+  return false
+}
+
+module.exports = {
+  APPLY_MODES,
+  isValidPreferenceValue,
+  preferenceMetadata,
+  preferenceRequiresRestart,
+  THEMES,
+  writableConfigKeys
+}
diff --git a/app/utilities/electronBridge/index.js b/app/utilities/electronBridge/index.js
index 5fda629d..9a49b654 100644
--- a/app/utilities/electronBridge/index.js
+++ b/app/utilities/electronBridge/index.js
@@ -34,6 +34,9 @@ function createUnavailableBridge () {
       getAccessToken: unavailableBridgeMethod,
       setAccessToken: unavailableBridgeMethod
     },
+    dialog: {
+      showMessage: unavailableBridgeMethod
+    },
     files: {
       ensureConfigFile: unavailableBridgeMethod
     },
diff --git a/build/icon/icon.png b/build/icon/icon.png
index 11378583..04bfcc6f 100644
Binary files a/build/icon/icon.png and b/build/icon/icon.png differ
diff --git a/docs/img/app-icon.png b/docs/img/app-icon.png
index 11378583..04bfcc6f 100644
Binary files a/docs/img/app-icon.png and b/docs/img/app-icon.png differ
diff --git a/docs/img/portfolio/find-in-page.png b/docs/img/portfolio/find-in-page.png
index 418d3cdf..afc0e5df 100644
Binary files a/docs/img/portfolio/find-in-page.png and b/docs/img/portfolio/find-in-page.png differ
diff --git a/docs/img/portfolio/preferences.png b/docs/img/portfolio/preferences.png
new file mode 100644
index 00000000..65000c95
Binary files /dev/null and b/docs/img/portfolio/preferences.png differ
diff --git a/docs/img/pr-669/draft-available.png b/docs/img/pr-669/draft-available.png
index dbb2766f..cc4e63a7 100644
Binary files a/docs/img/pr-669/draft-available.png and b/docs/img/pr-669/draft-available.png differ
diff --git a/docs/img/pr-669/draft-loaded.png b/docs/img/pr-669/draft-loaded.png
index fc348ec2..33c86039 100644
Binary files a/docs/img/pr-669/draft-loaded.png and b/docs/img/pr-669/draft-loaded.png differ
diff --git a/main.js b/main.js
index e90b0b77..c3868246 100755
--- a/main.js
+++ b/main.js
@@ -40,6 +40,9 @@ const {
   clearGitHubAuthWindowStorageAndDestroy
 } = require('./app/utilities/auth/githubAuthWindow')
 const { applyDefaultZoomPercent } = require('./app/utilities/zoom')
+const {
+  isValidPreferenceValue
+} = require('./app/utilities/config/preferences')
 
 const logger = createMainLogger()
 const electronLocalStorage = createElectronLocalStorage({
@@ -80,8 +83,6 @@ let operationType = 0
 
 const MACOS_TRAY_ICON_SIZE = 18
 
-const shortcuts = nconf.get('shortcuts')
-
 function getConfigPath() {
   if (process && process.env && process.env.XDG_CONFIG_HOME) {
     return path.join(process.env.XDG_CONFIG_HOME, '.leptonrc')
@@ -345,6 +346,7 @@ function handleNonMacWindowClose (e, win) {
 }
 
 function setUpApplicationMenu () {
+  const shortcuts = nconf.get('shortcuts')
   // Create the Application's main menu
   let { buildMainMenuTemplate } = require('./app/utilities/menu/mainMenu')
   let gistMenu = {
@@ -414,8 +416,6 @@ function setUpApplicationMenu () {
 function setUpBridgeIpcHandlers () {
   const loggerMethods = new Set(['debug', 'error', 'info', 'warn'])
   const appPathNames = new Set(['appData', 'home', 'temp', 'userData'])
-  const writableConfigKeys = new Set(['i18n:locale'])
-
   function isAllowedConfigKey (key) {
     if (typeof key !== 'string' || key.length === 0) return false
     const rootKey = key.split(':')[0]
@@ -505,7 +505,7 @@ function setUpBridgeIpcHandlers () {
   })
 
   ipcMain.handle('lepton:config:set', (event, key, value) => {
-    if (!isMainWindowSender(event) || !writableConfigKeys.has(key)) {
+    if (!isMainWindowSender(event) || !isValidPreferenceValue(key, value)) {
       logger.warn(`[bridge] Rejected config write for "${key}"`)
       return undefined
     }
@@ -513,13 +513,31 @@ function setUpBridgeIpcHandlers () {
     const persistedValue = key === 'i18n:locale' ? configureI18n(value) : value
     nconf.set(key, persistedValue)
     writeConfigValue(key, persistedValue)
-    setUpApplicationMenu()
-    if (key !== 'i18n:locale' && mainWindow && !mainWindow.isDestroyed()) {
-      mainWindow.reload()
+    if (key === 'autoUpdate') autoUpdater.autoDownload = persistedValue
+    if (key === 'startAtLogin') {
+      applyStartAtLoginSetting({ app, enabled: persistedValue, logger })
+    }
+    if (key === 'logger:level') logger.level = persistedValue
+    if (key === 'zoom:percent' && mainWindow && !mainWindow.isDestroyed()) {
+      applyDefaultZoomPercent({ webContents: mainWindow.webContents, percent: persistedValue, logger })
     }
+    setUpApplicationMenu()
     return persistedValue
   })
 
+  ipcMain.handle('lepton:dialog:show-message', (event, options = {}) => {
+    if (!isMainWindowSender(event)) return undefined
+    const title = typeof options.title === 'string' ? options.title.slice(0, 100) : appInfo.name
+    const message = typeof options.message === 'string' ? options.message.slice(0, 500) : ''
+    if (!message) return undefined
+    return dialog.showMessageBox(mainWindow, {
+      type: 'info',
+      title,
+      message,
+      buttons: ['OK']
+    })
+  })
+
   ipcMain.on('lepton:account:get', (event) => {
     if (!isMainWindowSender(event)) {
       event.returnValue = {}
diff --git a/preload.js b/preload.js
index f1f6f0ad..95f9f03b 100644
--- a/preload.js
+++ b/preload.js
@@ -43,6 +43,9 @@ const leptonApi = {
     getAccessToken: () => ipcRenderer.sendSync('lepton:credentials:get-access-token'),
     setAccessToken: (token) => ipcRenderer.sendSync('lepton:credentials:set-access-token', token)
   },
+  dialog: {
+    showMessage: (options) => ipcRenderer.invoke('lepton:dialog:show-message', options)
+  },
   files: {
     ensureConfigFile: (defaults) => ipcRenderer.invoke('lepton:files:ensure-config', defaults)
   },
diff --git a/tests/smoke/electron-render-smoke.js b/tests/smoke/electron-render-smoke.js
index 00919c6d..427c1b23 100644
--- a/tests/smoke/electron-render-smoke.js
+++ b/tests/smoke/electron-render-smoke.js
@@ -56,7 +56,8 @@ const RENDER_FIXTURES = [
   {
     name: 'about',
     selector: '.about-modal .modal-title',
-    text: 'About'
+    text: 'Settings|Preferences|Cancel|Apply|Save',
+    forbiddenSelector: '.preferences-section h3'
   },
   {
     name: 'dashboard',
diff --git a/tests/utilities/preferences.test.js b/tests/utilities/preferences.test.js
new file mode 100644
index 00000000..fca5726e
--- /dev/null
+++ b/tests/utilities/preferences.test.js
@@ -0,0 +1,50 @@
+import { createRequire } from 'node:module'
+import { describe, expect, it } from 'vitest'
+
+const require = createRequire(import.meta.url)
+const {
+  APPLY_MODES,
+  isValidPreferenceValue,
+  preferenceMetadata,
+  preferenceRequiresRestart,
+  writableConfigKeys
+} = require('../../app/utilities/config/preferences')
+
+describe('preferences config boundary', () => {
+  it('allowlists the preference page settings', () => {
+    expect([...writableConfigKeys]).toEqual(expect.arrayContaining([
+      'theme',
+      'i18n:locale',
+      'snippet:downloadAll',
+      'editor:tabSize',
+      'proxy:address',
+      'enterprise:token',
+      'shortcuts:keyAboutPage'
+    ]))
+  })
+
+  it('defines application behavior for every writable preference', () => {
+    expect(Object.keys(preferenceMetadata).sort()).toEqual([...writableConfigKeys].sort())
+    expect(preferenceMetadata.theme.applyMode).toBe(APPLY_MODES.IMMEDIATE)
+    expect(preferenceMetadata['snippet:downloadAll'].applyMode).toBe(APPLY_MODES.NEXT_USE)
+    expect(preferenceRequiresRestart('i18n:locale')).toBe(true)
+    expect(preferenceRequiresRestart('proxy:address')).toBe(true)
+    expect(preferenceRequiresRestart('notifications:success')).toBe(false)
+    expect(preferenceRequiresRestart('unknown:key')).toBe(false)
+  })
+
+  it('validates values before writing .leptonrc', () => {
+    expect(isValidPreferenceValue('theme', 'github-dark')).toBe(true)
+    expect(isValidPreferenceValue('i18n:locale', 'fr')).toBe(true)
+    expect(isValidPreferenceValue('editor:tabSize', 4)).toBe(true)
+    expect(isValidPreferenceValue('notifications:success', false)).toBe(true)
+    expect(isValidPreferenceValue('zoom:percent', 120)).toBe(true)
+    expect(isValidPreferenceValue('proxy:address', 'pac+https://example.com/proxy.pac')).toBe(true)
+    expect(isValidPreferenceValue('shortcuts:keyAboutPage', 'CommandOrControl+,')).toBe(true)
+    expect(isValidPreferenceValue('theme', 'unknown')).toBe(false)
+    expect(isValidPreferenceValue('editor:tabSize', 3)).toBe(false)
+    expect(isValidPreferenceValue('zoom:percent', 400)).toBe(false)
+    expect(isValidPreferenceValue('shortcuts:keyAboutPage', '')).toBe(false)
+    expect(isValidPreferenceValue('unknown:key', 'secret')).toBe(false)
+  })
+})