diff --git a/.eslintrc b/.eslintrc
index 50fa8f0..cb4c5c4 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -3,12 +3,12 @@
     "ignorePatterns": ["**/*.min.js"],
     "env": {
         "browser": true,
-        "es6": true,
+        "es2022": true,
         "jquery": true,
         "webextensions": true
     },
     "parserOptions": {
-        "ecmaVersion": 2020
+        "ecmaVersion": 13
     },
     "rules": {
         "array-bracket-spacing": ["error", "always"],
@@ -101,6 +101,7 @@
         "DatabaseState": true,
         "debugLogMessage": true,
         "EXTENSION_NAME": true,
+        "getCurrentTab": true,
         "getTopLevelDomainFromUrl": true,
         "httpAuth": true,
         "Icon": true,
diff --git a/keepassxc-browser/background/browserAction.js b/keepassxc-browser/background/browserAction.js
index 149673b..d724eaa 100755
--- a/keepassxc-browser/background/browserAction.js
+++ b/keepassxc-browser/background/browserAction.js
@@ -3,10 +3,7 @@
 const browserAction = {};
 
 browserAction.show = function(tab, popupData) {
-    if (!popupData) {
-        popupData = page.popupData;
-    }
-
+    popupData ??= page.popupData;
     page.popupData = popupData;
 
     browser.browserAction.setIcon({
@@ -38,13 +35,9 @@ browserAction.showDefault = async function(tab) {
     }
 
     // Get the current tab if no tab given
+    tab ??= await getCurrentTab();
     if (!tab) {
-        const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-        if (tabs.length === 0) {
-            return;
-        }
-
-        tab = tabs[0];
+        return;
     }
 
     if (page.tabs[tab.id]?.loginList.length > 0) {
@@ -65,10 +58,7 @@ browserAction.generateIconName = function(iconType) {
 
 browserAction.ignoreSite = async function(url) {
     await browser.windows.getCurrent();
-
-    // Get current active window
-    const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-    const tab = tabs[0];
+    const tab = await getCurrentTab();
 
     // Send the message to the current tab's content script
     await browser.runtime.getBackgroundPage();
diff --git a/keepassxc-browser/background/client.js b/keepassxc-browser/background/client.js
index bb7f194..fe6800d 100644
--- a/keepassxc-browser/background/client.js
+++ b/keepassxc-browser/background/client.js
@@ -81,7 +81,7 @@ keepassClient.sendNativeMessage = function(request, enableTimeout = false, timeo
 
         const listener = ((port, action) => {
             const handler = (msg) => {
-                if (msg && msg.action === action) {
+                if (msg && msg?.action === action) {
                     // If the request has a separate requestID, check if it matches when there's no nonce (an error message)
                     const isNotificationOrError = !msg.nonce && request.requestID === msg.requestID;
 
diff --git a/keepassxc-browser/background/event.js b/keepassxc-browser/background/event.js
index 459d5c4..ec14232 100755
--- a/keepassxc-browser/background/event.js
+++ b/keepassxc-browser/background/event.js
@@ -4,7 +4,7 @@ const kpxcEvent = {};
 
 kpxcEvent.onMessage = async function(request, sender) {
     if (request.action in kpxcEvent.messageHandlers) {
-        if (!sender.hasOwnProperty('tab') || sender.tab.id < 1) {
+        if (!Object.hasOwn(sender, 'tab') || sender.tab.id < 1) {
             sender.tab = {};
             sender.tab.id = page.currentTabId;
         }
@@ -56,8 +56,8 @@ kpxcEvent.onLoadKeyRing = async function() {
     keepass.keyRing = item.keyRing;
     if (keepass.isAssociated() && !keepass.keyRing[keepass.associated.hash]) {
         keepass.associated = {
-            'value': false,
-            'hash': null
+            value: false,
+            hash: null
         };
     }
 
@@ -113,7 +113,7 @@ kpxcEvent.lockDatabase = async function(tab) {
 };
 
 kpxcEvent.onGetTabInformation = async function(tab) {
-    const id = tab.id || page.currentTabId;
+    const id = tab?.id || page.currentTabId;
     return page.tabs[id];
 };
 
@@ -143,7 +143,7 @@ kpxcEvent.onUpdateAvailableKeePassXC = async function() {
 };
 
 kpxcEvent.onRemoveCredentialsFromTabInformation = async function(tab) {
-    const id = tab.id || page.currentTabId;
+    const id = tab?.id || page.currentTabId;
     page.clearCredentials(id);
     page.clearSubmittedCredentials();
 };
diff --git a/keepassxc-browser/background/init.js b/keepassxc-browser/background/init.js
index 6d84218..80cfc8f 100644
--- a/keepassxc-browser/background/init.js
+++ b/keepassxc-browser/background/init.js
@@ -21,14 +21,14 @@
  * @param {object} tab
  */
 browser.tabs.onCreated.addListener((tab) => {
-    if (tab.id > 0) {
-        if (tab.selected) {
-            page.currentTabId = tab.id;
-            if (!page.tabs[tab.id]) {
-                page.createTabEntry(tab.id);
-            }
-            page.switchTab(tab);
+    if (tab?.id > 0 && tab?.selected) {
+        page.currentTabId = tab.id;
+
+        if (!page.tabs[tab.id]) {
+            page.createTabEntry(tab.id);
         }
+
+        page.switchTab(tab);
     }
 });
 
@@ -39,12 +39,8 @@ browser.tabs.onCreated.addListener((tab) => {
  */
 browser.tabs.onRemoved.addListener(async function(tabId, removeInfo) {
     if (page.currentTabId === tabId) {
-        const activeTabs = await browser.tabs.query({ active: true, currentWindow: true });
-        if (activeTabs.length > 0) {
-            page.currentTabId = activeTabs[0].id;
-        } else {
-            page.currentTabId = -1;
-        }
+        const currentTab = await getCurrentTab();
+        page.currentTabId = currentTab ? currentTab.id : -1;
     }
     delete page.tabs[tabId];
 });
@@ -97,8 +93,7 @@ browser.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  * @param {object} details
  */
 browser.webNavigation.onCommitted.addListener((details) => {
-    if ((details.transitionQualifiers.length > 0 && details.transitionQualifiers[0] === 'client_redirect')
-        || details.transitionType === 'form_submit') {
+    if (details.transitionQualifiers?.[0] === 'client_redirect' || details.transitionType === 'form_submit') {
         page.redirectCount += 1;
         return;
     }
@@ -153,9 +148,9 @@ browser.commands.onCommand.addListener(async (command) => {
         || command === 'choose_credential_fields'
         || command === 'retrive_credentials_forced'
         || command === 'reload_extension') {
-        const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-        if (tabs.length) {
-            browser.tabs.sendMessage(tabs[0].id, { action: command });
+        const tab = await getCurrentTab();
+        if (tab) {
+            browser.tabs.sendMessage(tab.id, { action: command });
         }
     }
 });
diff --git a/keepassxc-browser/background/keepass.js b/keepassxc-browser/background/keepass.js
index 82ad4d1..ee15d32 100755
--- a/keepassxc-browser/background/keepass.js
+++ b/keepassxc-browser/background/keepass.js
@@ -15,8 +15,6 @@ keepass.latestVersionUrl = 'https://api.github.com/repos/keepassxreboot/keepassx
 keepass.cacheTimeout = 30 * 1000; // Milliseconds
 keepass.databaseHash = '';
 keepass.previousDatabaseHash = '';
-keepass.keyId = 'keepassxc-browser-cryptokey-name';
-keepass.keyBody = 'keepassxc-browser-key';
 keepass.reconnectLoop = null;
 
 const kpActions = {
@@ -644,7 +642,7 @@ keepass.migrateKeyRing = function() {
 };
 
 keepass.saveKey = function(hash, id, key) {
-    if (!(hash in keepass.keyRing)) {
+    if (!Object.hasOwn(keepass.keyRing, hash)) {
         keepass.keyRing[hash] = {
             id: id,
             key: key,
@@ -663,7 +661,7 @@ keepass.saveKey = function(hash, id, key) {
 };
 
 keepass.updateLastUsed = function(hash) {
-    if ((hash in keepass.keyRing)) {
+    if (Object.hasOwn(keepass.keyRing, hash)) {
         keepass.keyRing[hash].lastUsed = new Date().valueOf();
         browser.storage.local.set({ 'keyRing': keepass.keyRing });
     }
@@ -691,6 +689,7 @@ keepass.deleteKey = function(hash) {
 keepass.getCryptoKey = function() {
     let dbkey = null;
     let dbid = null;
+
     if (!(keepass.databaseHash in keepass.keyRing)) {
         return [ dbid, dbkey ];
     }
@@ -712,7 +711,7 @@ keepass.setCryptoKey = function(id, key) {
 // Connection
 //--------------------------------------------------------------------------
 
-keepass.enableAutomaticReconnect = function() {
+keepass.enableAutomaticReconnect = async function() {
     // Disable for Windows if KeePassXC is older than 2.3.4
     if (!page.settings.autoReconnect
         || (navigator.platform.toLowerCase().includes('win')
@@ -767,7 +766,7 @@ keepass.generateNewKeyPair = function() {
 keepass.isConfigured = async function() {
     if (typeof(keepass.databaseHash) === 'undefined') {
         const hash = keepass.getDatabaseHash();
-        return hash in keepass.keyRing;
+        return Object.hasOwn(keepass.keyRing, hash);
     }
 
     return keepass.databaseHash in keepass.keyRing;
@@ -870,10 +869,10 @@ keepass.updateDatabase = async function() {
 
 keepass.updateDatabaseHashToContent = async function() {
     try {
-        const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-        if (tabs.length) {
+        const tab = await getCurrentTab();
+        if (tab) {
             // Send message to content script
-            browser.tabs.sendMessage(tabs[0].id, {
+            browser.tabs.sendMessage(tab.id, {
                 action: 'check_database_hash',
                 hash: { old: keepass.previousDatabaseHash, new: keepass.databaseHash },
                 connected: keepass.isKeePassXCAvailable
diff --git a/keepassxc-browser/background/page.js b/keepassxc-browser/background/page.js
index fe1aec7..d787818 100755
--- a/keepassxc-browser/background/page.js
+++ b/keepassxc-browser/background/page.js
@@ -58,116 +58,11 @@ page.initSettings = async function() {
         page.settings = item.settings;
         page.settings.autoReconnect = false;
 
-        if (!('afterFillSorting' in page.settings)) {
-            page.settings.afterFillSorting = defaultSettings.afterFillSorting;
-        }
-
-        if (!('afterFillSortingTotp' in page.settings)) {
-            page.settings.afterFillSortingTotp = defaultSettings.afterFillSortingTotp;
-        }
-
-        if (!('autoCompleteUsernames' in page.settings)) {
-            page.settings.autoCompleteUsernames = defaultSettings.autoCompleteUsernames;
-        }
-
-        if (!('showGroupNameInAutocomplete' in page.settings)) {
-            page.settings.showGroupNameInAutocomplete = defaultSettings.showGroupNameInAutocomplete;
-        }
-
-        if (!('autoFillAndSend' in page.settings)) {
-            page.settings.autoFillAndSend = defaultSettings.autoFillAndSend;
-        }
-
-        if (!('autoFillSingleEntry' in page.settings)) {
-            page.settings.autoFillSingleEntry = defaultSettings.autoFillSingleEntry;
-        }
-
-        if (!('autoRetrieveCredentials' in page.settings)) {
-            page.settings.autoRetrieveCredentials = defaultSettings.autoRetrieveCredentials;
-        }
-
-        if (!('autoSubmit' in page.settings)) {
-            page.settings.autoSubmit = defaultSettings.autoSubmit;
-        }
-
-        if (!('checkUpdateKeePassXC' in page.settings)) {
-            page.settings.checkUpdateKeePassXC = defaultSettings.checkUpdateKeePassXC;
-        }
-
-        if (!('colorTheme' in page.settings)) {
-            page.settings.colorTheme = defaultSettings.colorTheme;
-        }
-
-        if (!('clearCredentialsTimeout' in page.settings)) {
-            page.settings.clearCredentialsTimeout = defaultSettings.clearCredentialsTimeout;
-        }
-
-        if (!('credentialSorting' in page.settings)) {
-            page.settings.credentialSorting = defaultSettings.credentialSorting;
-        }
-
-        if (!('debugLogging' in page.settings)) {
-            page.settings.debugLogging = defaultSettings.debugLogging;
-        }
-
-        if (!('defaultGroup' in page.settings)) {
-            page.settings.defaultGroup = defaultSettings.defaultGroup;
-        }
-
-        if (!('defaultGroupAlwaysAsk' in page.settings)) {
-            page.settings.defaultGroupAlwaysAsk = defaultSettings.defaultGroupAlwaysAsk;
-        }
-
-        if (!('downloadFaviconAfterSave' in page.settings)) {
-            page.settings.downloadFaviconAfterSave = defaultSettings.downloadFaviconAfterSave;
-        }
-
-        if (!('redirectAllowance' in page.settings)) {
-            page.settings.redirectAllowance = defaultSettings.redirectAllowance;
-        }
-
-        if (!('saveDomainOnly' in page.settings)) {
-            page.settings.saveDomainOnly = defaultSettings.saveDomainOnly;
-        }
-
-        if (!('showGettingStartedGuideAlert' in page.settings)) {
-            page.settings.showGettingStartedGuideAlert = defaultSettings.showGettingStartedGuideAlert;
-        }
-
-        if (!('showTroubleshootingGuideAlert' in page.settings)) {
-            page.settings.showTroubleshootingGuideAlert = defaultSettings.showTroubleshootingGuideAlert;
-        }
-
-        if (!('showLoginFormIcon' in page.settings)) {
-            page.settings.showLoginFormIcon = defaultSettings.showLoginFormIcon;
-        }
-
-        if (!('showLoginNotifications' in page.settings)) {
-            page.settings.showLoginNotifications = defaultSettings.showLoginNotifications;
-        }
-
-        if (!('showNotifications' in page.settings)) {
-            page.settings.showNotifications = defaultSettings.showNotifications;
-        }
-
-        if (!('showOTPIcon' in page.settings)) {
-            page.settings.showOTPIcon = defaultSettings.showOTPIcon;
-        }
-
-        if (!('usePasswordGeneratorIcons' in page.settings)) {
-            page.settings.usePasswordGeneratorIcons = defaultSettings.usePasswordGeneratorIcons;
-        }
-
-        if (!('useObserver' in page.settings)) {
-            page.settings.useObserver = defaultSettings.useObserver;
-        }
-
-        if (!('usePasswordGeneratorIcons' in page.settings)) {
-            page.settings.usePasswordGeneratorIcons = defaultSettings.usePasswordGeneratorIcons;
-        }
-
-        if (!('usePredefinedSites' in page.settings)) {
-            page.settings.usePredefinedSites = defaultSettings.usePredefinedSites;
+        // Set default settings if needed
+        for (const [ key, value ] of Object.entries(defaultSettings)) {
+            if (!Object.hasOwn(page.settings, key)) {
+                page.settings[key] = value;
+            }
         }
 
         await browser.storage.local.set({ 'settings': page.settings });
@@ -186,13 +81,13 @@ page.initOpenedTabs = async function() {
         }
 
         // Set initial tab-ID
-        const currentTabs = await browser.tabs.query({ active: true, currentWindow: true });
-        if (currentTabs.length === 0) {
+        const currentTab = await getCurrentTab();
+        if (!currentTab) {
             return;
         }
 
-        page.currentTabId = currentTabs[0].id;
-        browserAction.showDefault(currentTabs[0]);
+        page.currentTabId = currentTab.id;
+        browserAction.showDefault(currentTab);
     } catch (err) {
         logError('page.initOpenedTabs error: ' + err);
         return Promise.reject();
@@ -372,11 +267,7 @@ page.setAutoSubmitPerformed = async function(tab) {
 };
 
 page.getLoginList = async function(tab) {
-    if (page.tabs[tab.id]) {
-        return page.tabs[tab.id].loginList;
-    }
-
-    return [];
+    return page.tabs[tab.id] ? page.tabs[tab.id].loginList : [];
 };
 
 page.fillHttpAuth = async function(tab, credentials) {
@@ -410,8 +301,8 @@ page.updateContextMenu = async function(tab, credentials) {
             // Show username inside [] if there are KPH attributes inside multiple credentials
             const attributeName = Object.keys(attribute)[0].slice(5);
             const finalName = credentials.length > 1
-                       ? `[${cred.login}] ${attributeName}`
-                       : attributeName;
+                            ? `[${cred.login}] ${attributeName}`
+                            : attributeName;
 
             page.attributeMenuItemIds.push(createContextMenuItem({
                 action: 'fill_attribute',
diff --git a/keepassxc-browser/common/global.js b/keepassxc-browser/common/global.js
index 65a5c4a..fe84b65 100755
--- a/keepassxc-browser/common/global.js
+++ b/keepassxc-browser/common/global.js
@@ -148,12 +148,17 @@ const logError = function(message) {
 // Returns file name and line number from error stack
 const getFileAndLine = function() {
     const err = new Error().stack.split('\n');
-    const line = err[4] ?? err[err.length - 1];
+    const line = err[4] ?? err.at(-1);
     const result = line.substring(line.lastIndexOf('/') + 1, line.lastIndexOf(':'));
 
     return result;
 };
 
+const getCurrentTab = async function() {
+    const tabs = await browser.tabs.query({ active: true, currentWindow: true });
+    return tabs.length > 0 ? tabs[0] : undefined;
+};
+
 HTMLElement.prototype.show = function() {
     this.style.display = 'block';
 };
diff --git a/keepassxc-browser/common/sites.js b/keepassxc-browser/common/sites.js
index a4c4f24..a695037 100644
--- a/keepassxc-browser/common/sites.js
+++ b/keepassxc-browser/common/sites.js
@@ -172,7 +172,7 @@ kpxcSites.formSubmitButtonExceptionFound = function(form) {
             'login.microsoftonline.us',
         ].some(u => form.action.includes(u))) {
         const buttons = Array.from(form.querySelectorAll(kpxcForm.formButtonQuery));
-        if (buttons && buttons.length > 1) {
+        if (buttons?.length > 1) {
             return buttons[1];
         }
     }
@@ -186,7 +186,7 @@ kpxcSites.formSubmitButtonExceptionFound = function(form) {
  * @returns {boolean}       True if exception found
  */
 kpxcSites.popupExceptionFound = function(combinations) {
-    if (combinations.length > 1 && combinations[0].form && combinations[0].form.action.startsWith(googleUrl)) {
+    if (combinations?.[0].form?.action.startsWith(googleUrl)) {
         return true;
     }
 
diff --git a/keepassxc-browser/content/banner.js b/keepassxc-browser/content/banner.js
index 2338ea9..ce1e799 100644
--- a/keepassxc-browser/content/banner.js
+++ b/keepassxc-browser/content/banner.js
@@ -61,9 +61,9 @@ kpxcBanner.create = async function(credentials = {}) {
     const usernameText = kpxcUI.createElement('span', 'small', {}, tr('popupUsername') + ' ');
     const usernameSpan = kpxcUI.createElement('span', 'small info information-username', {}, credentials.username);
 
-    const newButton = kpxcUI.createElement('button', 'kpxc-button kpxc-green-button', { 'id': 'kpxc-banner-btn-new' }, tr('popupButtonNew'));
-    const updateButton = kpxcUI.createElement('button', 'kpxc-button kpxc-orange-button', { 'id': 'kpxc-banner-btn-update' }, tr('popupButtonUpdate'));
-    const dismissButton = kpxcUI.createElement('button', 'kpxc-button kpxc-red-button', { 'id': 'kpxc-banner-btn-dismiss' }, tr('popupButtonDismiss'));
+    const newButton = kpxcUI.createElement('button', GREEN_BUTTON, { 'id': 'kpxc-banner-btn-new' }, tr('popupButtonNew'));
+    const updateButton = kpxcUI.createElement('button', ORANGE_BUTTON, { 'id': 'kpxc-banner-btn-update' }, tr('popupButtonUpdate'));
+    const dismissButton = kpxcUI.createElement('button', RED_BUTTON, { 'id': 'kpxc-banner-btn-dismiss' }, tr('popupButtonDismiss'));
 
     const separator = kpxcUI.createElement('div', 'kpxc-separator');
     const ignoreCheckbox = kpxcUI.createElement('input', 'kpxc-checkbox', { type: 'checkbox', name: 'ignoreCheckbox', id: 'kpxc-banner-ignoreCheckbox' });
@@ -238,11 +238,9 @@ kpxcBanner.saveNewCredentials = async function(credentials = {}) {
 
 kpxcBanner.updateCredentials = async function(credentials = {}) {
     //  Only one entry which could be updated
-    if (credentials.list.length === 1) {
+    if (credentials.list?.length === 1) {
         // Use the current username if it's empty
-        if (!credentials.username) {
-            credentials.username = credentials.list[0].login;
-        }
+        credentials.username ??= credentials.list[0].login;
 
         const res = await sendMessage('update_credentials', [ credentials.list[0].uuid, credentials.username, credentials.password, credentials.url ]);
         kpxcBanner.verifyResult(res);
@@ -259,8 +257,8 @@ kpxcBanner.updateCredentials = async function(credentials = {}) {
             kpxcBanner.shadowSelector('.kpxc-banner-dialog .username-exists').style.display = 'none';
         }
 
-        for (let i = 0; i < credentials.list.length; i++) {
-            const a = kpxcUI.createElement('a', 'list-group-item', { 'href': '#', 'entryId': i }, `${credentials.list[i].login} (${credentials.list[i].name})`);
+        for (const [ i, cred ] of credentials.list.entries()) {
+            const a = kpxcUI.createElement('a', 'list-group-item', { 'href': '#', 'entryId': i }, `${cred.login} (${cred.name})`);
             a.addEventListener('click', function(e) {
                 e.preventDefault();
                 if (!e.isTrusted) {
@@ -271,7 +269,7 @@ kpxcBanner.updateCredentials = async function(credentials = {}) {
 
                 // Use the current username if it's empty
                 if (!credentials.username) {
-                    credentials.username = credentials.list[entryId].login;
+                    credentials.username = cred.login;
                 }
 
                 let url = credentials.url;
@@ -292,7 +290,7 @@ kpxcBanner.updateCredentials = async function(credentials = {}) {
                 });
             });
 
-            if (credentials.usernameExists && credentials.username === credentials.list[i].login) {
+            if (credentials.usernameExists && credentials.username === cred.login) {
                 a.style.fontWeight = 'bold';
             }
 
diff --git a/keepassxc-browser/content/custom-fields-banner.js b/keepassxc-browser/content/custom-fields-banner.js
index b06ad8b..f811e26 100644
--- a/keepassxc-browser/content/custom-fields-banner.js
+++ b/keepassxc-browser/content/custom-fields-banner.js
@@ -6,12 +6,6 @@ const STEP_SELECT_PASSWORD = 2;
 const STEP_SELECT_TOTP = 3;
 const STEP_SELECT_STRING_FIELDS = 4;
 
-const BLUE_BUTTON = 'kpxc-button kpxc-blue-button';
-const GREEN_BUTTON = 'kpxc-button kpxc-green-button';
-const ORANGE_BUTTON = 'kpxc-button kpxc-orange-button';
-const RED_BUTTON = 'kpxc-button kpxc-red-button';
-const GRAY_BUTTON_CLASS = 'kpxc-gray-button';
-
 const DEFINED_CUSTOM_FIELDS = 'defined-custom-fields';
 const FIXED_FIELD_CLASS = 'kpxcDefine-fixed-field';
 const DARK_FIXED_FIELD_CLASS = 'kpxcDefine-fixed-field-dark';
@@ -309,11 +303,11 @@ kpxcCustomLoginFieldsBanner.confirm = async function() {
     // If the new selection is already used in some other field, clear it
     const clearIdenticalField = function(path, location) {
         const currentSite = kpxc.settings[DEFINED_CUSTOM_FIELDS][location];
-        if (currentSite.username && currentSite.username[0] === path[0]) {
+        if (currentSite.username?.[0] === path[0]) {
             kpxc.settings[DEFINED_CUSTOM_FIELDS][location].username = undefined;
-        } else if (currentSite.password && currentSite.password[0] === path[0]) {
+        } else if (currentSite.password?.[0] === path[0]) {
             kpxc.settings[DEFINED_CUSTOM_FIELDS][location].password = undefined;
-        } else if (currentSite.totp && currentSite.totp[0] === path[0]) {
+        } else if (currentSite.totp?.[0] === path[0]) {
             kpxc.settings[DEFINED_CUSTOM_FIELDS][location].totp = undefined;
         }
     };
diff --git a/keepassxc-browser/content/fields.js b/keepassxc-browser/content/fields.js
index f0c5c93..e363643 100644
--- a/keepassxc-browser/content/fields.js
+++ b/keepassxc-browser/content/fields.js
@@ -111,9 +111,9 @@ kpxcFields.getSegmentedTOTPFields = function(inputs, combinations) {
             combinations.push(combination);
 
             // Create an icon to the right side of the segmented fields
-            kpxcTOTPIcons.newIcon(totpInputs[totpInputs.length - 1], kpxc.databaseState, true);
+            kpxcTOTPIcons.newIcon(totpInputs.at(-1), kpxc.databaseState, true);
             kpxcIcons.icons.push({
-                field: totpInputs[totpInputs.length - 1],
+                field: totpInputs.at(-1),
                 iconType: kpxcIcons.iconTypes.TOTP,
                 segmented: true
             });
@@ -272,7 +272,7 @@ kpxcFields.getIdFromProperties = function(target) {
         return `${target.nodeName} ${target.type} ${target.name} ${target.placeholder}`;
     }
 
-    if (target.classList && target.classList.length > 0) {
+    if (target.classList?.length > 0) {
         return `${target.nodeName} ${target.type} ${target.classList.value} ${target.placeholder}`;
     }
 
@@ -285,11 +285,11 @@ kpxcFields.getIdFromProperties = function(target) {
 
 // Legacy unique ID generation for converting
 kpxcFields.getLegacyId = function(target) {
-    if (target.classList.length > 0) {
+    if (target.classList?.length > 0) {
         return `${target.nodeName} ${target.type} ${target.classList.value} ${target.name} ${target.placeholder}`;
     }
 
-    if (target.id && target.id !== '') {
+    if (target.id && target?.id !== '') {
         return `${target.nodeName} ${target.type} ${kpxcFields.prepareId(target.id)} ${target.name} ${target.placeholder}`;
     }
 
@@ -316,14 +316,13 @@ kpxcFields.isCustomLoginFieldsUsed = function() {
 kpxcFields.isSearchForm = function(form) {
     // Check form action
     const formAction = form.getLowerCaseAttribute('action');
-    if (formAction && (formAction.includes('search') && !formAction.includes('research'))) {
+    if (formAction?.includes('search') && !formAction?.includes('research')) {
         return true;
     }
 
     // Ignore form with search classes
     const formId = form.getLowerCaseAttribute('id');
-    if (form.className && (form.className.includes('search')
-        || (formId && formId.includes('search') && !formId.includes('research')))) {
+    if (form.className?.includes('search') || (formId?.includes('search') && !formId?.includes('research'))) {
         return true;
     }
 
diff --git a/keepassxc-browser/content/fill.js b/keepassxc-browser/content/fill.js
index 5353a7c..8f7cb02 100644
--- a/keepassxc-browser/content/fill.js
+++ b/keepassxc-browser/content/fill.js
@@ -114,12 +114,12 @@ kpxcFill.fillFromTOTP = async function(target) {
     const el = target || document.activeElement;
     const credentialList = await kpxc.updateTOTPList();
 
-    if (credentialList && credentialList.length === 0) {
+    if (credentialList?.length === 0) {
         kpxcUI.createNotification('warning', tr('credentialsNoTOTPFound'));
         return;
     }
 
-    if (credentialList && credentialList.length === 1) {
+    if (credentialList?.length === 1) {
         kpxcFill.fillTOTPFromUuid(el, credentialList[0].uuid);
         return;
     }
@@ -140,7 +140,7 @@ kpxcFill.fillTOTPFromUuid = async function(el, uuid) {
         return;
     }
 
-    if (user.totp && user.totp.length > 0) {
+    if (user.totp?.length > 0) {
         // Retrieve a new TOTP value
         const totp = await sendMessage('get_totp', [ user.uuid, user.totp ]);
         if (!totp) {
@@ -149,7 +149,7 @@ kpxcFill.fillTOTPFromUuid = async function(el, uuid) {
         }
 
         kpxcFill.setTOTPValue(el, totp);
-    } else if (user.stringFields && user.stringFields.length > 0) {
+    } else if (user.stringFields?.length > 0) {
         const stringFields = user.stringFields;
         for (const s of stringFields) {
             const val = s['KPH: {TOTP}'];
@@ -168,7 +168,7 @@ kpxcFill.setTOTPValue = function(elem, val) {
     }
 
     for (const comb of kpxc.combinations) {
-        if (comb.totpInputs && comb.totpInputs.length > 0) {
+        if (comb.totpInputs?.length > 0) {
             kpxcFill.fillSegmentedTotp(elem, val, comb.totpInputs);
             return;
         }
@@ -223,10 +223,9 @@ kpxcFill.fillInCredentials = async function(combination, predefinedUsername, uui
 
     // Use predefined username as default
     let usernameValue = predefinedUsername;
-    if (!usernameValue) {
-        // With single password field the combination.password is used instead
-        usernameValue = combination.username ? combination.username.value : combination.password.value;
-    }
+
+    // With single password field the combination.password is used instead
+    usernameValue ??= combination.username ? combination.username.value : combination.password.value;
 
     // Find the correct credentials
     const selectedCredentials = kpxc.credentials.find(c => c.uuid === uuid);
@@ -262,7 +261,7 @@ kpxcFill.fillInCredentials = async function(combination, predefinedUsername, uui
     }
 
     // Fill StringFields
-    if (selectedCredentials.stringFields && selectedCredentials.stringFields.length > 0) {
+    if (selectedCredentials.stringFields?.length > 0) {
         kpxcFill.fillInStringFields(combination.fields, selectedCredentials.stringFields);
     }
 
@@ -278,7 +277,7 @@ kpxcFill.fillInCredentials = async function(combination, predefinedUsername, uui
 // Fills StringFields defined in Custom Fields
 kpxcFill.fillInStringFields = function(fields, stringFields) {
     const filledInFields = [];
-    if (fields && stringFields && fields.length > 0 && stringFields.length > 0) {
+    if (fields && stringFields && fields?.length > 0 && stringFields?.length > 0) {
         for (let i = 0; i < fields.length; i++) {
             if (i >= stringFields.length) {
                 continue;
diff --git a/keepassxc-browser/content/form.js b/keepassxc-browser/content/form.js
index b693f76..3e4c9bc 100644
--- a/keepassxc-browser/content/form.js
+++ b/keepassxc-browser/content/form.js
@@ -51,7 +51,7 @@ kpxcForm.getFormSubmitButton = function(form) {
     // If any formaction overriding the default action is set, ignore those buttons.
     const buttons = Array.from(form.querySelectorAll(kpxcForm.formButtonQuery)).filter(b => !b.getAttribute('formAction'));
     if (buttons.length > 0) {
-        return buttons[buttons.length - 1];
+        return buttons.at(-1);
     }
 
     // Try to find similar buttons outside the form which are added via 'form' property
diff --git a/keepassxc-browser/content/keepassxc-browser.js b/keepassxc-browser/content/keepassxc-browser.js
index 067a196..2d1c43c 100755
--- a/keepassxc-browser/content/keepassxc-browser.js
+++ b/keepassxc-browser/content/keepassxc-browser.js
@@ -153,7 +153,7 @@ kpxc.getFormActionUrl = function(combination) {
     }
 
     let action = null;
-    if (combination.form && combination.form.length > 0) {
+    if (combination.form?.length > 0) {
         action = combination.form.action;
     }
 
@@ -386,13 +386,13 @@ kpxc.initLoginPopup = function() {
 
     // Initialize login items
     const loginItems = [];
-    for (let i = 0; i < kpxc.credentials.length; i++) {
-        const loginItem = getLoginItem(kpxc.credentials[i], showGroupNameInAutocomplete, i);
+    for (const [ i, login ] of kpxc.credentials.entries()) {
+        const loginItem = getLoginItem(login, showGroupNameInAutocomplete, i);
 
         // Ignore a duplicate entry if the password is empty, but there's already a similar entry with a password.
         // An usual use case with TOTP in a separate database.
         const similarEntryFound = kpxc.credentials.some(c => c.password !== '' && c.login === loginItem.login);
-        if (kpxc.credentials[i].password === '' && similarEntryFound) {
+        if (login.password === '' && similarEntryFound) {
             continue;
         }
 
@@ -586,7 +586,7 @@ kpxc.retrieveCredentials = async function(force = false) {
 // Handles credentials from 'retrieve_credentials' response
 kpxc.retrieveCredentialsCallback = async function(credentials) {
     _called.retrieveCredentials = true;
-    if (credentials && credentials.length > 0) {
+    if (credentials?.length > 0) {
         kpxc.credentials = credentials;
         await kpxc.prepareCredentials();
     }
@@ -599,7 +599,7 @@ kpxc.retrieveCredentialsCallback = async function(credentials) {
 
     // Retrieve submitted credentials if available
     const creds = await sendMessage('page_get_submitted');
-    if (creds && creds.submitted) {
+    if (creds?.submitted) {
         await sendMessage('page_clear_submitted');
         kpxc.rememberCredentials(creds.username, creds.password, creds.url, creds.oldCredentials);
     }
diff --git a/keepassxc-browser/content/totp-field.js b/keepassxc-browser/content/totp-field.js
index 8a99aea..3192d35 100644
--- a/keepassxc-browser/content/totp-field.js
+++ b/keepassxc-browser/content/totp-field.js
@@ -54,8 +54,8 @@ kpxcTOTPIcons.isAcceptedTOTPField = function(field) {
     const placeholder = field.getLowerCaseAttribute('placeholder');
 
     // Checks if the field id, name or placeholder includes some of the acceptedOTPFields but not any from ignoredTypes
-    if ((acceptedOTPFields.some(f => (id && id.includes(f)) || (name && name.includes(f) || placeholder && placeholder.includes(f))) || acceptedParents.some(s => field.closest(s)))
-        && !ignoredTypes.some(f => (id && id.includes(f)) || (name && name.includes(f) || placeholder && placeholder.includes(f)))) {
+    if ((acceptedOTPFields.some(f => id?.includes(f) || (name?.includes(f) || placeholder?.includes(f))) || acceptedParents.some(s => field.closest(s)))
+        && !ignoredTypes.some(f => id?.includes(f) || (name?.includes(f) || placeholder?.includes(f)))) {
         return true;
     }
 
diff --git a/keepassxc-browser/content/ui.js b/keepassxc-browser/content/ui.js
index 382917a..58104bb 100644
--- a/keepassxc-browser/content/ui.js
+++ b/keepassxc-browser/content/ui.js
@@ -7,6 +7,12 @@ const MIN_INPUT_FIELD_OFFSET_WIDTH = 60;
 const MIN_OPACITY = 0.7;
 const MAX_OPACITY = 1;
 
+const BLUE_BUTTON = 'kpxc-button kpxc-blue-button';
+const GREEN_BUTTON = 'kpxc-button kpxc-green-button';
+const ORANGE_BUTTON = 'kpxc-button kpxc-orange-button';
+const RED_BUTTON = 'kpxc-button kpxc-red-button';
+const GRAY_BUTTON_CLASS = 'kpxc-gray-button';
+
 const DatabaseState = {
     DISCONNECTED: 0,
     LOCKED: 1,
@@ -107,7 +113,7 @@ kpxcUI.monitorIconPosition = function(iconClass) {
     });
 
     window.addEventListener('transitionend', function(e) {
-        if (e.target && (e.target.nodeName === 'INPUT' || e.target.nodeName === 'TEXTAREA')) {
+        if (e.target?.nodeName === 'INPUT' || e.target?.nodeName === 'TEXTAREA') {
             kpxcUI.updateIconPosition(iconClass);
         }
     });
diff --git a/keepassxc-browser/manifest.json b/keepassxc-browser/manifest.json
index 5270d35..863c950 100755
--- a/keepassxc-browser/manifest.json
+++ b/keepassxc-browser/manifest.json
@@ -158,7 +158,7 @@
     "applications": {
         "gecko": {
             "id": "keepassxc-browser@keepassxc.org",
-            "strict_min_version": "74.0"
+            "strict_min_version": "91.0"
         }
     },
     "default_locale": "en"
diff --git a/keepassxc-browser/popups/popup.js b/keepassxc-browser/popups/popup.js
index cef6dc0..af022a8 100644
--- a/keepassxc-browser/popups/popup.js
+++ b/keepassxc-browser/popups/popup.js
@@ -61,12 +61,12 @@ function statusResponse(r) {
 }
 
 const sendMessageToTab = async function(message) {
-    const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-    if (tabs.length === 0) {
+    const tab = await getCurrentTab();
+    if (!tab) {
         return false; // Only the background devtools or a popup are opened
     }
 
-    await browser.tabs.sendMessage(tabs[0].id, {
+    await browser.tabs.sendMessage(tab.id, {
         action: message
     });
 
diff --git a/keepassxc-browser/popups/popup_functions.js b/keepassxc-browser/popups/popup_functions.js
index ac2c5ea..c21a9bd 100644
--- a/keepassxc-browser/popups/popup_functions.js
+++ b/keepassxc-browser/popups/popup_functions.js
@@ -25,11 +25,10 @@ async function initSettings() {
 
     customLoginFieldsButton.addEventListener('click', async () => {
         await browser.windows.getCurrent();
-        const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-        const tab = tabs[0];
+        const tab = await getCurrentTab();
         await browser.runtime.getBackgroundPage();
 
-        browser.tabs.sendMessage(tab.id, {
+        browser.tabs.sendMessage(tab?.id, {
             action: 'choose_credential_fields'
         });
         close();
@@ -49,8 +48,8 @@ async function initColorTheme() {
 }
 
 async function getLoginData() {
-    const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-    if (tabs.length === 0) {
+    const tab = getCurrentTab();
+    if (!tab) {
         return [];
     }
 
diff --git a/keepassxc-browser/popups/popup_httpauth.js b/keepassxc-browser/popups/popup_httpauth.js
index 1950ef9..0a37bfd 100644
--- a/keepassxc-browser/popups/popup_httpauth.js
+++ b/keepassxc-browser/popups/popup_httpauth.js
@@ -8,10 +8,11 @@
 
     const data = await getLoginData();
     const ll = document.getElementById('login-list');
-    for (let i = 0; i < data.logins.length; ++i) {
+
+    for (const [ i, login ] of data.logins.entries()) {
         const a = document.createElement('a');
         a.setAttribute('class', 'list-group-item');
-        a.textContent = data.logins[i].login + ' (' + data.logins[i].name + ')';
+        a.textContent = login.login + ' (' + login.name + ')';
         a.setAttribute('id', '' + i);
 
         a.addEventListener('click', (e) => {
diff --git a/keepassxc-browser/popups/popup_login.js b/keepassxc-browser/popups/popup_login.js
index c6604d1..b46c460 100644
--- a/keepassxc-browser/popups/popup_login.js
+++ b/keepassxc-browser/popups/popup_login.js
@@ -6,18 +6,18 @@
 
     $('#lock-database-button').show();
 
-    const tabs = await browser.tabs.query({ active: true, currentWindow: true });
-    if (tabs.length === 0) {
+    const tab = await getCurrentTab();
+    if (!tab) {
         return [];
     }
 
     const logins = await getLoginData();
     const ll = document.getElementById('login-list');
 
-    for (let i = 0; i < logins.length; i++) {
-        const uuid = logins[i].uuid;
+    for (const [ i, login ] of logins.entries()) {
+        const uuid = login.uuid;
         const a = document.createElement('a');
-        a.textContent = logins[i].text;
+        a.textContent = login.text;
         a.setAttribute('class', 'list-group-item');
         a.setAttribute('id', '' + i);
 
@@ -27,7 +27,7 @@
             }
 
             const id = e.target.id;
-            browser.tabs.sendMessage(tabs[0].id, {
+            browser.tabs.sendMessage(tab.id, {
                 action: 'fill_user_pass_with_specific_login',
                 id: Number(id),
                 uuid: uuid