diff --git a/.eslintrc.json b/.eslintrc.json
index 680642ac6..d5a54d46b 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -43,7 +43,6 @@
     ],
     "unicorn/consistent-function-scoping": "off",
     "unicorn/explicit-length-check": "off",
-    "unicorn/import-index": "off",
     "unicorn/no-array-callback-reference": "off",
     "unicorn/no-for-loop": "off",
     "unicorn/no-null": "off",
diff --git a/.github/workflows/browserstack.yml b/.github/workflows/browserstack.yml
index ea0a25704..a12bffcf7 100644
--- a/.github/workflows/browserstack.yml
+++ b/.github/workflows/browserstack.yml
@@ -5,7 +5,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   browserstack:
diff --git a/.github/workflows/bundlewatch.yml b/.github/workflows/bundlewatch.yml
index 989991f0d..b2bd5eed5 100644
--- a/.github/workflows/bundlewatch.yml
+++ b/.github/workflows/bundlewatch.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   bundlewatch:
diff --git a/.github/workflows/css.yml b/.github/workflows/css.yml
index 4463d52f4..a28059d79 100644
--- a/.github/workflows/css.yml
+++ b/.github/workflows/css.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   css:
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index cda6f7748..150e4d16c 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   docs:
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index e7a55083d..369aaced3 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   lint:
diff --git a/.github/workflows/node-sass.yml b/.github/workflows/node-sass.yml
index 285d4bcc8..ee64b2152 100644
--- a/.github/workflows/node-sass.yml
+++ b/.github/workflows/node-sass.yml
@@ -8,7 +8,7 @@ on:
 
 env:
   FORCE_COLOR: 2
-  NODE: 14.x
+  NODE: 14
 
 jobs:
   css:
diff --git a/.gitignore b/.gitignore
index 6208c57d7..0a0f88d15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,19 +1,8 @@
 # Ignore docs files
 /_gh_pages/
-# This is the old Jekyll docs dist folder;
-# keeping it here so that when we switch branches it doesn't show up
-/site/docs/**/dist/
-# Jekyll's cache folder; keeping it for the same reason as above
-/site/.jekyll-cache/
 # Hugo resources folder
 /resources/
 
-# Ignore ruby/bundler files;
-# keeping them here so that when we switch branches they don't show up
-/.bundle/
-/vendor/
-/.ruby-version
-
 # Numerous always-ignore extensions
 *.diff
 *.err
diff --git a/.stylelintrc b/.stylelintrc
index 1c9ee1811..c068d30b5 100644
--- a/.stylelintrc
+++ b/.stylelintrc
@@ -3,6 +3,10 @@
     "stylelint-config-twbs-bootstrap/scss"
   ],
   "rules": {
+    "declaration-property-value-disallowed-list": {
+      "border": "none",
+      "outline": "none"
+    },
     "function-disallowed-list": [
       "calc",
       "lighten",
diff --git a/build/build-plugins.js b/build/build-plugins.js
index 80a010a7f..d1930b855 100644
--- a/build/build-plugins.js
+++ b/build/build-plugins.js
@@ -29,6 +29,7 @@ const bsPlugins = {
   Manipulator: path.resolve(__dirname, '../js/src/dom/manipulator.js'),
   SelectorEngine: path.resolve(__dirname, '../js/src/dom/selector-engine.js'),
   Alert: path.resolve(__dirname, '../js/src/alert.js'),
+  Base: path.resolve(__dirname, '../js/src/base-component.js'),
   Button: path.resolve(__dirname, '../js/src/button.js'),
   Carousel: path.resolve(__dirname, '../js/src/carousel.js'),
   Collapse: path.resolve(__dirname, '../js/src/collapse.js'),
@@ -44,11 +45,13 @@ const bsPlugins = {
 const defaultPluginConfig = {
   external: [
     bsPlugins.Data,
+    bsPlugins.Base,
     bsPlugins.EventHandler,
     bsPlugins.SelectorEngine
   ],
   globals: {
     [bsPlugins.Data]: 'Data',
+    [bsPlugins.Base]: 'Base',
     [bsPlugins.EventHandler]: 'EventHandler',
     [bsPlugins.SelectorEngine]: 'SelectorEngine'
   }
@@ -73,6 +76,7 @@ const getConfigByPluginKey = pluginKey => {
   }
 
   if (
+    pluginKey === 'Base' ||
     pluginKey === 'Button' ||
     pluginKey === 'Carousel' ||
     pluginKey === 'Collapse' ||
@@ -112,11 +116,13 @@ const getConfigByPluginKey = pluginKey => {
     return {
       external: [
         bsPlugins.Data,
+        bsPlugins.Base,
         bsPlugins.EventHandler,
         bsPlugins.Manipulator
       ],
       globals: {
         [bsPlugins.Data]: 'Data',
+        [bsPlugins.Base]: 'Base',
         [bsPlugins.EventHandler]: 'EventHandler',
         [bsPlugins.Manipulator]: 'Manipulator'
       }
diff --git a/build/change-version.js b/build/change-version.js
index abd7a288a..8086ed774 100644
--- a/build/change-version.js
+++ b/build/change-version.js
@@ -11,11 +11,9 @@
 
 const fs = require('fs')
 const path = require('path')
+const sh = require('shelljs')
 
-const VERBOSE = process.argv.includes('--verbose')
-const DRY_RUN = process.argv.includes('--dry') || process.argv.includes('--dry-run')
-
-const ROOT_DIR = path.join(__dirname, '..')
+sh.config.fatal = true
 
 // Blame TC39... https://github.com/benjamingr/RegExp.escape/issues/37
 function regExpQuote(string) {
@@ -26,6 +24,8 @@ function regExpQuoteReplacement(string) {
   return string.replace(/\$/g, '$$')
 }
 
+const DRY_RUN = false
+
 function walkAsync(directory, excludedDirectories, fileCallback, errback) {
   if (excludedDirectories.has(path.parse(directory).base)) {
     return
@@ -56,45 +56,21 @@ function walkAsync(directory, excludedDirectories, fileCallback, errback) {
 }
 
 function replaceRecursively(directory, excludedDirectories, allowedExtensions, original, replacement) {
-  const updateFile = filepath => {
-    if (!allowedExtensions.has(path.parse(filepath).ext) && VERBOSE) {
-      console.log(`EXCLUDED: ${filepath}`)
-      return
-    }
-
-    fs.readFile(filepath, 'utf8', (error, originalData) => {
-      if (error) {
-        throw error
-      }
-
-      const newData = originalData.replace(
-        new RegExp(regExpQuote(original), 'g'),
-        regExpQuoteReplacement(replacement)
-      )
-
-      if (originalData === newData) {
-        if (VERBOSE) {
-          console.log(`SKIPPED: ${filepath}`)
-        }
-
-        return
-      }
-
-      if (VERBOSE) {
+  original = new RegExp(regExpQuote(original), 'g')
+  replacement = regExpQuoteReplacement(replacement)
+  const updateFile = DRY_RUN ?
+    filepath => {
+      if (allowedExtensions.has(path.parse(filepath).ext)) {
         console.log(`FILE: ${filepath}`)
+      } else {
+        console.log(`EXCLUDED:${filepath}`)
       }
-
-      if (DRY_RUN) {
-        return
+    } :
+    filepath => {
+      if (allowedExtensions.has(path.parse(filepath).ext)) {
+        sh.sed('-i', original, replacement, filepath)
       }
-
-      fs.writeFile(filepath, newData, 'utf8', err => {
-        if (err) {
-          throw err
-        }
-      })
-    })
-  }
+    }
 
   walkAsync(directory, excludedDirectories, updateFile, err => {
     console.error('ERROR while traversing directory!:')
@@ -104,22 +80,22 @@ function replaceRecursively(directory, excludedDirectories, allowedExtensions, o
 }
 
 function main(args) {
-  const [oldVersion, newVersion] = args
-
-  if (!oldVersion || !newVersion) {
-    console.error('USAGE: change-version old_version new_version [--verbose] [--dry[-run]]')
+  if (args.length !== 2) {
+    console.error('USAGE: change-version old_version new_version')
     console.error('Got arguments:', args)
     process.exit(1)
   }
 
+  const oldVersion = args[0]
+  const newVersion = args[1]
   const EXCLUDED_DIRS = new Set([
     '.git',
     '_gh_pages',
     'node_modules',
-    'resources'
+    'vendor'
   ])
   const INCLUDED_EXTENSIONS = new Set([
-    // This extensions list is how we avoid modifying binary files
+    // This extension allowlist is how we avoid modifying binary files
     '',
     '.css',
     '.html',
@@ -130,8 +106,7 @@ function main(args) {
     '.txt',
     '.yml'
   ])
-
-  replaceRecursively(ROOT_DIR, EXCLUDED_DIRS, INCLUDED_EXTENSIONS, oldVersion, newVersion)
+  replaceRecursively('.', EXCLUDED_DIRS, INCLUDED_EXTENSIONS, oldVersion, newVersion)
 }
 
 main(process.argv.slice(2))
diff --git a/build/zip-examples.js b/build/zip-examples.js
index 898e5860f..b2f156502 100644
--- a/build/zip-examples.js
+++ b/build/zip-examples.js
@@ -15,34 +15,64 @@ const sh = require('shelljs')
 const pkg = require('../package.json')
 
 const versionShort = pkg.config.version_short
-const folderName = `bootstrap-${pkg.version}-examples`
+const distFolder = `bootstrap-${pkg.version}-examples`
+const rootDocsDir = '_gh_pages'
+const docsDir = `${rootDocsDir}/docs/${versionShort}/`
+
+// these are the files we need in the examples
+const cssFiles = [
+  'bootstrap.min.css',
+  'bootstrap.min.css.map',
+  'bootstrap.rtl.min.css',
+  'bootstrap.rtl.min.css.map'
+]
+const jsFiles = [
+  'bootstrap.bundle.min.js',
+  'bootstrap.bundle.min.js.map'
+]
+const imgFiles = [
+  'bootstrap-logo.svg',
+  'bootstrap-logo-white.svg'
+]
 
 sh.config.fatal = true
 
-if (!sh.test('-d', '_gh_pages')) {
-  throw new Error('The "_gh_pages" folder does not exist, did you forget building the docs?')
+if (!sh.test('-d', rootDocsDir)) {
+  throw new Error(`The "${rootDocsDir}" folder does not exist, did you forget building the docs?`)
 }
 
 // switch to the root dir
 sh.cd(path.join(__dirname, '..'))
 
-// remove any previously created folder with the same name
-sh.rm('-rf', folderName)
-// create any folders so that `cp` works
-sh.mkdir('-p', folderName)
-sh.mkdir('-p', `${folderName}/assets/brand/`)
+// remove any previously created folder/zip with the same name
+sh.rm('-rf', [distFolder, `${distFolder}.zip`])
 
-sh.cp('-Rf', `_gh_pages/docs/${versionShort}/examples/*`, folderName)
-sh.cp('-Rf', `_gh_pages/docs/${versionShort}/dist/`, `${folderName}/assets/`)
-// also copy the two brand images we use in the examples
-sh.cp('-f', [
-  `_gh_pages/docs/${versionShort}/assets/brand/bootstrap-logo.svg`,
-  `_gh_pages/docs/${versionShort}/assets/brand/bootstrap-logo-white.svg`
-], `${folderName}/assets/brand/`)
-sh.rm(`${folderName}/index.html`)
+// create any folders so that `cp` works
+sh.mkdir('-p', [
+  distFolder,
+  `${distFolder}/assets/brand/`,
+  `${distFolder}/assets/dist/css/`,
+  `${distFolder}/assets/dist/js/`
+])
+
+sh.cp('-Rf', `${docsDir}/examples/*`, distFolder)
+
+cssFiles.forEach(file => {
+  sh.cp('-f', `${docsDir}/dist/css/${file}`, `${distFolder}/assets/dist/css/`)
+})
+
+jsFiles.forEach(file => {
+  sh.cp('-f', `${docsDir}/dist/js/${file}`, `${distFolder}/assets/dist/js/`)
+})
+
+imgFiles.forEach(file => {
+  sh.cp('-f', `${docsDir}/assets/brand/${file}`, `${distFolder}/assets/brand/`)
+})
+
+sh.rm(`${distFolder}/index.html`)
 
 // get all examples' HTML files
-sh.find(`${folderName}/**/*.html`).forEach(file => {
+sh.find(`${distFolder}/**/*.html`).forEach(file => {
   const fileContents = sh.cat(file)
     .toString()
     .replace(new RegExp(`"/docs/${versionShort}/`, 'g'), '"../')
@@ -54,7 +84,7 @@ sh.find(`${folderName}/**/*.html`).forEach(file => {
 })
 
 // create the zip file
-sh.exec(`zip -r9 "${folderName}.zip" "${folderName}"`, { fatal: true })
+sh.exec(`zip -r9 "${distFolder}.zip" "${distFolder}"`)
 
 // remove the folder we created
-sh.rm('-rf', folderName)
+sh.rm('-rf', distFolder)
diff --git a/js/src/dom/event-handler.js b/js/src/dom/event-handler.js
index 2ee13bafc..e3c685530 100644
--- a/js/src/dom/event-handler.js
+++ b/js/src/dom/event-handler.js
@@ -112,6 +112,7 @@ function bootstrapDelegationHandler(element, selector, fn) {
           event.delegateTarget = target
 
           if (handler.oneOff) {
+            // eslint-disable-next-line unicorn/consistent-destructuring
             EventHandler.off(element, event.type, fn)
           }
 
diff --git a/js/src/dropdown.js b/js/src/dropdown.js
index 008294e9b..bada537c9 100644
--- a/js/src/dropdown.js
+++ b/js/src/dropdown.js
@@ -263,7 +263,7 @@ class Dropdown extends BaseComponent {
       typeof config.reference.getBoundingClientRect !== 'function'
     ) {
       // Popper virtual elements require a getBoundingClientRect method
-      throw new Error(`${NAME}: Option "reference" provided type "object" without a required "getBoundingClientRect" method.`)
+      throw new TypeError(`${NAME.toUpperCase()}: Option "reference" provided type "object" without a required "getBoundingClientRect" method.`)
     }
 
     return config
diff --git a/js/src/modal.js b/js/src/modal.js
index 87c22943a..fe1b5a4c6 100644
--- a/js/src/modal.js
+++ b/js/src/modal.js
@@ -590,7 +590,7 @@ EventHandler.on(document, EVENT_CLICK_DATA_API, SELECTOR_DATA_TOGGLE, function (
     data = new Modal(target, config)
   }
 
-  data.show(this)
+  data.toggle(this)
 })
 
 /**
diff --git a/js/src/util/index.js b/js/src/util/index.js
index 9ccad1cbb..22d0a578b 100644
--- a/js/src/util/index.js
+++ b/js/src/util/index.js
@@ -111,15 +111,14 @@ const typeCheckConfig = (componentName, config, configTypes) => {
   Object.keys(configTypes).forEach(property => {
     const expectedTypes = configTypes[property]
     const value = config[property]
-    const valueType = value && isElement(value) ?
-      'element' :
-      toType(value)
+    const valueType = value && isElement(value) ? 'element' : toType(value)
 
     if (!new RegExp(expectedTypes).test(valueType)) {
-      throw new Error(
+      throw new TypeError(
         `${componentName.toUpperCase()}: ` +
         `Option "${property}" provided type "${valueType}" ` +
-        `but expected type "${expectedTypes}".`)
+        `but expected type "${expectedTypes}".`
+      )
     }
   })
 }
diff --git a/js/src/util/sanitizer.js b/js/src/util/sanitizer.js
index d908dd661..ce3d455a6 100644
--- a/js/src/util/sanitizer.js
+++ b/js/src/util/sanitizer.js
@@ -37,7 +37,7 @@ const allowedAttribute = (attr, allowedAttributeList) => {
 
   if (allowedAttributeList.includes(attrName)) {
     if (uriAttrs.has(attrName)) {
-      return Boolean(attr.nodeValue.match(SAFE_URL_PATTERN) || attr.nodeValue.match(DATA_URL_PATTERN))
+      return Boolean(SAFE_URL_PATTERN.test(attr.nodeValue) || DATA_URL_PATTERN.test(attr.nodeValue))
     }
 
     return true
@@ -47,7 +47,7 @@ const allowedAttribute = (attr, allowedAttributeList) => {
 
   // Check if a regular expression validates the attribute.
   for (let i = 0, len = regExp.length; i < len; i++) {
-    if (attrName.match(regExp[i])) {
+    if (regExp[i].test(attrName)) {
       return true
     }
   }
diff --git a/js/tests/karma.conf.js b/js/tests/karma.conf.js
index 38c7003bb..cd4946525 100644
--- a/js/tests/karma.conf.js
+++ b/js/tests/karma.conf.js
@@ -1,5 +1,7 @@
 /* eslint-env node */
 
+'use strict'
+
 const path = require('path')
 const ip = require('ip')
 const { babel } = require('@rollup/plugin-babel')
@@ -12,10 +14,11 @@ const {
   browsersKeys
 } = require('./browsers')
 
-const { env } = process
-const browserStack = env.BROWSER === 'true'
-const debug = env.DEBUG === 'true'
-const jQueryTest = env.JQUERY === 'true'
+const ENV = process.env
+const BROWSERSTACK = Boolean(ENV.BROWSERSTACK)
+const DEBUG = Boolean(ENV.DEBUG)
+const JQUERY_TEST = Boolean(ENV.JQUERY)
+
 const frameworks = [
   'jasmine'
 ]
@@ -30,16 +33,16 @@ const reporters = ['dots']
 const detectBrowsers = {
   usePhantomJS: false,
   postDetection(availableBrowser) {
-    if (env.CI === true || availableBrowser.includes('Chrome')) {
-      return debug ? ['Chrome'] : ['ChromeHeadless']
+    if (ENV.CI === true || availableBrowser.includes('Chrome')) {
+      return DEBUG ? ['Chrome'] : ['ChromeHeadless']
     }
 
     if (availableBrowser.includes('Chromium')) {
-      return debug ? ['Chromium'] : ['ChromiumHeadless']
+      return DEBUG ? ['Chromium'] : ['ChromiumHeadless']
     }
 
     if (availableBrowser.includes('Firefox')) {
-      return debug ? ['Firefox'] : ['FirefoxHeadless']
+      return DEBUG ? ['Firefox'] : ['FirefoxHeadless']
     }
 
     throw new Error('Please install Chrome, Chromium or Firefox')
@@ -67,7 +70,7 @@ const conf = {
     'node_modules/hammer-simulator/index.js',
     {
       pattern: 'js/tests/unit/**/!(jquery).spec.js',
-      watched: !browserStack
+      watched: !BROWSERSTACK
     }
   ],
   preprocessors: {
@@ -101,11 +104,11 @@ const conf = {
   }
 }
 
-if (browserStack) {
+if (BROWSERSTACK) {
   conf.hostname = ip.address()
   conf.browserStack = {
-    username: env.BROWSER_STACK_USERNAME,
-    accessKey: env.BROWSER_STACK_ACCESS_KEY,
+    username: ENV.BROWSER_STACK_USERNAME,
+    accessKey: ENV.BROWSER_STACK_ACCESS_KEY,
     build: `bootstrap-${new Date().toISOString()}`,
     project: 'Bootstrap',
     retryLimit: 2
@@ -114,7 +117,7 @@ if (browserStack) {
   conf.customLaunchers = browsers
   conf.browsers = browsersKeys
   reporters.push('BrowserStack', 'kjhtml')
-} else if (jQueryTest) {
+} else if (JQUERY_TEST) {
   frameworks.push('detectBrowsers')
   plugins.push(
     'karma-chrome-launcher',
@@ -155,7 +158,7 @@ if (browserStack) {
     }
   }
 
-  if (debug) {
+  if (DEBUG) {
     conf.hostname = ip.address()
     plugins.push('karma-jasmine-html-reporter')
     reporters.push('kjhtml')
@@ -169,7 +172,6 @@ conf.plugins = plugins
 conf.reporters = reporters
 
 module.exports = karmaConfig => {
-  // possible values: karmaConfig.LOG_DISABLE || karmaConfig.LOG_ERROR || karmaConfig.LOG_WARN || karmaConfig.LOG_INFO || karmaConfig.LOG_DEBUG
-  conf.logLevel = karmaConfig.LOG_ERROR || karmaConfig.LOG_WARN
+  conf.logLevel = karmaConfig.LOG_ERROR
   karmaConfig.set(conf)
 }
diff --git a/js/tests/unit/carousel.spec.js b/js/tests/unit/carousel.spec.js
index 0286762fa..787a276de 100644
--- a/js/tests/unit/carousel.spec.js
+++ b/js/tests/unit/carousel.spec.js
@@ -1136,11 +1136,9 @@ describe('Carousel', () => {
       jQueryMock.fn.carousel = Carousel.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.carousel.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/collapse.spec.js b/js/tests/unit/collapse.spec.js
index 4af21e13f..ff493cf51 100644
--- a/js/tests/unit/collapse.spec.js
+++ b/js/tests/unit/collapse.spec.js
@@ -819,11 +819,9 @@ describe('Collapse', () => {
       jQueryMock.fn.collapse = Collapse.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.collapse.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/dropdown.spec.js b/js/tests/unit/dropdown.spec.js
index ba1d0f443..cc4139603 100644
--- a/js/tests/unit/dropdown.spec.js
+++ b/js/tests/unit/dropdown.spec.js
@@ -393,13 +393,13 @@ describe('Dropdown', () => {
 
       expect(() => new Dropdown(btnDropdown, {
         reference: {}
-      })).toThrow()
+      })).toThrowError(TypeError, 'DROPDOWN: Option "reference" provided type "object" without a required "getBoundingClientRect" method.')
 
       expect(() => new Dropdown(btnDropdown, {
         reference: {
           getBoundingClientRect: 'not-a-function'
         }
-      })).toThrow()
+      })).toThrowError(TypeError, 'DROPDOWN: Option "reference" provided type "object" without a required "getBoundingClientRect" method.')
 
       // use onFirstUpdate as Poppers internal update is executed async
       const dropdown = new Dropdown(btnDropdown, {
@@ -1557,11 +1557,9 @@ describe('Dropdown', () => {
       jQueryMock.fn.dropdown = Dropdown.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.dropdown.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/modal.spec.js b/js/tests/unit/modal.spec.js
index f645e9892..29c90bbf1 100644
--- a/js/tests/unit/modal.spec.js
+++ b/js/tests/unit/modal.spec.js
@@ -870,7 +870,7 @@ describe('Modal', () => {
   })
 
   describe('data-api', () => {
-    it('should open modal', done => {
+    it('should toggle modal', done => {
       fixtureEl.innerHTML = [
         '<button type="button" data-bs-toggle="modal" data-bs-target="#exampleModal"></button>',
         '<div id="exampleModal" class="modal"><div class="modal-dialog"></div></div>'
@@ -885,6 +885,15 @@ describe('Modal', () => {
         expect(modalEl.getAttribute('aria-hidden')).toEqual(null)
         expect(modalEl.style.display).toEqual('block')
         expect(document.querySelector('.modal-backdrop')).toBeDefined()
+        setTimeout(() => trigger.click(), 10)
+      })
+
+      modalEl.addEventListener('hidden.bs.modal', () => {
+        expect(modalEl.getAttribute('aria-modal')).toEqual(null)
+        expect(modalEl.getAttribute('role')).toEqual(null)
+        expect(modalEl.getAttribute('aria-hidden')).toEqual('true')
+        expect(modalEl.style.display).toEqual('none')
+        expect(document.querySelector('.modal-backdrop')).toEqual(null)
         done()
       })
 
@@ -1061,11 +1070,9 @@ describe('Modal', () => {
       jQueryMock.fn.modal = Modal.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.modal.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
 
     it('should call show method', () => {
diff --git a/js/tests/unit/popover.spec.js b/js/tests/unit/popover.spec.js
index 3c04e7ac1..e5c235e2a 100644
--- a/js/tests/unit/popover.spec.js
+++ b/js/tests/unit/popover.spec.js
@@ -206,11 +206,9 @@ describe('Popover', () => {
       jQueryMock.fn.popover = Popover.jQueryInterface
       jQueryMock.elements = [popoverEl]
 
-      try {
+      expect(() => {
         jQueryMock.fn.popover.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
 
     it('should should call show method', () => {
diff --git a/js/tests/unit/scrollspy.spec.js b/js/tests/unit/scrollspy.spec.js
index eab9183aa..0d175aafa 100644
--- a/js/tests/unit/scrollspy.spec.js
+++ b/js/tests/unit/scrollspy.spec.js
@@ -625,11 +625,9 @@ describe('ScrollSpy', () => {
       jQueryMock.fn.scrollspy = ScrollSpy.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.scrollspy.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/tab.spec.js b/js/tests/unit/tab.spec.js
index 67a85b2e4..d098ab027 100644
--- a/js/tests/unit/tab.spec.js
+++ b/js/tests/unit/tab.spec.js
@@ -397,11 +397,9 @@ describe('Tab', () => {
       jQueryMock.fn.tab = Tab.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.tab.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/toast.spec.js b/js/tests/unit/toast.spec.js
index cc873d1fe..2920eb2ef 100644
--- a/js/tests/unit/toast.spec.js
+++ b/js/tests/unit/toast.spec.js
@@ -368,11 +368,9 @@ describe('Toast', () => {
       jQueryMock.fn.toast = Toast.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.toast.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 
diff --git a/js/tests/unit/tooltip.spec.js b/js/tests/unit/tooltip.spec.js
index 8224c3437..213dcc91f 100644
--- a/js/tests/unit/tooltip.spec.js
+++ b/js/tests/unit/tooltip.spec.js
@@ -1207,11 +1207,9 @@ describe('Tooltip', () => {
       jQueryMock.fn.tooltip = Tooltip.jQueryInterface
       jQueryMock.elements = [div]
 
-      try {
+      expect(() => {
         jQueryMock.fn.tooltip.call(jQueryMock, action)
-      } catch (error) {
-        expect(error.message).toEqual(`No method named "${action}"`)
-      }
+      }).toThrowError(TypeError, `No method named "${action}"`)
     })
   })
 })
diff --git a/js/tests/unit/util/index.spec.js b/js/tests/unit/util/index.spec.js
index d4b09bf77..00ab44f1e 100644
--- a/js/tests/unit/util/index.spec.js
+++ b/js/tests/unit/util/index.spec.js
@@ -212,7 +212,7 @@ describe('Util', () => {
 
       expect(() => {
         Util.typeCheckConfig(namePlugin, config, defaultType)
-      }).toThrow(new Error('COLLAPSE: Option "parent" provided type "number" but expected type "(string|element)".'))
+      }).toThrowError(TypeError, 'COLLAPSE: Option "parent" provided type "number" but expected type "(string|element)".')
     })
 
     it('should return null stringified when null is passed', () => {
diff --git a/package-lock.json b/package-lock.json
index a8d8dd4a9..ca8de9e55 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1253,6 +1253,24 @@
         "defer-to-connect": "^1.0.1"
       }
     },
+    "@types/component-emitter": {
+      "version": "1.2.10",
+      "resolved": "https://registry.npmjs.org/@types/component-emitter/-/component-emitter-1.2.10.tgz",
+      "integrity": "sha512-bsjleuRKWmGqajMerkzox19aGbscQX5rmmvvXl3wlIp5gMG1HgkiwPxsN5p070fBDKTNSPgojVbuY1+HWMbFhg==",
+      "dev": true
+    },
+    "@types/cookie": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/@types/cookie/-/cookie-0.4.0.tgz",
+      "integrity": "sha512-y7mImlc/rNkvCRmg8gC3/lj87S7pTUIJ6QGjwHR9WQJcFs+ZMTOaoPrkdFA/YdbuqVEmEbb5RdhVxMkAcgOnpg==",
+      "dev": true
+    },
+    "@types/cors": {
+      "version": "2.8.9",
+      "resolved": "https://registry.npmjs.org/@types/cors/-/cors-2.8.9.tgz",
+      "integrity": "sha512-zurD1ibz21BRlAOIKP8yhrxlqKx6L9VCwkB5kMiP6nZAhoF5MvC7qS1qPA7nRcr1GJolfkQC7/EAL4hdYejLtg==",
+      "dev": true
+    },
     "@types/estree": {
       "version": "0.0.39",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.39.tgz",
@@ -1356,12 +1374,6 @@
       "integrity": "sha512-K0Ptm/47OKfQRpNQ2J/oIN/3QYiK6FwW+eJbILhsdxh2WTLdl+30o8aGdTbm5JbffpFFAg/g+zi1E+jvJha5ng==",
       "dev": true
     },
-    "after": {
-      "version": "0.8.2",
-      "resolved": "https://registry.npmjs.org/after/-/after-0.8.2.tgz",
-      "integrity": "sha1-/ts5T58OAqqXaOcCvaI7UF+ufh8=",
-      "dev": true
-    },
     "agent-base": {
       "version": "4.3.0",
       "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.3.0.tgz",
@@ -1566,12 +1578,6 @@
         "es-abstract": "^1.18.0-next.1"
       }
     },
-    "arraybuffer.slice": {
-      "version": "0.0.7",
-      "resolved": "https://registry.npmjs.org/arraybuffer.slice/-/arraybuffer.slice-0.0.7.tgz",
-      "integrity": "sha512-wGUIVQXuehL5TCqQun8OW81jGzAWycqzFF8lFp+GOM5BXLYj3bKNsYC4daB7n6XjCqxQA/qgTJ+8ANR3acjrog==",
-      "dev": true
-    },
     "arrify": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/arrify/-/arrify-1.0.1.tgz",
@@ -1665,12 +1671,6 @@
         "object.assign": "^4.1.0"
       }
     },
-    "backo2": {
-      "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/backo2/-/backo2-1.0.2.tgz",
-      "integrity": "sha1-MasayLEpNjRj41s+u2n038+6eUc=",
-      "dev": true
-    },
     "bail": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/bail/-/bail-1.0.5.tgz",
@@ -1908,12 +1908,6 @@
         "safe-buffer": "^5.1.1"
       }
     },
-    "blob": {
-      "version": "0.0.5",
-      "resolved": "https://registry.npmjs.org/blob/-/blob-0.0.5.tgz",
-      "integrity": "sha512-gaqbzQPqOoamawKg0LGVd7SzLgXS+JH61oWprSLH+P+abTczqJbhTR8CmJ2u9/bUYNmHTGJx/UEmn6doAvvuig==",
-      "dev": true
-    },
     "bluebird": {
       "version": "3.4.7",
       "resolved": "https://registry.npmjs.org/bluebird/-/bluebird-3.4.7.tgz",
@@ -2646,24 +2640,12 @@
       "integrity": "sha1-3dgA2gxmEnOTzKWVDqloo6rxJTs=",
       "dev": true
     },
-    "component-bind": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/component-bind/-/component-bind-1.0.0.tgz",
-      "integrity": "sha1-AMYIq33Nk4l8AAllGx06jh5zu9E=",
-      "dev": true
-    },
     "component-emitter": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.3.0.tgz",
       "integrity": "sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg==",
       "dev": true
     },
-    "component-inherit": {
-      "version": "0.0.3",
-      "resolved": "https://registry.npmjs.org/component-inherit/-/component-inherit-0.0.3.tgz",
-      "integrity": "sha1-ZF/ErfWLcrZJ1crmUTVhnbJv8UM=",
-      "dev": true
-    },
     "concat-map": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
@@ -2796,6 +2778,16 @@
       "integrity": "sha1-tf1UIgqivFq1eqtxQMlAdUUDwac=",
       "dev": true
     },
+    "cors": {
+      "version": "2.8.5",
+      "resolved": "https://registry.npmjs.org/cors/-/cors-2.8.5.tgz",
+      "integrity": "sha512-KIHbLJqu73RGr/hnbrO9uBeixNGuvSQjul/jdFvS/KFSIH1hWVd1ng7zOHx+YrEfInLG7q4n6GHQ9cDtxv/P6g==",
+      "dev": true,
+      "requires": {
+        "object-assign": "^4",
+        "vary": "^1"
+      }
+    },
     "cosmiconfig": {
       "version": "6.0.0",
       "resolved": "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-6.0.0.tgz",
@@ -3348,77 +3340,44 @@
       }
     },
     "engine.io": {
-      "version": "3.5.0",
-      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-3.5.0.tgz",
-      "integrity": "sha512-21HlvPUKaitDGE4GXNtQ7PLP0Sz4aWLddMPw2VTyFz1FVZqu/kZsJUO8WNpKuE/OCL7nkfRaOui2ZCJloGznGA==",
+      "version": "4.0.6",
+      "resolved": "https://registry.npmjs.org/engine.io/-/engine.io-4.0.6.tgz",
+      "integrity": "sha512-rf7HAVZpcRrcKEKddgIzYUnwg0g5HE1RvJaTLwkcfJmce4g+po8aMuE6vxzp6JwlK8FEq/vi0KWN6tA585DjaA==",
       "dev": true,
       "requires": {
         "accepts": "~1.3.4",
         "base64id": "2.0.0",
         "cookie": "~0.4.1",
-        "debug": "~4.1.0",
-        "engine.io-parser": "~2.2.0",
+        "cors": "~2.8.5",
+        "debug": "~4.3.1",
+        "engine.io-parser": "~4.0.0",
         "ws": "~7.4.2"
       },
       "dependencies": {
         "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "version": "4.3.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.1.tgz",
+          "integrity": "sha512-doEwdvm4PCeK4K3RQN2ZC2BYUBaxwLARCqZmMjtF8a51J2Rb0xpVloFRnCODwqjpwnAoao4pelN8l3RJdv3gRQ==",
           "dev": true,
           "requires": {
-            "ms": "^2.1.1"
+            "ms": "2.1.2"
           }
         },
         "ms": {
-          "version": "2.1.3",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
-          "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
           "dev": true
         }
       }
     },
-    "engine.io-client": {
-      "version": "3.5.0",
-      "resolved": "https://registry.npmjs.org/engine.io-client/-/engine.io-client-3.5.0.tgz",
-      "integrity": "sha512-12wPRfMrugVw/DNyJk34GQ5vIVArEcVMXWugQGGuw2XxUSztFNmJggZmv8IZlLyEdnpO1QB9LkcjeWewO2vxtA==",
-      "dev": true,
-      "requires": {
-        "component-emitter": "~1.3.0",
-        "component-inherit": "0.0.3",
-        "debug": "~3.1.0",
-        "engine.io-parser": "~2.2.0",
-        "has-cors": "1.1.0",
-        "indexof": "0.0.1",
-        "parseqs": "0.0.6",
-        "parseuri": "0.0.6",
-        "ws": "~7.4.2",
-        "xmlhttprequest-ssl": "~1.5.4",
-        "yeast": "0.1.2"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "3.1.0",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-3.1.0.tgz",
-          "integrity": "sha512-OX8XqP7/1a9cqkxYw2yXss15f26NKWBpDXQd0/uK/KPqdQhxbPa994hnzjcE2VqQpDslf55723cKPUOGSmMY3g==",
-          "dev": true,
-          "requires": {
-            "ms": "2.0.0"
-          }
-        }
-      }
-    },
     "engine.io-parser": {
-      "version": "2.2.1",
-      "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-2.2.1.tgz",
-      "integrity": "sha512-x+dN/fBH8Ro8TFwJ+rkB2AmuVw9Yu2mockR/p3W8f8YtExwFgDvBDi0GWyb4ZLkpahtDGZgtr3zLovanJghPqg==",
+      "version": "4.0.2",
+      "resolved": "https://registry.npmjs.org/engine.io-parser/-/engine.io-parser-4.0.2.tgz",
+      "integrity": "sha512-sHfEQv6nmtJrq6TKuIz5kyEKH/qSdK56H/A+7DnAuUPWosnIZAS2NHNcPLmyjtY3cGS/MqJdZbUjW97JU72iYg==",
       "dev": true,
       "requires": {
-        "after": "0.8.2",
-        "arraybuffer.slice": "~0.0.7",
-        "base64-arraybuffer": "0.1.4",
-        "blob": "0.0.5",
-        "has-binary2": "~1.0.2"
+        "base64-arraybuffer": "0.1.4"
       }
     },
     "enquirer": {
@@ -3802,17 +3761,17 @@
       }
     },
     "eslint-plugin-unicorn": {
-      "version": "25.0.1",
-      "resolved": "https://registry.npmjs.org/eslint-plugin-unicorn/-/eslint-plugin-unicorn-25.0.1.tgz",
-      "integrity": "sha512-MEyEWoyou/qhJH6rEER9YHACtCsQT+eewc6Fdxbi2eiTvsGrBR8JZMA6qaeof3oMQeRxOpaERoBKzU7R5c4A/w==",
+      "version": "26.0.1",
+      "resolved": "https://registry.npmjs.org/eslint-plugin-unicorn/-/eslint-plugin-unicorn-26.0.1.tgz",
+      "integrity": "sha512-SWgF9sIVY74zqkkSN2dclSCqRfocWSUGD0haC0NX2oRfmdp9p8dQvJYkYSQePaCyssPUE/pqpsIEEZNTh8crUA==",
       "dev": true,
       "requires": {
         "ci-info": "^2.0.0",
         "clean-regexp": "^1.0.0",
         "eslint-ast-utils": "^1.1.0",
-        "eslint-template-visitor": "^2.2.1",
+        "eslint-template-visitor": "^2.2.2",
         "eslint-utils": "^2.1.0",
-        "import-modules": "^2.0.0",
+        "import-modules": "^2.1.0",
         "lodash": "^4.17.20",
         "pluralize": "^8.0.0",
         "read-pkg-up": "^7.0.1",
@@ -4976,29 +4935,6 @@
         "function-bind": "^1.1.1"
       }
     },
-    "has-binary2": {
-      "version": "1.0.3",
-      "resolved": "https://registry.npmjs.org/has-binary2/-/has-binary2-1.0.3.tgz",
-      "integrity": "sha512-G1LWKhDSvhGeAQ8mPVQlqNcOB2sJdwATtZKl2pDKKHfpf/rYj24lkinxf69blJbnsvtqqNU+L3SL50vzZhXOnw==",
-      "dev": true,
-      "requires": {
-        "isarray": "2.0.1"
-      },
-      "dependencies": {
-        "isarray": {
-          "version": "2.0.1",
-          "resolved": "https://registry.npmjs.org/isarray/-/isarray-2.0.1.tgz",
-          "integrity": "sha1-o32U7ZzaLVmGXJ92/llu4fM4dB4=",
-          "dev": true
-        }
-      }
-    },
-    "has-cors": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/has-cors/-/has-cors-1.1.0.tgz",
-      "integrity": "sha1-XkdHk/fqmEPRu5nCPu9J/xJv/zk=",
-      "dev": true
-    },
     "has-flag": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/has-flag/-/has-flag-3.0.0.tgz",
@@ -5267,12 +5203,6 @@
       "integrity": "sha1-8w9xbI4r00bHtn0985FVZqfAVgc=",
       "dev": true
     },
-    "indexof": {
-      "version": "0.0.1",
-      "resolved": "https://registry.npmjs.org/indexof/-/indexof-0.0.1.tgz",
-      "integrity": "sha1-gtwzbSMrkGIXnQWrMpOmYFn9Q10=",
-      "dev": true
-    },
     "inflight": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.6.tgz",
@@ -5926,9 +5856,9 @@
       "dev": true
     },
     "karma": {
-      "version": "5.2.3",
-      "resolved": "https://registry.npmjs.org/karma/-/karma-5.2.3.tgz",
-      "integrity": "sha512-tHdyFADhVVPBorIKCX8A37iLHxc6RBRphkSoQ+MLKdAtFn1k97tD8WUGi1KlEtDZKL3hui0qhsY9HXUfSNDYPQ==",
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/karma/-/karma-6.0.0.tgz",
+      "integrity": "sha512-Tc9VlrmAlOUjsi+5tyNlo18TWiOps3wo4HJYqfZImyTrek2gUASmW6q+bEIE1U5w9f+sQ97P5PbbUCp3uVNqrQ==",
       "dev": true,
       "requires": {
         "body-parser": "^1.19.0",
@@ -5949,13 +5879,22 @@
         "qjobs": "^1.2.0",
         "range-parser": "^1.2.1",
         "rimraf": "^3.0.2",
-        "socket.io": "^2.3.0",
+        "socket.io": "^3.0.4",
         "source-map": "^0.6.1",
         "tmp": "0.2.1",
-        "ua-parser-js": "0.7.22",
-        "yargs": "^15.3.1"
+        "ua-parser-js": "^0.7.23",
+        "yargs": "^16.1.1"
       },
       "dependencies": {
+        "ansi-styles": {
+          "version": "4.3.0",
+          "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-4.3.0.tgz",
+          "integrity": "sha512-zbB9rCJAT1rbjiVDb2hqKFHNYLxgtk8NURxZ3IZwD3F6NtxbXZQCnnSi1Lkx+IDohdPlFp222wVALIheZJQSEg==",
+          "dev": true,
+          "requires": {
+            "color-convert": "^2.0.1"
+          }
+        },
         "braces": {
           "version": "3.0.2",
           "resolved": "https://registry.npmjs.org/braces/-/braces-3.0.2.tgz",
@@ -5965,6 +5904,32 @@
             "fill-range": "^7.0.1"
           }
         },
+        "cliui": {
+          "version": "7.0.4",
+          "resolved": "https://registry.npmjs.org/cliui/-/cliui-7.0.4.tgz",
+          "integrity": "sha512-OcRE68cOsVMXp1Yvonl/fzkQOyjLSu/8bhPDfQt0e0/Eb283TKP20Fs2MqoPsr9SwA595rRCA+QMzYc9nBP+JQ==",
+          "dev": true,
+          "requires": {
+            "string-width": "^4.2.0",
+            "strip-ansi": "^6.0.0",
+            "wrap-ansi": "^7.0.0"
+          }
+        },
+        "color-convert": {
+          "version": "2.0.1",
+          "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-2.0.1.tgz",
+          "integrity": "sha512-RRECPsj7iu/xb5oKYcsFHSppFNnsj/52OVTRKb4zP5onXwVF3zVmmToNcOfGC+CRDpfK/U584fMg38ZHCaElKQ==",
+          "dev": true,
+          "requires": {
+            "color-name": "~1.1.4"
+          }
+        },
+        "color-name": {
+          "version": "1.1.4",
+          "resolved": "https://registry.npmjs.org/color-name/-/color-name-1.1.4.tgz",
+          "integrity": "sha512-dOy+3AuW3a2wNbZHIuMZpTcgjGuLU/uBL/ubcZF9OXbDo8ff4O8yVp5Bf0efS8uEoYo5q4Fx7dY9OgQGXgAsQA==",
+          "dev": true
+        },
         "fill-range": {
           "version": "7.0.1",
           "resolved": "https://registry.npmjs.org/fill-range/-/fill-range-7.0.1.tgz",
@@ -5994,6 +5959,44 @@
           "requires": {
             "is-number": "^7.0.0"
           }
+        },
+        "wrap-ansi": {
+          "version": "7.0.0",
+          "resolved": "https://registry.npmjs.org/wrap-ansi/-/wrap-ansi-7.0.0.tgz",
+          "integrity": "sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q==",
+          "dev": true,
+          "requires": {
+            "ansi-styles": "^4.0.0",
+            "string-width": "^4.1.0",
+            "strip-ansi": "^6.0.0"
+          }
+        },
+        "y18n": {
+          "version": "5.0.5",
+          "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.5.tgz",
+          "integrity": "sha512-hsRUr4FFrvhhRH12wOdfs38Gy7k2FFzB9qgN9v3aLykRq0dRcdcpz5C9FxdS2NuhOrI/628b/KSTJ3rwHysYSg==",
+          "dev": true
+        },
+        "yargs": {
+          "version": "16.2.0",
+          "resolved": "https://registry.npmjs.org/yargs/-/yargs-16.2.0.tgz",
+          "integrity": "sha512-D1mvvtDG0L5ft/jGWkLpG1+m0eQxOfaBvTNELraWj22wSVUMWxZUvYgJYcKh6jGGIkJFhH4IZPQhR4TKpc8mBw==",
+          "dev": true,
+          "requires": {
+            "cliui": "^7.0.2",
+            "escalade": "^3.1.1",
+            "get-caller-file": "^2.0.5",
+            "require-directory": "^2.1.1",
+            "string-width": "^4.2.0",
+            "y18n": "^5.0.5",
+            "yargs-parser": "^20.2.2"
+          }
+        },
+        "yargs-parser": {
+          "version": "20.2.4",
+          "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-20.2.4.tgz",
+          "integrity": "sha512-WOkpgNhPTlE73h4VFAFsOnomJVaovO8VqLDzy5saChRBFQFBoMYirowyW+Q9HB4HFF4Z7VZTiG3iSzJJA29yRA==",
+          "dev": true
         }
       }
     },
@@ -7573,18 +7576,6 @@
         "parse5": "^6.0.1"
       }
     },
-    "parseqs": {
-      "version": "0.0.6",
-      "resolved": "https://registry.npmjs.org/parseqs/-/parseqs-0.0.6.tgz",
-      "integrity": "sha512-jeAGzMDbfSHHA091hr0r31eYfTig+29g3GKKE/PPbEQ65X0lmMwlEoqmhzu0iztID5uJpZsFlUPDP8ThPL7M8w==",
-      "dev": true
-    },
-    "parseuri": {
-      "version": "0.0.6",
-      "resolved": "https://registry.npmjs.org/parseuri/-/parseuri-0.0.6.tgz",
-      "integrity": "sha512-AUjen8sAkGgao7UyCX6Ahv0gIK2fABKmYjvP4xmy5JaKvcbTRueIqIPHLAfq30xJddqSE033IOMUSOMCcK3Sow==",
-      "dev": true
-    },
     "parseurl": {
       "version": "1.3.3",
       "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",
@@ -9472,125 +9463,69 @@
       }
     },
     "socket.io": {
-      "version": "2.4.1",
-      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-2.4.1.tgz",
-      "integrity": "sha512-Si18v0mMXGAqLqCVpTxBa8MGqriHGQh8ccEOhmsmNS3thNCGBwO8WGrwMibANsWtQQ5NStdZwHqZR3naJVFc3w==",
+      "version": "3.0.5",
+      "resolved": "https://registry.npmjs.org/socket.io/-/socket.io-3.0.5.tgz",
+      "integrity": "sha512-5yWQ43P/4IttmPCGKDQ3CVocBiJWGpibyhYJxgUhf69EHMzmK8XW0DkmHIoYdLmZaVZJyiEkUqpeC7rSCIqekw==",
       "dev": true,
       "requires": {
-        "debug": "~4.1.0",
-        "engine.io": "~3.5.0",
-        "has-binary2": "~1.0.2",
-        "socket.io-adapter": "~1.1.0",
-        "socket.io-client": "2.4.0",
-        "socket.io-parser": "~3.4.0"
+        "@types/cookie": "^0.4.0",
+        "@types/cors": "^2.8.8",
+        "@types/node": "^14.14.10",
+        "accepts": "~1.3.4",
+        "base64id": "~2.0.0",
+        "debug": "~4.3.1",
+        "engine.io": "~4.0.6",
+        "socket.io-adapter": "~2.0.3",
+        "socket.io-parser": "~4.0.3"
       },
       "dependencies": {
         "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "version": "4.3.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.1.tgz",
+          "integrity": "sha512-doEwdvm4PCeK4K3RQN2ZC2BYUBaxwLARCqZmMjtF8a51J2Rb0xpVloFRnCODwqjpwnAoao4pelN8l3RJdv3gRQ==",
           "dev": true,
           "requires": {
-            "ms": "^2.1.1"
+            "ms": "2.1.2"
           }
         },
         "ms": {
-          "version": "2.1.3",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
-          "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
           "dev": true
         }
       }
     },
     "socket.io-adapter": {
-      "version": "1.1.2",
-      "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-1.1.2.tgz",
-      "integrity": "sha512-WzZRUj1kUjrTIrUKpZLEzFZ1OLj5FwLlAFQs9kuZJzJi5DKdU7FsWc36SNmA8iDOtwBQyT8FkrriRM8vXLYz8g==",
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/socket.io-adapter/-/socket.io-adapter-2.0.3.tgz",
+      "integrity": "sha512-2wo4EXgxOGSFueqvHAdnmi5JLZzWqMArjuP4nqC26AtLh5PoCPsaRbRdah2xhcwTAMooZfjYiNVNkkmmSMaxOQ==",
       "dev": true
     },
-    "socket.io-client": {
-      "version": "2.4.0",
-      "resolved": "https://registry.npmjs.org/socket.io-client/-/socket.io-client-2.4.0.tgz",
-      "integrity": "sha512-M6xhnKQHuuZd4Ba9vltCLT9oa+YvTsP8j9NcEiLElfIg8KeYPyhWOes6x4t+LTAC8enQbE/995AdTem2uNyKKQ==",
-      "dev": true,
-      "requires": {
-        "backo2": "1.0.2",
-        "component-bind": "1.0.0",
-        "component-emitter": "~1.3.0",
-        "debug": "~3.1.0",
-        "engine.io-client": "~3.5.0",
-        "has-binary2": "~1.0.2",
-        "indexof": "0.0.1",
-        "parseqs": "0.0.6",
-        "parseuri": "0.0.6",
-        "socket.io-parser": "~3.3.0",
-        "to-array": "0.1.4"
-      },
-      "dependencies": {
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-          "dev": true,
-          "requires": {
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-          }
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-        "isarray": {
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-          "resolved": "https://registry.npmjs.org/isarray/-/isarray-2.0.1.tgz",
-          "integrity": "sha1-o32U7ZzaLVmGXJ92/llu4fM4dB4=",
-          "dev": true
-        },
-        "socket.io-parser": {
-          "version": "3.3.1",
-          "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-3.3.1.tgz",
-          "integrity": "sha512-1QLvVAe8dTz+mKmZ07Swxt+LAo4Y1ff50rlyoEx00TQmDFVQYPfcqGvIDJLGaBdhdNCecXtyKpD+EgKGcmmbuQ==",
-          "dev": true,
-          "requires": {
-            "component-emitter": "~1.3.0",
-            "debug": "~3.1.0",
-            "isarray": "2.0.1"
-          }
-        }
-      }
-    },
     "socket.io-parser": {
-      "version": "3.4.1",
-      "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-3.4.1.tgz",
-      "integrity": "sha512-11hMgzL+WCLWf1uFtHSNvliI++tcRUWdoeYuwIl+Axvwy9z2gQM+7nJyN3STj1tLj5JyIUH8/gpDGxzAlDdi0A==",
+      "version": "4.0.3",
+      "resolved": "https://registry.npmjs.org/socket.io-parser/-/socket.io-parser-4.0.3.tgz",
+      "integrity": "sha512-m4ybFiP4UYVORRt7jcdqf8UWx+ywVdAqqsJyruXxAdD3Sv6MDemijWij34mOWdMJ55bEdIb9jACBhxUgNK6sxw==",
       "dev": true,
       "requires": {
-        "component-emitter": "1.2.1",
-        "debug": "~4.1.0",
-        "isarray": "2.0.1"
+        "@types/component-emitter": "^1.2.10",
+        "component-emitter": "~1.3.0",
+        "debug": "~4.3.1"
       },
       "dependencies": {
-        "component-emitter": {
-          "version": "1.2.1",
-          "resolved": "https://registry.npmjs.org/component-emitter/-/component-emitter-1.2.1.tgz",
-          "integrity": "sha1-E3kY1teCg/ffemt8WmPhQOaUJeY=",
-          "dev": true
-        },
         "debug": {
-          "version": "4.1.1",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
-          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "version": "4.3.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.3.1.tgz",
+          "integrity": "sha512-doEwdvm4PCeK4K3RQN2ZC2BYUBaxwLARCqZmMjtF8a51J2Rb0xpVloFRnCODwqjpwnAoao4pelN8l3RJdv3gRQ==",
           "dev": true,
           "requires": {
-            "ms": "^2.1.1"
+            "ms": "2.1.2"
           }
         },
-        "isarray": {
-          "version": "2.0.1",
-          "resolved": "https://registry.npmjs.org/isarray/-/isarray-2.0.1.tgz",
-          "integrity": "sha1-o32U7ZzaLVmGXJ92/llu4fM4dB4=",
-          "dev": true
-        },
         "ms": {
-          "version": "2.1.3",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
-          "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
+          "version": "2.1.2",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.2.tgz",
+          "integrity": "sha512-sGkPx+VjMtmA6MX27oA4FBFELFCZZ4S4XqeGOXCv68tT+jb3vk/RyaKWP0PTKyWtmLSM0b+adUTEvbs1PEaH2w==",
           "dev": true
         }
       }
@@ -10427,12 +10362,6 @@
         "rimraf": "^3.0.0"
       }
     },
-    "to-array": {
-      "version": "0.1.4",
-      "resolved": "https://registry.npmjs.org/to-array/-/to-array-0.1.4.tgz",
-      "integrity": "sha1-F+bBH3PdTz10zaek/zI46a2b+JA=",
-      "dev": true
-    },
     "to-buffer": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/to-buffer/-/to-buffer-1.1.1.tgz",
@@ -10606,9 +10535,9 @@
       }
     },
     "ua-parser-js": {
-      "version": "0.7.22",
-      "resolved": "https://registry.npmjs.org/ua-parser-js/-/ua-parser-js-0.7.22.tgz",
-      "integrity": "sha512-YUxzMjJ5T71w6a8WWVcMGM6YWOTX27rCoIQgLXiWaxqXSx9D7DNjiGWn1aJIRSQ5qr0xuhra77bSIh6voR/46Q==",
+      "version": "0.7.23",
+      "resolved": "https://registry.npmjs.org/ua-parser-js/-/ua-parser-js-0.7.23.tgz",
+      "integrity": "sha512-m4hvMLxgGHXG3O3fQVAyyAQpZzDOvwnhOTjYz5Xmr7r/+LpkNy3vJXdVRWgd1TkAb7NGROZuSy96CrlNVjA7KA==",
       "dev": true
     },
     "unbzip2-stream": {
@@ -10972,6 +10901,12 @@
         "spdx-expression-parse": "^3.0.0"
       }
     },
+    "vary": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
+      "integrity": "sha1-IpnwLG3tMNSllhsLn3RSShj2NPw=",
+      "dev": true
+    },
     "vfile": {
       "version": "4.2.1",
       "resolved": "https://registry.npmjs.org/vfile/-/vfile-4.2.1.tgz",
@@ -11111,12 +11046,6 @@
       "integrity": "sha512-PSNhEJDejZYV7h50BohL09Er9VaIefr2LMAf3OEmpCkjOi34eYyQYAXUTjEQtZJTKcF0E2UKTh+osDLsgNim9Q==",
       "dev": true
     },
-    "xmlhttprequest-ssl": {
-      "version": "1.5.5",
-      "resolved": "https://registry.npmjs.org/xmlhttprequest-ssl/-/xmlhttprequest-ssl-1.5.5.tgz",
-      "integrity": "sha1-wodrBhaKrcQOV9l+gRkayPQ5iz4=",
-      "dev": true
-    },
     "xtend": {
       "version": "4.0.2",
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
@@ -11180,12 +11109,6 @@
         "fd-slicer": "~1.1.0"
       }
     },
-    "yeast": {
-      "version": "0.1.2",
-      "resolved": "https://registry.npmjs.org/yeast/-/yeast-0.1.2.tgz",
-      "integrity": "sha1-AI4G2AlDIMNy28L47XagymyKxBk=",
-      "dev": true
-    },
     "yocto-queue": {
       "version": "0.1.0",
       "resolved": "https://registry.npmjs.org/yocto-queue/-/yocto-queue-0.1.0.tgz",
diff --git a/package.json b/package.json
index 531d66861..9ecb9c9dd 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,7 @@
     "js-test-karma": "karma start js/tests/karma.conf.js",
     "js-test-integration-bundle": "rollup --config js/tests/integration/rollup.bundle.js",
     "js-test-integration-modularity": "rollup --config js/tests/integration/rollup.bundle-modularity.js",
-    "js-test-cloud": "cross-env BROWSER=true npm run js-test-karma",
+    "js-test-cloud": "cross-env BROWSERSTACK=true npm run js-test-karma",
     "js-test-jquery": "cross-env JQUERY=true npm run js-test-karma",
     "lint": "npm-run-all --parallel js-lint css-lint lockfile-lint",
     "docs": "npm-run-all docs-build docs-lint",
@@ -115,14 +115,14 @@
     "eslint": "^7.17.0",
     "eslint-config-xo": "^0.34.0",
     "eslint-plugin-import": "^2.22.1",
-    "eslint-plugin-unicorn": "^25.0.1",
+    "eslint-plugin-unicorn": "^26.0.1",
     "find-unused-sass-variables": "^3.1.0",
     "glob": "^7.1.6",
     "hammer-simulator": "0.0.1",
     "hugo-bin": "^0.68.0",
     "ip": "^1.1.5",
     "jquery": "^3.5.1",
-    "karma": "^5.2.3",
+    "karma": "^6.0.0",
     "karma-browserstack-launcher": "1.4.0",
     "karma-chrome-launcher": "^3.1.0",
     "karma-coverage-istanbul-reporter": "^3.0.3",
diff --git a/scss/_toasts.scss b/scss/_toasts.scss
index 7a1cf7354..5c533d7f5 100644
--- a/scss/_toasts.scss
+++ b/scss/_toasts.scss
@@ -47,4 +47,5 @@
 
 .toast-body {
   padding: $toast-padding-x; // apply to both vertical and horizontal
+  word-wrap: break-word;
 }
diff --git a/site/assets/scss/_subnav.scss b/site/assets/scss/_subnav.scss
index 8979aa3cd..8377ff423 100644
--- a/site/assets/scss/_subnav.scss
+++ b/site/assets/scss/_subnav.scss
@@ -1,7 +1,7 @@
 .bd-subnavbar {
   // The position and z-index are needed for the dropdown to stay on top of the content
   position: relative;
-  z-index: $bd-navbar-zindex;
+  z-index: $zindex-sticky;
   background-color: rgba($white, .95);
   box-shadow: 0 .5rem 1rem rgba(0, 0, 0, .05), inset 0 -1px 0 rgba(0, 0, 0, .15);
 
diff --git a/site/assets/scss/_variables.scss b/site/assets/scss/_variables.scss
index 6e1ae2efd..110600260 100644
--- a/site/assets/scss/_variables.scss
+++ b/site/assets/scss/_variables.scss
@@ -11,6 +11,3 @@ $bd-warning:       #f0ad4e;
 $bd-danger:        #d9534f;
 $dropdown-active-icon: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'><path fill='#292b2c' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/></svg>");
 $sidebar-collapse-icon: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16'><path fill='none' stroke='rgba(0,0,0,.5)' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M5 14l6-6-6-6'/></svg>");
-
-// Higher than core's $zindex-tooltip, which is 1070
-$bd-navbar-zindex: 1080;
diff --git a/site/content/docs/5.0/components/toasts.md b/site/content/docs/5.0/components/toasts.md
index b6f7e3893..bd7bcae9c 100644
--- a/site/content/docs/5.0/components/toasts.md
+++ b/site/content/docs/5.0/components/toasts.md
@@ -43,7 +43,7 @@ Toasts are as flexible as you need and have very little required markup. At a mi
 
 ### Translucent
 
-Toasts are slightly translucent, too, so they blend over whatever they might appear over. For browsers that support the `backdrop-filter` CSS property, we'll also attempt to blur the elements under a toast.
+Toasts are slightly translucent, too, so they blend over whatever they might appear over.
 
 {{< example class="bg-dark" >}}
 <div class="toast" role="alert" aria-live="assertive" aria-atomic="true">
@@ -120,7 +120,7 @@ Alternatively, you can also add additional controls and components to toasts.
 
 ### Color schemes
 
-Building on the above example, you can create different toast color schemes with our [color utilities]({{< docsref "/utilities/colors" >}}). Here we've added `.bg-primary` and `.text-white` to the `.toast`, and then added `.text-white` to our close button. For a crisp edge, we remove the default border with `.border-0`.
+Building on the above example, you can create different toast color schemes with our [color utilities]({{< docsref "/utilities/colors" >}}). Here we've added `.bg-primary` and `.text-white` to the `.toast`, and then added `.btn-close-white` to our close button. For a crisp edge, we remove the default border with `.border-0`.
 
 {{< example class="bg-light" >}}
 <div class="toast d-flex align-items-center text-white bg-primary border-0" role="alert" aria-live="assertive" aria-atomic="true">
diff --git a/site/content/docs/5.0/customize/overview.md b/site/content/docs/5.0/customize/overview.md
index 16847589e..ce94ebfc4 100644
--- a/site/content/docs/5.0/customize/overview.md
+++ b/site/content/docs/5.0/customize/overview.md
@@ -34,3 +34,18 @@ While we cannot go into details here on how to use every package manager, we can
 For those who want to use the distribution files, review the [getting started page]({{< docsref "/getting-started/introduction" >}}) for how to include those files and an example HTML page. From there, consult the docs for the layout, components, and behaviors you'd like to use.
 
 As you familiarize yourself with Bootstrap, continue exploring this section for more details on how to utilize our global options, making use of and changing our color system, how we build our components, how to use our growing list of CSS custom properties, and how to optimize your code when building with Bootstrap.
+
+## CSPs and embedded SVGs
+
+Several Bootstrap components include embedded SVGs in our CSS to style components consistently and easily across browsers and devices. **For organizations with more strict <abbr title="Content Security Policy">CSP</abbr> configurations**, we've documented all instances of our embedded SVGs (all of which are applied via `background-image`) so you can more thoroughly review your options.
+
+- [Accordion]({{< docsref "/components/accordion" >}})
+- [Close button]({{< docsref "/components/close-button" >}}) (used in alerts and modals)
+- [Form checkboxes and radio buttons]({{< docsref "/forms/checks-radios" >}})
+- [Form switches]({{< docsref "/forms/checks-radios#switches" >}})
+- [Form validation icons]({{< docsref "/forms/validation#server-side" >}})
+- [Select menus]({{< docsref "/forms/select" >}})
+- [Carousel controls]({{< docsref "/components/carousel#with-controls" >}})
+- [Navbar toggle buttons]({{< docsref "/components/navbar#responsive-behaviors" >}})
+
+Based on [community conversation](https://github.com/twbs/bootstrap/issues/25394), some options for addressing this in your own codebase include replacing the URLs with locally hosted assets, removing the images and using inline images (not possible in all components), and modifying your CSP. Our recommendation is to carefully review your own security policies and decide on a best path forward, if necessary.
\ No newline at end of file
diff --git a/site/content/docs/5.0/customize/sass.md b/site/content/docs/5.0/customize/sass.md
index 46b822525..d21dff7aa 100644
--- a/site/content/docs/5.0/customize/sass.md
+++ b/site/content/docs/5.0/customize/sass.md
@@ -6,7 +6,7 @@ group: customize
 toc: true
 ---
 
-Utilize our source Sass files to take advantage of variables, maps, mixins, and more. In our build we've increased the Sass rounding precision to 6 (by default it's 5) to prevent issues with browser rounding.
+Utilize our source Sass files to take advantage of variables, maps, mixins, and more.
 
 ## File structure
 
diff --git a/site/content/docs/5.0/examples/carousel-rtl/index.html b/site/content/docs/5.0/examples/carousel-rtl/index.html
index a55560e26..def1abde8 100644
--- a/site/content/docs/5.0/examples/carousel-rtl/index.html
+++ b/site/content/docs/5.0/examples/carousel-rtl/index.html
@@ -49,7 +49,7 @@ extra_css:
           <div class="carousel-caption text-start">
             <h1>عنوان المثال.</h1>
             <p> نهاية الأوضاع ان أضف, هو مما رجوعهم وقدّموا. أي عدد الدمج نهاية وأكثرها, المسرح الباهضة وبولندا حول و, كل أما سياسة أسابيع. مع حيث قُدُماً الكونجرس, بها و خيار ٢٠٠٤, كلا في مكّن وقام. مع يكن زهاء بالفشل, الجوي الصين الشمال إذ على.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">سجل اليوم</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">سجل اليوم</a></p>
           </div>
         </div>
       </div>
@@ -59,7 +59,7 @@ extra_css:
           <div class="carousel-caption">
             <h1>عنوان مثال آخر.</h1>
             <p>ثم تزامناً الفرنسي الإقتصادية دار. لكل عن الضغوط المتّبعة, أن حتى إختار المدن بالإنزال. عن الشمل بالفشل تلك, بل أراض أوزار بلديهما حول. دون لكون والتي ثم, كُلفة ويعزى استطاعوا أن لمّ. جُل بخطوط واحدة البشريةً.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">أعرف أكثر</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">أعرف أكثر</a></p>
           </div>
         </div>
       </div>
@@ -69,7 +69,7 @@ extra_css:
           <div class="carousel-caption text-end">
             <h1>واحد أكثر لقياس جيد.</h1>
             <p>قررت العصبة إيطاليا وتم أن, عن سكان وقامت الحكومة وفي. كان بـ اوروبا اليابانية, ثمّة بوابة يتعلّق عل بعض. عدم رئيس الآلاف أن حدى.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">تصفح المعرض</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">تصفح المعرض</a></p>
           </div>
         </div>
       </div>
@@ -97,19 +97,19 @@ extra_css:
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>عنوان</h2>
         <p>ان وتم عجّل الأجل, قبل نتيجة المشترك بـ, أي جعل جورج أوزار المسرح. أن وإعلان الساحل تلك, مكن ان استبدال الباهضة التكاليف. الى ماذا اليميني الحكومة في, إجلاء نتيجة قبل تم. مساعدة بولندا، أي هذه الحكم.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">عرض التفاصيل</a></p>
+        <p><a class="btn btn-secondary" href="#">عرض التفاصيل</a></p>
       </div><!-- /.col-lg-4 -->
       <div class="col-lg-4">
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>عنوان</h2>
         <p>هو أخر إتفاقية الدولارات الأوروبيّون, ثانية طوكيو و به،, ونتج أعمال مما أم. عن الا يونيو أفريقيا, السيطرة التقليدي ومن ٣٠. هو الغالي الإتفاقية ويكيبيديا، مكن, و الى هُزم اعتداء وايرلندا. وقبل بمباركة الأوروبيّون عن فقد, بتحدّي والفلبين ما كلا.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">عرض التفاصيل</a></p>
+        <p><a class="btn btn-secondary" href="#">عرض التفاصيل</a></p>
       </div><!-- /.col-lg-4 -->
       <div class="col-lg-4">
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>عنوان</h2>
         <p>غير عن الثقيل وسمّيت الأوضاع, لم تاريخ بالحرب للسيطرة حين, دار اللا تطوير تم. الى بشرية اليابان في. أما الشهيرة الإثنان وايرلندا ما, لإعلان واشتدّت و مدن. في غير والحزب للسيطرة الإكتفاء. ثانية الكونجرس الا من, جُل ٣٠ وبداية الشرقية.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">عرض التفاصيل</a></p>
+        <p><a class="btn btn-secondary" href="#">عرض التفاصيل</a></p>
       </div><!-- /.col-lg-4 -->
     </div><!-- /.row -->
 
diff --git a/site/content/docs/5.0/examples/carousel/index.html b/site/content/docs/5.0/examples/carousel/index.html
index 07d579c43..2c0bc5129 100644
--- a/site/content/docs/5.0/examples/carousel/index.html
+++ b/site/content/docs/5.0/examples/carousel/index.html
@@ -48,7 +48,7 @@ extra_css:
           <div class="carousel-caption text-start">
             <h1>Example headline.</h1>
             <p>Some representative placeholder content for the first slide of the carousel.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">Sign up today</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">Sign up today</a></p>
           </div>
         </div>
       </div>
@@ -58,7 +58,7 @@ extra_css:
           <div class="carousel-caption">
             <h1>Another example headline.</h1>
             <p>Some representative placeholder content for the second slide of the carousel.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">Learn more</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">Learn more</a></p>
           </div>
         </div>
       </div>
@@ -68,7 +68,7 @@ extra_css:
           <div class="carousel-caption text-end">
             <h1>One more for good measure.</h1>
             <p>Some representative placeholder content for the third slide of this carousel.</p>
-            <p><a class="btn btn-lg btn-primary" href="#" role="button">Browse gallery</a></p>
+            <p><a class="btn btn-lg btn-primary" href="#">Browse gallery</a></p>
           </div>
         </div>
       </div>
@@ -96,19 +96,19 @@ extra_css:
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>Heading</h2>
         <p>Some representative placeholder content for the three columns of text below the carousel. This is the first column.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">View details &raquo;</a></p>
+        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
       </div><!-- /.col-lg-4 -->
       <div class="col-lg-4">
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>Heading</h2>
         <p>Another exciting bit of representative placeholder content. This time, we've moved on to the second column.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">View details &raquo;</a></p>
+        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
       </div><!-- /.col-lg-4 -->
       <div class="col-lg-4">
         {{< placeholder width="140" height="140" background="#777" color="#777" class="rounded-circle" >}}
         <h2>Heading</h2>
         <p>And lastly this, the third column of representative placeholder content.</p>
-        <p><a class="btn btn-secondary" href="#" role="button">View details &raquo;</a></p>
+        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
       </div><!-- /.col-lg-4 -->
     </div><!-- /.row -->
 
diff --git a/site/content/docs/5.0/extend/approach.md b/site/content/docs/5.0/extend/approach.md
index 552b5f29b..32efbf541 100644
--- a/site/content/docs/5.0/extend/approach.md
+++ b/site/content/docs/5.0/extend/approach.md
@@ -76,3 +76,11 @@ Specifically regarding custom CSS, utilities can help combat increasing file siz
 ## Flexible HTML
 
 While not always possible, we strive to avoid being overly dogmatic in our HTML requirements for components. Thus, we focus on single classes in our CSS selectors and try to avoid immediate children selectors (`>`). This gives you more flexibility in your implementation and helps keep our CSS simpler and less specific.
+
+## Code conventions
+
+[Code Guide](https://codeguide.co/) (from Bootstrap co-creator, @mdo) documents how we write our HTML and CSS across Bootstrap. It specifices guidelines for general formatting, common sense defaults, property and attribute orders, and more.
+
+We use [Stylelint](https://stylelint.io/) to enforce these standards and more in our Sass/CSS. [Our custom Stylelint config](https://github.com/twbs/stylelint-config-twbs-bootstrap) is open source and available for others to use and extend.
+
+We use [vnu-jar](https://www.npmjs.com/package/vnu-jar) to enforce standard and semantic HTML, as well as detecting common errors.
diff --git a/site/content/docs/5.0/forms/floating-labels.md b/site/content/docs/5.0/forms/floating-labels.md
index 3163ea8e0..2012a4e82 100644
--- a/site/content/docs/5.0/forms/floating-labels.md
+++ b/site/content/docs/5.0/forms/floating-labels.md
@@ -61,7 +61,7 @@ To set a custom height on your `<textarea>`, do not use the `rows` attribute. In
 
 ## Selects
 
-Other than `.form-control`, floating labels are only available on `.form-select`s. They work in the same way, but unlike `<input>`s, they'll always show the `<label>` in its floated state.
+Other than `.form-control`, floating labels are only available on `.form-select`s. They work in the same way, but unlike `<input>`s, they'll always show the `<label>` in its floated state. **Selects with `size` and `multiple` are not supported.**
 
 {{< example >}}
 <div class="form-floating">
diff --git a/site/content/docs/5.0/getting-started/build-tools.md b/site/content/docs/5.0/getting-started/build-tools.md
index 46ad928d4..fcee8cc26 100644
--- a/site/content/docs/5.0/getting-started/build-tools.md
+++ b/site/content/docs/5.0/getting-started/build-tools.md
@@ -65,6 +65,12 @@ Our [package.json]({{< param repo >}}/blob/v{{< param current_version >}}/packag
   </tbody>
 </table>
 
+## Sass
+
+Bootstrap uses [Dart Sass](https://sass-lang.com/dart-sass) for compiling our Sass source files into CSS files (included in our build process), and we recommend you do the same if you're compiling Sass using your own asset pipeline. We previously used Node Sass for Bootstrap v4, but LibSass and packages built on top of it, including Node Sass, are now [deprecated](https://sass-lang.com/blog/libsass-is-deprecated).
+
+Dart Sass uses a rounding precision of 10 and for efficiency reasons does not allow adjustment of this value. We don't lower this precision during further processing of our generated CSS, such as during minification, but if you chose to do so we recommend maintaining a precision of at least 6 to prevent issues with browser rounding.
+
 ## Autoprefixer
 
 Bootstrap uses [Autoprefixer][autoprefixer] (included in our build process) to automatically add vendor prefixes to some CSS properties at build time. Doing so saves us time and code by allowing us to write key parts of our CSS a single time while eliminating the need for vendor mixins like those found in v3.
diff --git a/site/content/docs/5.0/getting-started/download.md b/site/content/docs/5.0/getting-started/download.md
index e053eac39..af2d5a5de 100644
--- a/site/content/docs/5.0/getting-started/download.md
+++ b/site/content/docs/5.0/getting-started/download.md
@@ -21,10 +21,10 @@ This doesn't include documentation, source files, or any optional JavaScript dep
 
 Compile Bootstrap with your own asset pipeline by downloading our source Sass, JavaScript, and documentation files. This option requires some additional tooling:
 
-- Sass compiler (Libsass or Ruby Sass is supported) for compiling your CSS.
+- [Sass compiler]({{< docsref "/getting-started/build-tools#sass" >}}) for compiling Sass source files into CSS files
 - [Autoprefixer](https://github.com/postcss/autoprefixer) for CSS vendor prefixing
 
-Should you require [build tools]({{< docsref "/getting-started/build-tools#tooling-setup" >}}), they are included for developing Bootstrap and its docs, but they're likely unsuitable for your own purposes.
+Should you require our full set of [build tools]({{< docsref "/getting-started/build-tools#tooling-setup" >}}), they are included for developing Bootstrap and its docs, but they're likely unsuitable for your own purposes.
 
 <a href="{{< param "download.source" >}}" class="btn btn-bd-primary" onclick="ga('send', 'event', 'Getting started', 'Download', 'Download source');">Download source</a>
 
@@ -52,7 +52,7 @@ If you're using our compiled JavaScript and prefer to include Popper separately,
 
 ## Package managers
 
-Pull in Bootstrap's **source files** into nearly any project with some of the most popular package managers. No matter the package manager, Bootstrap will **require a Sass compiler and [Autoprefixer](https://github.com/postcss/autoprefixer)** for a setup that matches our official compiled versions.
+Pull in Bootstrap's **source files** into nearly any project with some of the most popular package managers. No matter the package manager, Bootstrap will **require a [Sass compiler]({{< docsref "/getting-started/build-tools#sass" >}}) and [Autoprefixer](https://github.com/postcss/autoprefixer)** for a setup that matches our official compiled versions.
 
 ### npm
 
diff --git a/site/content/docs/5.0/getting-started/rtl.md b/site/content/docs/5.0/getting-started/rtl.md
index cd209298b..4ade8359c 100644
--- a/site/content/docs/5.0/getting-started/rtl.md
+++ b/site/content/docs/5.0/getting-started/rtl.md
@@ -136,6 +136,42 @@ $font-family-sans-serif:
   "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji" !default;
 ```
 
+### LTR and RTL at the same time
+
+Need both LTR and RTL on the same page? Thanks to [RTLCSS String Maps](https://rtlcss.com/learn/usage-guide/string-map/), this is pretty straightforward. Wrap your `@import`s with a class, and set a custom rename rule for RTLCSS:
+
+```scss
+/* rtl:begin:options: {
+  "autoRename": true,
+  "stringMap":[
+    "name": "ltr-rtl",
+    "priority": 100,
+    "search": ["ltr"],
+    "replace": ["rtl"],
+    "options": {
+      "scope": "*",
+      "ignoreCase": false
+    }
+  ]
+} */
+.ltr {
+  @import "../node_modules/bootstrap/scss/bootstrap";
+}
+/*rtl:end:options*/
+```
+
+After running Sass then RTLCSS, each selector in your CSS files will be prepended by `.ltr`, and `.rtl` for RTL files. Now you're able to use both files on the same page, and simply use `.ltr` or `.rtl` on your components wrappers to use one or the other direction.
+
+{{< callout warning >}}
+#### Edge cases and known limitations
+
+While this approach is understandable, please pay attention to the following:
+
+1. When switching `.ltr` and `.rtl`, make sure you add `dir` and `lang` attributes accordingly.
+2. Loading both files can be a real performance bottleneck: consider some [optimization]({{< docsref "/customize/optimize" >}}), and maybe try to [load one of those files asynchronously](https://www.filamentgroup.com/lab/load-css-simpler/).
+3. Nesting styles this way will prevent our `form-validation-state()` mixin from working as intended, thus require you tweak it a bit by yourself. [See #31223](https://github.com/twbs/bootstrap/issues/31223).
+{{< /callout >}}
+
 ## The breadcrumb case
 
 The [breadcrumb separator]({{< docsref "/components/breadcrumb" >}}/#changing-the-separator) is the only case requiring its own brand new variable— namely `$breadcrumb-divider-flipped` —defaulting to `$breadcrumb-divider`.
diff --git a/site/content/docs/5.0/migration.md b/site/content/docs/5.0/migration.md
index 895b8c275..5be6c6fa1 100644
--- a/site/content/docs/5.0/migration.md
+++ b/site/content/docs/5.0/migration.md
@@ -50,7 +50,9 @@ Horizontal direction sensitive variables, utilities and mixins are renamed with
 - Renamed `.pl-*` and `.pr-*` to `.ps-*` and `.pe-*`.
 - Renamed `.text-left` and `.text-right` to `.text-start` and `.text-end`.
 
-Breakpoints specific variants are consequently renamed too (eg. `.text-md-start` replaces `.text-md-left`).
+Breakpoints specific variants are consequently renamed too (e.g. `.text-md-start` replaces `.text-md-left`).
+
+**Note**: if you used v4 to make RTL pages, ensure to reverse changes mentioned above: e.g. use `.*-start` were you used `.*-right`.
 
 ##### Mixins
 
@@ -127,6 +129,7 @@ Breakpoints specific variants are consequently renamed too (eg. `.text-md-start`
   - Renamed `.font-style-*` utilities as `.fst-*` for brevity and consistency.
 - Added `.d-grid` to display utilities
 - Added new `gap` utilities (`.gap`) for CSS Grid layouts
+- Removed `.rounded-sm` and `rounded-lg`, and introduced `.rounded-0` to `.rounded-3`. [See #31687](https://github.com/twbs/bootstrap/pull/31687).
 
 ## v5.0.0-alpha2
 
diff --git a/site/content/docs/5.0/utilities/api.md b/site/content/docs/5.0/utilities/api.md
index 7cd002faf..ecd80af5b 100644
--- a/site/content/docs/5.0/utilities/api.md
+++ b/site/content/docs/5.0/utilities/api.md
@@ -289,6 +289,25 @@ $utilities: map-merge(
 );
 ```
 
+#### Rename utilities
+
+Missing v4 utilities, or used to another naming convention? The utilities API can be used to override the resulting `class` of a given utility—for example, to rename `.ms-*` utilities to oldish `.ml-*`:
+
+```scss
+@import "bootstrap/scss/functions";
+@import "bootstrap/scss/variables";
+@import "bootstrap/scss/utilities";
+
+$utilities: map-merge(
+  $utilities, (
+    "margin-start": map-merge(
+      map-get($utilities, "margin-start"),
+      ( class: ml ),
+    ),
+  )
+);
+```
+
 ### Remove utilities
 
 Remove any of the default utilities by setting the group key to `null`. For example, to remove all our `width` utilities, create a `$utilities` `map-merge` and add `"width": null` within.