diff --git a/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.js b/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.js
index 34965307b..a3ba522c3 100644
--- a/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.js
+++ b/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.js
@@ -278,7 +278,7 @@ function Styles() {
         width: 100%;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         max-height: 300px;
         z-index: 1;
         position: absolute;
diff --git a/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.tsx b/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.tsx
index 239968932..7eaa986e7 100644
--- a/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.tsx
+++ b/docs/data/base/components/autocomplete/AutocompleteIntroduction/css/index.tsx
@@ -255,7 +255,7 @@ function Styles() {
         width: 100%;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         max-height: 300px;
         z-index: 1;
         position: absolute;
diff --git a/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.js b/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.js
index 3a8d047c2..bf7209a57 100644
--- a/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.js
+++ b/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.js
@@ -205,7 +205,7 @@ const StyledListbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
diff --git a/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.tsx b/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.tsx
index 00d8c19d7..20e90175e 100644
--- a/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.tsx
+++ b/docs/data/base/components/autocomplete/AutocompleteIntroduction/system/index.tsx
@@ -191,7 +191,7 @@ const StyledListbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
diff --git a/docs/data/base/components/autocomplete/ControlledStates.js b/docs/data/base/components/autocomplete/ControlledStates.js
index 039291df3..e2225cae0 100644
--- a/docs/data/base/components/autocomplete/ControlledStates.js
+++ b/docs/data/base/components/autocomplete/ControlledStates.js
@@ -136,7 +136,7 @@ const Listbox = styled('ul')(
   max-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   position: absolute;
diff --git a/docs/data/base/components/autocomplete/ControlledStates.tsx b/docs/data/base/components/autocomplete/ControlledStates.tsx
index b5044424e..ad1d32572 100644
--- a/docs/data/base/components/autocomplete/ControlledStates.tsx
+++ b/docs/data/base/components/autocomplete/ControlledStates.tsx
@@ -136,7 +136,7 @@ const Listbox = styled('ul')(
   max-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   position: absolute;
diff --git a/docs/data/base/components/autocomplete/UseAutocomplete.js b/docs/data/base/components/autocomplete/UseAutocomplete.js
index 7ca907429..53e6a9eb5 100644
--- a/docs/data/base/components/autocomplete/UseAutocomplete.js
+++ b/docs/data/base/components/autocomplete/UseAutocomplete.js
@@ -127,7 +127,7 @@ const Listbox = styled('ul')(
   width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   position: absolute;
diff --git a/docs/data/base/components/autocomplete/UseAutocomplete.tsx b/docs/data/base/components/autocomplete/UseAutocomplete.tsx
index d0b212c1c..9a7458d03 100644
--- a/docs/data/base/components/autocomplete/UseAutocomplete.tsx
+++ b/docs/data/base/components/autocomplete/UseAutocomplete.tsx
@@ -129,7 +129,7 @@ const Listbox = styled('ul')(
   width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   position: absolute;
diff --git a/docs/data/base/components/autocomplete/UseAutocompletePopper.js b/docs/data/base/components/autocomplete/UseAutocompletePopper.js
index 0c5385b8b..bea14f9d7 100644
--- a/docs/data/base/components/autocomplete/UseAutocompletePopper.js
+++ b/docs/data/base/components/autocomplete/UseAutocompletePopper.js
@@ -152,7 +152,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
diff --git a/docs/data/base/components/autocomplete/UseAutocompletePopper.tsx b/docs/data/base/components/autocomplete/UseAutocompletePopper.tsx
index 7b9333884..a2d5efbbb 100644
--- a/docs/data/base/components/autocomplete/UseAutocompletePopper.tsx
+++ b/docs/data/base/components/autocomplete/UseAutocompletePopper.tsx
@@ -163,7 +163,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   max-height: 300px;
   z-index: 1;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
diff --git a/docs/data/base/components/menu/MenuIntroduction/css/index.js b/docs/data/base/components/menu/MenuIntroduction/css/index.js
index bc20c6ddc..1abf2e8b1 100644
--- a/docs/data/base/components/menu/MenuIntroduction/css/index.js
+++ b/docs/data/base/components/menu/MenuIntroduction/css/index.js
@@ -125,7 +125,7 @@ function Styles() {
       min-width: 200px;
       border-radius: 12px;
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       background: ${isDarkMode ? grey[900] : '#fff'};
       border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
       color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuIntroduction/css/index.tsx b/docs/data/base/components/menu/MenuIntroduction/css/index.tsx
index 7082c7d52..903a96213 100644
--- a/docs/data/base/components/menu/MenuIntroduction/css/index.tsx
+++ b/docs/data/base/components/menu/MenuIntroduction/css/index.tsx
@@ -123,7 +123,7 @@ function Styles() {
       min-width: 200px;
       border-radius: 12px;
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       background: ${isDarkMode ? grey[900] : '#fff'};
       border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
       color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuIntroduction/system/index.js b/docs/data/base/components/menu/MenuIntroduction/system/index.js
index 28b3ee1f3..a3374a21f 100644
--- a/docs/data/base/components/menu/MenuIntroduction/system/index.js
+++ b/docs/data/base/components/menu/MenuIntroduction/system/index.js
@@ -65,7 +65,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuIntroduction/system/index.tsx b/docs/data/base/components/menu/MenuIntroduction/system/index.tsx
index c1dc9009f..e5cf6b437 100644
--- a/docs/data/base/components/menu/MenuIntroduction/system/index.tsx
+++ b/docs/data/base/components/menu/MenuIntroduction/system/index.tsx
@@ -64,7 +64,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuSimple/css/index.js b/docs/data/base/components/menu/MenuSimple/css/index.js
index 0e9970c08..fbe46ad61 100644
--- a/docs/data/base/components/menu/MenuSimple/css/index.js
+++ b/docs/data/base/components/menu/MenuSimple/css/index.js
@@ -92,7 +92,7 @@ function Styles() {
       min-width: 200px;
       border-radius: 12px;
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       background: ${isDarkMode ? grey[900] : '#fff'};
       border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
       color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuSimple/css/index.tsx b/docs/data/base/components/menu/MenuSimple/css/index.tsx
index 864904df6..456c3b445 100644
--- a/docs/data/base/components/menu/MenuSimple/css/index.tsx
+++ b/docs/data/base/components/menu/MenuSimple/css/index.tsx
@@ -92,7 +92,7 @@ function Styles() {
       min-width: 200px;
       border-radius: 12px;
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       background: ${isDarkMode ? grey[900] : '#fff'};
       border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
       color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuSimple/system/index.js b/docs/data/base/components/menu/MenuSimple/system/index.js
index a0d6b896f..5287ea2a5 100644
--- a/docs/data/base/components/menu/MenuSimple/system/index.js
+++ b/docs/data/base/components/menu/MenuSimple/system/index.js
@@ -62,7 +62,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuSimple/system/index.tsx b/docs/data/base/components/menu/MenuSimple/system/index.tsx
index 2d6a35137..5e77a149b 100644
--- a/docs/data/base/components/menu/MenuSimple/system/index.tsx
+++ b/docs/data/base/components/menu/MenuSimple/system/index.tsx
@@ -62,7 +62,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuTransitions.js b/docs/data/base/components/menu/MenuTransitions.js
index e6dd9b342..4eb7608c3 100644
--- a/docs/data/base/components/menu/MenuTransitions.js
+++ b/docs/data/base/components/menu/MenuTransitions.js
@@ -65,7 +65,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/MenuTransitions.tsx b/docs/data/base/components/menu/MenuTransitions.tsx
index 59d026e46..51f73f3ef 100644
--- a/docs/data/base/components/menu/MenuTransitions.tsx
+++ b/docs/data/base/components/menu/MenuTransitions.tsx
@@ -64,7 +64,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/UseMenu.js b/docs/data/base/components/menu/UseMenu.js
index 5ac17d551..ea96404ff 100644
--- a/docs/data/base/components/menu/UseMenu.js
+++ b/docs/data/base/components/menu/UseMenu.js
@@ -137,7 +137,7 @@ function Styles() {
       border-radius: 0.75em;
       color: ${grey[900]};
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       box-shadow: 0 4px 6px 0 rgba(0, 0, 0, 0.05);
     }
 
diff --git a/docs/data/base/components/menu/UseMenu.tsx b/docs/data/base/components/menu/UseMenu.tsx
index 0d656cc46..2fe50a37c 100644
--- a/docs/data/base/components/menu/UseMenu.tsx
+++ b/docs/data/base/components/menu/UseMenu.tsx
@@ -136,7 +136,7 @@ function Styles() {
       border-radius: 0.75em;
       color: ${grey[900]};
       overflow: auto;
-      outline: 0px;
+      outline: 0;
       box-shadow: 0 4px 6px 0 rgba(0, 0, 0, 0.05);
     }
 
diff --git a/docs/data/base/components/menu/WrappedMenuItems.js b/docs/data/base/components/menu/WrappedMenuItems.js
index 1c876728c..0a8047714 100644
--- a/docs/data/base/components/menu/WrappedMenuItems.js
+++ b/docs/data/base/components/menu/WrappedMenuItems.js
@@ -90,7 +90,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/menu/WrappedMenuItems.tsx b/docs/data/base/components/menu/WrappedMenuItems.tsx
index 856ebf83a..ed6957419 100644
--- a/docs/data/base/components/menu/WrappedMenuItems.tsx
+++ b/docs/data/base/components/menu/WrappedMenuItems.tsx
@@ -84,7 +84,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectBasic/css/index.js b/docs/data/base/components/select/UnstyledSelectBasic/css/index.js
index 99b05e1d9..e320ce8be 100644
--- a/docs/data/base/components/select/UnstyledSelectBasic/css/index.js
+++ b/docs/data/base/components/select/UnstyledSelectBasic/css/index.js
@@ -135,7 +135,7 @@ function Styles() {
         min-width: 320px;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         background: ${isDarkMode ? grey[900] : '#fff'};
         border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
         color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectBasic/css/index.tsx b/docs/data/base/components/select/UnstyledSelectBasic/css/index.tsx
index 5384968d8..8be4e7c79 100644
--- a/docs/data/base/components/select/UnstyledSelectBasic/css/index.tsx
+++ b/docs/data/base/components/select/UnstyledSelectBasic/css/index.tsx
@@ -135,7 +135,7 @@ function Styles() {
         min-width: 320px;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         background: ${isDarkMode ? grey[900] : '#fff'};
         border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
         color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectBasic/system/index.js b/docs/data/base/components/select/UnstyledSelectBasic/system/index.js
index 3e6665503..021a51f77 100644
--- a/docs/data/base/components/select/UnstyledSelectBasic/system/index.js
+++ b/docs/data/base/components/select/UnstyledSelectBasic/system/index.js
@@ -117,7 +117,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectBasic/system/index.tsx b/docs/data/base/components/select/UnstyledSelectBasic/system/index.tsx
index 5a71d3b35..b923ee2b3 100644
--- a/docs/data/base/components/select/UnstyledSelectBasic/system/index.tsx
+++ b/docs/data/base/components/select/UnstyledSelectBasic/system/index.tsx
@@ -127,7 +127,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectControlled.js b/docs/data/base/components/select/UnstyledSelectControlled.js
index 1f0fea715..4bb5e6070 100644
--- a/docs/data/base/components/select/UnstyledSelectControlled.js
+++ b/docs/data/base/components/select/UnstyledSelectControlled.js
@@ -138,7 +138,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectControlled.tsx b/docs/data/base/components/select/UnstyledSelectControlled.tsx
index cb3ffbf55..d89fc015b 100644
--- a/docs/data/base/components/select/UnstyledSelectControlled.tsx
+++ b/docs/data/base/components/select/UnstyledSelectControlled.tsx
@@ -127,7 +127,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectCustomRenderValue.js b/docs/data/base/components/select/UnstyledSelectCustomRenderValue.js
index 9bbfe640d..5c9e9c075 100644
--- a/docs/data/base/components/select/UnstyledSelectCustomRenderValue.js
+++ b/docs/data/base/components/select/UnstyledSelectCustomRenderValue.js
@@ -140,7 +140,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectCustomRenderValue.tsx b/docs/data/base/components/select/UnstyledSelectCustomRenderValue.tsx
index 9d6fd0411..5d06f4a0c 100644
--- a/docs/data/base/components/select/UnstyledSelectCustomRenderValue.tsx
+++ b/docs/data/base/components/select/UnstyledSelectCustomRenderValue.tsx
@@ -132,7 +132,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectForm.js b/docs/data/base/components/select/UnstyledSelectForm.js
index febaa99a6..9a57aa29d 100644
--- a/docs/data/base/components/select/UnstyledSelectForm.js
+++ b/docs/data/base/components/select/UnstyledSelectForm.js
@@ -132,7 +132,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectForm.tsx b/docs/data/base/components/select/UnstyledSelectForm.tsx
index b4da86548..389cfb15a 100644
--- a/docs/data/base/components/select/UnstyledSelectForm.tsx
+++ b/docs/data/base/components/select/UnstyledSelectForm.tsx
@@ -142,7 +142,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectGrouping.js b/docs/data/base/components/select/UnstyledSelectGrouping.js
index 48d009c34..c5ef5c11d 100644
--- a/docs/data/base/components/select/UnstyledSelectGrouping.js
+++ b/docs/data/base/components/select/UnstyledSelectGrouping.js
@@ -161,7 +161,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectGrouping.tsx b/docs/data/base/components/select/UnstyledSelectGrouping.tsx
index d32e66ef5..0f6f4a7ba 100644
--- a/docs/data/base/components/select/UnstyledSelectGrouping.tsx
+++ b/docs/data/base/components/select/UnstyledSelectGrouping.tsx
@@ -146,7 +146,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.js b/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.js
index 5da7f1add..4c51da525 100644
--- a/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.js
+++ b/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.js
@@ -165,7 +165,7 @@ function Styles() {
         min-width: 320px;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         background: ${isDarkMode ? grey[900] : '#fff'};
         border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
         color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.tsx b/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.tsx
index 3c22fae9a..d42a0b141 100644
--- a/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.tsx
+++ b/docs/data/base/components/select/UnstyledSelectIntroduction/css/index.tsx
@@ -172,7 +172,7 @@ function Styles() {
         min-width: 320px;
         border-radius: 12px;
         overflow: auto;
-        outline: 0px;
+        outline: 0;
         background: ${isDarkMode ? grey[900] : '#fff'};
         border: 1px solid ${isDarkMode ? grey[700] : grey[200]};
         color: ${isDarkMode ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.js b/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.js
index ce0ae92f8..c35c6de1e 100644
--- a/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.js
+++ b/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.js
@@ -132,7 +132,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.tsx b/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.tsx
index 32924f754..34f5ea9da 100644
--- a/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.tsx
+++ b/docs/data/base/components/select/UnstyledSelectIntroduction/system/index.tsx
@@ -128,7 +128,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectMultiple.js b/docs/data/base/components/select/UnstyledSelectMultiple.js
index 1beed3b4c..a90d1c7ae 100644
--- a/docs/data/base/components/select/UnstyledSelectMultiple.js
+++ b/docs/data/base/components/select/UnstyledSelectMultiple.js
@@ -129,7 +129,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectMultiple.tsx b/docs/data/base/components/select/UnstyledSelectMultiple.tsx
index 6e685cf4a..839b73f2d 100644
--- a/docs/data/base/components/select/UnstyledSelectMultiple.tsx
+++ b/docs/data/base/components/select/UnstyledSelectMultiple.tsx
@@ -124,7 +124,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectObjectValues.js b/docs/data/base/components/select/UnstyledSelectObjectValues.js
index cc501801b..ff46f1f94 100644
--- a/docs/data/base/components/select/UnstyledSelectObjectValues.js
+++ b/docs/data/base/components/select/UnstyledSelectObjectValues.js
@@ -145,7 +145,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectObjectValues.tsx b/docs/data/base/components/select/UnstyledSelectObjectValues.tsx
index 1665e01fb..a134996b6 100644
--- a/docs/data/base/components/select/UnstyledSelectObjectValues.tsx
+++ b/docs/data/base/components/select/UnstyledSelectObjectValues.tsx
@@ -144,7 +144,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectObjectValuesForm.js b/docs/data/base/components/select/UnstyledSelectObjectValuesForm.js
index 1b037851c..f6362adcf 100644
--- a/docs/data/base/components/select/UnstyledSelectObjectValuesForm.js
+++ b/docs/data/base/components/select/UnstyledSelectObjectValuesForm.js
@@ -209,7 +209,7 @@ const Listbox = styled('ul')(
   border-radius: 8px;
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   box-shadow: 0px 2px 6px ${
     theme.palette.mode === 'dark' ? 'rgba(0,0,0, 0.50)' : 'rgba(0,0,0, 0.05)'
   };
diff --git a/docs/data/base/components/select/UnstyledSelectObjectValuesForm.tsx b/docs/data/base/components/select/UnstyledSelectObjectValuesForm.tsx
index 6681e2b87..cf636736e 100644
--- a/docs/data/base/components/select/UnstyledSelectObjectValuesForm.tsx
+++ b/docs/data/base/components/select/UnstyledSelectObjectValuesForm.tsx
@@ -208,7 +208,7 @@ const Listbox = styled('ul')(
   border-radius: 8px;
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   box-shadow: 0px 2px 6px ${
     theme.palette.mode === 'dark' ? 'rgba(0,0,0, 0.50)' : 'rgba(0,0,0, 0.05)'
   };
diff --git a/docs/data/base/components/select/UnstyledSelectRichOptions.js b/docs/data/base/components/select/UnstyledSelectRichOptions.js
index f5856a40f..750557198 100644
--- a/docs/data/base/components/select/UnstyledSelectRichOptions.js
+++ b/docs/data/base/components/select/UnstyledSelectRichOptions.js
@@ -138,7 +138,7 @@ const Listbox = styled('ul')(
   max-height: 400px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectRichOptions.tsx b/docs/data/base/components/select/UnstyledSelectRichOptions.tsx
index 2fa6edba1..bcc76af39 100644
--- a/docs/data/base/components/select/UnstyledSelectRichOptions.tsx
+++ b/docs/data/base/components/select/UnstyledSelectRichOptions.tsx
@@ -133,7 +133,7 @@ const Listbox = styled('ul')(
   max-height: 400px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectTransitions.js b/docs/data/base/components/select/UnstyledSelectTransitions.js
index c2cbfe87a..ea94bed12 100644
--- a/docs/data/base/components/select/UnstyledSelectTransitions.js
+++ b/docs/data/base/components/select/UnstyledSelectTransitions.js
@@ -135,7 +135,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UnstyledSelectTransitions.tsx b/docs/data/base/components/select/UnstyledSelectTransitions.tsx
index ea27f0d96..ddd4db2b3 100644
--- a/docs/data/base/components/select/UnstyledSelectTransitions.tsx
+++ b/docs/data/base/components/select/UnstyledSelectTransitions.tsx
@@ -131,7 +131,7 @@ const Listbox = styled('ul')(
   min-width: 320px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[700] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/components/select/UseSelect.js b/docs/data/base/components/select/UseSelect.js
index 503245be7..6701c1b5b 100644
--- a/docs/data/base/components/select/UseSelect.js
+++ b/docs/data/base/components/select/UseSelect.js
@@ -99,7 +99,7 @@ const Listbox = styled('ul')(
   width: 100%;
   overflow: auto;
   z-index: 1;
-  outline: 0px;
+  outline: 0;
   list-style: none;
   box-shadow: 0px 2px 6px ${
     theme.palette.mode === 'dark' ? 'rgba(0,0,0, 0.50)' : 'rgba(0,0,0, 0.05)'
diff --git a/docs/data/base/components/select/UseSelect.tsx b/docs/data/base/components/select/UseSelect.tsx
index 153f88ed7..de23c3976 100644
--- a/docs/data/base/components/select/UseSelect.tsx
+++ b/docs/data/base/components/select/UseSelect.tsx
@@ -102,7 +102,7 @@ const Listbox = styled('ul')(
   width: 100%;
   overflow: auto;
   z-index: 1;
-  outline: 0px;
+  outline: 0;
   list-style: none;
   box-shadow: 0px 2px 6px ${
     theme.palette.mode === 'dark' ? 'rgba(0,0,0, 0.50)' : 'rgba(0,0,0, 0.05)'
diff --git a/docs/data/base/getting-started/accessibility/KeyboardNavigation.js b/docs/data/base/getting-started/accessibility/KeyboardNavigation.js
index 21b4f4840..15ea9b22f 100644
--- a/docs/data/base/getting-started/accessibility/KeyboardNavigation.js
+++ b/docs/data/base/getting-started/accessibility/KeyboardNavigation.js
@@ -139,7 +139,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[800] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/data/base/getting-started/accessibility/KeyboardNavigation.tsx b/docs/data/base/getting-started/accessibility/KeyboardNavigation.tsx
index ca64e0cec..87c7a97b6 100644
--- a/docs/data/base/getting-started/accessibility/KeyboardNavigation.tsx
+++ b/docs/data/base/getting-started/accessibility/KeyboardNavigation.tsx
@@ -149,7 +149,7 @@ const Listbox = styled('ul')(
   min-width: 200px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: ${theme.palette.mode === 'dark' ? grey[900] : '#fff'};
   border: 1px solid ${theme.palette.mode === 'dark' ? grey[800] : grey[200]};
   color: ${theme.palette.mode === 'dark' ? grey[300] : grey[900]};
diff --git a/docs/public/static/components-gallery/base-theme.css b/docs/public/static/components-gallery/base-theme.css
index 937fc23ee..d31371059 100644
--- a/docs/public/static/components-gallery/base-theme.css
+++ b/docs/public/static/components-gallery/base-theme.css
@@ -410,7 +410,7 @@
   min-width: 200px;
   border-radius: var(--border-radius-lg);
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: var(--bg-default);
   border: var(--border-soft);
   box-shadow: var(--shadow-elevation-2);
@@ -620,7 +620,7 @@
   margin: 12px 0;
   border-radius: var(--border-radius-lg);
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background: var(--bg-default);
   border: var(--border-soft);
   box-shadow: var(--shadow-elevation-2);
diff --git a/docs/src/modules/home/BaseUIThemesDemo.tsx b/docs/src/modules/home/BaseUIThemesDemo.tsx
index 60ac455f3..600568bea 100644
--- a/docs/src/modules/home/BaseUIThemesDemo.tsx
+++ b/docs/src/modules/home/BaseUIThemesDemo.tsx
@@ -589,7 +589,7 @@ const StyledMenuListbox = styled('ul')(`
   min-width: 230px;
   border-radius: 12px;
   overflow: auto;
-  outline: 0px;
+  outline: 0;
   background-color: var(--muidocs-palette-background-default);
   border-radius: min(var(--border-radius), 16px);
   border: var(--border-width) solid;