diff --git a/index.css b/index.css
index a9f3544..55d2787 100644
--- a/index.css
+++ b/index.css
@@ -98,7 +98,11 @@ dialog:not([open]) {
 }
 dialog {
   position: absolute;
-  justify-self: dialog;
+  inset-inline-start: 0;
+  inset-inline-end: 0;
+  width: fit-content;
+  height: fit-content;
+  margin: auto;
   border: solid;
   padding: 1em;
   background-color: Canvas;
@@ -106,8 +110,8 @@ dialog {
 }
 dialog:modal {
   position: fixed;
-  place-self: dialog;
   overflow: auto;
+  inset-block: 0;
   max-width: calc(100% - 6px - 2em);
   max-height: calc(100% - 6px - 2em);
 }
@@ -125,7 +129,10 @@ dialog:popover-open {
 
 [popover] {
   position: fixed;
-  place-self: dialog;
+  inset: 0;
+  width: fit-content;
+  height: fit-content;
+  margin: auto;
   border: solid;
   padding: 0.25em;
   overflow: auto;
diff --git a/index.js b/index.js
index 3c3c881..b3c0ee6 100644
--- a/index.js
+++ b/index.js
@@ -200,8 +200,24 @@ export default [
         value: 'absolute',
       },
       {
-        property: 'justify-self',
-        value: 'dialog',
+        property: 'inset-inline-start',
+        value: '0',
+      },
+      {
+        property: 'inset-inline-end',
+        value: '0',
+      },
+      {
+        property: 'width',
+        value: 'fit-content',
+      },
+      {
+        property: 'height',
+        value: 'fit-content',
+      },
+      {
+        property: 'margin',
+        value: 'auto',
       },
       {
         property: 'border',
@@ -229,14 +245,14 @@ export default [
         property: 'position',
         value: 'fixed',
       },
-      {
-        property: 'place-self',
-        value: 'dialog',
-      },
       {
         property: 'overflow',
         value: 'auto',
       },
+      {
+        property: 'inset-block',
+        value: '0',
+      },
       {
         property: 'max-width',
         value: 'calc(100% - 6px - 2em)',
@@ -286,8 +302,20 @@ export default [
         value: 'fixed',
       },
       {
-        property: 'place-self',
-        value: 'dialog',
+        property: 'inset',
+        value: '0',
+      },
+      {
+        property: 'width',
+        value: 'fit-content',
+      },
+      {
+        property: 'height',
+        value: 'fit-content',
+      },
+      {
+        property: 'margin',
+        value: 'auto',
       },
       {
         property: 'border',