fix(Button): correct loading alignment

.changeset/light-pants-listen.md

@@ -0,0 +1,5 @@
+---
+"@primer/react": patch
+---
+
+fix(Button): correct loading alignment

packages/react/src/AnchoredOverlay/__snapshots__/AnchoredOverlay.test.tsx.snap

@@ -13,7 +13,7 @@ exports[`AnchoredOverlay > should render consistently when open 1`] = `
       aria-describedby=":rd:-loading-announcement"
       aria-expanded="true"
       aria-haspopup="true"
-      class="_ButtonBase_130zs_2"
+      class="_ButtonBase_149hc_2"
       data-loading="false"
       data-no-visuals="true"
       data-size="medium"
@@ -23,12 +23,12 @@ exports[`AnchoredOverlay > should render consistently when open 1`] = `
       type="button"
     >
       <span
-        class="_ButtonContent_130zs_101"
+        class="_ButtonContent_149hc_101"
         data-align="center"
         data-component="buttonContent"
       >
         <span
-          class="_Label_130zs_128"
+          class="_Label_149hc_128"
           data-component="text"
         >
           Anchor Button

packages/react/src/Button/ButtonBase.module.css

@@ -243,6 +243,14 @@
     }
   }
 
+  /* Styles for the spinner element displayed when the Button is in a loading state.
+   * Ensures the spinner is centered within its container. */
+  .LoadingSpinner {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+  }
+
   /* Default Variant */
 
   &:where([data-variant='default']) {