theme: extract more styles (#22734)

Extract shared styling into appropriate utilities.
Improve toc width.

assets/css/components.css

@@ -94,6 +94,9 @@
     @apply h-12 w-12 overflow-hidden;
   }
 }
+.button {
+  @apply mt-1 inline-block rounded-sm bg-blue-500 p-1 px-3 text-blue-50 text-white hover:bg-blue-600 dark:bg-blue-500 hover:dark:bg-blue-400;
+}
 
 .summary-bar {
   @apply my-1 mt-4 flex flex-col rounded-sm border-1 border-gray-100 bg-gray-50 p-4 dark:border-gray-800 dark:bg-gray-900;

assets/css/utilities.css

@@ -251,3 +251,6 @@
     }
   }
 }
+@utility chip {
+  @apply border-divider-light dark:border-divider-dark inline-flex items-center gap-1 rounded-full border bg-gray-100 px-2 text-sm text-gray-800 select-none dark:bg-gray-700 dark:text-gray-200;
+}