feat: add new btn-default style

src/assets/styles/tailwind.css

@@ -146,3 +146,9 @@ thead .fc-day-selected:hover {
 .is-mismatched {
   color: var(--orange);
 }
+
+@layer components {
+  .btn-default {
+    @apply tw-bg-gray-100 tw-border tw-border-solid tw-border-black/5 tw-transition hover:enabled:tw-brightness-95 focus-visible:enabled:tw-brightness-95;
+  }
+}