refactor: change page header style

src/components/PageHeader.vue

 <template>
   <div class="tw-flex tw-items-center tw-justify-between">
-    <h3 class="tw-m-0">
+    <h1 class="tw-text-5xl tw-font-black tw-m-0">
       {{ title }}
       <small
         v-if="selectedShow"
@@ -9,7 +9,7 @@
       >
         {{ selectedShow.name }}
       </small>
-    </h3>
+    </h1>
     <div class="tw-flex tw-justify-end tw-gap-4">
       <slot />
     </div>