fix(layout): 공개 페이지 2중 패딩 제거

- 레이아웃 그리드의 px만 남기고 메인/섹션의 중복 px를 제거.

Co-authored-by: Cursor <cursoragent@cursor.com>

pages/tag/[slug].vue

@@ -29,7 +29,7 @@ const tagPosts = computed(() => posts.value
 
 <template>
   <MainColumn>
-    <section class="px-5 pt-4 sm:px-6 sm:pt-5">
+    <section class="pt-4 sm:pt-5">
       <div class="mx-auto flex max-w-[720px] flex-col gap-4 border-b border-[var(--site-line)] pb-4 sm:pb-5">
         <div class="flex flex-col gap-1">
           <h1 class="text-lg font-medium leading-tight sm:text-xl">
@@ -42,7 +42,7 @@ const tagPosts = computed(() => posts.value
       </div>
     </section>
 
-    <section class="px-5 sm:px-6">
+    <section>
       <div class="mx-auto flex max-w-[720px] flex-col gap-8">
         <div class="flex flex-col divide-y divide-[var(--site-line)]" data-post-feed="latest">
           <article
@@ -127,7 +127,7 @@ const tagPosts = computed(() => posts.value
       </div>
     </section>
 
-    <section v-if="tagPosts.length === 0" class="px-5 py-4 sm:px-6">
+    <section v-if="tagPosts.length === 0" class="py-4">
       <div class="mx-auto max-w-[720px] text-sm site-muted">
         이 태그에 연결된 글이 없습니다.
       </div>