에디터 보조 UI 컴포넌트 분리

components/admin/AdminMarkdownMediaPickerModal.vue

@@ -313,3 +313,50 @@ const handleFileChange = (event) => {
     </div>
   </div>
 </template>
+
+<style scoped>
+.admin-markdown-media-picker__upload-zone--uploading::before {
+  position: absolute;
+  inset: 0;
+  content: '';
+  background: linear-gradient(110deg, transparent 0%, rgba(255, 255, 255, 0.72) 45%, transparent 72%);
+  transform: translateX(-100%);
+  animation: admin-markdown-media-picker-upload-sheen 1.4s ease-in-out infinite;
+}
+
+.admin-markdown-media-picker__upload-spinner {
+  animation: admin-markdown-media-picker-upload-spin 0.8s linear infinite;
+}
+
+.admin-markdown-media-picker__upload-skeleton::before {
+  display: block;
+  width: 40%;
+  height: 100%;
+  content: '';
+  border-radius: inherit;
+  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.86), transparent);
+  animation: admin-markdown-media-picker-upload-skeleton 1.15s ease-in-out infinite;
+}
+
+@keyframes admin-markdown-media-picker-upload-spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+
+@keyframes admin-markdown-media-picker-upload-sheen {
+  to {
+    transform: translateX(100%);
+  }
+}
+
+@keyframes admin-markdown-media-picker-upload-skeleton {
+  from {
+    transform: translateX(-120%);
+  }
+
+  to {
+    transform: translateX(260%);
+  }
+}
+</style>