fix downloading icon

src/components/cards/DownloadingCard.vue

@@ -109,9 +109,10 @@ async function deleteDownload() {
     </VCardText>
 
     <VCardActions class="justify-space-between">
-      <VBtn @click="toggleDownload">
-        <span class="ms-2">{{ isDownloading ? "暂停" : "开始" }}</span>
-      </VBtn>
+      <VBtn
+        :icon="`${isDownloading ? 'mdi-pause' : 'mdi-play'}`"
+        @click="toggleDownload"
+      />
       <VBtn
         color="error"
         icon="mdi-trash-can-outline"