fix UI

src/admin/announcement/detail.vue

@@ -98,7 +98,7 @@ onMounted(init)
     v-model:value="announcement.content"
     :min-height="200"
   />
-  <n-flex justify="end">
+  <n-flex style="margin-bottom: 100px;" justify="end">
     <n-button type="primary" @click="submit">保存</n-button>
   </n-flex>
 </template>

src/admin/contest/detail.vue

@@ -127,7 +127,7 @@ onMounted(getContestDetail)
     v-model:value="contest.description"
     :min-height="200"
   />
-  <n-flex justify="end">
+  <n-flex style="margin-bottom: 100px;" justify="end">
     <n-button type="primary" @click="submit">保存</n-button>
   </n-flex>
 </template>

src/admin/problem/detail.vue

@@ -511,7 +511,7 @@ watch(
       </n-flex>
     </template>
   </n-alert>
-  <n-space justify="space-between">
+  <n-space style="margin-bottom: 100px;" justify="space-between">
     <n-form inline label-placement="left" :show-feedback="false">
       <n-form-item label="语言">
         <n-checkbox-group v-model:value="problem.languages">