fix: 修复素材API配置页面UI问题

frontend/src/views/Settings.vue

@@ -1203,7 +1203,7 @@
                 style="margin-bottom: 24px;"
               />
 
-              <a-form :model="externalAssetApiConfig" layout="vertical" class="external-api-form">
+              <a-form :model="externalAssetApiConfig" layout="vertical" class="external-api-form" style="max-width: 600px;">
                 <a-form-item label="启用第三方素材API">
                   <a-switch
                     v-model:checked="externalAssetApiConfig.enabled"
@@ -1233,6 +1233,7 @@
                     placeholder="请输入API密钥"
                     size="large"
                     :disabled="!externalAssetApiConfig.enabled"
+                    style="width: 100%;"
                   />
                   <div style="margin-top: 8px; font-size: 12px; color: #888;">
                     用于调用第三方素材API的密钥（X-API-Key）
@@ -1245,8 +1246,14 @@
                       <template #icon><Icon name="check" size="sm" /></template>
                       保存配置
                     </a-button>
-                    <a-button size="large" @click="handleTestExternalAssetApi" :loading="testingExternalAssetApi" :disabled="!externalAssetApiConfig.apiUrl || !externalAssetApiConfig.apiKey">
-                      <template #icon><Icon name="refresh" size="sm" /></template>
+                    <a-button 
+                      size="large" 
+                      @click="handleTestExternalAssetApi" 
+                      :loading="testingExternalAssetApi" 
+                      :disabled="!externalAssetApiConfig.apiUrl || !externalAssetApiConfig.apiKey"
+                      style="background: transparent; border-color: #31f08b; color: #31f08b;"
+                    >
+                      <template #icon><Icon name="refresh" size="sm" color="#31f08b" /></template>
                       测试连接
                     </a-button>
                   </a-space>