style(Tools_800_Upload): 调整上传组件样式

- 修改进度列表文本颜色为黑色
- 调整按钮容器宽度从45vw改为90vw，设置最小和最大宽度均为90vw
- 保持滚动条高度为400px的布局结构

frontend/src/components/Tools_800_Upload.vue

@@ -101,7 +101,7 @@ watch(() => progressList.value.length, () => {
       <el-scrollbar height="400px"  ref="scrollbarRef">
         <el-empty v-if="progressList.length==0" description="请根据上述提示选择目录" :image-size="100" />
         <div v-else style="padding-bottom: 15%">
-          <el-text class="mx-1" type="success" v-for="item in progressList">
+          <el-text class="mx-1" style="color:#000" type="success" v-for="item in progressList">
             {{item.message}}<br/>
           </el-text>
         </div>
@@ -139,7 +139,8 @@ watch(() => progressList.value.length, () => {
 }
 .handler_btn{
   flex: 1;
-  max-width: 45vw;
+  min-width: 90vw;
+  max-width: 90vw;
 }
 :deep(.el-card__body){
 padding: 0 3%;