element -plus dialog里面的线怎么去掉？

 <div>
      <el-dialog class="my-dialog" v-model="visible" :show-close="false" width="30%" top="40vh">
        <template #header="{ titleId, titleClass }">
          <div class="my-header">
            <div class="title">
              <el-icon class="title-icon"><InfoFilled /></el-icon>
              <h4 :id="titleId" :class="titleClass">是否确定删除该任务项!</h4>
            </div>
          </div>
        </template>
        <div class="content">删除后该项不可恢复</div>
        <div class="close">
          <el-button @click="close"> 取消 </el-button>
          <el-button type="primary" @click="deleteHandle"> 确定 </el-button>
        </div>
      </el-dialog>
    </div>