diff --git a/src/components/bottom-detail-panel/main.vue b/src/components/bottom-detail-panel/main.vue
new file mode 100644
index 0000000..cf7e1af
--- /dev/null
+++ b/src/components/bottom-detail-panel/main.vue
@@ -0,0 +1,123 @@
+<template>
+  <teleport to="body">
+    <transition name="el-fade-in-linear">
+      <section v-if="modelValue" class="bottom-detail-panel" aria-label="详情面板">
+        <header class="bottom-detail-panel__header">
+          <h3>{{ title }}</h3>
+          <el-tooltip content="关闭" placement="top">
+            <el-button :icon="Close" text aria-label="关闭详情面板" @click="close" />
+          </el-tooltip>
+        </header>
+        <div class="bottom-detail-panel__body">
+          <slot />
+        </div>
+        <footer class="bottom-detail-panel__footer">
+          <el-button @click="close">关闭</el-button>
+        </footer>
+      </section>
+    </transition>
+  </teleport>
+</template>
+
+<script>
+import { Close } from '@element-plus/icons-vue';
+
+/**
+ * 底部弹出详情面板（表单页通用）
+ * 固定于视口底部并避让侧边栏，交互对齐应收/应付明细页点「单据号」弹出的单据详情面板
+ */
+export default {
+  name: 'BottomDetailPanel',
+  props: {
+    modelValue: { type: Boolean, default: false },
+    title: { type: String, default: '详情' },
+  },
+  emits: ['update:modelValue'],
+  data() {
+    return { Close };
+  },
+  watch: {
+    // 表单页多被 keep-alive 缓存，切换菜单时组件不销毁，需监听路由收起 teleport 到 body 的面板
+    $route() {
+      this.close();
+    },
+  },
+  methods: {
+    close() {
+      this.$emit('update:modelValue', false);
+    },
+  },
+};
+</script>
+
+<style scoped lang="scss">
+.bottom-detail-panel {
+  position: fixed;
+  z-index: 100;
+  bottom: 0;
+  left: $sidebar_width;
+  width: calc(100% - #{$sidebar_width});
+  max-height: min(60vh, 560px);
+  border-top: 1px solid #eff1f7;
+  background: #fff;
+  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.04);
+}
+
+:global(.avue--collapse) .bottom-detail-panel {
+  left: $sidebar_collapse;
+  width: calc(100% - #{$sidebar_collapse});
+}
+
+:global(.avue-layout--horizontal) .bottom-detail-panel {
+  left: 0;
+  width: 100%;
+}
+
+.bottom-detail-panel__header {
+  display: flex;
+  min-height: 48px;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 20px;
+  border-bottom: 1px solid #eff1f7;
+
+  h3 {
+    margin: 0;
+    padding-left: 12px;
+    border-left: 4px solid #409eff;
+    font-size: 16px;
+    font-weight: 600;
+  }
+}
+
+.bottom-detail-panel__body {
+  max-height: calc(min(60vh, 560px) - 106px);
+  padding: 16px 20px;
+  overflow: auto;
+
+  :deep(.el-table) {
+    --el-table-border-color: #eff1f7;
+  }
+
+  :deep(.el-table__row:nth-child(even) td.el-table__cell) {
+    background: #fafafa;
+  }
+}
+
+.bottom-detail-panel__footer {
+  display: flex;
+  min-height: 57px;
+  align-items: center;
+  justify-content: flex-end;
+  gap: 8px;
+  padding: 0 20px;
+  border-top: 1px solid #eff1f7;
+}
+
+@media screen and (max-width: 992px) {
+  .bottom-detail-panel {
+    left: 0;
+    width: 100%;
+  }
+}
+</style>
diff --git a/src/components/invoice-write-off-table/main.vue b/src/components/invoice-write-off-table/main.vue
index 4da42c0..f229f45 100644
--- a/src/components/invoice-write-off-table/main.vue
+++ b/src/components/invoice-write-off-table/main.vue
@@ -43,7 +43,6 @@
         </el-table-column>
       </el-table-column>
     </el-table>
-    <div v-if="!loading && !rows.length" class="invoice-write-off-table__empty">暂无冲销明细</div>
   </div>
 </template>
 
@@ -134,12 +133,3 @@ export default {
   },
 };
 </script>
-
-<style scoped>
-.invoice-write-off-table__empty {
-  padding: 24px 0;
-  text-align: center;
-  color: #909399;
-  font-size: 13px;
-}
-</style>
diff --git a/src/views/payment/invoice-application-form.vue b/src/views/payment/invoice-application-form.vue
index 83b8138..954f466 100644
--- a/src/views/payment/invoice-application-form.vue
+++ b/src/views/payment/invoice-application-form.vue
@@ -91,7 +91,7 @@
               <el-input
                 :model-value="profitRatePercent"
                 :disabled="readonly"
-                placeholder="选结算单后自动带出，可修改"
+                placeholder="选结算单带出，可修改"
                 @input="handleProfitRateInput"
               >
                 <template #append>%</template>
@@ -363,6 +363,11 @@
       </section-card>
 
       <section-card title="开票明细">
+        <template #extra>
+          <el-button v-if="recordId" type="primary" @click="writeOffPanelVisible = true"
+            >发票冲销</el-button
+          >
+        </template>
         <el-table
           ref="detailTable"
           :data="detailRows"
@@ -412,9 +417,9 @@
         </el-table>
       </section-card>
 
-      <section-card v-if="recordId" title="发票冲销明细">
+      <bottom-detail-panel v-model="writeOffPanelVisible" title="发票冲销明细">
         <invoice-write-off-table biz-type="invoice_apply" :biz-id="recordId" />
-      </section-card>
+      </bottom-detail-panel>
 
       <section-card title="附件信息">
         <vehicle-attachment-table v-model="form.attachments" :readonly="readonly" />
@@ -519,10 +524,12 @@ import * as api from '@/api/payment/invoiceApplication';
 import { getAll as getInvoiceItems } from '@/api/base/invoice-item';
 import { getList as getWaybillList } from '@/api/business/waybill-manage';
 import { getList as getReceivablePayableDetailList } from '@/api/settlement/receivable-payable-detail';
+import { getDetail as getProjectApplyDetail } from '@/api/business/project-apply';
 import { getDictionary } from '@/api/system/dictbiz';
 import { invoiceApplicationDetailColumns } from '@/option/payment/invoiceApplication';
 import VehicleAttachmentTable from '@/components/vehicle-attachment-table/main.vue';
 import InvoiceWriteOffTable from '@/components/invoice-write-off-table/main.vue';
+import BottomDetailPanel from '@/components/bottom-detail-panel/main.vue';
 import { getMkPublicDetail } from '@/api/mk-process';
 import { loadMkEnabled, submitMkApprovalFlow } from '@/utils/mk-approval';
 
@@ -579,12 +586,14 @@ export default {
   components: {
     VehicleAttachmentTable,
     InvoiceWriteOffTable,
+    BottomDetailPanel,
   },
   data() {
     return {
       form: emptyForm(),
       detailRows: [],
       selectedDetailIds: [],
+      writeOffPanelVisible: false,
       receiverInvoiceOptions: [],
       contactOptions: [],
       departmentEmailOptions: [],
@@ -978,11 +987,27 @@ export default {
         allocatedInvoiceAmount: 0,
       }));
       this.form.projectName = first.projectName;
+      this.form.projectId = first.projectId;
       this.form.deptName = first.deptName;
       this.form.issuerName = first.issuerName;
       this.form.undertakingDeptName = first.deptName;
       this.settlementDialog.visible = false;
-      await Promise.all([this.loadSettlementDetails(), this.loadReceiverInformation()]);
+      await Promise.all([
+        this.loadSettlementDetails(),
+        this.loadReceiverInformation(),
+        this.loadProjectProfitRate(),
+      ]);
+    },
+    // 项目利润率：选结算单后带出项目立项利润率（百分数转小数存 form），已手填时不覆盖
+    async loadProjectProfitRate() {
+      if (!this.form.projectId || Number(this.form.profitRate) > 0) return;
+      try {
+        const data = this.unwrapData(await getProjectApplyDetail(this.form.projectId));
+        const rate = Number(data?.profitRate);
+        if (Number.isFinite(rate) && rate > 0) this.form.profitRate = rate / 100;
+      } catch {
+        // 带出失败不阻断选单，保存时后端仍会兜底取项目立项利润率
+      }
     },
     async loadSettlementDetails(resetSelection = true) {
       this.detailRows =
diff --git a/src/views/payment/payment-application-form.vue b/src/views/payment/payment-application-form.vue
index 1cecfd0..5a1b6cc 100644
--- a/src/views/payment/payment-application-form.vue
+++ b/src/views/payment/payment-application-form.vue
@@ -290,6 +290,11 @@
         </el-table>
       </section-card>
       <section-card v-if="showInvoiceSection" title="发票信息">
+        <template #extra>
+          <el-button v-if="recordId" type="primary" @click="writeOffPanelVisible = true"
+            >发票冲销</el-button
+          >
+        </template>
         <el-table :data="form.invoices" border>
           <el-table-column type="index" label="序号" width="70" />
           <el-table-column prop="settlementNo" label="结算单号" min-width="120">
@@ -350,9 +355,9 @@
           </el-table-column>
         </el-table>
       </section-card>
-      <section-card v-if="recordId" title="发票冲销明细">
+      <bottom-detail-panel v-model="writeOffPanelVisible" title="发票冲销明细">
         <invoice-write-off-table biz-type="payment_receipt" :biz-id="recordId" />
-      </section-card>
+      </bottom-detail-panel>
       <section-card title="付款记录">
         <el-table :data="paymentRecords" border
           ><el-table-column type="index" label="序号" width="70" /><el-table-column
@@ -764,6 +769,7 @@ import {
 } from '@/utils/kingdee-attachment';
 import PdfPreview from '@/components/pdf-preview/main.vue';
 import InvoiceWriteOffTable from '@/components/invoice-write-off-table/main.vue';
+import BottomDetailPanel from '@/components/bottom-detail-panel/main.vue';
 
 const attachmentViewerPlugins = [
   imagePlugin(),
@@ -841,12 +847,14 @@ export default {
     OpenFileViewer,
     PdfPreview,
     InvoiceWriteOffTable,
+    BottomDetailPanel,
   },
   data() {
     return {
       form: emptyForm(),
       amountSyncing: false,
       transferPayload: null,
+      writeOffPanelVisible: false,
       // 金蝶侧发票附件查看/下载进行中（行组级 loading 守卫）
       kingdeeAttachmentBusy: false,
       referenceRows: [],