diff --git a/src/App.vue b/src/App.vue
index 031025a..552be6b 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -196,17 +196,6 @@
                     />
                   </button>
                 </div>
-                <div class="column-row total-row">
-                  <img :src="iconDescription" alt="总和" class="column-icon" />
-                  <span class="column-label">总和</span>
-                  <button
-                    class="select-btn"
-                    type="button"
-                    @click="targetShowTotal = !targetShowTotal"
-                  >
-                    <img :src="targetShowTotal ? iconCheckboxOn : iconCheckboxOff" alt="复选" />
-                  </button>
-                </div>
               </div>
             </template>
           </div>
@@ -259,6 +248,18 @@
                 <span class="direction-switch-thumb" />
               </span>
             </button>
+            <label class="label-position-control">
+              <span class="label-position-label">标签位置</span>
+              <select v-model="labelPositionMode" class="label-position-select">
+                <option
+                  v-for="option in labelPositionOptions"
+                  :key="option.value"
+                  :value="option.value"
+                >
+                  {{ option.label }}
+                </option>
+              </select>
+            </label>
           </div>
         </div>
 
@@ -296,7 +297,7 @@ import * as echarts from 'echarts/core';
 import type { EChartsOption } from 'echarts';
 import { SankeyChart } from 'echarts/charts';
 import { TooltipComponent } from 'echarts/components';
-import { CanvasRenderer } from 'echarts/renderers';
+import { CanvasRenderer, SVGRenderer } from 'echarts/renderers';
 import {
   applyDirection,
   buildSankeyData,
@@ -325,7 +326,7 @@ import iconZhedie from '../assets/icons/zhedie.svg';
 import iconGap from '../assets/icons/gap.svg';
 import iconPadding from '../assets/icons/padding.svg';
 
-echarts.use([SankeyChart, TooltipComponent, CanvasRenderer]);
+echarts.use([SankeyChart, TooltipComponent, CanvasRenderer, SVGRenderer]);
 
 const themes = THEME_PRESETS;
 const selectedThemeId = ref<string>('figma-violet');
@@ -350,7 +351,7 @@ const buildResult = ref<SankeyBuildResult | null>(null);
 
 const mapping = reactive<MappingConfig>({
   sourceDataColumn: 2,
-  sourceDescriptionColumns: [0, 1],
+  sourceDescriptionColumns: [0],
   targetDescriptionColumns: [2],
   delimiter: '-'
 });
@@ -358,7 +359,14 @@ const mapping = reactive<MappingConfig>({
 const direction = ref<'source-to-target' | 'target-to-source'>('source-to-target');
 const nodeGap = ref(5);
 const chartPadding = ref(24);
-const targetShowTotal = ref(true);
+type LabelPositionMode = 'inner' | 'outer' | 'left' | 'right';
+const labelPositionMode = ref<LabelPositionMode>('inner');
+const labelPositionOptions: Array<{ value: LabelPositionMode; label: string }> = [
+  { value: 'inner', label: '向内' },
+  { value: 'outer', label: '向外' },
+  { value: 'left', label: '向左' },
+  { value: 'right', label: '向右' }
+];
 /**
  * 左侧字段区块的展开/折叠状态。
  * true 表示展开，false 表示折叠。
@@ -385,65 +393,70 @@ const columnHeaders = computed(() => {
   return ['列1', '列2', '列3', '列4'];
 });
 
-/**
- * 格式化总和数值，统一使用千分位显示。
- */
-function formatTotalValue(value: number): string {
-  return value.toLocaleString('zh-CN', { maximumFractionDigits: 10 });
-}
-
-/**
- * 统计每个 target 的汇总值，用于展示“目标管道总和”。
- */
-const targetTotalValueMap = computed(() => {
-  const result = buildResult.value;
-  const map = new Map<string, number>();
-  if (!result) {
-    return map;
-  }
-
-  result.links.forEach((link) => {
-    map.set(link.target, (map.get(link.target) ?? 0) + link.value);
-  });
-
-  return map;
-});
-
-/**
- * 将原始 target 名称映射为“target + 总和”显示名。
- * 例如：男 -> 男 1,200
- */
-const targetDisplayNameMap = computed(() => {
-  const map = new Map<string, string>();
-  if (!targetShowTotal.value) {
-    return map;
-  }
-
-  targetTotalValueMap.value.forEach((total, targetName) => {
-    map.set(targetName, `${targetName} ${formatTotalValue(total)}`);
-  });
-
-  return map;
-});
-
 const buildWarnings = computed(() => buildResult.value?.meta.warnings.slice(0, 8) ?? []);
 
+/**
+ * 根据“标签位置”下拉框值，计算左右端节点的标签朝向。
+ * - 向内：左端标签朝右，右端标签朝左
+ * - 向外：左端标签朝左，右端标签朝右
+ * - 向左：两端都朝左
+ * - 向右：两端都朝右
+ */
+function resolveEdgeLabelPosition(
+  incomingCount: number,
+  outgoingCount: number,
+  mode: LabelPositionMode
+): 'left' | 'right' | undefined {
+  const isLeftEdge = incomingCount === 0 && outgoingCount > 0;
+  const isRightEdge = outgoingCount === 0 && incomingCount > 0;
+
+  if (!isLeftEdge && !isRightEdge) {
+    return undefined;
+  }
+
+  if (mode === 'left') {
+    return 'left';
+  }
+  if (mode === 'right') {
+    return 'right';
+  }
+  if (mode === 'inner') {
+    return isLeftEdge ? 'right' : 'left';
+  }
+  return isLeftEdge ? 'left' : 'right';
+}
+
 const chartNodes = computed(() => {
   const links = chartLinks.value;
   const names = new Set<string>();
+  const incomingCountMap = new Map<string, number>();
+  const outgoingCountMap = new Map<string, number>();
 
   links.forEach((link) => {
     names.add(link.source);
     names.add(link.target);
+    outgoingCountMap.set(link.source, (outgoingCountMap.get(link.source) ?? 0) + 1);
+    incomingCountMap.set(link.target, (incomingCountMap.get(link.target) ?? 0) + 1);
   });
 
   const palette = selectedTheme.value.colors;
-  return Array.from(names).map((name, index) => ({
-    name,
-    itemStyle: {
-      color: palette[index % palette.length]
-    }
-  }));
+  return Array.from(names).map((name, index) => {
+    const incomingCount = incomingCountMap.get(name) ?? 0;
+    const outgoingCount = outgoingCountMap.get(name) ?? 0;
+    const position = resolveEdgeLabelPosition(incomingCount, outgoingCount, labelPositionMode.value);
+
+    return {
+      name,
+      itemStyle: {
+        color: palette[index % palette.length]
+      },
+      label: position
+        ? {
+            position
+          }
+        : undefined
+    };
+  });
 });
 
 const chartLinks = computed(() => {
@@ -451,12 +464,7 @@ const chartLinks = computed(() => {
     return [];
   }
 
-  const linksWithDisplayName = buildResult.value.links.map((link) => ({
-    ...link,
-    target: targetDisplayNameMap.value.get(link.target) ?? link.target
-  }));
-
-  return applyDirection(linksWithDisplayName, direction.value);
+  return applyDirection(buildResult.value.links, direction.value);
 });
 
 const chartOption = computed<EChartsOption>(() => {
@@ -742,15 +750,40 @@ function openFileDialog(): void {
   fileInputRef.value?.click();
 }
 
-function setDefaultMappingByColumns(columnSize: number): void {
-  const safeSize = Math.max(columnSize, 1);
-  const safeColumn = (index: number): number => Math.min(index, safeSize - 1);
+/**
+ * 将表头统一为可匹配字符串：小写 + 去空格/下划线/中划线。
+ */
+function normalizeHeaderName(header: string): string {
+  return header.trim().toLowerCase().replace(/[\s_-]+/g, '');
+}
 
-  mapping.sourceDataColumn = safeColumn(2);
-  mapping.sourceDescriptionColumns = [safeColumn(0), safeColumn(1)].filter(
+/**
+ * 根据候选列名查找列索引；未命中返回 -1。
+ */
+function findHeaderIndex(headers: string[], aliases: string[]): number {
+  const aliasSet = new Set(aliases.map((item) => normalizeHeaderName(item)));
+  return headers.findIndex((header) => aliasSet.has(normalizeHeaderName(header)));
+}
+
+/**
+ * 上传文件后按列名设置默认映射：
+ * - 源数据-数据列：value
+ * - 源数据-描述列：source
+ * - 目标数据-描述列：target
+ * 若未找到对应列名，回退到安全列索引。
+ */
+function setDefaultMappingByHeaders(headers: string[]): void {
+  const safeSize = Math.max(headers.length, 1);
+  const safeColumn = (index: number): number => Math.min(index, safeSize - 1);
+  const sourceDataByName = findHeaderIndex(headers, ['value']);
+  const sourceDescByName = findHeaderIndex(headers, ['source']);
+  const targetDescByName = findHeaderIndex(headers, ['target']);
+
+  mapping.sourceDataColumn = sourceDataByName >= 0 ? sourceDataByName : safeColumn(2);
+  mapping.sourceDescriptionColumns = [sourceDescByName >= 0 ? sourceDescByName : safeColumn(0)].filter(
     (item, index, list) => list.indexOf(item) === index
   );
-  mapping.targetDescriptionColumns = [safeColumn(2), safeColumn(3)].filter(
+  mapping.targetDescriptionColumns = [targetDescByName >= 0 ? targetDescByName : safeColumn(2)].filter(
     (item, index, list) => list.indexOf(item) === index
   );
 }
@@ -764,7 +797,7 @@ async function loadDataFile(file: File): Promise<void> {
   try {
     const parsed = await parseDataFile(file);
     rawTable.value = parsed;
-    setDefaultMappingByColumns(parsed.headers.length);
+    setDefaultMappingByHeaders(parsed.headers);
     uploadMessage.value = `已加载: ${file.name}（${parsed.rows.length} 行）`;
   } catch (error) {
     parseError.value = error instanceof Error ? error.message : '文件解析失败';
@@ -808,7 +841,7 @@ async function loadDefaultExampleFile(): Promise<void> {
     const buffer = await response.arrayBuffer();
     const parsed = parseXlsxBuffer(buffer);
     rawTable.value = parsed;
-    setDefaultMappingByColumns(parsed.headers.length);
+    setDefaultMappingByHeaders(parsed.headers);
     uploadMessage.value = `已加载: example0.xlsx（${parsed.rows.length} 行）`;
     parseError.value = '';
   } catch (error) {
@@ -838,22 +871,33 @@ function exportSvg(): void {
     return;
   }
 
-  const svgEl = chartRef.value?.querySelector('svg');
-  if (svgEl) {
-    const serialized = new XMLSerializer().serializeToString(svgEl);
-    const blob = new Blob([serialized], { type: 'image/svg+xml;charset=utf-8' });
-    const url = URL.createObjectURL(blob);
-    downloadByDataUrl(url, `sankey_${formatFileTimestamp()}.svg`);
-    URL.revokeObjectURL(url);
-    return;
-  }
+  const width = chartInstance.getWidth();
+  const height = chartInstance.getHeight();
+  const tempContainer = document.createElement('div');
+  tempContainer.style.position = 'fixed';
+  tempContainer.style.left = '-99999px';
+  tempContainer.style.top = '-99999px';
+  tempContainer.style.width = `${width}px`;
+  tempContainer.style.height = `${height}px`;
+  tempContainer.style.opacity = '0';
+  tempContainer.style.pointerEvents = 'none';
+  document.body.append(tempContainer);
 
-  const dataUrl = chartInstance.getDataURL({
-    type: 'svg',
-    backgroundColor: '#ffffff',
-    pixelRatio: 2
-  });
-  downloadByDataUrl(dataUrl, `sankey_${formatFileTimestamp()}.svg`);
+  let svgChart: echarts.EChartsType | null = null;
+  try {
+    // 主图继续走 canvas，导出时单独用 SVG 渲染器重建一份，保证导出格式正确。
+    svgChart = echarts.init(tempContainer, undefined, { renderer: 'svg', width, height });
+    svgChart.setOption(chartInstance.getOption() as EChartsOption, true);
+
+    const dataUrl = svgChart.getDataURL({
+      type: 'svg',
+      backgroundColor: '#ffffff'
+    });
+    downloadByDataUrl(dataUrl, `sankey_${formatFileTimestamp()}.svg`);
+  } finally {
+    svgChart?.dispose();
+    tempContainer.remove();
+  }
 }
 
 function exportPng(): void {
diff --git a/src/styles.css b/src/styles.css
index d638c19..00d6ea0 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -399,10 +399,6 @@ body {
   text-overflow: ellipsis;
 }
 
-.total-row .column-label {
-  color: var(--text-4);
-}
-
 .select-btn {
   border: 0;
   background: transparent;
@@ -587,6 +583,32 @@ body {
   flex-direction: row-reverse;
 }
 
+.label-position-control {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+}
+
+.label-position-label {
+  font-size: 14px;
+  font-weight: 600;
+  color: #000;
+  line-height: 1;
+  white-space: nowrap;
+}
+
+.label-position-select {
+  min-width: 64px;
+  height: 24px;
+  border: 1px solid #c9aee0;
+  border-radius: 2px;
+  background: #fff;
+  color: #1d2129;
+  font-size: 14px;
+  padding: 0 20px 0 6px;
+  line-height: 22px;
+}
+
 .example-line {
   margin: 4px 0 8px;
   color: var(--text-4);
@@ -668,6 +690,10 @@ body {
     gap: 12px;
   }
 
+  .label-position-control {
+    margin-left: 0;
+  }
+
   .footer {
     font-size: 14px;
   }