diff --git a/docs/project_context.md b/docs/project_context.md
index 5f5560b..45f76a2 100644
--- a/docs/project_context.md
+++ b/docs/project_context.md
@@ -808,3 +808,9 @@
 - CellData「规则设置」弹窗中的映射规则增加“图形化 / JSON”切换。图形化模式可维护目标表、主键字段、主键表达式、来源目录、CSV 前缀和字段映射；字段映射支持“CSV 字段”和“固定值”两种模式。
 - JSON 模式仍使用 Monaco 编辑器，支持格式化、校验、恢复默认；两种模式共用同一份 `CellData.mapping` JSON，切换时自动互转。
 - 验证：`frontend` `npm run build` 通过；构建产物已清理。
+
+## 2026-06-25：固定图形化映射基础区与添加来源按钮
+
+- CellData「规则设置」弹窗不再整体滚动；高级匹配、目标表、主键字段和主键表达式固定显示，图形化模式下仅来源列表滚动。
+- “添加来源”按钮固定在来源列表下方，始终可见；弹窗底部保存按钮也保持可见。
+- 验证：`frontend` `npm run build` 通过；构建产物已清理。
diff --git a/frontend/src/components/SettingsPanel.vue b/frontend/src/components/SettingsPanel.vue
index 26b9d43..a798500 100644
--- a/frontend/src/components/SettingsPanel.vue
+++ b/frontend/src/components/SettingsPanel.vue
@@ -774,7 +774,9 @@
                 <n-button size="small" @click="addCellDataMappingField(sourceIndex)">添加字段</n-button>
               </div>
             </div>
-            <n-button size="small" @click="addCellDataMappingSource">添加来源</n-button>
+            <div class="cell-data-mapping-actions">
+              <n-button size="small" @click="addCellDataMappingSource">添加来源</n-button>
+            </div>
           </div>
         </section>
       </div>
diff --git a/frontend/src/styles.css b/frontend/src/styles.css
index 29caa05..6525e4e 100644
--- a/frontend/src/styles.css
+++ b/frontend/src/styles.css
@@ -1640,16 +1640,24 @@ select {
 }
 
 .cell-data-settings-body {
-  display: grid;
+  display: flex;
+  height: min(68vh, 680px);
+  min-height: 0;
+  flex-direction: column;
   gap: 14px;
-  max-height: 68vh;
-  overflow-y: auto;
   padding-right: 4px;
+  overflow: hidden;
 }
 
 .cell-data-settings-section {
   display: grid;
+  flex: 0 0 auto;
   gap: 8px;
+  min-height: 0;
+}
+
+.cell-data-settings-section:last-child {
+  flex: 1 1 auto;
 }
 
 .cell-data-section-title {
@@ -1668,12 +1676,16 @@ select {
 }
 
 .cell-data-mapping-form,
-.cell-data-source-list,
 .cell-data-source-card {
   display: grid;
   gap: 10px;
 }
 
+.cell-data-mapping-form {
+  min-height: 0;
+  grid-template-rows: auto minmax(0, 1fr) auto;
+}
+
 .cell-data-mapping-key {
   display: grid;
   grid-template-columns: minmax(140px, 0.8fr) minmax(120px, 0.6fr) minmax(240px, 1.4fr);
@@ -1687,6 +1699,19 @@ select {
   border-radius: var(--td-radius-default);
 }
 
+.cell-data-source-list {
+  display: grid;
+  gap: 10px;
+  min-height: 0;
+  overflow-y: auto;
+  padding-right: 4px;
+}
+
+.cell-data-mapping-actions {
+  display: flex;
+  justify-content: flex-start;
+}
+
 .cell-data-source-header,
 .cell-data-source-meta,
 .cell-data-field-row {