diff --git a/src/app/panels/chart/ContourPlotItem.cpp b/src/app/panels/chart/ContourPlotItem.cpp
index cb45281..e5e469d 100644
--- a/src/app/panels/chart/ContourPlotItem.cpp
+++ b/src/app/panels/chart/ContourPlotItem.cpp
@@ -183,7 +183,7 @@ void ContourPlotItem::draw(QPainter* painter, const QwtScaleMap& xMap, const Qwt
         painter->save();
         painter->setRenderHint(QPainter::Antialiasing, true);
         QPen pen(QColor(0, 0, 0));
-        pen.setWidthF(0.0);  // cosmetic：恒 1px，不随缩放变粗
+        pen.setWidthF(1.0);  // 1px 黑色等值线
         painter->setPen(pen);
         for (const auto& ln : lines_) {
             if (ln.pts.size() < 2) continue;
diff --git a/src/app/panels/chart/GridDataChartView.cpp b/src/app/panels/chart/GridDataChartView.cpp
index f7f84bb..31c5046 100644
--- a/src/app/panels/chart/GridDataChartView.cpp
+++ b/src/app/panels/chart/GridDataChartView.cpp
@@ -10,6 +10,8 @@
 #include <qwt_plot.h>
 #include <qwt_plot_grid.h>
 #include <QSplitter>
+#include <QScrollArea>
+#include <QFrame>
 #include <qwt_plot_rescaler.h>
 
 #include "PanelHeader.hpp"
@@ -141,15 +143,24 @@ GridDataChartView::GridDataChartView(QWidget* parent) : QWidget(parent) {
     };
     auto tabbedBottom = buildTabbedPanel(bottomTabs, {});
 
-    // 图表区 | 底部表 用竖直 QSplitter：自适应 dock 高度、可拖拽、不强制固定 200px
-    //（避免内容溢出滚动条；也使本页与「原数据」页高度互不耦合）。
-    auto* splitter = new QSplitter(Qt::Vertical, this);
+    // 图表区 | 底部表 竖直 QSplitter（可拖拽调整比例）。给定最小高度→分割器有最小尺寸。
+    chartArea->setMinimumHeight(280);
+    tabbedBottom.container->setMinimumHeight(160);
+    auto* splitter = new QSplitter(Qt::Vertical);
     splitter->addWidget(chartArea);
     splitter->addWidget(tabbedBottom.container);
     splitter->setStretchFactor(0, 3);
     splitter->setStretchFactor(1, 1);
     splitter->setChildrenCollapsible(false);
-    lay->addWidget(splitter, 1);
+
+    // 页签内滚动：把(图表+异常)分割器放进 QScrollArea。dock 够高→分割器填满(可拖动调整)；
+    // dock 太矮→在页签内部出现竖滚动条(工具条/页签/标题固定)，而非整个面板滚动。
+    auto* scroll = new QScrollArea(this);
+    scroll->setWidgetResizable(true);
+    scroll->setFrameShape(QFrame::NoFrame);
+    scroll->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    scroll->setWidget(splitter);
+    lay->addWidget(scroll, 1);
 
     // ---- 工具条开关 → 重建/重绘 ----
     connect(chkShowAnom, &QCheckBox::toggled, this, [this](bool on) {
diff --git a/src/render/ContourBands.cpp b/src/render/ContourBands.cpp
index 3f6a53c..330e903 100644
--- a/src/render/ContourBands.cpp
+++ b/src/render/ContourBands.cpp
@@ -11,6 +11,7 @@
 #include <vtkPointData.h>
 #include <vtkPoints.h>
 #include <vtkPolyData.h>
+#include <vtkStripper.h>
 #include <vtkUnstructuredGrid.h>
 
 #include <cmath>
@@ -152,14 +153,20 @@ ContourBandsResult buildContourBands(const Grid& g, const ColorScale& cs, const
         out.bands.push_back(std::move(bp));
     }
 
-    // port1：等值线（polylines）+ DP 简化。仅 makeLines=true 时生成（否则不提取）。
+    // port1：等值线。banded 边输出是大量 2 点短线段——用 vtkStripper 连成长折线，
+    // 便于沿线标注与减少绘制调用。仅 makeLines=true 时生成。
     if (opt.makeLines) {
         vtkPolyData* edges = banded->GetContourEdgesOutput();
         if (edges) {
-            edges->BuildCells();
-            const vtkIdType nLines = edges->GetNumberOfCells();
+            vtkNew<vtkStripper> stripper;
+            stripper->SetInputData(edges);
+            stripper->JoinContiguousSegmentsOn();
+            stripper->Update();
+            vtkPolyData* joined = stripper->GetOutput();
+            joined->BuildCells();
+            const vtkIdType nLines = joined->GetNumberOfCells();
             for (vtkIdType c = 0; c < nLines; ++c) {
-                vtkCell* cell = edges->GetCell(c);
+                vtkCell* cell = joined->GetCell(c);
                 vtkPoints* cp = cell->GetPoints();
                 ContourLine cl; cl.level = 0.0;
                 for (vtkIdType p = 0; p < cp->GetNumberOfPoints(); ++p) {
diff --git a/tests/render/test_contour_bands.cpp b/tests/render/test_contour_bands.cpp
index c4b7b48..b87998b 100644
--- a/tests/render/test_contour_bands.cpp
+++ b/tests/render/test_contour_bands.cpp
@@ -53,3 +53,38 @@ TEST(ContourBands, ProducesNonEmptyBands) {
     ASSERT_FALSE(r.bands.empty());
     for (const auto& b : r.bands) EXPECT_GE(b.ring.size(), 3u);
 }
+
+// 诊断：等值线(lines)应非空——网格跨越多个色阶级时应产生等值线。
+TEST(ContourBands, ProducesContourLines) {
+    Grid g(10, 10);
+    g.x.resize(10); g.y.resize(10);
+    for (int i = 0; i < 10; ++i) { g.x[i] = i; g.y[i] = i; }
+    for (int j = 0; j < 10; ++j)
+        for (int i = 0; i < 10; ++i) g.valueAt(i, j) = i + j;  // 0..18
+    g.vmin = 0; g.vmax = 18;
+    ColorScale cs;
+    cs.addStop(0, Rgba{0,0,255,255}); cs.addStop(6, Rgba{0,255,0,255});
+    cs.addStop(12, Rgba{255,255,0,255}); cs.addStop(18, Rgba{255,0,0,255});
+    ContourOptions opt; opt.upsample = 1; opt.smooth = 0; opt.simplifyTol = 0; opt.makeLines = true;
+    auto r = buildContourBands(g, cs, opt);
+    EXPECT_FALSE(r.lines.empty());
+}
+
+// 诊断(真实参数复现)：大网格 + 默认 opt(upsample=2,smooth=0.3,simplifyTol=0.5) + 17 级色阶。
+TEST(ContourBands, ProducesLinesRealisticOptions) {
+    Grid g(60, 40);
+    g.x.resize(60); g.y.resize(40);
+    for (int i = 0; i < 60; ++i) g.x[i] = i * 3.0;
+    for (int j = 0; j < 40; ++j) g.y[j] = -33.0 + j * 1.2;
+    for (int j = 0; j < 40; ++j)
+        for (int i = 0; i < 60; ++i)
+            g.valueAt(i, j) = 2.0 + 340.0 * (0.5 + 0.5 * std::sin(i * 0.2) * std::cos(j * 0.25));
+    g.vmin = 2; g.vmax = 348;
+    ColorScale cs;
+    const double bars[17] = {2.08,4.59,7.81,11.02,14.26,17.25,20.56,23.55,27.05,
+                             31.16,36.83,43.64,51.98,62.09,81.14,108.24,348.52};
+    for (int i = 0; i < 17; ++i) cs.addStop(bars[i], Rgba{(unsigned char)(i*15),0,200,255});
+    ContourOptions opt;  // 默认 upsample=2, smooth=0.3, simplifyTol=0.5, makeLines=true
+    auto r = buildContourBands(g, cs, opt);
+    EXPECT_FALSE(r.lines.empty());
+}