diff --git a/scripts/assets/web-probe-sentinel-dashboard/dashboard.css b/scripts/assets/web-probe-sentinel-dashboard/dashboard.css
index 5e9dd415..9af6b424 100644
--- a/scripts/assets/web-probe-sentinel-dashboard/dashboard.css
+++ b/scripts/assets/web-probe-sentinel-dashboard/dashboard.css
@@ -989,6 +989,17 @@ select {
   font-size: 12px;
 }
 
+.aggregation-root-cause {
+  align-items: stretch;
+}
+
+.root-cause-chip {
+  max-width: 100%;
+  justify-content: flex-start;
+  white-space: normal;
+  text-align: left;
+}
+
 .finding-list {
   display: grid;
   gap: 8px;
@@ -1052,6 +1063,10 @@ select {
   display: none;
 }
 
+.finding-item.is-collapsed {
+  gap: 5px;
+}
+
 .finding-row {
   display: flex;
   align-items: center;
@@ -1077,6 +1092,21 @@ select {
   gap: 6px;
 }
 
+.finding-direct-cause {
+  display: grid;
+  grid-template-columns: auto minmax(0, 1fr);
+  gap: 6px;
+  align-items: start;
+  color: #1f2937;
+  font-size: 11px;
+  line-height: 1.35;
+  overflow-wrap: anywhere;
+}
+
+.finding-direct-cause strong {
+  color: #1d4ed8;
+}
+
 .finding-summary {
   color: #1f2937;
   font-size: 12px;
diff --git a/scripts/assets/web-probe-sentinel-dashboard/dashboard.js b/scripts/assets/web-probe-sentinel-dashboard/dashboard.js
index 3340738a..71c09775 100644
--- a/scripts/assets/web-probe-sentinel-dashboard/dashboard.js
+++ b/scripts/assets/web-probe-sentinel-dashboard/dashboard.js
@@ -306,6 +306,10 @@ async function loadDashboard(options) {
       state.runViews = null;
       state.selectedTraceChoiceIndex = 0;
     }
+    if (state.selectedRunId === null) {
+      const latestRunId = latestRunIdFrom(overview, state.runs);
+      if (latestRunId) state.selectedRunId = latestRunId;
+    }
     renderDashboard();
     if (state.selectedRunId && state.runDetail === null) await selectRun(state.selectedRunId);
   } catch (error) {
@@ -477,7 +481,8 @@ function renderFindings() {
   refs.findingsList.innerHTML = groups.map((group) => {
     const visibleItems = group.items.slice(0, findingVisibleLimit(group.key));
     const hiddenCount = Math.max(0, group.items.length - visibleItems.length);
-    return `<details class="finding-group finding-group-${escapeAttr(group.key)}">
+    const defaultOpen = group.items.some(findingHasRootCause) || isBlockingSeverity(group.key) || groups.length <= 2;
+    return `<details class="finding-group finding-group-${escapeAttr(group.key)}"${defaultOpen ? " open" : ""}>
       <summary>
         <span>${escapeHtml(displaySeverity(group.key))}</span>
         <strong>${formatNumber(group.totalCount)}</strong>
@@ -526,11 +531,13 @@ function renderFindingItemCollapsed(item) {
   const rootCause = findingRootCauseText(item);
   const evidence = findingEvidenceText(item);
   const nextAction = item.nextAction || findingNextAction(code);
+  const directCause = rootCause || nextAction;
   return `<article class="finding-item is-collapsed" data-finding-run-id="${escapeAttr(latestRunId)}">
     <div class="finding-row" data-finding-toggle>
       <span class="finding-title">${escapeHtml(codeLabel)}${codeLabel === code ? "" : ` <small class="mono">${escapeHtml(code)}</small>`}<small> · ${formatNumber(item.count ?? 0)} 次</small></span>
       <span class="severity-pill ${severityClass(item.severity)}">${escapeHtml(displaySeverity(item.severity))}</span>
     </div>
+    ${directCause ? `<div class="finding-direct-cause"><strong>${rootCause ? "根因" : "下一步"}</strong><span>${escapeHtml(shortText(directCause, 180))}</span></div>` : ""}
     <div class="finding-detail">
       <div class="finding-summary">${escapeHtml(shortText(displayFindingSummary(code, item.summary || ""), 220))}</div>
       <div class="finding-actions">
@@ -586,12 +593,27 @@ function groupedFindingsBySeverity(findings) {
   return Array.from(groups.entries())
     .map(([key, items]) => ({
       key,
-      items: items.sort((a, b) => Number(b.count || 0) - Number(a.count || 0)),
+      items: items.sort(compareFindingsForVisibility),
       totalCount: items.reduce((sum, item) => sum + Number(item.count || 0), 0),
     }))
     .sort((a, b) => severityRank(a.key, severityOrder) - severityRank(b.key, severityOrder));
 }
 
+function compareFindingsForVisibility(a, b) {
+  return Number(findingHasRootCause(b)) - Number(findingHasRootCause(a))
+    || Number(b.count || 0) - Number(a.count || 0)
+    || String(a.code || a.findingId || "").localeCompare(String(b.code || b.findingId || ""));
+}
+
+function findingHasRootCause(item) {
+  return Boolean(findingRootCauseText(item));
+}
+
+function isBlockingSeverity(severity) {
+  const key = String(severity || "").toLowerCase();
+  return key === "red" || key === "critical" || key === "error";
+}
+
 function severityRank(key, order) {
   const index = order.indexOf(key);
   return index >= 0 ? index : order.length;
@@ -605,9 +627,11 @@ function renderFindingAggregation() {
   const severityEntries = aggregateFindings((item) => item.severity || "unknown").slice(0, 5);
   const codeEntries = aggregateFindings((item) => item.code || item.findingId || "unknown").slice(0, 5);
   const scenarioEntries = aggregateFindings((item) => item.scenarioId || "unknown").slice(0, 5);
+  const rootCauseEntries = state.findings.filter(findingHasRootCause).sort(compareFindingsForVisibility).slice(0, 3);
   refs.findingAggregation.innerHTML = [
     aggregationGroup("严重级别", severityEntries.map((item) => ({ ...item, label: displaySeverity(item.key) })), "severity"),
     aggregationGroup("代码", codeEntries.map((item) => ({ ...item, label: displayFindingCode(item.key) })), "code"),
+    rootCauseEntries.length > 0 ? aggregationRootCauseGroup(rootCauseEntries) : "",
     aggregationGroup("场景", scenarioEntries, "scenario"),
     `<div class="aggregation-group"><span>窗口</span><button type="button" class="filter-chip active">${escapeHtml(state.findingFilters.window || "全部")}</button></div>`,
   ].join("");
@@ -623,6 +647,15 @@ function aggregationGroup(label, entries, filterKey) {
   return `<div class="aggregation-group"><span>${escapeHtml(label)}</span>${chips}</div>`;
 }
 
+function aggregationRootCauseGroup(entries) {
+  const chips = entries.map((item) => {
+    const code = item.code || item.findingId || "finding";
+    const text = findingRootCauseText(item);
+    return `<button type="button" class="filter-chip root-cause-chip" data-finding-filter="code" data-filter-value="${escapeAttr(code)}">${escapeHtml(displayFindingCode(code))}: ${escapeHtml(shortText(text, 96))}</button>`;
+  }).join("");
+  return `<div class="aggregation-group aggregation-root-cause"><span>根因</span>${chips}</div>`;
+}
+
 function aggregateFindings(keyFn) {
   const counts = new Map();
   for (const item of state.findings) {
@@ -977,6 +1010,11 @@ function jumpToLatestRun() {
   if (latest) selectRun(latest.runId || latest.id);
 }
 
+function latestRunIdFrom(overview, runs) {
+  const latest = overview?.latestRun || null;
+  return latest?.runId || latest?.id || runs[0]?.runId || runs[0]?.id || "";
+}
+
 function toggleRedOnly() {
   const active = refs.filterRed.classList.toggle("active");
   if (active) {