diff --git a/static/style.css b/static/style.css
index 2f5ee2b..0c6bb63 100644
--- a/static/style.css
+++ b/static/style.css
@@ -591,6 +591,28 @@ body {
   transition: all var(--duration-fast) var(--ease-default);
 }
 
+.btn-sm.btn-icon {
+  padding: var(--space-1) var(--space-2);
+  min-width: 28px;
+  background: var(--bg-tertiary);
+  border: 1px solid var(--border-default);
+}
+
+.btn-sm.btn-icon:hover {
+  background: var(--gray-200);
+}
+
+.dropdown-icon {
+  display: inline-block;
+  font-size: 10px;
+  transition: transform var(--duration-fast) var(--ease-default);
+  color: var(--text-secondary);
+}
+
+.dropdown-icon.expanded {
+  transform: rotate(180deg);
+}
+
 .btn-sm.btn-primary {
   background: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-600) 100%);
   color: white;
diff --git a/static/vue-app.js b/static/vue-app.js
index 9848d26..30084c5 100644
--- a/static/vue-app.js
+++ b/static/vue-app.js
@@ -995,8 +995,8 @@ const MoldInsightView = {
                       <button v-if="file.latest_status === 'completed'" class="btn-sm btn-primary" @click="viewResult({task_id: file.latest_task_id})">
                         查看最新
                       </button>
-                      <button class="btn-sm btn-secondary" @click="toggleFileHistory(file.filename)">
-                        {{ state.expandedFiles[file.filename] ? '收起' : '历史记录' }}
+                      <button class="btn-sm btn-icon" @click="toggleFileHistory(file.filename)" :title="state.expandedFiles[file.filename] ? '收起' : '展开历史记录'">
+                        <span class="dropdown-icon" :class="{ 'expanded': state.expandedFiles[file.filename] }">▼</span>
                       </button>
                     </div>
                   </td>